Page 57 - Energy from Toxic Organic Waste for Heat and Power Generation

Toxic Waste From Textile Industries 45

and auxiliary chemicals are utilized to impart the required quality in the
textile fabrics. The wastewater of the textile industry is extremely alka-
line and contains high concentration or biological oxygen demand (BOD),
chemical oxygen demand (COD), total dissolved solids (TDS), and alka-
linity. This effluent leads to environmental complications if it is not ap-
propriately treated prior to its disposal. The textile industry also produces
air pollution. The processing of fibers before and during the spinning and
weaving operations creates dust and lint, which damages the working envi-
ronment of the textile industry. Dust may lead to respiratory diseases among
the workers. A chronic lung disease, byssinosis, is frequently experienced by
the workers exposed to cotton, flax, and hemp dust. In addition to this, there
are a number of process operations in textile industry that produce sound in
the range of 90 dB(A) leading to noise pollution [8].
As said earlier, the major environmental concern in the textile industry
is the amount of water discharged and the chemical load it carries. Other
important issues are energy consumption, air emissions, solid wastes, and
odors, which can be of significant problem in certain treatments.
Air emissions are usually collected at their origin point. As they have
long been controlled in different countries, there are good historical data
on air emissions from specific processes. This is not the case with emissions
to water. The various streams coming from the different processes are mixed
together to produce a final effluent whose characteristics are the result of
a complex combination of factors such as the kind of processed fibers, the
techniques applied, and the types of chemicals and auxiliaries used.
Presence of sulfur, naphthol, vat dyes, nitrates, acetic acid, soaps, chro-
mium compounds, and heavy metals like copper, arsenic, lead, cadmium,
mercury, nickel, and cobalt, and certain auxiliary chemicals all collectively
make the effluent highly toxic. Other harmful chemicals present in the
water may be formaldehyde-based dye fixing agents, hydrocarbon-based
softeners, and nonbiodegradable dyeing chemicals. The mill effluent is also
often of a high temperature and pH, both of which are extremely damaging.
Textile effluent is a cause of significant amount of environmental deg-
radation and human illnesses. About 40% of globally used colorants contain
organically bound chlorine, a known carcinogen. All the organic materials
present in the wastewater from a textile industry are of great concern in
water treatment because they react with many disinfectants, especially chlo-
rine. Chemicals evaporate into the air we breathe or are absorbed through
our skin and show up as allergic reactions and may cause harm to human
life [9–11].