Page 146 - Energy from Toxic Organic Waste for Heat and Power Generation

128 Energy from Toxic Organic Waste for Heat and Power Generation

Some of the chemicals are highly toxic to most life forms. That’s why
they are considered as hazardous. When such hazardous compounds
are available in a waste stream at levels equal to or greater than their
threshold levels, the entire waste stream is classified as hazardous [14].
Biomedical wastes: Biomedical waste consists of solid, liquid, sharps,
and laboratory waste that are highly infectious. Biomedical wastes are
collected or manufactured from different areas like nursing homes, hos-
pitals, health clinics, medical research laboratories, physicians office, den-
tists, and veterinaries area [15]. These also include human anatomical
sludge, animal sludge, microbiological waste or biotechnology wastes,
sharps needles, expired or unwanted medicines, cytotoxic drugs, soiled
waste, solid and liquid waste, incineration ash particles, and chemical
wastes [15]. The toxic pathological waste includes sharps needle wastes,
materials contaminated with blood and body fluids, chemical and phar-
maceutical waste, etc. [16]. The list of biomedical waste materials’ ratios
is given below.

Noninfectious waste 80%
Pathological and infectious waste 15%
Sharps waste 1%
Chemical and pharmaceutical waste 3%
Others 1%

Flammable or combustible wastes: Flammable or combustible liq-
uids can be ignited easily by a light up, hot surface, or a spark generated
by electricity, or some other mechanical work also. The highest hazard
is posed by highly volatile solvents because the vapor can reach ignition
sources from many feet away. Once the vapor is ignited, the fire can
reach the bulk liquid in a very quick time. A flammable vapor and air
mixture with a particular concentration can detonate violently. Vapors
are generally heavier than air and will get collected near the floor or
bottom of the lid [17]. The flash point is the minimum temperature at
which the liquid starts to emit the vapor to form a flammable mixture
in the presence of air that can be ignited by contact with a hot surface,
spark, or flame. If a solvent has a flash point lesser than the room tem-
perature, it is heavily combustible. Combustible liquids can be classified
into different varieties depending on their boiling and flash points.
Explosives: Explosive hazardous wastes are mainly ordnance (artillery)
materials, i.e., the wastes resulting from ordnance manufacturing and