Water plays a vital role in human life and civilization development, but the development and human multiplicity activities led to water pollution. Various factors cause water pollution like environmental and climate changes, agricultural activities, geological changes, civilization, domestic, and industrial processes. These activities release different types of chemical and biological pollutants with different concentrations. Last decades, the quantity and quality of water are declining at horrible rate due to uncontrolled population growth, growing urbanization, expanding industrialization and increasing non-standard agriculture activities, near the drought that is affecting several countries in the different continents.  While most developed countries have installed advanced technologies to treat wastewater, developing countries still suffer from water supply because of the high cost of water treatment or desalination facilities. International organizations such as EPA (U.S. Environmental Protection Agency) and WHO (World Health Organization) develop standards for controlling water quality in terms of chemical and biological concentrations to preserve human health and protect biodiversity.