EVT627 HAZARDOUS WASTE TECHNOLOGY AND MANAGEMENT NUR SYAHIZA ZAINUDDIN
Learning Outcomes At the end of of lectures of week week 3 student will Be able to interpret the principle of waste minimization Able to identify the responsibility responsibility of many parties involves involves in minimization minimization proc p rocess ess Be able to identify identif y the technique of waste minimization Able to identify the current management management practice/disposal technique
TOPIC TO COVER
Introduction Principles of waste minimization Responsibility Techniques of waste minimization Example of waste types Phase separation process Design criteria and examples
INTRODUCTION
Minimization is defined as practices to reduce the volume generated, the toxicity, or the recycle, reclaim, or reuse of the wastes to the extent practicable. Hazardous waste minimization is the first option before treatment or final disposal, and is preferably the source reduction rather than recycling, recovering or reusing. Minimization is an environmental option to solve the hazardous waste management problems and an economic opportunity to reduce production costs as well as treatment and disposal costs.
PRINCIPLE OF WASTE MINIMIZATION
Reduction of waste disposal costs Reduce the volume and toxicity of waste minimization waste minimization by volume reduction represent significant opportunities for protection of human health and the environment. The concepts of waste reduction and waste minimization can and should apply equally to industry, government, and other institutions, and to the private citizen.
RESPONSIBILITY
ENVIRONMENTAL HEALTH AND SAFETY (EHS)
Environmental Health and Safety’s responsibilities include:
Act as a resource to College personnel, providing technical assistance and guidance on waste minimization. Review and monitor existing waste minimization practices. Conduct College-wide waste minimization studies to identify new waste minimization programs to be implemented. Provide training as requested.
RESPONSIBILITY (Cont..)
PRINCIPAL INVESTIGATIORS AND SUPERVISORS
Principal Investigator and Supervisor responsibilities include:
Promote and practice waste minimization concepts. Establish procedures for conducting specific waste minimization activities. Ensure that all personnel and/or contractors adhere to the waste minimization concepts provided in this procedure and Department internal procedures.
4.3 PERSONNEL USING CHEMICALS
Personnel using chemicals should:
Practice the waste minimization concepts provided in this procedure. Follow internal procedures developed by their Principal Investigator (PI) and/or supervisor.
RESPONSIBILITY (Cont..)
CONTRACTORS
Contractors must ensure that:
All unopened or unused portions of chemicals brought on-site are removed by the contractor upon completion of services. Waste minimization techniques are used when feasible.
TECHNIQUES OF WASTE MINIMIZATION Waste minimization and pollution prevention techniques include the following:
TRAINING
Personnel should be trained when they are first hired, yearly thereafter, and when procedures change.
CHEMICAL REDISTRIBUTION
Unopened or unused portions of chemicals may be redistributed within the College to other users. For example, if a chemical is needed, especially exotic, high-hazard and single-use chemicals, check with other laboratory personnel and colleagues within the College for availability before ordering.
TECHNIQUES OF WASTE MINIMIZATION (Cont..)
PROCESS MODIFICATION To the extent that it does not compromise research, teaching, or service, laboratories are encouraged to
modify experimental or standard processes to decrease the quantity of hazardous chemicals used and generated. Where possible, micro and semi-micro techniques should be used to reduce the volumes of waste generated.
TECHNIQUES OF WASTE MINIMIZATION (Cont..)
PRODUCT SUBSTITUTION Substitute non-hazardous or less toxic materials in your chemical processes and experiments. Some examples include:
Non-mercury thermometers (e.g., Enviro-Safe™). Detergents and enzymatic cleaners can be substituted for sulfuric acid/potassium dichromate (chromerge) cleaning solutions and ethanol/potassium hydroxide cleaning solutions.
Avoid the use of known carcinogens, mutagens, or extremely hazardous chemicals where possible.
RECYCLING
Recycling means that less hazardous waste requires disposal When a waste material is used for another purpose, treated and reused in the same process, or reclaimed for another process. The following are some examples:
Re-distill used-solvents. When solvents are used for cleaning purposes, use contaminated solvents for the initial cleaning and use new solvents for the final rinse. Purchase compressed gas cylinders (including lecture bottles) from manufacturers who will accept the return of the empty or partially used cylinders. Return excess pesticides to the distributor.
TECHNIQUES OF WASTE MINIMIZATION (Cont..)
