2. INTRODUCTION
Every year, billions of tons of solid wastes are discarded into our environment.
These wastes range in nature from common household trash to complex
materials in industrial wastes, range in nature from common household trash to
complex materials in industrial wastes, such as hospitals and laboratories.
Waste is defined as 'any material that are no longer desired and has no current or
substance that has been discarded or otherwise designated as a waste material, or
one that may become hazardous by interaction with other substances
3. Hazardous waste can be defined as…
waste that has the potential, even in low concentrations, to have a significant
adverse effect on public health and the environment because of its inherent
toxicological, chemical and physical characteristics
Classification with Respect to Characteristics
• Solid waste has to be examined whether it exhibits a characteristic that makes it
hazardous.
• All persons who generate a solid waste have to ascertain whether their wastes
exhibit one or more of the characteristics as follows: Ignitability, Corrosivity,
Reactivity, Toxicity
4. Ignitability
• The hazardous waste characteristic of ignitability was established to identify solid
wastes capable during routine handling of causing a fire, or provoking a fire once
started.
• A solid waste is deemed to exhibit the characteristics of ignitability if meets one of
the four descriptions.
Corrosivity
• Corrosive substances may exhibit extremes of acidity or basicity or a tendency to
corrode steel. Wastes capable of corroding metal could escape their own containers
and liberate other wastes.
• In addition, wastes with a pH at either the high or low end of the scale can harm
human tissue and aquatic life and may react dangerously with other wastes.
5. Reactivity
• Reactive substances are those, which are extremely unstable and have a
tendency to undergo violent chemical change or explode during stages of its
management.
• The regulation lists several situations where this may happen which guarantee
specific consideration like the behavior of the substance when mixed with
water, when heated etc.
• Instead of developing a precise scientific description of this characteristic,
EPA has publicized a descriptive, prose definition as a suitable test protocols
for measuring reactivity are unavailable
6. Toxicity
• One of the most significant dangers posed by hazardous wastes is the leaching of
toxic constituents (of land disposed wastes) into the ground water .
• EPA designed the (Toxicity Characteristic) TC Toxicity, to identify wastes that
pose a threat to human health
• And the environment resulting from ground water contamination by simulating the
leaching process that occurs in a municipal landfill.
• EP A treats mixtures of a characteristic hazardous waste and a solid waste
differently than it does a mixture of a listed hazardous and solid waste. Toxicity
can be determined by fish bioassay tests. Toxicity value defined by LC50
7. LC 50
• The LC50 for a contaminant is the concentration being lethal to 50
per cent of an exposed population of test fish with a given time. For
estimation of LCso values, various procedures using different test
species and experimental conditions can be found in literature.
• The entire volume of a mixed waste is treated as hazardous if; the
listed hazardous waste in the mixture was not listed separately due
to its hazardous characteristics or mixture does not consist of certain
specified hazardous wastes
8. HAZARDOUS WASTE ISSUES
• WATER DISCHARGES
• HAZARDOUS WASTE
• NON-HAZARDOUS WASTE
• BIOLOGICAL AND MEDICAL WASTE
• RADIOACTIVE WASTE
• HAZARDOUS MATERIAL SPILLS
HAZARDOUS MATERIALS HANDLING AND STORAGE
9. HAZARDOUS MATERIALS AND WASTE MANAGEMENT
• Each lab must develop as part of their chemical hygiene plan a standing
operating procedure for management of hazardous materials in their labs. This is
called an Environmental Management System.
• This System includes but is not limited to receiving, storing, and proper use of
materials in each individual and unique lab.
• Also, the Standard Operating Procedures (SOP)/Chemical Hygiene Plan
should include waste minimization, use of personal protective equipment, and
environmental training. Environmental training includes waste labeling, storing,
and responding to chemical spills.
10. HAZARDOUS MATERIALS AND WASTE MANAGEMENT
• These play an important role particularly in terms of disposal cycle and in
control.
• Most incidents of improper disposal of hazardous waste have occurred
during transport and may result from disposal contracts between the waste
generator and hauler rather than between the waste generator and disposer.
• Thus, any reduction of cost for disposal (e.g. by means of improper
dumping) will increase the profit of waste haulage firm.
11. Management, Treatment and Disposal
• Waste Reduction
• Waste sorting and Recycling
• Waste transfer and Transboundry movement
• Energy and Material recovery
• Thermal Processing/ Waste Incineration
• Ultimate Disposal/ H.W. Sites
12. Physical Treatment
• Lagooning and tank storage are widely used to seperate oil and water from
mixed wastes
• Solidification fixation processes are generally used as pretreatment prior to
landfill disposal
• Air flotation and various filtration and centrifugation techniques
Chemical Treatment
• Cyanide Oxidation
• Heavy Metal Precipitation
• Hexavalent Chromium Reduction
• Acid neutralization
13. Biological Treatment
• The in-plant biological treatment of dilute aqueous effluents is well
established, and m.o. Have been developed to selectively degrade specific
toxic chemicals
• Composting may also be useful for certain organic chemical products
Disposal
• Landfill
• Incinaration
• Dumping at sea
• Underground disposal
• Deep-well disposal
14. Management Strategies for Identification
• Management strategies also play an important role in defining a hazardous waste.
These steps may include; the source of the waste, generators, waste transport,
waste storage, appropriate treatment technologies, Final disposal.
• Once a waste is identified as hazardous, quantities must be tracked. In order to
identify whether a solid waste is hazardous or not, generator should have to refer
to lists or various tests.
• Effective identification and labelling by the generators are essential for control.
Mismanagement of Hazardous Waste leads to a 'cradle to grave' control system
• This system regulates the hazardous waste from the time it is first generated
through the transport to final treatment or disposal.
• Some hazardous wastes require special control from the time of generation
through their transportation, temporary storage, treatment and disposal.
15. Security Guidelines
• Recognize that security is related to but different from safety.
• Develop a site-specific security policy
• Control access to areas where hazardous materials are stored
• Know who is in the area
• Secure highly hazardous materials
• Have an emergency plan
• Take precautions, know what is in your area and who belongs there