Treatment of Wastewater for Agricultural Applications in Regions of Water Scarcity

This paper analyses the latest techniques for treating wastewater to make it suitable for agricultural applications in regions where irrigation water is scarce. Micro-filtration (MF) techniques yield a significant reduction in Chemical Oxygen Demand (COD), Biological Oxygen Demand (BOD), Total Suspended Solids (TSS), and Total Bacterial Count (TBC) of wastewater, which makes it suitable to be used for irrigational purposes. Microbial Fuel Cell (MFC) technology is a viable solution for treating wastewater discharged from many industrial sectors, such as the food processing industry, for reclaiming water for agro-applications. Such industrial water may seal soil pores if directed untreated to agricultural fields. Concerning the treatment of microbial contamination of wastewater, the removal rate of pressurized membrane bio-booster (MBR) is significantly large for coliform and metals such as lead, copper, chromium, and arsenic. Both electrocoagulation and chemical coagulation are applied in the removal of oxidable chemicals from wastewater. However, the electrocoagulation process shows a higher efficiency in terms of removing COD. Contamination of agricultural fields with heavy metals is considered an adverse impact on the human and animal safety of discharging wastewater into agro-fields. Thus, removing such contaminants should be given the utmost priority in wastewater treatment, especially from industrial discharge, before they are directed to agricultural usage. Factors that govern the sustainability of a given method in a water-scarce region are also discussed.