This Presentation is clearly explain about the chemical wastes, management, Physical Processes involved in waste treatment, packaging and disposal methods.

1. CHEMICALWASTES
02-04-2023 DR. A. MUSHIRA BANU, ASSISTANT PROFESSOR OF CHEMISTRY, JMC 1

2. Definition
 Chemical waste is a waste that is made from harmful chemicals
(mostly produced by large factories).
 Chemical waste includes solids, liquids or gases containing or contaminated
with any of the following:
 Flammable solvents (e.g., Acetone, alcohols, acetonitrile);
 Leachate toxic materials (e.g., Heavy metals, pesticides);
 Corrosives (e.g., Hydrochloric acid, potassium hydroxide pellets);
02-04-2023 DR. A. MUSHIRA BANU, ASSISTANT PROFESSOR OF CHEMISTRY, JMC 2

3. Contd..
 Reactives such as oxidizers, cyanides, sulphides, explosives,
unstable materials
 Water-reactive materials (e.g., Sodium metal, benzoyl peroxide);
 Toxic materials including mutagenic, carcinogenic, acute or
chronic toxicity materials (e.g., Chloroform, ethidium bromide);
 Polychlorinated biphenyls (> 50 ppm concentration);
02-04-2023 DR. A. MUSHIRA BANU, ASSISTANT PROFESSOR OF CHEMISTRY, JMC 3

4.  Chemical waste may or may not be classed as hazardous waste. A chemical hazardous
waste is a solid, liquid, or gaseous material that displays either a “Hazardous
Characteristic” or is specifically “listed” by name as a hazardous waste.
 There are four characteristics chemical wastes may have to be considered as hazardous.
 These are Ignitability, Corrosivity, Reactivity, and Toxicity. This type of hazardous waste
must be categorized as to its identity, constituents, and hazards so that it may be safely
handled and managed.
 In the laboratory, chemical wastes are usually segregated on-site into appropriate
waste carboys, and disposed by a specialist contractor in order to meet safety, health, and
legislative requirements.
02-04-2023 DR. A. MUSHIRA BANU, ASSISTANT PROFESSOR OF CHEMISTRY, JMC 4

5. KitchenWaste
 Kitchen’s produce a variety of waste which will require different disposal
methods, such as recycling for cardboard and glass and expert removal of
knives and chemical waste. Some of the most common types of kitchen
waste that we handle are as follows:
 Biodegradable waste represents more than 30 percent of all domestic
waste. It is prohibited to mix kitchen waste with other waste types, or to
cut, crush or grind the waste in order to deposit it via wastewater into a
cesspool or sewers.
02-04-2023 DR. A. MUSHIRA BANU, ASSISTANT PROFESSOR OF CHEMISTRY, JMC 5

6. Items that can be put in the container for
biodegradable kitchen waste:
 Vegetable and fruit waste of different types (fruit, vegetable, vegetable and
fruit remains and peelings),
 Eggshells and coffee sediments,
 Tea and coffee filter bags,
 Tainted food,
 Non-liquid cooked food waste, bones,
 Stale bread and biscuits,
 Tissues, paper towels and paper sacks.
02-04-2023 DR. A. MUSHIRA BANU, ASSISTANT PROFESSOR OF CHEMISTRY, JMC 6

7. Items that CANNOT BE PUT in the container for
biodegradable kitchen waste:
 Green garden waste (grass, leaves, branches, flowers, hedges),
 Oils and fats,
 Liquid food waste,
 Cigarette ends,
 Napkins and sanitary towels,
 Textiles, leather, cork,
 Ashes,
 Slaughter waste, dead animals
 Pet excrement,
 Hazardous waste,
 Packaging waste, mixed waste.
02-04-2023 DR. A. MUSHIRA BANU, ASSISTANT PROFESSOR OF CHEMISTRY, JMC 7

