PDF_ Nopal as Natural Coagulant

European Joint Master in Water and a nd Coastal Management 2009

APP LICATION OF A NATURAL COAGULANT APPPLICATION DERIVE p. IN WATER TREATMENT DERIVED ED FROM Opuntia ss sssp.

by José Miguel García Moreno

European Joint Master in Water and Coastal Management March 2009

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European Joint Master in Water and a nd Coastal Management 2009 Research Guides Dr.Daniell Prats and Dr.Pedro Varó Dr.Danie

Research co co--Guide -Guide Dr. Angel Del Valls Casillas

Author has been financially supported by Erasmus Mundus

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This Master Thesis was carried out in the Water Institute and The Chemical Technology Centre of Alicante University (UA), as part of the master program “Erasmus Mundus: Water and Coastal Management” of Cadiz University. The author was supported by Erasmus Mundus and Spanish Government scholarships.

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STATEMENT

I here reby by declare that this work has been carried out by me aand nd the thesis has been composed by here me and has not been submitted for any other degree or professional qualification. This work is presented to obtain a masters degree in water and coastal management.

---------------------------- José Miguel García Moreno

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European Joint Master in Water and a nd Coastal Management 2009 D. ANGEL DEL VALLS CASILLAS, Profesor Titular del Departamento de Química-Física de la Universidad de Cádiz Cádiz , D DANIEL PRATS RICO, Director del Instituto del agua de la Universidad de Alicante y PEDRO JOSE VARÓ GALVÁN , como sus directores.

HACEN CONSTAR: Que esta Memoria, titulada titulada APLICATTION OF A NATURAL COAGULANT DERIVADED FROM OPUNTIA SP. IN WATER TREATMENT, presentada por D. José Miguel García Moreno, resume su trabajo de Tesis de Master y, considerando que reúne todos los requisitos legales, autorizan su presentación y defensa para optar al grado de Master en Gestión del Agua y Costera.

Cádiz, Mayo de 2009

________________________________

________________________________

Dr. Daniel Prats Rico

Dr. Pedro José Varó

--------------------------------------------------------------------------------------------------------------------------------------------------Dr. Ángel Del Valls Casillas

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ACKNOWLEDGEMENTS

I am deeply indebted to Pedro José Varó Galvan, Doctor of Chemical Engineering at Alicante University, without his benevolent commitment and constant support this project would not have been possible.

Also thank to Dr. Daniel Prats Rico, director of water Institute of Alicante University, for investing trust in me and for providing all the necessary materials for the experimental work.

My deepest gratitude to Dr. Ángel Del Valls Casillas and Prof. Alice Newton, coordinators of this master program for allowing me to participate in this adventure.

Thanks to all the colleagues of Alicante University, who I have annoyed this year with a thousand questions, doubts, reflections and favours. Thanks to friends’ for helping me and thanks to everybody with whom my path has crossed at this great University.

My best wishes go to the Master colleagues; all the experiences we have shared throughout this year have been very enriching

Thanks to Carmen Lopez the real motor of this Master.

Last thank to my Parents for being as they are, and for shaping me as I am; thanks to my brothers, thanks to my girlfriend for enduring this with me and of course thanks to Pachamama for showing me my way in life.

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SYNOPSIS The following study is an experimental approach to the possible uses of Opuntia ssp. for water treatment. In this investigation the properties of a dry and liquid extracts of Opuntia Ficus Indica were evaluated as primary coagulant and coagulant aids in synthetic and “true” water samples by jar test method. There is ancestral evidence for the use of several cacti for water clarification. Recent authors have investigated the properties of Opuntia ssp., obtaining excellent results.

Opuntia plants have an enormous potential for application on both local and commercial levels, as a cheap alternative with large socioeconomic benefits. The biological characteristics of this plant allow it to be applied for the integration of water management, environmental control and economic development of arid areas.

Is necessary a thorough research of its coagulation properties and the compromise of institutions to develop this new ecological alternative able to reduce the actual social, economic and environmental disequilibrium.

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TABLE O OFF CONTENTS

Contents Contents

No.. Page No

Aim of the work

9

1. - Introduction 1.1. -The natural resource (Opuntia ficus indica)

10 14

1.2. - Nopal as natural coagulant

18

2. - Methodology 2.2. - Coagulant extraction

21 21

2.3. - Water model 2.4. - Work method

23 24

2.5. - Experimental objectives

26

3. - Results 3.1. - Turbidity removes

27 27

3.2. - Potabilization parameters remove

33 34

3.3. - Waste water parameters remove 4. - Discussion

36

5. - Conclusion/The future

41

6. - References

43

7. - Scientific paper

48

88- Appendix

60

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Aim of the study The principal objective of this Master project is evaluating the properties of nopal mucilage in the water treatment.

The research focuses on:

-

Study the qualities of two different Opuntia ssp. extracts as primary coagulants and flocculants aids in synthetic waters experiments and in drinking and waste water samples.

-

Encouraging about the use of Opuntia ssp. in an integrated develop project project for water management and socioeconomic grow of arid places around the world.

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1.1.-INTRODUCTION -INTRODUCTION One of the more important Challenges of the modern World is to make human development economically and environmentally compatible; directing their efforts eff orts towards social equality. Water is vitally important in this process because it is used in a variety of ways at many different levels, producing social, spatial and organizational problems.

Growing population, increase in economic activity and industrialization has not only created an increased demand for fresh water but also resulted in severe misuse of this natural resource. According to a survey conducted by UNEP (2º United Nations World Water Development Report ), 20% of the world’s population lacks access to safe drinking water and 50% of the world’s population lacks access to safe sanitation. Polluted water is estimated to affect the health of about 1200 million people and contribute to the death of 15 million children under the age of five every year.

Water resources all over the world are threatened not only by over exploitation and poor management but also by ecological degradation.

With increased industrial growth and urbanization, the volume of domestic and industrial effluent, agricultural waste and urban runoffs is steadily growing. Water bodies have an inherent capability to dilute the pollutants which enter into the system, however, the indiscriminate dumping of untreated sewage and chemical wastes directly into rivers, lakes, and drains have made these water bodies unable to cope up with the pollutant load.

It is necessary to recognise water as a limited resource and to encourage the application of clean

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European Joint Master in Water and a nd Coastal Management 2009 technologies which reduce negative environmental impact and assist in the development of poor countries.

In this sense the use of biological methods for water treatment is a fair and efficient way to support the ecologic control of residues and increase access to drinking water in rural places.

Natural water treatment systems are designed to take advantage of the physical, chemical, and biological processes that occur in the natural environment when water, soil, plants, microorganisms and the atmosphere interact (Metcalf & Eddy 3º Edition).

Natural treatment systems include, among others: land treatment, floating aquatic plants, constructed wetlands, solar irradiation, natural coagulants, microbiological degradation and active carbon. The investigation and development of new ecofriendly technologies are being implemented in both small and large scale ventures.

Natural materials have been used in traditional domestic water treatment for centuries. Many of these plants and other biological substances have been investigated as natural coagulants, proving their capacity to reduce turbidity, co-precipitated metals me tals and pathogen reduction (Table 1).

Unfortunately the application of these new technologies is limited to NGO projects and pilot plants. There is not yet a clear interest from companies and government for the commercial development of these methods.

Of all the plant material investigated, the seeds of Moringa oleifera are one of the most effective sources as a primary coagulant for water treatment (Sutherland, 1994, Ndabigengesere, 1998).

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European Joint Master in Water and a nd Coastal Management 2009 Species

Natural Coagulant

Reference

Opuntia ficus indica

Mucilage

Kirchmer Cliff J. 1975

Marine algae

All

Hauc A. 1964

Corn, potatoes , yucca, wheat

Starch of Seed or Roots

Gyulla Marrtton 2001

Beans

Seeds

Bulusu K.R.1974

Agave

Saponins

M. Madrid 2007

Acacia (samaena saman)

Sap

G.Gonzales et al. 2006

Moringa oleifera

Seeds

Sutherland, G. et all, 1994 ,

Calotropis Procera

Latex

Ndabigengesere, et all 1998 Okonko 2007

Cactus latifaria

Mucilage

Diaz A. et al.1999

Nirmali Plant

Seeds

Bulusu 1965

Microorganims

Al-Shahwani, M.F et all, 1989 Kurane, R., Takeda, K. 1986 Table 1. - Natural coagulants review in bibliography Variable

This tree is native of Northern India but is actually distributed throughout tropical climates around the world. The traditional use of M. oleifera seeds for domestic water treatment is common practice in rural areas of some developing countries. The dried seeds are shelled, crushed and sieved. A seed powder is mixed with turbid water that produces positively charged watersoluble proteins. These proteins bind to the suspended particles forming large agglomerated solids, which then sink.

