Fresh water applied in agriculture represents more than 70% of the total water use in the world. In regions with limited freshwater resources, sewage and industrial wastewater can be used as alternative water sources for crop production. While using wastewater in irrigation can alleviate the problem of water scarcity and wastewater disposal, it may educe crop yield and quality, and harm the environment. Organic matter overloading limits oxygen availability in the soil due to oxygen consumption by microbial aerobic degradation of organic matter. Therefore, the United States Environmental Protection Agency has limited the average weekly Biological Oxygen Demand (BOD) application rate for land application of wastewater to 112 kg/ha/d. In addition to the limitation of oxygen availability, organic carbon overloading can block soil pores and harm soil health. This reduced soil porosity is caused by biofilm growth. The presence of heavy metals and high concentrations of inorganic nutrients such as nitrogen and phosphorus are also detrimental to the soil and crops.
Therefore, treatment is required before wastewater use in agricultural
production