8. o Legislation in the area of waste management requires reduced quantities
of biodegradable waste at waste dumps.
o The separate collection of waste requires reduced quantities of disposed
waste at waste dumps and reduced volumes of greenhouse gases (methane
is generated during the decomposition of biodegradable waste on landfills,
which threatens the ozone layer 21-times more than CO2), and
biodegradable waste can finally be processed into a compost or biogas of
high quality.
02-04-2023 DR. A. MUSHIRA BANU, ASSISTANT PROFESSOR OF CHEMISTRY, JMC 8

9. KitchenWasteManagement
 A large majority of the waste that kitchen’s produce is food waste. There are
many regulations surrounding food waste, due to the fact that raw meats, fish
and eggs cannot be landfilled.
 We are committed to reducing the unnecessary waste of resources that ends
up being set to landfill. Not only is this damaging the environment but it is also
costing businesses thousands due to increasing landfill tax.
 By recycling your food waste and other kitchen waste that is recyclable,
your business could save money and improve your environmental image.
02-04-2023 DR. A. MUSHIRA BANU, ASSISTANT PROFESSOR OF CHEMISTRY, JMC 9

10. Guidance for Disposal of Laboratory
Chemical Wastes
 Chemical waste category that should be followed for proper packaging, labelling, and
disposal of chemical waste.
 Innocuous aqueous waste (such as solutions of sodium chloride) may be poured down
the sink. Some chemicals are washed down with excess water. This includes:
concentrated and dilute acids and alkalis, harmless soluble inorganic salts (all drying
agents), alcohols containing salts, hypochlorite solutions, fine (tlc
grade) silica and alumina. Aqueous waste containing toxic compounds are collected
separately.
 Waste elemental mercury, spent acids and bases may be collected separately
for recycling.
02-04-2023 DR. A. MUSHIRA BANU, ASSISTANT PROFESSOR OF CHEMISTRY, JMC 10

11. Waste organic solvents are separated into chlorinated and non-chlorinated
solvent waste. Chlorinated solvent waste is usually incinerated at high
temperature to minimize the formation of dioxins. Non-chlorinated solvent waste
can be burned for energy recovery.
02-04-2023 DR. A. MUSHIRA BANU, ASSISTANT PROFESSOR OF CHEMISTRY, JMC 11

12. In contrast to this, chemical materials on the "Red List" should never be washed down a drain. This
list includes: compounds with transitional metals, biocides, cyanides, mineral
oils and hydrocarbons, poisonous organosilicon compounds, metal
phosphides, phosphorus element, and fluorides and nitrites.
 Including flammable liquids, liquids capable of causing damage to wastewater facilities (this can be
determined by the pH), highly viscous materials capable of causing an obstruction in
the wastewater system, radioactive materials, materials that have or create a strong odour,
wastewater capable of significantly raising the temperature of the system,
and pharmaceuticals or endocrine disruptors.
 Broken glassware are usually collected in plastic-lined cardboard boxes for landfilling. Due to
contamination, they are usually not suitable for recycling. Similarly, used hypodermic needles are
collected as sharps and are incinerated as medical waste.
 Packaging, labelling, storage are the three requirements for disposing chemical waste.
02-04-2023 DR. A. MUSHIRA BANU, ASSISTANT PROFESSOR OF CHEMISTRY, JMC 12

13. Packaging
 In addition to the general packaging requirements outlined here. These specific
requirements for chemical waste must be followed:
 Never mix incompatible materials together in a single container.
 Wastes must be stored in containers compatible with the chemicals stored.
 For example, hydrofluoric acid waste must not
be stored in glass containers, corrosive chemicals
must not be stored in metal containers, etc.
02-04-2023 DR. A. MUSHIRA BANU, ASSISTANT PROFESSOR OF CHEMISTRY, JMC 13