Pilot scale and full-scale water treatment plants using M. oleifera seeds are successfully operating in Malawi. Also NGOs are implementing “Moringa sand filters” successfully for household water potabilisation in India and Africa, helping to improve the quality of water and the lives of local communities (RAWDP).

Synthetic Coagulants also act to electrostatically distort the colloids suspended in water, producing its precipitation and consequently removing turbidity. Aluminium is the coagulant

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European Joint Master in Water and a nd Coastal Management 2009 used most widely in water and wastewater treatment globally. The annual world production of aluminium approached approximately 28 million metrics in 2003 (AAC, 2005). 2005) . Spain annually consumes about 200,000 tonnes of chemical coagulants involving an outlay of 30,000 million euros (Kemitra report, Spanish Ministry).

More than the economic cost, this enormous volume of chemical compounds involves a high cost in different ways; toxicological problems of treated sludge, the energy consumption for its synthesis and distribution, the economic dependence of developing countries; and most seriously, problems for human health (Normatov I. , 2002). Studies Studies of different scholars advise the the risk of introducing aluminium into the environment and report that the remnants of alum after coagulation may induce Alzheimer’s disease (Letterman, 1990, McLauchlan D. R., 1995).

In other ways, biocoagulants are a renewable resource; have a low cost production, are available locally, have possibilities of industrial and local application, are innocuous and contribute to rural growth (Biron M. 2003).

However, the use of biocoagulant is very limited; the tendency towards sustainable development and social equilibrium make necessary the gradual abandonment of synthetic products and the generalist the use of natural coagulants (Chen YC & Xiao J., 1997).

Only through agreement between public organisations and private companies is it possible to make these changes.

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1.1.The natural resource (Opuntia ssp.) 1.1.--The

The genus opuntia is the largest under the Cactaceae family with more than 250 endemic species from Central America. The Opuntia s sp. sp. chosen as natural coagulant source for this project was Opuntia ficus indica , also named chumbera in Spain, cactus pear in North America and nopal in

Mexico.

Picture 1.- Opuntia ficus indica

The nopals are succulent plants which grow up to 3-5 metres, many times in a dense and tangled structure. It´s recognized by its green thick long pads that look like sports rackets. They grow one linked to the next next and can be considered as both both leaves and stalks. The plant surface is covering by spines which help to conduct water, reduce water loss, and protect the succulent tissue from herbivores and other predators (Mondragon C., 1995).

Nopals are strong plants with w ith not much water and nutrient requirements, are ar e highly adaptable

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European Joint Master in Water and a nd Coastal Management 2009 and propagate easily. After the American conquest, it was very treasured by explorers for its properties and introduced to Europe, Asia, Australia and Africa where it rapidly adapted to various environments (Barbera, G. et all, 1992).

Opuntia is the most widely distributed genus of cacti, Species of this genus are the most northern

ranging of cacti, occurring to 56° Northern latitude in British Columbia and Canada (Areces A., 2004) and are also some of the most frost-tolerant cacti.

Different cultures know different uses for this plant, being especially appreciated for its organoleptic and medicinal properties. In developing countries where it is present, nopal represents an important economic and nourishing resource.

The fruit, named higo chumbo in Spain and Tuna in Mexico, is very rich in sugars and typically is dried for use during the winter. Its uses include: syrup (“tuna” honey), fermented and unfermented drinks and also the skin as a food colouring, even its seed can be ground and used as flour.

The use of Opuntia as a vegetable crop is less popular. Only the young leaves of the nopal (nopalitos) are appreciated as a vegetable in Mexico for its nutritional aspects. They are typically cooked as a green vegetable or marinated as part of a salad. Nopal leaves present a general composition of 87% water, 1% protein, 0.1% fat, 1.3% ash, 1.1% crude fibre, and 5.4% carbohydrates (Loayza D.et all, 2007) being also an excellent forage for livestock in arid climates (E. Órnelas, 2007).

Moreover in Mexico and South America it is used to treat numerous maladies and researchers are interested in its medicinal use.

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European Joint Master in Water and a nd Coastal Management 2009 Preparations of nopal are variously considered anti-diabetic, anti-inflammatory, analgesic, galactogogue, hypoglycemic, antiviral and anti-oxidant. Preparations have been used to regulate weight, blood sugar, increase fibber intake and facilitate childbirth and are used in the treatment of asthma, fatigue, liver injury following alcohol abuse, diarrhea, dysentery, dyspnoea, gastritis, colitis, gonorrhoea and syphilis, hypercholesterolemia, measles, nosebleeds, obesity, snakebite, sore throat, virginities, and inflammation of the eyes, among other disorders (Feugang, J. M, 2006, Duke, J. A. et all, 2002, Martínez, M, 1999).

The wide variety of uses involves a big industry for nopal commercialisation. This market of nopal moves millions of euros and produces millions of tonnes for different applications as food, medicines, cosmetics, pigments and as a paint additive. Sub products Tuna

Products Leaves

Juice and nectars

Jam , gel and jelly

Tuna and Leaves

Juice Pickle and brine

Seed oil Leave mucilage

Fruit and dried sheet

Jam and jelly

Pigments from peel and fruit

Edulcorant

Flour

Dietary fibber from leaves

Alcohols , wine and vinegar

Alcohol

Canned fruit

Compote

Fruit and pulp freezer

Sauce Nopalitos

Table 2. - Alimentary products, subproducts and additives obtained from tunas and leaves of nopal, Source: Saenz 2000; Corrales and Flores 2003.

Within the nopal nopal industry the the tuna market isis the larger; in 2000 it obtained a volume of 973,400 tonnes. Mexico provides 44% of the total, Tunisia 13%, Argentina 8%, Italy7% and

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European Joint Master in Water and a nd Coastal Management 2009 South Africa 4% along with over 30 producing countries. The area cultivated around the world is estimated to reach 1,114,000 hectares (SAGARPA).

All the time more countries are integrating the nopal in different ways and uses, for commercial application or for internal supply.

Picture 2. - Some commercial products made with nopal

The nopal requires only that it be planted and left to grow on its own, without fertilizer or watering. The high efficiency of converting water water in nopal biomass produces a high productivity productivity value. For example a nopal fruit crop can generate production of 20 tonnes per hectare annually and produce up to 50 tonnes of dry material with the potential use as a natural coagulant.

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Picture 3.- Nopal leaves ready to grown

The biological characteristics of nopal and the socioeconomic repercussions of its possible uses in water treatment make it an excellent candidate for this study.

1.2.1.2.-Nopal -Nopal as Natural Coagulant.

Historically, there is evidence to suggest the use of cactus mucilage for water clarification. Opuntia ssp. and cactus latiferi mucilage respectively were used by Chilean and Venezuelan indigenous peoples for centuries to remove pathogens pathogens and turbidity of surface water water (Diaz A. et all.1999, Sutherland, J.P. et all 1990 ).

The ability of cactaceae to retain water under such unfavourable climatic conditions is due to the water-binding capacity of mucilage, which involves the consequent coagulation properties (Mindt L. et all, 1975). When it is mixed with water or other fluids, forms a sticky and slippery gel which has the capacity to catch the suspension particles and carry them to the bottom. Experiments suggest that the coagulation mechanism of opuntia ssp. is not by charge

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European Joint Master in Water and a nd Coastal Management 2009 neutralization like metallic salts, instead it occurs by adsorption and bridging mechanisms (Miller S. et all, 2008).

Mucilage is a slimy storage substance mainly in the parenquima tissue of leaves. It is composed of 55 sugar residues, mostly L-arabinose, D-galactose, L-rhamnose, D-xylose, and galacturonic acid, although proportions can vary with different factors such as age, ambient conditions, species or extraction method (Amin E.S. et all,1970). a ll,1970).

Nopal has been considered a potential source of an industrial hydrocolloid gum. Also the mucilage has been extracted and evaluated as dietary fibre, digestive, paint additive or emulsion agent (Saenza C. et all,2003, Sáenz, 1997, Garti N. , 1998) First coagulation experiments were carried out in 70s but the promising results fell into oblivion (Kirchmer, Cliff J., 1975). In the last few years different scholars have returned to this research and the nopal coagulant properties are starting to be revealed (Jingdong Zhang et all ,2005, , N. Quezada,2004 , López, E., 2000, P. Miretzky Mire tzky 2007, Young K. et all, 2006).

