Environment Pollution – Water Pollutants
Water
Pollutants
Sources – community waste water, Industrial waste, Agricultural
chemicals waste, Thermal & nuclear pollution, Oil spills, Radioactive dump
waste, Groundwater seepage etc.
§
Sudden rise in water temperature due to thermal pollution, which uses water as
coolant & releases hot water to source, kills aquatic animals as they have
a very narrow tolerance limit with respect to temperature
§ Polluted
water reduces dissolved oxygen which leads to depletion of aquatic flora &
fauna
§ Oil spills in water can be cleaned with the help of Bregoli – a
byproduct of paper industry
§ Water hyacinth (an aquatic weed) can purify water by taking
some toxic materials & a number of heavy metals from water.
Biochemical oxygen demand
§ amount
of dissolved oxygen needed by bacteria in decomposing the organic waste present
in water
§ Actually
a measurement of pollution by organic wastes expressed as milligram of oxygen /
liter water
Higher value of BOD indicates low dissolved oxygen in water
(BOD is only limited to biodegradable materials only)
Chemical oxygen demand
§ a
measure of oxygen equivalent required for oxidation of total organic matter
i.e. degradable & non degradable, present in water.
Diseases by Water Pollution
Minamata
§ A
crippling deformity caused by methyl mercury poisoning mainly by
industrial waste water
§ first
described in the inhabitants of Minamata Bay, Japan and resulted from their
eating fish contaminated with mercury industrial waste
itai itai
§ Also
known as ouch ouch disease (pain in bones & joints) caused by water
contamination by cadmium
Blue Baby Syndrome
§ Excess
nitrates in drinking water reacts with hemoglobin to form nonfunctional
methaemoglobin which impairs oxygen transport
Skeletal Fluorosis
§ Excess
of fluorides in drinking water can cause neuromuscular disorders, teeth
deformity, and hardening of bones, painful joints & outward bending of legs
from knees – Knock knee syndrome
Black foot disease
§ Caused
by leaching of arsenic from soil & rocks to ground water used for drinking
purposes
Water contaminated with lead
§ Cause
anemia, loss of muscle power & bluish lines around the gums
Iodine 131
§ Produced
by nuclear tests, passed to vegetation & then appears in milk of the cattle
that consume the contaminated vegetation & is passed to humans.
§ causes
serious damage to thyroid glands especially among children
Sick building syndrome (SBS)
§ a
situations in which building occupants experience acute health and comfort
effects that appear to be linked to time spent in a building, but no specific
illness or cause can be identified
§ causes
are frequently pinned down to flaws in the heating, ventilation & air
conditioning (HVAC) systems
Pollution in Leather Industry
§ Leather
industry in India has become 0 discharge industry as ~80% of the effluents are
treated and recycled back into use and remaining 20% are solidified and their
salts used for other purposes.
§ As a
result, Indian leather industry is REACH compliant (EU norms) and exported $4.5
bio in 2011-12 and the target is $14 bio by 2015-16 (growth rate of 20% p.a.)
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