14. Package halogenated and non-halogenated solvents separately, if possible. The University pays
a premium for disposing of halogenated solvents (e.g., chloroform, carbon tetrachloride).
 Solvent safety cans should to be used to collect and temporarily store large volumes (10-20 litres) of
flammable organic waste solvents. The researcher is responsible for providing these cans to the
laboratory. Cans submitted for disposal will be emptied and returned promptly to the laboratory,
provided that they are properly identified with the building and laboratory room number.
 Do not insert precipitates, solids or other non-fluid wastes into safety cans.
 Do not package solid chemical waste into biohazard bags, because this incorrectly indicates a hazard
that is not present.
 Buildings with Central Waste Storage will have drums for contaminated glass and plastic where lab
staff can empty their containers into.
02-04-2023 DR. A. MUSHIRA BANU, ASSISTANT PROFESSOR OF CHEMISTRY, JMC 14

15. Labelling
In addition to the general labelling requirements outlined, these specific
requirements for chemical waste must be followed:
→ Attach a Chemical Waste label directly to the waste container. Chemical waste labels
are available free of charge from EHS staff.
→ All information requested on the Chemical Waste Label should be
provided. Chemical generic names of the chemicals must be listed. No abbreviations,
acronyms or trade mark names are to be used. Vague categories (e.g., solvent waste)
are not acceptable.
02-04-2023 DR. A. MUSHIRA BANU, ASSISTANT PROFESSOR OF CHEMISTRY, JMC 15

16.  When storing chemical wastes, the containers must be in good condition and should
remain closed unless waste is being added.
 Hazardous waste must be stored safely prior to removal from the laboratory and
should not be allowed to accumulate. Container should be sturdy and leakproof, also
has to be labelled.
 All liquid waste must be stored in leakproof containers with a screw-top or other
secure lid. Snap caps, mis-sized caps, parafilm and other loose fitting lids are not
acceptable.
 If necessary, transfer waste material to a container that can be securely closed. Keep
waste containers closed except when adding waste.
 Secondary containment should be in place to capture spills and leaks from the
primary container, segregate incompatible hazardous wastes, such as acids and bases.
02-04-2023 DR. A. MUSHIRA BANU, ASSISTANT PROFESSOR OF CHEMISTRY, JMC 16

17. The physical processes that are commonly used in waste treatment operations are as
follows:
Screening is a process for removing particles from waste streams, and it is used to protect
downstream pre-treatment processes.
Sedimentation is a process for removing suspended solid particles from a waste stream.
Sedimentation is usually accomplished by providing sufficient time and space in special tanks or
holding ponds for settling. Chemical coagulating agents are often added to encourage the settling
of fine particles.
Flotation is a process for removing solids from liquids by floating the particles to the surface by
using tiny air bubbles. Flotation is useful for removing particles too small to be removed by
sedimentation.
Filtration is a process for separating liquids and solids by using various types of porous
materials. There are many types of filters designed to achieve various levels of separation.
02-04-2023 DR. A. MUSHIRA BANU, ASSISTANT PROFESSOR OF CHEMISTRY, JMC 17

18.  Centrifugation is a process for separating solid and liquid components of a waste stream by
rapidly rotating a mixture of solids and liquids inside a vessel. Centrifugation is most often
used to dewater sludges.
 Dialysis is a process for separating components in a liquid stream by using a membrane.
Components of a liquid stream will diffuse through the membrane if a stream with a greater
concentration of the component is on the other side of the membrane. Dialysis is used to
extract pure process solutions from mixed waste streams.
 Electrodialysis is an extension of dialysis. This process is used to separate the components
of an ionic solution by applying an electric current to the solution, which causes ions to move
through the dialysis membrane. It is very effective for extracting acids and metal salts from
solutions.
 Reverse osmosis separates components in a liquid stream by applying external pressure to
one side of a membrane so that solvent will flow in the opposite direction.
02-04-2023 DR. A. MUSHIRA BANU, ASSISTANT PROFESSOR OF CHEMISTRY, JMC 18