Some considerations about this research are described below:

-In comparative experiments with Moringa oleifera and Al2 (SO4)3, nopal extract presents a similar capacity to remove turbidity in synthetic and real waters.

-Temperature has slight influence on the coagulation effect of nopal.

-The coagulation activity of Nopal is greatest in basic Waters .

-Nopal coagulation produces significant reductions of metals (As, Pb, Fe, Al, and Mg).

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European Joint Master in Water and a nd Coastal Management 2009 -Possible DOQ and coliform removal.

Results suggest that nopal has a great potential for water treatment. It is necessary to undertake deep investigation for a better understanding of the coagulation qualities of nopal and in this way to develop cheap and efficient commercial substances which can minimise the use of synthetic coagulants.

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2.2.-METHODOLOGY -METHODOLOGY

The effectiveness of opuntia ssp. as a primary coagulant and flocculant aid in water treatment was compared with Al2 (SO4)3 by jar test method. Properties of the dry and liquid extract obtained from fresh nopal leaves and were tested in four different water models. This water models were; Kaolin clay suspension, a pre-potable water source and industrial and urban wastewaters.

Turbidity was the parameter measured to obtain the optimal work dose and calculate coagulation activities. From the supernatant of each optimal jar other key parameters were measured relating to every water model. Data collected was used to calculate the removal efficiencies of each parameter.

The present work was performed in the laboratories of the Water Institute and the Chemical Technology Centre of Alicante University.

2.1.2.1.-Natural -Natural coagulant extraction Nopal mucilage extraction is abundantly reported in the bibliography . It is possible to obtain the pure mucilage using organic solvents; however the data states which easy extraction methods also obtain excellent results of turbidity removal (Jingdong Zhang et all 2005). Natives used the water after boiling fresh opuntia leaves for water clarification, in our case the mucilage was extracted by maceration and desiccation.

A Liquid extract is more easy and fast to extract but has a short life span and therefore could possibly be used for a low scale application; on the other hand the dry extract needs an oven to

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European Joint Master in Water and a nd Coastal Management 2009 control the temperature but is easier to transport and conserve and therefore its character is suited to a more industrial application. a pplication.

Leaves of Opuntia ficus indica were collected around the University of Alicante and two different extracts were obtained through the following f ollowing methods:

-

Dry Extract (DE)

Dry coagulant was prepared by hand cutting of fresh nopal leaves. The skin and other superficial tissue was scored and only the internal mucilaginous component was used. It was cut into strips approx. 1cm in width and dried in an oven at 65 ºC over 72 hours. Samples were then ground in a coffee grinder to obtain particles with less than 300 µ metres metres diameter. This white powder was stored at 4ºC preserving its its properties for more than two months.

The output was 2% of dry powder per 100 grams of fresh leaves.

- Liquid Extract (LE)

Gummy coagulant was prepared by maceration. Entire leaves were cut into strips 1cm in width and mixed with the same volume of tap water. After 24 hours it was filtered through a nylon material to obtain a transparent slime soluble in water. The liquid was stored at 4ºC preserving its properties for no more than 3 days.

The output was 200ml of coagulant for every 100 grams of fresh leaves.

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2.2.2.2.-Water -Water model Jar test experiments were realised with four different water models:

-Synthetic turbidity mode ls were prepared by the addition of kaolin clay (KAOLIN CH-N PRS, 3TQ) into tap water to provide a turbidity of 75 and 200 NTU. Tap water characteristics are collected in appendix 1.

-Real waste water was recollected from the entry of Benidorms and Elda water treatment plants. Both residual Waters were collected after the sieve and before any physicochemical treatment. Water samples were stored at 4ºC for a maximum of two days before the experiments. Elda waste water treatment plant receives a high industrial charge while the Benidorm plant receives a higher urban charge, which implies that both water samples had very different physicochemical characteristics.

-A potable water source was collected from Amadorio reservoir. This is situated in the Villajoyosa municipality, has a surface area of 103 hectares and a capacity of 16 hm³ with recreational and cropping use.

The characteristics of “true” water models follow: Amadorio Reservour

Value

Elda wastewater

Value

Benidorm wastewater

Value

Turbidity

13 NTU

Turbidity

235 NTU

Turbidity

106 NTU

Conductivity

485 µS

Conductivity

3,11 mS

Conductivity

2,48 mS

pH

8,63

pH

7,81

pH

7,75

Fecal Streptococcus

110 UFC /100ml

Suspension Solids

754 mg/l

Suspension Solids

243 mg/l

Fecal Coliforms

1920UFC/100ml

DQO

1095 mg/l

DBO

507 mg/l

DQO DBO

460 mg/l 293 mg/l

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2.3.2.3.-Work -Work Method The experimental method to measure the efficiency of nopal extracts for water treatment in the different water models was designed based on the removal of turbidity.

The Residual turbidity tests were carried ca rried out according with ASTM jar test standard method. Coagulants were added to six water samples (1000 ml) and stirred at 125 rpm for 2 minutes and next the speed was reduced to 70 rpm for 20 min. After the agitation, stirring was stopped and the samples would stand for 20 min. Turbidity of the supernatant were recorded in triplicates and measured using a calibrated turbidymeter. turbidymeter.

In each jar test experiment one of the six jars received no treatment, serving as a control for comparison of the turbidity reduction for all a ll other jars. Coagulation activity was calculated ca lculated using the equation defined in the bibliography (Okuda 2001):

(Residual turbidity control - Residual turbidity sample) Coagulation activity = -------------------------------------------------------------------------------------------------------------------------- x 100 (Residual turbidity control)

Dry extract, liquid extract and Aluminium were compared as primary coagulants. The dry extract was previously diluted in distilled water for a correct mix.

For flocculation tests were aided a low optimal dose of aluminium and the nopal extracts at the same time before starting the agitation.

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European Joint Master in Water and a nd Coastal Management 2009 A total of 25 experiments analysed the flocculation and coagulation properties of nopal in synthetic and real water without ph correction. The water samples analysed in experiments had an approximate temperature of 20 ºC.

In “true” water experiments only the supernatant of the jar with the more effective reduction of turbidity was used to measure the key key parameters of every water model. model. The key parameters for wastewater were DQO, DBO and Suspension Solids; and for pre-potable water were fecals Streptococcus and fecals Coliforms.

Next are collected the techniques and instruments used for the analysis of parameters:

DQO-----------------------Kit LCK 114 CSB/COD/DCO, HACH LANGE S.L.U. Appendix 3. DBO----------------------- Biochemical Oxygen Demand sensor set determination systems, Velp Scientifica. Appendix 4. Microorganisms-----------Chromocult Coliform Agar ES (Enhanced Selectivity), Merck Microbiology Manual 12th Edition. Appendix 5.

Suspension solids---------- APHA-AWPCF 2540 Normalized methods for analyses of drinking and residual water, Díaz de Santos, Madrid (1992).

pH--------------------------CRISON basic 20

Conductivity-------------- CRISON micro CM 2200

Turbidity------------------ Merck turbiquant 1500 IR

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2.4.2.4.-Experiment -Experiment Objectives -Obtain optimal work dose and coagulation activities in every water model for both nopal extracts.

-Determine the flocculation efficiency of nopal in the interaction with aluminium sulphate.

-Analyse the key parameters for every water model and determine the potential of both extracts for possible small and large applications.

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3.RESULTS 3.-RE -RESULTS 3.1.3.1.-Turbidity -Turbidity removes The efficiency of turbidity remove at optimal dosages of both extracts in each water model is presented in next table.

Turbidity Removal %

Synthetic water

Synthetic water Pre-potable

Urban

Industrial

75NTU

200 NTU

Wastewater

Wastewater

water

Dry Extract

88

90

75

40

19

Liquid Extract

92

98

76

8

12

Control + Al

74

93

45

42

44

Dry Extract + Al

89

96

59

46

48

Liquid Extract + Al

96

98

42

38

4

Table 3.Turbidity 3.Turbidity removal of water models

The turbidity reduction was approx. 90% and 75% in kaolin synthetic suspensions and prepotable water samples respectively. In residual water the output was dependent on the type of extract and the charge of the water. Liquid extract did not perform well and the maximum turbidity reduction for the dry extract reached 40% when applied to urban wastewater. Both extracts worked better as primary coagulant than as coagulant aid. The activity of aluminium sulphate when applied together with nopal was increased by a maximum of 15%.

Effect of Synthetic water water..-.of Nopal when used to treat Synthetic The effectiveness of nopal to reduce the turbidity in synthetic clay solutions absent of natural organic matter is similar to Aluminium sulphate.

Nopal as primary coagulant reduces the turbidity between 88% and 98%, however, as flocculant aid; it does not produce a significant increase in the flocculation activity.

