CHAPTER 1 DCC5152.ppt

DCC 5152 WATER SUPPLY AND WASTE WATER ENGINEERING 1

TOPIC 1.0 : WATER RESOURCES AND QUALITY

BY NORAIDAWATI BINTI NORDIN

1.1.1 List the importance of water usage

2

1.1.2 Describe the sources of water supply; a)Surface water resources: rivers,lakes, reservoirs/dam b)Ground water resources 1.1 know the sources of water supply


1.2.1 Physical Characteristics: a.Turbidity b.Taste and odour c.Colour d.Temperature


1.2.2 Chemical Characteristics: a.pH 3 b.Hardness c.Chlorides d.Sulphates e.Iron f.Solids g.Nitrates

1.2.3 Biological Characteristics: a.Coliform b.Bacteria c.Virus d.Protozoa

4

1.3 Study about water contaminant generation


1.3.1 Study the human impact results in a reduction of fresh water and degradation of water quality

1.1 – 1.1.1 Importance of Water Usage 5 1. Water Supply – drinking water , irrigation and industrial purposes after the water chemistry is determined based on its suitability for intended purposes. 2. Water resources management – groundwater reservoirs cross property line and political boundaries. Therefore, decision on who is allowed to pump, how much can be pumped, location of potential contaminant sources etc should be made. Surface water projects e.g dams, diversions for irrigation and sewer systems have impact on groundwater quality and quality and must be properly considered. 3. Engineering and construction – Dewatering of excavations is important in many construction projects. Groundwater flowing into the excavation may depress local water table and cause settlement of nearby land. All dams leak to some extent, and this seepage rate and the pore water pressure affect stability of the dam. Landfills and other waste storage facilities should be designed to limit the risk of groundwater and surface water contamination. 4. Environmental Investigations and clean-up – some contaminants are degraded by naturally occurring microbes that live in groundwater, but other contaminants require more active remediation efforts, e.g contruction of trenches to capture contaminants, pumping and treating water, and injecting air. 5. Geologic processes – Large –scale geologic processes involving groundwater are studied for academic interest and to better understand processes involving the origins of oil, gas, and mineral deposits. Some investigations are shedding light on past climates, earthquake mechanisms, and geologic hazards. BY NORAIDAWATI BINTI NORDIN

1..1.2 – describe the sources of water supply (surface water resources:river,lakes, reservoirs/dam) 6


1..1.2 – describe the sources of water supply (surface water resources:river,lakes, reservoirs/dam) 7  Characteristics of groundwater: a) Groundwater spread over a wide area and therefore is available for utilization or b) c) d) e) f)

g.

development. Movement of groundwater is very slow. Changes to discharge and storage are small and the storage is not affected by the dry spell. Cost of pumping operation to extract groundwater is higher than the treatment of surface water. Groundwater require low capital investment cost. The quality of groundwater: i. are always free from harmful organisms ii. Are treated through layers of rock and soil iii. Contains high soluble salts iv. Are difficult to treat if contaminated v. have quite uniform temperature. Data for analyses are sparse and insufficient


1.2 – understand the surface and ground water quality characteristics 8

1. Physical Parameters

2. Chemical Parameters

3. Biological Parameters


1.2 –1.2.1 Physical Characteristics 9

- This parameters respond to the sense of sight, touch,

taste or smell. Turbidity

Taste & Odour

Temperature


Colour

1.2 –1.2.1 Physical Characteristics (Turbinity) 10

- Is a measure of the amount of particulate matter that

is suspended in water. Unit – NTU (Nephlometric Turbidity Unit) - Water that has HIGH turbidity appears CLOUDY / OPAQUE - HIGH turbidity can cause INCREASED of water TEMPERATURE


1.2 –1.2.1 Physical Characteristics (Turbinity Cont…) 11

- More suspended particle will absorb more heat

which in turn lowers dissolved O2 levels. - Such particles (SS – clay,silt,finely divided organic material, plankton) can also prevent sunlight from reaching plants below surface hence DECREASE the rate of PHOTOSYNTHESIS - So, LESS O2 is produced by plant.


1.2 –1.2.1 Physical Characteristics (Turbinity Cont…) 12

- Desirable limit – 5NTU should be below 1 NTU when

disinfection is practices. - Permissible limit-10NTU


1.2 –1.2.1 Physical Characteristics (Temperature) 13

- It is a major factor in determining which species are

present in the stream. - Temperature will impacts: i. The rates of metabolisme and growth of aquastic organism. ii. Rate of plant photosynthesis iii.Solubility of O2 in water [O0 C,DO=14.6mg/l; 200C, DO = 9.1 mg/l] iv.Organism’s sensitivity to disease, parasites and toxic materials. BY NORAIDAWATI BINTI NORDIN

1.2 –1.2.1 Physical Characteristics (Temperature Cont…) 14

- Cool water taste better - Temperature affects rate of chemical and

microbiological reactions - The most suitable drinking water are consistently cool and do not have temperature fluctuations of more than a few degrees. - Groundwater and surface water from mountain area generally meet these criteria.


1.2 –1.2.1 Physical Characteristics (Colour) 15

- It is due to the presence of dissolved and suspended

matter (metallic ions, chemical pollutants, plankton and plant pigments from humus and peat). - These substance do not threaten stream water

quality, but indicate INCREASE DEVELOPMENT in watershed.


1.2 –1.2.1 Physical Characteristics (Colour Cont….) 16

- Dissolved organic material from humic substance generally lend

a brown or ‘tea’ color to water. - Dissolved organic material from vegetation and certain

inorganic matter may cause colour in water - Taste problems relating to water could be indicators of changes

in water sources or treatment process - Inorganic compound such as magnesium,calcium, sodium,

copper, iron and zinc are generally detected by taste of water.