19.  Ultrafiltration is similar to reverse osmosis, but the separation begins at higher
molecular weights. The result is that dissolved components with low molecular weights
will pass through the membrane with the bulk liquid while the higher-molecular-
weight components become concentrated through the loss of solvent. Ultrafiltration
systems can handle much more corrosive fluids than reverse-osmosis units.
 Distillation is a process for separating liquids with different boiling points. The
mixed-liquid stream is exposed to increasing amounts of heat, and the various
components of the mixture are vapourized and recovered. The vapour may be recovered
and re-boiled several times to affect a complete separation of components.
 Solvent extraction is a process for separating liquids by mixing the stream with a
solvent which is immiscible with part of the waste but which will extract certain
components of the waste stream. The extracted components are then removed from the
immiscible solvent for reuse or disposal.
 Evaporation is a process for concentrating non-volatile solids in a solution by boiling
off the liquid portion of the waste stream. Evaporation units are often operated under
some degree of vacuum to lower the heat required to boil the solution.
 Adsorption is a process for removing low concentrations of organic materials on the
surface of a porous material, usually activated carbon. The carbon is replaced and
regenerated with heat or a suitable solvent when its capacity to attract organic
substances is reduced.
02-04-2023 DR. A. MUSHIRA BANU, ASSISTANT PROFESSOR OF CHEMISTRY, JMC 19

20. Chemical Treatment of Hazardous Waste:
The five chemical treatment operations commonly used in treating wastes
are as follows:
 Neutralisation is a process for reducing the acidity or alkalinity of a waste stream by mixing
acids and bases to produce a neutral solution. This has proven to be a viable waste
management process.
 Precipitation is a process for removing soluble compounds contained in a waste stream. A
specific chemical is added to produce a precipitate. This type of treatment is applicable to
streams containing heavy metals.
 Ion exchange is used to remove from solution ions derived from inorganic materials. The
solution is passed over a resin bed, which exchanges ions for the inorganic substances to be
removed. When the bed loses its capacity to remove the component, it can be regenerated
with a caustic solution.
 De-chlorination is a process for stripping chlorine atoms from chlorinated compounds such
as polychlorinated biphenyls (PCBs). One of the processes uses a metallic sodium reagent to
break the chlorine bond.
 Oxidation-reduction is a process for detoxifying toxic wastes in which the chemical bonds
are broken by the passage of electronics from one reactant to another.
02-04-2023 DR. A. MUSHIRA BANU, ASSISTANT PROFESSOR OF CHEMISTRY, JMC 20

21. BiologicalTreatmentofHazardousWaste
 Biological waste treatment is a generic term applied to processes that use micro-
organisms to decompose organic wastes either into water, carbon dioxide, and simple
inorganic substances, or into simpler organic substances, such as aldehydes and acids.
 Typically, the micro-organisms used in a biological process are present in the incoming
waste. In some instances, micro-organisms that were developed to attack specific
compounds are injected into a waste stream.
 The purpose of a biological treatment system is to control the environment for micro-
organisms so that their growth and activity are enhanced, and to provide a means for
maintaining high concentrations of the micro-organisms in contact with the wastes.
 Since biological treatment systems do not alter or destroy inorganic substances, and
high concentrations of such materials can severely inhibit decomposition activity,
chemical or physical treatment may be required to extract inorganic materials from a
waste stream prior to biological treatment.
02-04-2023 DR. A. MUSHIRA BANU, ASSISTANT PROFESSOR OF CHEMISTRY, JMC 21

22.  There are five principal types of conventional biological treatment. Treatment
with activated sludge involves exposing waste to a biological sludge that is
continuously extracted from the clarified waste stream and recycled.
 In the aerated lagoon method, waste is agitated with air in large enclosures to
increase oxygen-dependent biological oxidation. In treatment using trickling
filters, wastes are allowed to trickle through a bed of rocks coated with micro-
organisms that alter the waste components by using them as food.
 Waste stabilisation ponds are ponds in which wastes are allowed to
decompose over long periods of time, aeration is provided only by wind action.
Anaerobic digestion is a method for decomposing organic matter by using
anaerobic organisms in closed vessels in the absence of air; methane may be
produced in the process.
02-04-2023 DR. A. MUSHIRA BANU, ASSISTANT PROFESSOR OF CHEMISTRY, JMC 22