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Turbidity removal in Synthetic water at Opti mal dosages dosages Optimal 100 90 80 70 % l 60 a v 50 o m 40 e R 30 20 10 0

Initial turbidity 75 Initial turbidity 200

Dry Extract

Liquid Liquid Extract

Control + Al

Dry Extract +Al

Liquid Extact +Al

Graphic 1.-Turbidity Removal at optimal dosages in synthetic water

The optimal work dosages of the dry extract (DE) are around 20 mg/l at initial turbidity of 200 NTU and 10 mg/l at 75 NTU. The optimal work dosage of liquid extract (LE) is 0,2 ml/l with independence of the initial turbidity.

Low dosages of nopal coagulant tended to induce a strong initial reduction of turbidity whereas higher dosages tended towards a gradual increase of turbidity in the profile.

Synthetic water treated with Liquid Extract 100 100 90 U 80 T 70 N 60 y t 50 i d 40 i b r 30 u T 20 10 0

75 NTU 200 NTU 75 NTU + Al 200 NTU + Al

0

0,2

0,4

0,6

0,8

1

Concentration ml/l Graphic 2.-Turbidity reduction profile in synthetic water treated with LE

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Only the liquid extract reduced the turbidity at values lower than 5 NTU; this is related to the residual turbidity generated by the liquid extract. In Experiments incorporating tap water (turbidity less than 0,1 NTU) and the optimal work dosages of nopal extracts, the levels of residual turbidity increase at 6 NTU when water was treated with the DE; and at 2 NTU when treated with the LE. The different residual turbidity of the extracts is related to the extraction method. Synthetic water treated with Dry Extract 100 100 90 U 80 T 70 N 60 y t 50 i d i 40 b r 30 u T 20 10 0

75 NTU 200 NTU 75 NTU + Al 200 NTU + Al

0

10

20

30

40

50

60

Concentration mg/l Graphic 3.-Turbidity reduction profile in synthetic water treated with DE

In the case of the LE the maceration process produced a pure mixture made up of water and the mucilage without the presence of pigments or other plant materials. However, in the DE small, but significant, amounts of cuticle and other tissues of the plant are present in the final dust. These residues have dissolution problems and produce an increase in the basal turbidity level. The nopal extract doesn’t produce conductivity changes in the solution but instead produces a Light basify of the water.

The results are comparable with the previous kaolin experiments collated in the bibliography.

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European Joint Master in Water and a nd Coastal Management 2009 source..-.Effect of of Nopal on potable water source Both extracts work better as primary coagulants than as flocculant aids. When applied alone both extracts reduce the turbidity at levels less than 3 NTU, that is, they concede with the levels permitted by the Spanish drinking water normative. In this case, the optimal dosages were 0,3 ml/l and 6 mg/l for the LE and DE respectively.

Pre-potable Pre-potable water treated wit h liqui d extract 16 14 12 y t 10 i d i 8 b r u 6 T 4 2 0

Liquid Liquid Extract Extra ct Liquid Liquid Extract+ Extract + Al(1ppm)

0

0,5

1

1, 5

2

Concentration ml/l Graphic 4. Turbidity reduction profile in pre-potable water treated with LE

As an aluminium aid, both nopal extracts ex tracts do not produce a positive turbidity reduction.

Pre-potable Pre-potable water treat ith D ry Extract t reat wwith Dry 15 y 10 t i d i b r u 5 T

Dry Extract Dry Extract + Al(1ppm)

0 0

5

10

15

20

25

30

35

Concentration mg/l Graphic 5. Turbidity reduction profile in pre-potable water treated with DE

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European Joint Master in Water and a nd Coastal Management 2009 Effect of Nopal when used to treat industrial industrial wastewater.wastewater.It is no possible to reduce the turbidity more than 20%. The best results arise when the DE is applied as the primary coagulant. When combined with the aluminium the DE does not produce any change from the initial turbidity reduction while the LE increases the turbidity until reaching initial levels.

Industrial Industrial Wastewater treated with Liquid extract extract 250 U 200 T N 150 y t i d i 100 b r u T 50

Liquid Liquid Extract Extrac t Liquid Liquid Extract Al (50ppm)

0 0

0,5

1

1,5

2

Concentration ml/l

Graphic 5. Turbidity reduction reduction profile in Industrial Industrial water treated with LE

Industrial Wastewater treated with Dry extract 250 U 200 T N 150 y t i d i 100 b r u T 50

Dry Extract Dry Extract Al(50 ppm)

0 0

50

100

150

200

Concentration mg/l

Graphic 6. Turbidity reduction profile in Industrial wastewater treated with DE

Although these experiments do not clearly remove turbidity, in all experiments the nopal mucilage formed big flocs which quickly acquire an intense black colour.

31

European Joint Master in Water and a nd Coastal Management 2009 wastewater.-Effect of of Nopal when were used to treat Urban wastewater. Again, there exist clear differences in the behaviour of the DE and LE. The LE does not produce any significant reduction of turbidity and increases increase s it when applied together with aluminium. In this case, the DE reduces the initial turbidity charge by almost half but does not produce changes when is applied as a flocculant aid. Urban wastewater treated with N opal Liquid Extract 120 100 y t 80 i d i 60 b r u T 40

Liquid Extract Liquid Liquid Extract + Al

20 0 0

0, 5

1

1, 5

2

Concentration ml/L

Graphic 7.Turbidity reduction profile in Urban waste water treated with LE

Urban Wastewater treated with Nopal Dry E xtract 120 100 y t 80 i d i 60 b r u T 40

Dry Extract e

Dry Extract Extract + Al

20 0 0

50

100

150

200

Concentraction mg/l

Graphic 8.Turbidity reduction profile in urban waste water treated with DE

The maximum turbidity remove was 40% when the DE was apply as primary coagulant in an optimal dosage of 50 mg/l.

32


3.2.3.2.-Potabili -Potabiliz Potabilization zation parameters remove

To determine the potabilization properties of nopal were analysed its capacity to reduce the fecal streptoccocus and coliform charge from the Amadorio reservoir.

Removal efficiences in Pre-potable water 100 100 80

% l 60 a v o m 40 e R 20

Turbidity renoval Fecal coliforms renoval Fcal Streptococus renoval

0 Dry Extract 6 mg/l

Liquid Extract Control + Al Dry Extract Liquid Liquid Extact Extac t 0,4 ml/l (2ppm) 6 mg/l + Al 0,4 ml/l +Al

Sample Graphic 9.-Removal efficiencies of pre-potable water key parameters at optimal dose

The DE achieved the best results in reduction of the fecal streptococcus by 81% and the fecal coliforms by 45%. The LE has a similar capacity to remove turbidity but the microbiological reduction is more limited. Fecal coliforms are reduced when Aluminium sulphate is applied; behaving similarly to both nopal extracts although for the fecal streptococcus is less effective. Once again, the combined effect of aluminium with the natural coagulant does not achieve the results obtained when they are applied separately.

Any way the initial microbiological charge was too high and the results obtained are unacceptable for the levels established by the Spanish drinking water normative.

33


3.3.3.3.-Waste -Waste water parameters remove To test the effectiveness of nopal in waste water treatment some key parameters of this process were analysed (DQO, DBO, Suspended solids). Although both residual waters have different characteristics, results can be interpreted as a whole.

Industrial Wastewater removal eficience at optimal dosages 80 70 60 %50 l a v o 40 m 30 e R 20 10 0

Turbidity DQO Suspension solids DBO

Dry Extract 50 mg/l

Liquid Liquid Extract Extrac t 0,4 ml/l

Control + Al (50 ppm)

Dry Extract 50 mg/l + Al

Liquid Liquid Extact 0,4 ml/l +Al

Graphic 9.-Removal efficiencies of key Waste water key parameters

In any case it was possible to reduce the DQO and DBO by more than 25%, however, the suspended solids were notably reduced specially in the case of the DE treatment. Its achieved a maximum output of 58% when were applied as primary coagulant for both waste water samples.

In general nopal work better with urban waste water than the industrial waters.

The LE is not successful in producing a clear reduction of the parameter analysed, even when is applied together with aluminium produces a negative influence.

34


Urban wastewater removal efi eficiences optimal dosages ciences at optimal 80 70 60

Turbidity

% 50 l a v o 40 m e R 30

DQO Suspension solids DBO

20 10 0 Dry Extract 50 mg/l

Liquid Liquid Extract Extrac t Control + Al Dry Extract 0,4 ml/l (50ppm) 50 mg/l

Liquid Liquid Extact Extac t 0,4 ml/l


35


4.4.-DISCUSSION -DISCUSSION

The results obtained from this research suggest that nopal is a better primary coagulant than the flocculation aid of aluminium sulphate. Suspension solids reduction is the key parameter in this process and is related to the action mechanism of the nopal mucilage.

