Sources – community waste water, Industrial waste, Agricultural chemicals waste, Thermal & nuclear pollution, Oil spills, Radioactive dump waste, Groundwater seepage etc.
Water hyacinth (an aquatic weed) can purify water by taking some toxic materials & a number of heavy metals from water.
a measure of oxygen equivalent required for oxidation of total organic matter i.e. degradable & non degradable, present in water.
Produced by nuclear tests, passed to vegetation & then appears in milk of the cattle that consume the contaminated vegetation & is passed to humans.
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.