23. IncinerationandPyrolysisofHazardousWaste
 Incineration and pyrolysis techniques reduce the volume or toxicity of organic wastes by exposing
them to high temperatures. When organic chemical wastes are subjected to temperatures of 800-
3000°F (430-1700°C), they break down into simpler and less toxic forms.
 If the wastes are heated in the presence of oxygen, combustion occurs, and the process is known
as incineration. Incineration systems are designed to accept specific types of materials; they vary
according to feed mechanisms, operating temperatures, equipment design, and other parameters.
The main products from complete incineration include water, carbon dioxide, ash, and certain acids
and oxides, depending upon the waste in question.
 If the wastes are exposed to high temperatures in an oxygen-starved environment, the process is
known as pyrolysis. The products of this process are simpler organic compounds, which may be
recovered or incinerated, and a char or ash.
02-04-2023 DR. A. MUSHIRA BANU, ASSISTANT PROFESSOR OF CHEMISTRY, JMC 23

24. DisposalofHazardousWaste
There are five options for disposing of hazardous waste as follows:
Underground injection wells are steel and concrete-encased shafts placed deep below the
surface of the earth into which hazardous wastes are deposited by force and under
pressure. Some liquid waste streams are commonly disposed of in underground injection
wells.
Surface impoundment involves natural or engineered depressions or diked areas that can
be used to treat, store, or dispose of hazardous waste. Surface impoundments are often
referred to as pits, ponds, lagoons, and basins.
Landfills are disposal facilities where hazardous waste is placed in or on land. Properly
designed and operated landfills are lined to prevent leakage and contain systems to collect
potentially contaminated surface water run-off. Most landfills isolate wastes in discrete cells
or trenches, thereby preventing potential contact of incompatible wastes.
Land treatment is a disposal process in which hazardous waste is applied onto or
incorporated into the soil surface. Natural microbes in the soil break down or immobilise
the hazardous constituents. Land treatment facilities are also known as land application or
land farming facilities.
Waste piles are non-containerised accumulations of solid, non-flowing hazardous waste.
While some are used for final disposal, many waste piles are used for temporary storage
until the waste is transferred to its final disposal site.
02-04-2023 DR. A. MUSHIRA BANU, ASSISTANT PROFESSOR OF CHEMISTRY, JMC 24

25. There are five types of treatment technologies for abandoned
disposal sites
 Aqueous waste treatment
i. Activated carbon treatment, ii. Biological treatment, iii. Filtration,
iv. Precipitation/flocculation, v. Sedimentation technology, vi. Ion exchange and
sorptive resin, vii. Reverse osmosis, viii. Neutralisation, ix. Gravity separation, x.
Air stripping, xi. Oxidation, xii. Chemical reduction
 Solids treatment
i. Solids separation, ii. Dewatering
 Solidification/stabilisation
i. Cement-based solidification, ii. Silicate-based process, iii. Sorbents,
iv. Thermoplastic solidification, v. Surface micro-encapsulation, vi. Vitrification
02-04-2023 DR. A. MUSHIRA BANU, ASSISTANT PROFESSOR OF CHEMISTRY, JMC 25

26.  Gaseous waste treatment
i. Flaring, ii. Adsorption
 Thermal destruction of hazardous wastes
i. Liquid injection, ii. Rotary kiln, iii. Multiple hearth, iv. Fluidised bed
v. Mobile incineration
As the state of the art for remedial technology improves, there is a clear
preference for processes that result in the permanent destruction of
contaminants rather than the removal and storage of the contaminating
materials.
02-04-2023 DR. A. MUSHIRA BANU, ASSISTANT PROFESSOR OF CHEMISTRY, JMC 26

27. 02-04-2023 DR. A. MUSHIRA BANU, ASSISTANT PROFESSOR OF CHEMISTRY, JMC 27