1. Civil Engineering
IV Year - II Semester
Academic Year 2020-2021
Course:
Solid and Hazardous Waste
Management
(Course Code: R164201C)
2. 2
UNIT-5
U6M1 Hazardous Waste Management- sources, collection,
U6M2 transport, treatment and disposal methods
U6M3 transport, treatment and disposal methods
U6M4 Biomedical waste Management
U6M5 Biomedical waste Management
U6M6 Electronic waste Management;
U6M7 Electronic waste Management;
U6M8 Environmental law related to waste Management;
U6M9 Environmental law related to waste Management;
U6M10 Case studies
U6M11 Case studies
3. Hazardous Waste Management- sources, collection
A waste is classified as a hazardous waste if it exhibits any of the four primary characteristics
based on the physical or chemical properties of toxicity, reactivity, ignitability and corrosivity.
Toxic wastes are those substances that are poisonous even in very small or trace amounts.
Reactive wastes are those that have a tendency to react vigorously with air or water.
Ignitable wastes are those that burn at relatively low temperatures (less than 60°C) and are
capable of spontaneous combustion during storage, transport or disposal.
https://www.researchgate.net/figure/Some-hazardous-waste-property-symbols-Reproduced-with-permission-from-US-EPA-16_fig4_340132153
4. Hazardous Waste Management- sources, collection
A waste is classified as a hazardous waste if it exhibits any of the four primary characteristics
based on the physical or chemical properties of toxicity, reactivity, ignitability and corrosivity.
Corrosive wastes are those that destroy materials and living tissue by chemical reaction.
Infectious wastes include human tissue from surgery, used bandages and hypodermic needles,
microbiological materials, etc.
Radioactive waste is basically an output from the nuclear power plants and can persist in the
environment for thousands of years before it decays appreciably.
https://www.highspeedtraining.co.uk/hub/disposal-of-infectious-waste/
5. List of Hazardous Chemicals
The following hazardous chemicals selected as require priority consideration:
1. Arsenic and its compounds
2) Mercury and its compounds;
3) Cadmium and its compounds;
4) Thallium and its compounds
5) Beryllium and its compounds
6) Chromium (VI) compounds;
7) Lead and its compounds;
8) Phenolic compounds;
9) Antimony and its compounds;
10) Cyanide compounds;
11) Isocyanates;
12) Organo-halogenated compounds except inert
polymeric materials;
13) Chlorinated solvents;
14) Organic solvents;
15) Biocides and phytopharmaceutical substances;
16) Tarry materials from refining and tar residues
from distilling;
17) Pharmaceutical compounds;
18) Peroxides, chlorates, perchlorates, and azides
19) Ethers;
20) Chemical laboratory materials, not identifiable
and/or new, with unknown effects on the
environment;
6. 21) Asbestos
22) Selenium and compounds
23) Tellurium and compounds
24) Polycyclic aromatic hydrocarbons
25) Metal carbonyls
26) Soluble copper compounds
27) Acids and/or basic substances used in the surface treatment and finishing of metals.
7. Sources of Hazardous Waste
The term hazardous waste often includes by-products of industrial, domestic, commercial, and
health care activities. Rapid development and improvement of various industrial technologies,
products and practices may increase hazardous waste generation.
Most hazardous wastes are produced in the manufacturing of products for consumption or
further industrial application. Hazardous waste sources include industry, institutional
establishments, research laboratories, mining sites, mineral processing sites, agricultural
facilities and the natural environment. All sources that discharge liquid, gaseous or solid wastes
that fit the above definition can be regarded as sources of hazardous wastes.
Some major sources are agricultural land and agroindusty, households, mines and mineral
processing sites, health care facilities, commercial facilities, institutional facilities, industrial
sites, solid waste disposal sites, contaminated sites and building materials. Major hazardous
waste sources and their pollution routes in the environment are listed below.
8. Agricultural land and agro-industry: Hazardous wastes from agricultural land and agro-
industry can expose people to pesticides, fertilizers and hazardous veterinary product
wastes. Farms are a major source of these wastes, and agrochemicals can leach into the
environment while in storage or can cause damage after their application.
Domestic: Households stock various hazardous substances such as batteries and dry cells,
furniture polishes, wood preservatives, stain removers, paint thinners, rat poisons,
herbicides and pesticides, mosquito repellents, paints, disinfectants, and fuels (i.e.
kerosene) and other automotive products. These can present a variety of dangers during
storage, use and disposal.