1.2 –1.2.1 Physical Characteristics (Taste & Odor) 17

- Caused by foreign matters such as organics compounds,

inorganic salts, bacteria, algae and dissolved gases. - Measurement : Threshold Oder Number (TON) - Example; i. addition of ammonia to form monochloramine in the pipes. ii. Excessive manganese & iron present in the finish water. **manganese & iron often found in groundwater supplies where the overall quality of the water is good but there is a high amount of soluble salt. These metals then react with O2 in the distribution system to produced the reduced insoluble from of the metal**


1.2 –1.2.2 Chemical Characteristics 18

- Substance that dissolved in water - Total dissolved solid, alkalinity, hardness, metals,

organic compounds and nutrients. pH

HARDNESS

SOLIDS

SULPHATES

IRON


NITRATES

CHORIDES

1.2 –1.2.2 Chemical Characteristics (pH) 19

pH - it is a measure of the concentration of hydrogen ions - the term pH was derived from the manner in which the hydrogen ion concentration is calculated. - pH scale range from 0 to 14. A pH of 7 is consider to be neutral - Substances with pH of less than 7 are acidic Substances with pH greater than 7 are basic. Affect chemical and biological reaction; - Low pH is corrosive - High pH cause deposits 1.


1.2 –1.2.2 Chemical Characteristics (pH Cont…) 20

 Calculating the Hydronium Ion Concentration

from pH The hydronium ion concentration can be found from the pH by the reverse of the mathematical operation employed to find the pH. [H3O+] = 10-pH or [H3O+] = antilog (- pH)  Example: What is the hydronium ion concentration in a

solution that has a pH of 8.34?  8.34 = - log [H3O+] - 8.34 = log [H3O+] [H3O+] = 10-8.34 = 4.57 x 10-9 M On a calculator, calculate 10-8.34, or "inverse" log ( - 8.34). BY NORAIDAWATI BINTI NORDIN

1.2 –1.2.2 Chemical Characteristics (HARDNESS) 21

 Stream water hardness is the total of concentration of

cations, specifically calcium (Ca2+ ), Magnesium (Mg2+ ), iron (Fe2+ ), manganese (Mg2+ ) in the water.  Water rich in these cations is said to be ‘hard’. Stream water

hardness reflects the geology of the catchment area.  Sometimes it also provides a measure of the influence of

human activity.


1.2 –1.2.2 Chemical Characteristics (HARDNESS Cont..) 22

 For instance, acid mine drainage often results in the release

of iron into the stream. The iron produces extraordinarily high hardness is a useful water quality indicator.  Hardness is a reflection of the amount of calcium and

magnesium entering the stream through the weathering of rock such as limestone (CaCo3)



 Temporary or carbonate hardness: It is combination

calcium (Ca), magnesium (Mg) ion with Co32- or HCO3 Temporary hardness is mostly destroyed by boiling of water

or additional of lime.  The settlement of these ion will remove





Permanent or non-carbonate hardness: It is

combination calcium (Ca), magnesium (Mg) ion with Cl- , SO42- , NO3Unlike temporary hardness, permanent hardness is

not destroyed on boiling. The removal of noncarbonate using soda ash or soda lime.



The degree of hardness of drinking water has been

classified in terms of the equivalent CaCO3 concentration as follows




1.2 –1.2.2 Chemical Characteristics (NITRATES) 28

- Increasing level of nitrate due to Agricultural fertilizers, manure, animal dung, nitrogenous material, sewage pollution (blue baby diseases to infants) - Under normal conditions, the nitrogen cycle keeps the amount of available nitrogen in balance with the demands. However, excessive use of fertilizers and nutrient rich sewage release have created a surplus of nitrate. The result is eutrophication from excess algae and bacteria with reduced dissolved oxygen.


1.2 –1.2.2 Chemical Characteristics (IRON) 29

-One of the earth’s most plentiful resource -High iron causes brown or yellow staining of laundry,

household fixtures -Metallic taste, offensive odour, poor tasting coffee -Cause iron bacteria -Acceptable limit – 0.3 mg/l


1.2 –1.2.3 Biological Characteristics 30

- Living Organism that can be found in the water - It may lead to bad taste, odor,corrosion and

production - Pathogen Bacteria

Coliform

virus


Protozoa

1.2 –1.2.3 Biological Characteristics (Bacteria) 31

- Phatogenic bacteria causing cholera, typhoid fever

etc - Indicator Bacteria; - Coliform - Fecal Coliform (E.coli)


1.2 –1.2.3 Biological Characteristics (Virus) 32

- One virus can cause illness - Hard to detect - Specify treatment process (disinfection dose and

contact time) instead of measuring virus concentration. - Smallest microorganisms with sizes range from 0.01 to 0.3 μm. Could cause certain disease like hepatitis, flu, jaundice and polio. BY NORAIDAWATI BINTI NORDIN

1.2 –1.2.3 Biological Characteristics (Algae) 33

- Taste and odor - Some algae could be harmful to animals;

- fish - bird - Increase the level of DO in water. But too much algae, will affect taste and smell and can reduce the intensity of light penetration. BY NORAIDAWATI BINTI NORDIN

1.2 –1.2.3 Biological Characteristics (Protozoa) 34

- Simplest animal species. Infection are usually

characterized by gastrointestinal disorders.


1.3 –Study about water contaminant generation 35

- STUDENT MUST SEARCH 1( ONE ) ARTICLE

ABOUT HUMAN IMPACT RESULTS IN A REDUCTION OF FRESH WATER AND DEGRADATION OF WATER QUALITY. - P/s : Discuss this topic in next class.


CHAPTER 1 DCC5152.ppt

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