SEGREGATION AND CHARACTERIZATION Do not consolidate various process / experiment wastes into the same container unless the wastes contain similar constituents or otherwise authorized to do so by EHS. Accurately label waste containers including all chemical contents and approximate percentages. Segregation and characterization simplifies the waste stream facilitating treatment and disposal.
INVENTORY CONTROL It is important to audit chemical supplies and use inventory control measures. Purchase only the quantity of chemical required for a specific project and do not stockpile chemicals unnecessarily. Chemicals in storage should be examined periodically for changes in the condition of the chemical, the container holding the chemical, and/or the storage area. Before using or storing chemicals, become familiar with their physical and chemical hazards.
TECHNIQUES OF WASTE MINIMIZATION (Cont..)
STORAGE PRACTICES Chemical Segregation and Secondary Containment
Chemical containers should be stored and segregated according to their hazard (e.g., flammables, acids, bases, oxidizers, reactive, and poisons) and away from incompatible chemicals. Examples include: Water reactive chemicals are not to be stored under sinks. Acids are not to be stored under sinks. Flammables are not to be stored near ignition sources.
Chemical Labelling Practices
All containers must have an appropriate container label intact and legible at all times. Any defaced, faded or separating labels should be addressed immediately, either by correcting the label or offering the chemical for disposal to EHS. Any unknown chemicals should be immediately submitted to EHS for disposal.
Expired Chemicals
Expiration dates should be clearly marked for chemicals that are in reactive groups or develop hazardous functional groups on long-term storage (e.g., peroxide forming chemicals).
TECHNIQUES OF WASTE MINIMIZATION (Cont..)
Treatment:
The least preferable technique for waste minimization is treatment. The most common treatment is elementary neutralization. Example:
Consider the possibility of including detoxification and/or neutralization steps in your laboratory procedures.
Example of waste types
Industrial Hazardous Wastes
Acids
Cyanide
(Sources : Metal & chemical industries)
Arsenic
(Sources : Petroleum & chemical industries)
(Sources : Glass manufacturing processes, pesticides)
Cadmium
(Sources : paint & plastic industries, battery manufacturers)
Example of waste types
Industrial Hazardous Wastes
Lead
Infectious Waste
(Sources : Hospitals, Clinics)
Organic Solvents
(Sources : electronic industry)
(Sources : plastic, adhesive, cosmetic industries)
Radioactive Waste
(Sources : nuclear power plant)
Example of waste types
Domestic Hazardous Waste
Batteries – Corrosive, toxic Used oil – flammable, toxic Empty Insecticide spray can – unstable, toxic Broken thermometer – toxic Unused drug or medicine – toxic Floor detergents – corrosive, toxic Cigarette lighters - flammable
Separation Process
Widely used both in minimization of hazardous wastes and in the treatment of hazardous wastes before disposal. The treatment before disposal is done to recover valuable components and at the same time remove hazardous materials from the disposed stream. Closely linked to waste minimization practices because they recover valuable materials.
Waste Stream Waste Generation
Waste Handling, Separation, storage, and processing at sources
Collection Transfer and Transport Disposal
Separation, processing and transformation of solid waste
Phase Separation Process
Filtration, sedimentation, flocculation, centrifugation, distillation, evaporation, flotation, ultrafiltration, and precipitation, etc Chemical transformation processes include neutralization, precipitation, hydrolysis, oxidation, reduction, ozonolysis, calcination, chlorinolysis, electrolysis, and microwave treatment. Biological methods of treatment - microorganisms in nature that can break down anything into its constituent elements and thus detoxify it (unless of course the elements themselves are toxic, such as mercury or thallium).
Component of Separation Techniques
Schematic flow plans for (a) continuous distillation and (b)crystallization processes
Hazardous Waste Management
Reduce the amount of hazardous waste generated ‘Waste exchange method’ – one factory’s hazardous waste can be utilized by another factory Detoxify and neutralize liquid hazardous waste by chemical and biological treatment. Destroy combustible hazardous waste in special high temperature incinerators equipped with proper pollution control and monitoring systems Recycle metals or others useful materials contained in hazardous waste Disposal of HW at designated facilities
Management Practices/Disposal
Underground storage Secured Landfill Incineration Deep well injection, etc.
Underground Storage
Secure Hazardous-Waste Landfill
Incineration
Deep Well Injection
