Wastewater: Sources of Pollutants and Its Remediation

Water is a natural resource which is necessary for life. It is available in various sources like rivers, streams, lakes and oceans. Through the last century, fresh water has been depleted enormously due to the explosion of human population and eco-unfriendly activities. The disposal of human waste in water bodies causes severe threats to the environment which affects all kinds of living organisms. In order to save water bodies, we need to understand the sources of wastewater and its polluting components. Domestic, industrial and agricultural sectors are the three major sectors of wastewater. Domestic wastewater includes water from household activities. Industrial wastewater comes from various sectors of industry like food, chemical, paper and pulp, nuclear and thermal power, laundry, pharmaceuticals, mine, iron and steel, etc. These wastewaters are rich in organic and inorganic contents. But excessive release of such nutrients into the water causes a rise of minerals and nutrients in water bodies leading to the excessive growth of plants and algae, which in turn leads to oxygen depletion in water bodies and, hence, eutrophication. This wastewater can be reused, if treated suitably, by removing the different pollutants. Here we have reviewed pollutants from various industries and examined how wastewater can be treated and reused. It is necessary to first know the wastewater components so that suitable technologies can be developed for water treatment before it is released back into water bodies or recycled for irrigation, landscaping, etc. This review will help create general awareness about the limited availability of fresh water for human consumption and the consequent importance of recycling and conservation of water. At the end of the review, the recommendations given suggest how small steps in our daily life can be helpful for the conservation of water.