Mines and mineral processing sites: Mining and mineral processing sites handle
hazardous products that are present in the additives, the products and the wastes.
9. Health care facilities: Health care facilities are sources of pathological waste, human blood
and contaminated needles. Specific sources of these wastes include dentists, morticians,
veterinary clinics, home health care, blood banks, hospitals, clinics and medical laboratories.
Commercial wastes: Commercial waste sources include gasoline stations, dry cleaners and
automobile repair shops (workshops). The types of hazardous wastes generated by these
sources depend on the services provided.
Institutional hazardous waste sources: Institutional hazardous waste sources are mainly
research laboratories, research centers and military installations. Some military installations
are used for the manufacture and storage of ammunition, and they are also used as testing
grounds for military hardware. Military establishments also carry out activities that generate
other types of hazardous wastes of household, commercial and industrial nature.
10. Industrial hazardous waste sources: Hazardous wastes are created by many industrial
activities. For example, the hazardous wastes from the petroleum fuel industry include the
refinery products (fuels and tar), impurities like phenol and cyanides in the waste stream, and
sludge flushed from the storage tanks.
Solid waste disposal sites: These are mainly disposal sites for municipal solid waste, but
hazardous wastes that have not been properly separated from other wastes are also at these sites.
In developing countries, solid waste disposal sites are a major source of pollutant-laden leachate
to surrounding areas, as well as recyclable materials for scavengers, who can collect and resell
waste materials that have been exposed to or that contain hazardous substances.
Contaminated sites: These are sites that are contaminated with hazardous wastes due to
activities that use or produce hazardous substances or due to accidental spills. Former sites of
industries that used or produced hazardous materials belong to this group.
Building materials: Roofs and pipes made of materials incorporating asbestos, copper, or other
materials may present a source of hazardous waste.
11. Generation of Hazardous Waste
The major generators of hazardous waste among 15 industries studied by the
environmental protection agency (EPA) are as follows, more or less in order of the
quantities produced:
• primary metals,
• organic chemicals,
• electroplating,
• inorganic chemicals,
• textiles,
• petroleum refining, and
• rubber and plastics.
12. The elements of hazardous waste management that must be dealt with include
(1) source reduction at the point of generation;
(2) recycling both on- and off-site;
(3) transportation to processing and/or disposal facilities;
(4) treatment and processing to reduce or eliminate toxicity, to reduce the volume,
and to immobilize contaminants; and
(5) secure long-term storage and disposal.
13. Waste Collection and Transportation
Waste collection agents appear to be generally private companies and are essentially
local enterprises rather than national organisations. Most of the existing collectors in
Romania are municipal waste collection and transportation contractors and these
largely only collect municipal wastes. Some of these collectors also collect refuse-
type wastes from commercial and industrial sources, park wastes and construction
and demolition wastes. These contractors claim not to collect any hazardous wastes.
There are waste recycling organisations that collect wastes from generators, some of
these collect hazardous wastes, most notably waste oils, car batteries and, to a lesser
extent, solvents.
14. Hazardous Waste Reduction: In plant waste, reduction measures can be most
effective in reducing the air, liquid, and solid waste contaminants generated,
and hence the treatment needed to meet disposal standards, with resultant cost
savings.
Hazardous Waste Recycling: Often it may not be possible to reduce the
volume or toxicity of some hazardous wastes. However, it may be possible to
reuse the waste material in other processes within the same facility or other
related facilities. Hazardous wastes that may be recycled either directly or after
processing include water, solvents, spent oils, and selected solids.
Hazardous Waste Transportation: The transportation of hazardous wastes
always introduces the possibility of accidental spills.
15. Transportation and Disposal of Hazardous Waste
The transportation of hazardous waste can pose a threat to the public. To promote
safety and protect the public's health, companies follow four basic control
measures for the movement of hazardous waste from a source to disposal site;
1. Hazardous waste manifest:
The concept of a cradle-to-grave tracking system is considered key to proper
management of hazardous waste. Manifest copies accompany each barrel of
waste that leaves the site where it is generated, and are signed and mailed to the
receiving sites to indicate the transfer of waste from one location to another.