Miller S., 2008, demonstrated by z potential experiments that the nopal mucilage action mechanism takes place through processes of adsorption and bridging; in place of the charge destabilisation of synthetic coagulants. This supposes that the suspension solids can be caught physically by the mucilage but the diluted solids which form a colloid can only be removed by charge neutralization. When the mucilage is rough inside the water sample, it disperses and the suspension solids adhere to the mucilage surface, producing a posteriori co-precipitation and consequent removal of turbidity. Also, in theory, these action mechanisms could combine with and therefore remove some metals, parasites, microorganisms and other non diluted substances as current research suggests. After a minute of agitation the mucilage is dispersed into a multitude of fine strands which become intensely coloured, depending on the sample; for kaolin suspension the mucilage becomes a yellowish colour, in pre-potable water it becomes red and in wastewater, black. There is no clear relation between the colour strain and the turbidity reduction. In the case of waste water treated with the LE the floc formed have a similar appearance to the DE, however both extracts have very different behaviour relating to the turbidity and suspension solid reduction.

36

European Joint Master in Water and a nd Coastal Management 2009 It is clear from this report that there exists a direct relationship between the nopals mucilage action mechanism, suspension solids removal and reduction of turbidity in water treatment. In synthetic water experiments kaolin is distributed throughout the sample in the form of suspension solids producing all the total turbidity. The nopal performance upon the clay particles depends of the initial turbidity and nopal dosage applied. a pplied. In all the previous experiments using kaolin synthetic water and the optimal dosages of nopal; a turbidity reduction of greater than 90% was achieved; in water samples with low, medium and high turbidity.

In the case of waste water, it is probable that diluted solids produce mostly of turbidity and nopal only can reduce a lowest part of turbidity generated by suspension solids. Moreover diluted chemicals, organic matter, soaps, oils and other substances could interact in the coagulation properties of the nopal.

Generally in water analysis, DQO and DBO are the measurements used to evaluate the diluted chemical and organic compounds. In these coagulation experiments either one of these two parameters were reduced by the nopal action by more than 25%, although nopal was able to reduce the suspension solid by almost 60% in urban and industrial wastewater.

The turbidity was reduced up to a maximum of 40% for the urban waste water and 19% for the high industrial charge water when the DE was applied as primary coagulant. The LE does not produce a significant reduction of any parameter; something happened and decreased its coagulation capacity.

37

European Joint Master in Water and a nd Coastal Management 2009 Recognizing that one of the factors which affects the coagulant capacity of nopal nopal is the charge of the diluted solids within the samples; it is necessary to examine which parameters are affecting to this process. It is very interesting to research about the floc formed during the nopal coagulation process and to clarify more detailed information about the action of the nopal mechanism and what substances it is able to remove. From these premises it would be possible to develop new theories and practical applications for every specific type of water and therefore reduce reliance upon synthetic coagulants. Other factors, for example: ph, temperature and alkalinity can also change the coagulation qualities of nopal. In our case the samples from this study were obtained from a region with highly alkaline water and possibly can be an important factor in the low output obtained.

Picture 4.-Floc formed after nopal treatment in Synthetic water , Initial turbidity of 200 NTU

Picture 5. - Floc formation after nopal treatment in wastewater experiments.

38

European Joint Master in Water and a nd Coastal Management 2009 In theory the aluminium sulphate generates small flocs which could be easily attached to the nopal mucilage increasing its coagulation capacity. However, to the contrary, there was no clear relation in these experiments. The DE did not produce a significant increase in the removal of all the factors analysed and the LE generated a negative effect. It is necessary to study if there are any determining factors in the application of the nopal as a flocculant, for example, the moment of addition, the agitation velocity or additional water characteristics.

In pre-potable water experiments there was a significant reduction of microorganisms but not up to levels permitted by the drinking water normative because of the the high initial charge. It could be interesting determine the microorganisms and parasites removal capacity of nopal in controlled experiments and other fresh water systems.

The LE could be a better way to apply the nopal in water clarification because it is easier to produce at a local scale; on the other hand, the DE obtained better results in wastewater treatment and is also easier to transport and store, which implies it may be better suited for application in large scale application.

In many arid regions of the world where the nopal is present the turbidity of fresh water is made up of clay and slime, rendering water non-potable. Theoretically this is an ideal situation to apply the nopal, as a first step towards water clarification. Moreover it has been shown that nopal is totally innocuous and has the capacity to reduce re duce pathogens.

In developing countries the integration of nopal crop and nopal water treatment could produce enormous socioeconomic benefits.

39

European Joint Master in Water and a nd Coastal Management 2009 An increase in drinking water quality and the possibility of natural and sustainable residual water treatment systems would be sure to produce an increase in the quality of life of rural developing populations; in addition encouraging a sustainable environmental management system for preventing further degradation of natural systems.

Nopal is a resource highly productive and and beneficial , the combination of water management and nopal crops in an integrated develop project program for rural communities is a objective very plausible and one of the possibilities open with this new material.

We have the possibility to redress ecological and social imbalances in the world, through the introduction of new and socially empowering clean technologies; an obligation of this age. Deep research is necessary and the compromise of governments and corporations to generalise the use of this beneficial, effective and ecofriendly technique.

40


5.CONCLUSIONS/THE /THE FUTURE 5.-CONCLUSIONS -CONCLUSIONS

In general both nopal extracts worked better as primary coagulants than as aluminium sulphate aids.

As a primary coagulant, nopal is able to remove over 90% turbidity in kaolin clay suspensions.

In pre-potable water experiments, it reduced fecal streptococcus and fecal coliforms to a maximum of 81% and 45%, respectively.

In waste water experiments nopal did not produce a clear DQO or DBO reduction. Suspension solids were reduced by up to 58% and the removal of 40% of turbidity occurred when the DE was applied to urban waste water. LE was not successful in treating waste water.

The promising results obtained and the biological characteristics of this plant demonstrate its exciting potential for integration into sustainable water management manage ment programmes of both developed and developing countries. It appears to offer an excellent alternative to synthetic coagulants and also harbours the possibility of promoting empowering socioeconomic grown of arid regions worldwide.

At this point, it is necessary to increase the current body of knowledge we have on the coagulation properties of nopal; and for future research to build upon the numerous lines of questioning begun here, for example:

41

European Joint Master in Water and a nd Coastal Management 2009 •

Further research into nopal’s mucilage properties and its mechanism action.

•

More information on which metals it is able to remove; enabling satisfactory water potabilisation and industrial waste water treatment.

•

Further research into varying types of waste water and how nopal’s effects upon them differ.

•

Studies into the potabilisation possibilities of different fresh water sources.

•

Study the output of nopal as flocculant aid with other synthetic coagulants and in different mix conditions.

•

Further studies into the output of nopal; how as a s a flocculant it aids with w ith other synthetic coagulants; and which differing combinations promote optimum results.

•

Research into the combined usage of nopal and Moringa oleifera.

•

Pilot plant scale experimentation.

•

Nopal application as a previously step for sand filters treatment in water clarification.

•

The development of a project focusing on the integration of nopal crops into the water management of rural communities.

42


REFERENCE AAC, 2005. Association de l’Aluminium du Canada.Website : [http://www.aac. aluminium.qc.ca]. Almendárez N. Comprobacion de la efectividad del coagulante natural (cochifloc) en aguas del lago de Managua” Piedras azules”. Revista Iberoamericana de Polímeros Volumen 5(1), Marzo de 2004. Amin, E.S., O.M. Awad, and M.M. El-Sayed, The mucilage of Opuntia ficus indica. Carbohydr. Res. 15 1 pp. 159–161, (1970). Areces A. et all.Cactaceae In Flowering Plants of the Neotropics pp. 73-76. Princeton University Press, Princeton, NJ. 616 pp.2004. Al-Shahwani, M.F., Al-Rawi, E.H., Bacterial extracellular material from brewery wastewater for raw water treatment. Biol. Wastes 28,271–276. 1989 Barbera, G., F. Carmi, and P. Inglese. Past and present role of Opuntia Opuntia ficus-indica in the agriculture of Sicily. Economic Botany 46:10-20.1992. Biron M. Biodegradable, Sustainable, Renewable, Natural, Synthetic Polymers Debates and Dilemma, 2003 Bulsu K.R. & Pathak B.N. Seeds of red Sorella ;a new coagulant boon to villages. Indian J. Environ. Health,16(1):63-67 ,1974. Bulusu ,K.R & Sharma ,V.P. Pilot plant studies on the use of Nirmali seed as a coagulant aid.Induan J. Enrion. Health , 7:165, 1965. Chen YC, Xiao J. Researches and applications of natural macromolecular flocculants. flocculants. Evolvement Environ Sci;7(3):83–8, 1999.

