Water treatment and pollution

Water pollution is a global challenge that has increased in both developed and developing countries, undermining economic growth as well as the physical and environmental health of billions of people. Although global attention has focused primarily on water quantity, water-use efficiency and allocation issues, poor wastewater management has created serious water-quality problems in many parts of the world, worsening the water crisis. Global water scarcity is caused not only by the physical scarcity of the resource but also by the progressive deterioration of water quality in many countries, reducing the quantity of water that is safe to use. Human settlements, industries and agriculture are the major sources of water pollution. Globally, 80% of municipal wastewater is discharged into water bodies untreated, and industry is responsible for dumping millions of tonnes of heavy metals, solvents, toxic sludge and other wastes into water bodies each year.

Agriculture, which accounts for 70% of water abstractions worldwide, plays a major role in water pollution. Farms discharge large quantities of agrochemicals, organic matter, drug residues, sediments and saline drainage into water bodies. The resultant water pollution poses demonstrated risks to aquatic ecosystems, human health and productive activities. In most high-income countries and many emerging economies, agricultural pollution has already overtaken contamination from settlements and industries as the major factor in the degradation of inland and coastal waters (e.g. eutrophication). Nitrate from agriculture is the most common chemical contaminant in the world’s groundwater aquifers. Agriculture is the main source of pollution in rivers and streams, the second main source in wetlands and the third main source in lakes.

The large loads of untreated municipal and industrial wastewater are major concerns. Nevertheless, agricultural pollution, aggravated by increased sediment runoff and groundwater salinization, is also becoming an issue. This issue would focus on the effect of water treatment on physiological parameters for crops, and water treatment methods and uses in agricultural field.