2. Labeling:
Each container is labeled and marked. The transporting vehicle is labelled before
waste is transported from the generating site. Companies post warning labels such
as: explosive, strong oxidizer, compressed gas, flammable liquid, corrosive
material, and poisonous or toxic substances.
16. 3. Haulers:
Because of the dangers involved, haulers of hazardous waste are subject to
operator training, insurance coverage, and special registration of vehicles
transporting hazardous waste. Handling precautions include restrictive use of the
transport trucks and the use of gloves, face masks, and coveralls for the workers'
protection.
4. Incident and accident reporting:
Accidents involving hazardous waste must be reported immediately to the state
regulatory agency, as well as local health departments. Necessary information
that will help responders contains the material that should be made available.
17. Treatment, Storage and Disposal Facilities (TSDF)
TSDF is a facility that is permitted to treat, store and dispose hazardous wastes in special
hazardous waste management units. TSDFs can be commercial or private – i.e., they may
accept hazardous waste from outside generators for a fee, or they may be set up for a
manufacturing facility (in which case they do not accept waste from other generators).
Definitions:
Treatment – Incineration or oxidation are commonly used to alter the chemical properties
of the incoming hazardous waste. Other chemical processes seen in Module 6 may be
applied here too. Incineration is detailed in the sections below.
Storage – Storage units are used for temporary storage of hazardous wastes until they are
completely treated or disposed of.
Disposal – Hazardous waste landfills or deep underground injection wells are used for this
purpose.
18. Hazardous Waste Processing Technologies:
The principal objectives of hazardous waste treatment are
(1) toxicity reduction,
(2) conversion to forms that can subsequently be processed by other
technologies,
(3) total elimination (e.g., complete destruction),
(4) volume reduction, and
(5) immobilization.
Treatment technologies used to process hazardous wastes may be classified as
(1) biological methods, (2) physicochemical processes, (3) stabilization and
solidification, and (4) thermal destruction.
19. Biological methods
(1) Suspended growth processes (aerobic, anoxic, and anaerobic); (2) attached growth
processes (aerobic, anoxic, and anaerobic); (3) combined suspended and attached growth
processes (aerobic, anoxic, and anaerobic)
Physical methods: drying, screening, grinding, evaporation, sedimentation, filtration,
fixation, etc.
Chemical methods: Oxidation, reduction, neutralization, hydrolysis, etc.
Physicochemical processes:
(1) Carbon adsorption;
(2) chemical oxidation;
(3) gas stripping;
(4) steam stripping;
(5) membrane separation;
(6) supercritical fluids extraction and supercritical water oxidation
20. Stabilization and solidification:
(1) Cement-based solidification;
(2) pozzolan-based aggregate;
(3) thermoplastic;
(4) organic polymers
These are the processes designed to improve waste handling and physical
characteristics, decrease surface area across which pollutants can transfer or
leach, or limit the solubility, toxicity of the hazardous constituents.
Solidification/Stabilization can be simply classified in to two types
a) In situ S/S
b) Ex situ S/S
21. Solidification/stabilization (S/S) reduces the mobility of hazardous
substances and contaminants in the environment through both physical and
chemical means.
Unlike other remedial technologies, S/S seeks to trap or immobilize
contaminants within their "host" medium (i.e., the soil, sand, and/or building
materials that contain them) instead of removing them through chemical or
physical treatment.
Leachability testing is typically performed to measure the immobilization of
contaminants. S/S techniques can be used alone or combined with other
treatment and disposal methods to yield a product or material suitable for
land disposal or, in other cases, that can be applied to beneficial use. These
techniques have been used as both final and interim remedial measures.
22. In Situ Vitrification (ISV)
In situ vitrification (ISV) is another in situ S/S process which uses an electric current
to melt soil or other earthen materials at extremely high temperatures (1,600 to 2,000
°C or 2,900 to 3,650 °F) and thereby immobilize most inorganics and destroy organic
pollutants by pyrolysis. Inorganic pollutants are incorporated within the vitrified glass
and crystalline mass.
Water vapor and organic pyrolysis combustion
products are captured in a hood, which draws the
contaminants into an off-gas treatment system
that removes particulates and other pollutants
from the gas. The vitrification product is a
chemically stable, leach-resistant, glass and
crystalline material similar to obsidian or basalt
rock. The process destroys and/or removes
organic materials. Radionuclides and heavy
metals are retained within the molten soil.
