Assessment of kitchen wastewater quality for irrigation

In this study, the potential reuse of kitchen wastewater (KWW) in irrigation was analyzed to reduce the present freshwater demand. To know the suitability of KWW for irrigation, the samples were first collected from an educational institute in India and then characterized according to its physical, chemical, and bacteriological properties. The characterized data were then compared with the standard limit for irrigation Food and Agriculture Organization (FAO in Water quality for agriculture. Irrigation and drainage paper 29, M56, 1994) and the US Salinity Laboratory (USSL). Apart from the above irrigation standards, the characterized data were also compared with sodium adsorption ratio (SAR), residual sodium carbonate, sodium percentage (Na%), magnesium hazard (MH), Kelly’s ratio (KR), and permeability index to get better clarity. From the characterization, it was found that carbonate, fluoride, chromium, and Escherichia coli were absent, whereas parameters like pH, chloride, iron, copper, magnesium, lead, nickel, sodium, calcium, zinc, aluminum, and sodium adsorption ratio were within the permissible limit. The result obtained from the USSL classification system suggested that 30.77% of KWW samples are safe for irrigation. Moreover, its quality was found to be safe for irrigation based on SAR, Na%, KR, and MH. For better decision making of KWW reuse in irrigation, the output of Mamdani fuzzy inference system (MFIS) was compared with the USSL classification system. The overall agreement between USSL and MFIS was found to be 55.6% for KWW.