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European Joint Master in Water and a nd Coastal Management 2009 Diaz A. et all .A preliminary evaluation evaluation of turbidity turbidity removal by natural coagulants indigenous to Venezuela. University of Zulia Process Biochemistry 35 (1999) 391–395. Duke, J. A., M. Bogenschutz-Godwin, J. du Cellier, and P. Duke. Handbook of Medicinal Herbs. Second Edition. CRC Press LLC, Boca Raton, Florida. 870 pp..2002 Feugang, J. M., P. Konarski, D. Zou, F. C. Stintzing, and C. Zou.. Nutritional and medicinal use of Cactus pear (Opuntia ssp.) cladodes and fruits. Frontiers in Bioscience 11.2006 Garti, N. . Hydrocolloids as emulsifying agents for oil-in-water emulsions. Journal Disper. Sci.Technol. 20(1&2):327-355.1999

González G. et all. Use of exudates gum produced by Samanea saman in the potabilization of the water . Rev. Téc. Ing. Univ. Zulia. Vol. 29, Nº 1, 14 - 22, 2006 Gutiérrez E:, A. Elías, H. Bernal. Usos alternativos del nopal forrajero. Facultad de Agronomía UANL Revista salud publica y nutricion , No 14, 2007 Guzmán D., Jorge Jorge Chávez Estudio Bromatologico del cladodio del nopal (Opuntia ficus-indica) para el consumo humano. Revista de la Sociedad Química del Perú ISSN 1810-634X 2007 Haug, A. Composition and properties of alginatos. Norwegian Institute of Seaweed Research ,1964. Report 30 Informe del servicio de defensa de la competencia N-07072 Kemira/Arkena. Ministerio de economía y hacienda de España. Jingdong Z, et all .A preliminary study on cactus as coagulant in water treatment Wuhan University, Process Biochemistry 41 730–733, (2006). Kirchmer, Cliff J. “Aspectos químicos y físicos de la coagulación del agua”. CEPIS, Lima, Perú; 1975. 11277

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European Joint Master in Water and a nd Coastal Management 2009 Kurane, R., Takeda, K. & Suzuki, T. Screening for and characteristics of microbial flocculants. Agric. Biol. Chem., 50(9): 2301-2307. (1986). Letterman, R.D. and R.W. Pero: Contaminants in polyelectrolytes used in water treatment.J. Am. Wat. Wks. Assoc. 82 87-97.(1990 López, E. Utilización de productos naturales en la clarificación de aguas para consumo humano. Tesis de Maestrıa, Facultad de Ingeniería Química, ISPJAE, Universidad de la Habana, Cuba. 2000. Madrid M. et all. Use of an extract of leaves of agave durangensis like coagulant natural.Instituto Tecnológico de Durango .2007 Martínez, M. Las Plantas Medicinales de Mexico. 6th Edition, Ediciones Botas. Mexico, D.F. 656 pp. 1989 Marton G.. Production and application of environment-friendly starch derivatives for the protection of the environment .University of Veszprém. National Research and Development Programme 2001, Hungary McLauchlan. D. R.. Environmetrics, et all Geographical Geographical relation between Alzheimer Alzheimer s ’

disease and aluminium in drinking water. Environmetrics 6, 233-275 (1995). Metcalf and Eddy, Inc., Wastewater Engineering, 3rd edition. Editorial : Mcgraw Hill, 2006. Miller S. et all.Toward Understanding the Efficacy and Mechanism of Opuntia ssp. as a Natural Coagulant for Potential Application in Water Treatment. University of Virginia, Environ. Science Technol., 42, 4274–4279, 2008.

Mindt L., Saag, K.; Sanderson, G. R., Moyna, P., and G. Ramos. Cactaceae mucilage composition. Journal Science. Fd. Agric. 1975.

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Miretzky P. et all Experimental binding of lead to to a low cost on biosorbent: biosorbent: Nopal (Opuntia streptacantha). Bioresource Technology, , 1211-1217. 31,1999. Mondragon C., Pimienta-Barrios E. Agro-ecology, cultivation and uses of cactus pear. Ed. FAO, Roma: 64-70,1995. Ndabigengesere, A.; Narasiah, K. S. Use of Moringa oleifera seeds as a primary coagulant in wastewater treatment. Environ. Technol. 1998 Normatov I. et all. Problems of wastewater clearing. Institute of water problem, Hydropower and Ecology Academy of Sciences Republic of Tajikistan,2002. Okuda, T.; Baes, A. U.; Nishijima, W.; Okada, M. Isolation andcharacterization of coagulant extracted from Moringa oleifera seed by salt solution. Water Res. 2001, 35 (2), 405– 410. Okonko, I. O. and Shittu, O. B , Bioremediation of wastewater and a nd municipal water treatment using latex exudates from calotropis procera(Sodom apple) Nigeria University.Electronic journal of environmental , agricultural and food chemistry. ISSN: 15734377,2007. RAWDP. Rural African Water Develoment Project www.mor-sandfilter.org Saenza C., Sepulveda E., Matsuhirob B. .Opuntia ssp mucilage’s: a functional component with industrial perspectives . Journal of Arid Environments Volume 57, Issue 3, May 2004, Pages 275-290. Sáenz, C., Sepúlveda, E., Albornoz, N. y Pak, N. 1999. Vegetal soup cladodes (Opuntia ficus-indica) with cactus dietary fibber addition. 10th Word Congress on Food Science and Technology. Sidney, Australia. SAGARPA. 2004. Sistema de Información Agropecuaria de Consulta. Sistema Integral de Información Agroalimentaria y Pesquera. Secretaría de Agricultura, Ganadería, Desarrollo

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European Joint Master in Water and a nd Coastal Management 2009 Rural, Pesca y Alimentación. México.DF. Sutherland, G. et all, Moringa oleifera as a natural coagulant .University of Leicester, 20th WEDC Conference Colombo, Sri Lanka, 1994

Sutherland, J.P., Folkard, G.K. & Grant, W.D. "Natural coagulants for appropriate water treatment - a novel approach", Waterlines, Vol.8, No.4, pp.30-32. 1990. Young K and Alcantar N .The Mucilage of Opuntia Opuntia Ficus Indica: A Natural, Sustainable, and Viable Water Treatment Technology for Use in Rural Mexico for Reducing Turbidity and Arsenic Contamination in Drinking Water. Master of Science in Chemical Engineering, University of South Florida, 2006.

2º United Nations World Water Development Report “Water , a shared responsibility “ , 2006.

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APP LICATION TION OF A NATURAL COAGULANT DERIV DERIVEED APPLICA PLICA ED FROM Opuntia sssssp. p. IN WATER TREATMENT José Miguel García Moreno Erasmus Mundus master program May 2009

--------------------------------------------------------------------------------------------------------

Abstract

The following study is an experimental approach about the possible use of Opuntia ssp. for water treatment. In this investigation the properties of the dry and liquid extracts of Opuntia Ficus Indica were evaluated as primary coagulant and coagulant aids in synthetic and “true” water samples by jar test method. There is ancestral evidence for the use of several cacti for water clarification. Recent authors have investigated the properties of Opuntia ssp., obtaining excellent results. The biological characteristics of this plant allow it to be applied on both local and commercial levels, as a cheap alternative with large socioeconomic benefits. In experiments with Synthetic Kaolin suspensions, nopal extracts remove more than 90% of turbidity; however the effectiveness of coagulation was reduced in “true” water sample experiments. For pre-potable waters the maximum effectiveness was about 75%; urban waste water reached 40% and high industrial charge waste water did not exceed 20%. In general nopal extracts worked better as primary coagulant than as a coagulation aid of aluminum sulfate. Analysis of the other measured parameters suggests that the nopal mucilage works well to reduce suspension solids but not dissolved solids. In addition, total fecal coliforms and streptoccus were reduced by 45% and 81% respectively in the pre-potable water samples.

