Page 163 - Energy from Toxic Organic Waste for Heat and Power Generation

Cracking of Toxic Waste 143

10.3.2.7 Mercury
Mercury is one of the heavy metals and is hazardous to biotic species even
if consumed in small quantities. Mercury intake is mainly through fish con-
sumption as the levels of mercury are high in the sea due to dumping of
wastes. Exposure to mercury affects brain, kidneys, and developing foetuses.
The risk of heart attack and death also increases by consuming mercury.
Landfilling and incineration are the methods used for disposing mercury.

10.3.2.8 Polychlorinated Biphenyls
Polychlorinated biphenyls are abbreviated as PCBs. PCBs were used in
manufacturing of various components such as electrical transformers,
capacitors, vacuum pumps, etc. As PCBs are toxic in nature, they are banned
from use now as they have been classified as human carcinogens.

10.3.2.9 Persistent Organic Pollutants
Persistent organic pollutants, or as they are popularly called POPs, are toxic
wastes, hazardous to the human health. They bioaccumulate in the food
chain and also take a significant amount of time to degrade. POP wastes are
harmful when their concentration exceeds a certain limit. When this limit
is exceeded, the POP present in it should be either destroyed or converted
by different methods. Different types of POPs are decabromodiphenyl
ether (deca-BDE), dicofol, perfluorooctanoic acid (PFOA), and many more.
Products such as vehicles, paints, pesticides, electrical, and electronic equip-
ment may contain such POPs.

10.4 CRACKING OF TOXIC WASTE
10.4.1 Methods
Waste management is a serious global issue, which should be tackled in
such a manner that useful substances can be produced from the biowaste.
Some of the methods of generating useful fuels from wastes are mentioned
as follows.
10.4.1.1 Arsenic
Arsenic is present in contaminated water and such water need to be treated right
away. But, during the treatment, arsenic-bearing wastes are generated which
have to be taken care of. Methods of treating water for removal of arsenic are:
1. Oxidized arsenic-bearing wastes
a. Ion-exchange
b. Adsorbent media filtration