Processing Wastewater Containing Arsenic
Introduction
Arsenic is a toxic chemical element that exists in water either from natural sources such as rocks and soil or from human activities such as mining and industry. When the concentration of arsenic surpassed the limits set by public health organizations, contamination of water due to arsenic is reported, and it becomes necessary to treat the water if it is to be used for human consumption. Treatment of water with high arsenic concentrations involves a variety of processes in order to reduce the arsenic levels to safe concentrations.
Description of Process
The first step in treating wastewater containing arsenic is to identify the source of contamination and the concentration of arsenic present. This allows the appropriate treatment process to be chosen. Several processes have been developed in order to reduce the concentration of arsenic in wastewater. Coagulation and flocculation are commonly used to remove large suspended solids, while in some cases oxidation processes such as chemical oxidation can be used to reduce the concentration of arsenic in the water. In addition, reverse osmosis can be used to further reduce the concentration of arsenic, as well as other contaminants. After the concentration of arsenic has been reduced to safe levels, the water can then be disinfected through various means, such as chlorination.
Conclusion
Treatment of wastewater containing arsenic requires careful consideration of the sources of contamination and the required reduction levels. Several processes have been developed in order to reduce the concentration of arsenic and other contaminants, including coagulation, flocculation, chemical oxidation, reverse osmosis and disinfection. The appropriate process must be chosen in order to effectively reduce the arsenic concentration and provide safe drinking water.
References
WHO. Arsenic in drinking water. World Health Organization, Geneva. https://www.who.int/water_sanitation_health/chemicals/arsenic.htm (accessed June 20, 2020).
EPA. Arsenic and Drinking Water: An Overview. U.S. Environmental Protection Agency. https://www.epa.gov/ground-water-and-drinking-water/arsenic-and-drinking-water-overview (accessed June 20, 2020).
Water Research Center. Arsenic in Drinking Water. https://www.water-research.net/index.php/arsenic-in-drinking-water (accessed June 20, 2020).