23. Ex Situ Physical/Chemical Treatment (assuming excavation)
Ex situ S/S contaminants are physically bound or enclosed within a stabilized
mass (solidification), or chemical reactions are induced between the stabilizing
agent and contaminants to reduce their mobility (stabilization).
Nine distinct innovative processes or groups of processes include:
(1) bituminization,
(2) emulsified asphalt,
(3) modified sulfur cement,
(4) polyethylene extrusion,
(5) pozzolan/Portland cement,
(6) radioactive waste solidification,
(7) sludge stabilization,
(8) soluble phosphates, and
(9) vitrification/molten glass.
24. Encapsulation
Is the process where the wastes are enclosed within a stable water resistance material.
The encapsulated wastes must then be placed in a land fill or similar disposal site.
Stabilization/solidification relies upon mobility reduction resulting from a
combination of chemical reaction (e.g., precipitation) and physical entrapment (e.g.,
porosity reduction).
Hazardous waste materials can be encapsulated in two ways:
microencapsulation
macroencapsulation.
Microencapsulation involves mixing the waste together with the encasing material before
solidification occurs. Macroencapsulation involves pouring the encasing material over and
around a larger mass of waste, thereby enclosing it in a solidified block. Sometimes these
processes are combined.
25. Thermal methods:
(1) Vapor, liquid, and solid combustion; (2) catalytic volatile organic chemical
(VOC) combustion; (3) fluidized-bed incinerators; (4) pyrolysis reactors
Land disposal:
(1) Municipal landfills; (2) monofill landfills; (3) land farming; (4)
impoundment and storage facilities; (5) deep-well injection
26. I. Waste Analysis
The incoming waste is first analyzed in order to verify the composition – the
hazardous components are characterized. This is done by thorough physical
and chemical analysis in a laboratory. The waste analysis must have rules for
the following:
Parameters to be analyzed
Safe sampling methods
Labelling
Repeatability of tests
Standardized tests for physical and chemical properties
Trained personnel to handle equipment and hazardous substances
27. II. Hazardous Waste Landfills
A hazardous waste landfill must fulfill the following design
requirements:
Double liner
Double leachate collection removal systems
Leak detection system
Monitoring storm water run-on and run-off
Monitoring wind dispersal
Absence of liquid wastes
Cover system in place
28. III. Incineration of hazardous wastes
The definition of an incinerator is “any enclosed device that uses controlled
flame combustion and does not meet the criteria for classification as a boiler,
sludge dryer, carbon regeneration unit, or industrial furnace”. Typical
incinerators include rotary kilns, liquid injectors, controlled air incinerators, and
fluidized-bed incinerators. There are three factors which ensure the completeness
of combustion in an incinerator:
1. Temperature of combustion chamber
2. Length of time wastes are maintained at high temperatures
3. Turbulence (degree of mixing)
29. Hazardous Waste Disposal
The sound treatment and disposal of industrial waste and industrial hazardous
waste is an essential element of an effective overall waste management system. In
general terms, treatment at source is most appropriate for low-capital cost
treatment processes or for generators of very large volumes of waste whilst
centralised facilities are most appropriate for management of wastes requiring
larger capital investments and wastes generated by smaller enterprises.
It is generally accepted that centralised, strategic, facilities for environmentally
sound management of hazardous wastes are a necessary element of the overall
hazardous waste management system. The availability of suitable facilities is a
critical element in that the legislation cannot be complied with unless the facilities
exist.
30. The hazardous waste, after treatment, can be ultimately disposed using the
following methods:
a) Land farming: the treated waste can be used as a fertilizer or soil conditioner
with the approval of concerned regulatory entities;
b) Deep well injection: a special kind of drilled well is prepared for such
purposes. Brine (40% salt solution) is usually disposed in this manner.
Precautions for water pollution need to be a concern.
c) Surface impediment: encapsulation, fixation, or containment of the waste. This
method involves arresting or demobilizing the movement or migration of the
waste by containing it in a hard core: clay soil, thermoplastics polymers, non-
corrosive metallic containers (carbon-steel
tanks), cement, lime, fire glass, rocks.
d) Ocean dumping: was mostly practiced from 1945 to the 1970s. Despite the
existing public protest, this method continuous to be an alternative for the waste
generators.