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48


1.1.-Introduction -Introduction One of the more important Challenges of the modern World is to make human development economically and environmentally compatible; directing their efforts eff orts towards social equality. Water is vitally important in this process because it is used in a variety of ways at many different levels, producing social, spatial and organizational problems. Growing population, increase in economic activity and industrialization has not only created an increased demand for fresh water but also resulted in severe misuse of this natural resource. According to a survey conducted by UNEP(2º United Nations World Water Development Report ), 20% of the world’s population lacks access to safe drinking water and 50% of the world’s population lacks access to safe sanitation. Polluted water is estimated to affect the health of about 1200 million people and contribute to the death of 15 million children under the age of five every year. It is necessary to to recognise water as a limited resource and and to encourage encourage the application of clean technologies which reduce negative environmental impact and assist in the development of poor countries. In this sense the use of nopal for water treatment is a fair and efficient way to support the ecologic control of residues at local and industrial level level and is an excellent resource resource to increase access to drinking water in rural places and contribute to it socioeconomic soc ioeconomic development.

1.1.The natural resource (Opuntia ssp.) 1.1.--The The genus opuntia is the largest under the Cactaceae family with more than 250 endemic species from Central America. The Opuntia s sp. sp. chosen as natural coagulant source for this project was Opuntia ficus indica , also named chumbera in Spain, cactus pear in North America and nopal in

Mexico. The nopals are succulent plants which grow up to 3-5 metres, many times in a dense and tangled structure. It’s recognized by its green thick long pads that look like sports rackets. They grow one linked to the next and can be considered as both leaves and stalks. stalks. The plant surface is covering

49

European Joint Master in Water and a nd Coastal Management 2009 by spines which help to conduct water, reduce water loss, and protect the succulent tissue from herbivores and other predators (Mondragon C. 1995). Nopals are strong plants with not much water and nutrient requirements, are highly adaptable and propagate easily. After the American conquest, it was very treasured by explorers for its properties and introduced to Europe, Asia, Australia and Africa where it rapidly adapted to various environments (Barbera, G. et all 1992,). Different cultures know different uses for this plant, being especially appreciated for its organoleptic and medicinal properties. In developing countries where it is present, nopal represents an important economic and nourishing resource. Nopal leaves present a general composition of 87% water, 1% protein, 0.1% fat, 1.3% ash, 1.1% crude fibre, and 5.4% carbohydrates (D. Loayza et all 2007) being also an excellent forage for livestock in arid climates (E. Órnelas, 2007). Moreover in Mexico and South America it is used to treat numerous maladies and researchers are interested in its medicinal use.The nopal market moves millions of euros and produces millions of tonnes for different applications as food, medicines, cosmetics, pigments and as a paint additive. The biological characteristics of nopal and the socioeconomic repercussions of its possible uses in water treatment make it an excellent candidate for this study 1.2.1.2.-Nopal -Nopal as Natural Coagulant. The ability of cactaceae to retain water under such unfavourable climatic conditions is due to the water-binding capacity of mucilage, which involves the consequent coagulation properties (Mindt L., et all ,1975). When it is mixed with water or other fluids, forms a sticky and slippery gel which has the capacity to catch the suspension particles and carry them to the bottom. Experiments suggest that the coagulation mechanism of opuntia ssp. is not by charge neutralization like metallic salts, instead it occurs by adsorption and bridging mechanisms (Sarah Miller et all, 2008).

50

European Joint Master in Water and a nd Coastal Management 2009 In the last few years different scholars have returned to this research and the nopal coagulant properties are starting to be revealed (Jingdong Zhang et all 2005, 2005, N. Quezada,2004 , López, E. 2000, Miretzky P. 2007, Young K. et all, 2006). Some considerations about theses research are described below: -In comparative experiments with moringa oleifera and Al2 (SO4)3, nopal extract presents a similar capacity to remove turbidity in synthetic and real waters. -Temperature has slight influence on the coagulation effect of nopal. -The coagulation activity of Nopal is greatest in basic waters . -Nopal coagulation produces significant reductions of metals (As, Pb, Fe, Al, Mg). -Possible DOQ and coliforms removal.

2.2.-Methodology -Methodology The effectiveness of opuntia ssp. as a primary coagulant and flocculant aid in water treatment was compared with Al2 (SO4)3 by jar test method. Properties of the dry and liquid extract obtained from fresh nopal leaves and were tested in four different water models. This water models were; a Kaolin clay suspension, a “true” pre-potable water source, an industrial water source and urban wastewater. Leaves of Opuntia ficus indica were collected around the University of Alicante and were obtained a dry (DE) and liquid extract (LE) were obtained for the experimentation. Dry coagulant was prepared by hand cutting of fresh nopal leaves. The skin and other superficial tissue was scored and only the internal mucilaginous component was used. It was cut into strips approx. 1cm in width and dried in an oven at 65 ºC over 72 hours. Samples were then ground in a coffee grinder to obtain particles with less tham 300 µ metres metres diameter. This white powder was stored at 4ºC preserving its its properties for more than two months.

51

European Joint Master in Water and a nd Coastal Management 2009 Gummy coagulant was prepared by maceration. Entire leaves were cut into strips 1cm in width and mixed with the same volume of tap water. After 24 hours it was filtered through a nylon material to obtain a transparent slime soluble in water.The liquid was stored at 4ºC mantening its properties for no more than 3 days. Jar test experiments were realised with four different water models: Synthetic turbidity mode ls were prepared by the addition of kaolin clay (KAOLIN CH-N PRS, 3TQ ) into tap water to provide a turbidity of 75 and and 200 NTU; “true” waste water was recollected from the entry of Benidorms (urban charge) and Elda water treatment plants (industrial charge) ; a potable water source was collected from amadorio reservoir. The characteristics of all real water models follow: Amadorio Reservour

Value

Elda wastewater

Value

Benidorm wastewater

Value

Turbidity

13 NTU

Turbidity

235 NTU

Turbidity

106 NTU

Conductivity

485 µS

Conductivity

3,11 mS

Conductivity

2,48 mS

pH

8,63

pH

7,81

pH

7,75

Fecal Streptoccocus

110 UFC /100ml

Suspension Solids

754 mg/l

Suspension Solids

243 mg/l

Fecal Coliforms

1920UFC/100ml

DQO

1095 mg/l

DBO

507 mg/l

DQO DBO

460 mg/l 293 mg/l

The experimental method to measure the efficiency of nopal extracts for water treatment in the different water models was designed based on the removal of turbidity . The Residual turbidity tests were carried out according with ASTM jar test standard method Coagulants were added to six water samples (1000 ml) and stirred at 125 rpm for 2 minutes and next the speed was reduced to 70 rpm for 20 min. After the agitation, stirring was stopped and the samples would stand for 20 min. Turbidity of the supernatant were recorded in triplicates and measured using a calibrated turbidymeter.

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European Joint Master in Water and a nd Coastal Management 2009 In each jar test experiment one of the six jars received no treatment, serving as a control for comparison of the turbidity reduction for all a ll other jars. Coagulation activity was calculated ca lculated using the equation defined in the bibliography (Okuda 2001):

(residual turbidity control - residual turbidity sample) Coagulation activity = -------------------------------------------------------------------------------------------------------------------------- x 100 (residual turbidity control )

Dry extract (previously diluted in water for a correct mix ), liquid extract and Aluminium were compared as primary coagulants. In real water experiments only the supernatant of the jar with the more effective reduction of turbidity was used to measure the key key parameters of every water model. model. The key parameters for wastewater were DQO, DBO and Suspension Solids; and for pre-potable water were fecals streptococcus and fecal coliforms .

3.3.-Results -Results The efficiency of turbidity reduction at optimal dosages of both extracts in each water model is presented in next table. Synthetic water Turbidity Removal %

75NTU

Dry Extract

88

Liquid Extract

Synthetic water 200 NTU

Pre-potable Urban

Industrial

water

Wastewater

Wastewater

90

75

40

19

92

98

76

8

12

Control + Al

74

93

45

42

44

Dry Extract + Al

89

96

59

46

48

Liquid Extact + Al

96

98

42

38

4

Table1.Turbidity removal of water models

In all the the cases turbidity reduction was around 90% in kaolin synthetic suspensions. The optimal work dosages of the dry extract (DE) are around 20 mg/l at initial turbidity of 200

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European Joint Master in Water and a nd Coastal Management 2009 NTU and 10 mg/l at 75 NTU. The optimal work dosage of liquid extract (LE) is 0,2 ml/l with independence of the initial turbidity. In pre potable water both extract reduce the turbidity more than 75 % until remains values less than 3 NTU.

Turbidity reduction with Liquid extract 250 250 200 U 200 T N 150 150 y t i d 100 i 100 b r u T 50

Synthetic water 75 NTU Synthetic water 200 NTU Prepotable water Urban wate water Industrial waste water

0 0

0, 2

0,4

0,6

0,8

1

1,2

Concentration ml/L Graphic 1. Turbidity reduction in the water models treated with LE

In waste water LE doesn’t produce any effect, while DE only obtains good results treating urban waste water. An optimal dose of 50 mg/L of DE produced 40 % of turbidity remove.

