This document discusses biological treatment of hazardous waste. It describes hazardous waste and explains that biological treatment uses microorganisms to decompose organic wastes. It then outlines five principal types of conventional biological treatment: treatment with activated sludge; aerated lagoon method; trickling filters; waste stabilization ponds; and anaerobic digestion. Each treatment type is then briefly described.

1. BIOLOGICAL
TREATMENT OF
HAZARDOUS WASTE
Presented by:
ABDUL HAI 170011601048
ASRAR SHAH 170011601049
ANEES ANSARI 170011601050

2. WHAT IS HAZARDOUS WASTE?
Hazardous waste is the
waste that possesses
substantial or potential
threats to public health or
the environment.
Hazardous wastes may be
found in different physical
states such as gaseous,
liquids, or solids.

3. Biological treatment of hazardous
wastes are the processes that use micro-
organisms to decompose organic wastes
either into water, carbon dioxide, or into
simpler organic substances, such as
aldehydes and acids.
FIGURE.1 The central theme and the relationships
among three major aspects of (BTHW).
BIOLOGICAL TREATMENT OF
HAZARDOUS WASTE

4. TYPES OF
HAZARDOUS WASTE
(1) Hazardous waste from households
(2) Small quantity generators
(3) Aqueous effluents discharged to sewer
(4) Sewage sludge
(5) Agricultural/mining waste
(6) Nuclear waste

5. MAJOR
BTHW
SYSTEMS
BTHW is mainly classified as in situ
(treatment occurs at the site without moving
the contaminated soil or water) or ex situ
(transporting the contaminants to different
sites).
Systems for BTHW can also be classified by :
(1) The hazardous wastes are liquid, slurry,
solid, or vapor phase
(2) Microbes are in the suspended or biofilm
form
(3) Systems use aerobic or anaerobic
conditions

6. TYPES OF BIOLOGICAL TREATMENT OF
HAZARDOUS WASTE
• Treatment with activated
sludge
• Treatment with aerated
lagoon method
• Treatment using trickling
filters
• Waste stabilisation ponds
• Anaerobic digestion
There are five
principal types
of
conventional
biological
treatment:

7. ACTIVATED SLUDGE
TREATMENT
The activated sludge process is an integral
process used to treat wastewater. Air or
oxygen is blown into raw sewage. It is most
effective for large volumes of water.
Wastewater is mixed and aerated in a
special tank. This step in the process occurs
by pumping air or oxygen into the activated
sludge tank or using surface aerators.
The process oxidizes organic matters in the
wastewater, producing new cells, carbon
dioxide, and water. The sludge particles can
then be removed through the process of
gravity settling.

8. ANAEROBIC
DIGESTION
Anaerobic sludge digestion is a biological
process in which organic solids from
hazardous wastes are decomposed into stable
substances. Digestion reduces the total mass
of solids, destroys pathogens, and makes it
easier to dry the sludge.
It is achieved using a two-staged digestor and
the final product of the process is biogas, a
mixture of carbon dioxide and methane.

9. WASTE STABILIZATION PONDS
Waste Stabilization Ponds (WSPs) are
large, man-made water bodies in
which liquid hazardous sludge is
treated by natural occurring
processes and the influence of solar
light, wind, microorganisms and
algae to convert it into Sludge,
Fertigation Water and Biogas.
There are three types of ponds:
(1) anaerobic, (2) facultative (3)
aerobic (maturation), each with
different treatment and design
characteristics.

10. TRICKLING FILTER
Trickling filter is a widely used
aerobic biological treatment system.
It consists of a fixed bed made up of
different inert materials. Hazardous
wastewater enters from the top of
the fixed bed.
Microbial biofilm grown on the
surface of the inert bed support
helps to degrade the waste.
Aerobic condition is achieved by
active or passive aeration by using
either a fan or natural convection of
air.

11. AERATED LAGOONS
Aerated lagoons are deep waste
stabilization ponds in which
sewage is aerated by mechanical
aerators to stabilize the organic
matter present in the wastewater,
rather than relying only on
photosynthetic oxygen produced
by algae.
Thus aerated lagoons represent a
system of sewage treatment that
is intermediate between
oxidation ponds and activated
sludge systems.