Main causes of water pollution is due to the wastes discharged from factories, refineries into water bodies. These wastes contains harmful chemicals such as alkalis, acids etc., and toxic metals like mercury, lead, arsenic etc. which kill aquatic life.
The following steps can be taken to reduce the industrial pollution :
(i) Restructuring the manufacturing processes to reduce or eliminate pollutants, like, lead, zinc, arsenic through a process called Pollution Prevention. Chimneys for treating of gaseous waste are also important.
(ii) It is necessary to encourage industries to promote 'green' methods of product production and. It includes environmentfriendly operating processes.
(iii) It is advisable to create cooling ponds which are man-made and designed to cool the heated waters of industries by evaporation, condensation and radiation.
(iv) It is very important to attach water treatment plant in industries for filtration of sewage before it enters the water bodies. Sewage treatment plants are important for treatment of polluted water.