Turbidity reduction with Dry extract 250 250 200 U 200 T N 150 150 y t i d 100 i 100 b r u T 50

Synthetic water 75 NTU Synthetic water 200 NTU Pre-potable water Urban waste water Industrial waste water

0 0

10

20

30

40

50

Concentration mg/l Graphic 2. Turbidity reduction in the water models treated with DE

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European Joint Master in Water and a nd Coastal Management 2009 For other side there isn’t a clear increase of flocculation activity when aluminium and nopal were added together. In any case could be increased the flocculation activity more than 15 %. The DE achieved the best results in reduction of the fecal streptococcus by 81% and the fecal coliforms by 45%. The LE has a similar capacity to remove turbidity but the microbiological reduction is more limited.

Removal Removal effi ciences in Pre-potable water 100 100 80

% l 60 a v o m 40 e R 20

Turbidity renoval Fecal coliforms renoval Fcal Streptococus renoval

0 Dry Extract 6 mg/l

Liquid Extract Control + Al Dry Extract Liquid Liquid Extact Extac t 0,4 ml/l (2ppm) 6 mg/l + Al 0,4 ml/l +Al

Sample Graphic 3. Removal efficiencies of key parameters in pre-potable water

Fecal coliforms are reduced when Aluminium sulphate is applied; behaving similarly to both nopal extracts although for the fecal streptococcus is less effective.

Urban wastewater removal efi eficiences optimal dosages ciences at optimal 80 70 60

Turbidity

% 50 l a v o 40 m e R 30

DQO Suspension solids DBO

20 10 0 Dry Extract 50 mg/l

Liquid Liquid Extract Extrac t Control + Al Dry Extract 0,4 ml/l (50ppm) 50 mg/l

Liquid Liquid Extact Extac t 0,4 ml/l


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European Joint Master in Water and a nd Coastal Management 2009 In any case it was possible to reduce the DQO and DBO by more than 25%, however, the suspended solids were notably reduced specially in the case of the DE treatment. Its achieved a maximum output of 58% when were applied as primary coagulant for both waste water samples. In general nopal work better with urban waste water than the high indusrial charge waters.

Industrial Wastewater removal eficience at optimal dosages 80 70 60 %50 l a v o 40 m 30 e R 20 10 0

Turbidity DQO Suspension solids DBO

Dry Extract 50 mg/l

Liquid Liquid Extract Extrac t 0,4 ml/l

Control + Al (50 ppm)

Dry Extract 50 mg/l + Al

Liquid Liquid Extact 0,4 ml/l +Al

Graphic 5.-Removal efficiencies of key waste waste water parameters

The LE is not successful in producing a clear reduction of the parameter analysed , even when is applied together with aluminium produces a negative influence.

4.Discussion 4.- Discussion Suspension solids reduction is the key parameter in this process and is related to the action mechanism of the nopal mucilage. It is clear exists a direct relationship between the nopal mucilage action mechanism , suspension solids removal and reduction reduction of turbidity in water treatment. In synthetic water experiments kaolin is distributed throughout the sample in the form of suspension solids producing all the total turbidity. The nopal performance upon the clay particles depends of the initial turbidity and nopal dosage applied. a pplied.

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European Joint Master in Water and a nd Coastal Management 2009 In all the previous experiments using kaolin synthetic water and optimal dosages of nopal; a turbidity reduction of greater than 90% was achieved; in water samples with low, medium and high turbidity. In the case of waste water, it is probable that diluted solids produce most of turbidity and nopal only can reduce a lowest part of turbidity generated by suspension solids. Moreover diluted chemicals, organic matter, soaps, oils and other substances could interact in the coagulation properties of the nopal. In this way DQO and DBO remove experiment doesn’t produce a output higher than 25 %. The LE does not produce a significant reduction of any parameter; something happened and decreased its coagulation capacity. The results obtained from this research suggest that nopal is a better primary coagulant than the flocculation aid of aluminium sulphate. However the theory says that aluminium sulphate generates small flocs which could be easily attached to the nopal mucilage increasing its coagulation capacity. However, to the contrary, there was no clear relation in these experiments. The DE did not produce a significant increase in the removal of all the factors analysed and the LE generated a negative effect. In pre-potable water experiments there was a significant reduction of microorganisms but not up to levels permitted by the drinking water normative because of the the high initial charge. It could be interesting determine the microorganisms and parasites removal capacity of nopal in controlled experiments and other fresh water systems. In many arid regions of the world where the nopal is present the turbidity of fresh water is made up of clay and slime, rendering water non-potable. Theoretically this is an ideal situation to apply the nopal, as a first step towards water clarification. Moreover it has been shown that nopal is totally innocuous and has the capacity to reduce re duce pathogens. In developing countries the integration of nopal crop and nopal water treatment could produce enormous socioeconomic benefits.

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European Joint Master in Water and a nd Coastal Management 2009 An increase in drinking water quality and the possibility of natural and sustainable residual water treatment systems would be sure to produce an increase in the quality of life of rural developing populations; in addition encouraging a sustainable environmental management system for preventing further degradation of natural systems. Nopal is a resource highly productive and and beneficial , the combination of water management and nopal crops in a Integrated develop project program for rural communities is a objective very plausible and one of the possibilities open with this new material. We have the possibility to redress ecological and social imbalances in the world, through the introduction of new and socially empowering clean technologies; an obligation of this age. Deep research is necessary and the compromise of governments and corporations to generalise the use of this beneficial, effective and ecofriendly technique.

5.5.-Conclusion -Conclusion /the future The promising results obtained and the biological characteristic of this plant ,convert to it in a excellent resource susceptible to be integrated in a water management plan for develop and developing countries. Could be an alternative to reduce the use of synthetic coagulants and also promote the socioeconomic grown of arid regions. At the moment is necessary to increase the knowledge which we have about the coagulation properties of nopal and develop the numerous research lines opened for a future: •

Further research into nopal’s mucilage properties and its mechanism action.

•

More information on which metals it is able to remove; enabling satisfactory water potabilisation and industrial waste water treatment.

•

Further research into varying types of waste water and how nopal’s effects upon them differ.

•

Studies into the potabilisation possibilities of different fresh water sources.

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European Joint Master in Water and a nd Coastal Management 2009 •

Study the output of nopal as flocculant aid with other synthetic coagulants and in different mix conditions.

•

Further studies into the output of nopal; how as a s a flocculant it aids with w ith other synthetic coagulants; and which differing combinations promote optimum results.

•

Research into the combined usage of nopal and Moringa oleifera.

•

Pilot plant scale experimentation.

•

Nopal application as a previously step for sand filters treatment in water clarification.

•

The development of a project focusing on the integration of nopal crops into the water management of rural communities.

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APPENDIX 1. 1.-- Water characteristic of Alicante tap water used for synthetic water .

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61


APPENDIX 2.2.- Amadorio reservoir water characteristics .

62


APPENDIX 3.- DQO kit identification

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APPENDIX 44. DBO analysis method

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APPENDIX 5.5 Microbiological analysis method

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APPENDIX 6.6 Microbiological analysis

Parte Analítico DATOS GENERALES E IDENTIFICACION MUESTRA REMITIDA POR: JOSE MIGUEL GARCIA MORENO. DENOMINACION DE LA MUESTRA: NUMERICA SUCESIVA 1,2,3,4,5,6 DESCRIPCION DE LOS ENVASES RECIBIDOS: BOTELLAS DE CRISTAL BOROSILICATADO ESTERILES DE 1 L DE CAPACIDAD CON CAMARA DE AIRE.

FECHA DE RECEPCIÓN: 24 de marzo de 2009 FECHA DE FINALIZACIÓN: 26 de marzo de 2009

Resultados Microbiológicos Muestra 1

Parámetro Coliformes Fecales Estreptococos Fecales

Métodos

Resultados

Unidades

Filtro de Membrana (FM) Filtro de Membrana (FM)

1920 110

u.f.c/100mL u.f.c./100 mL

2

Coliformes Fecales Estreptococos Fecales


3



1200 45


4



1155 69


5



920 51


6



1123 62


Silvia Gabriela Avilés Robles Especialista Técnico IUACA

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1050 20



THANK YOU , I HOPE YOU ENJOY AND LEARN WITH MY WORK. GOOD LUCK.

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PDF_ Nopal as Natural Coagulant

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