Wastewater irrigation and its impact on crops in major cultivated belt of Rechna Doab, Pakistan

Abstract

The purpose of this study was to evaluate the toxicity of wastewater that is used for irrigation in study area. This research focused on the wastewater irrigation in suburban areas of Faisalabad district. The study involved collection of wastewater samples from ten different locations from Faisalabad, Jaranwala and Saddar districts to assess its quality at different sites. Areas covered by wastewater irrigation ranged from 100 to 2000 acres and major crops were cultivated using this contaminated water, including wheat, cauliflower, radish, spinach, and fenugreek. Physiochemical characteristics of wastewater, including the presence of heavy metals, were measured. The ionic compositions and heavy metal toxicity of wastewater was determined to fall at poisonous levels. Physiochemical properties and quality indices used in the current study also depict the unsuitable nature of the wastewater used in the area. The sources of wastewater varied from drains, sewage water, and the Chakkera Disposal system. Maps generated in Arc Map 10.5 show the spatial distribution of constituents via the geostatistical IDW (Inverse Distance Weighted) technique. The Piper and Durov diagrams highlighted the wastewater chemistry and showed that the dominant water type obtained was NaCl. Results were statistically analyzed by a correlation matrix. Dominant ions, pH levels, electric conductivity (EC), and heavy metals were detected by lab analysis and results indicated variability in toxic levels of these properties within the site and the area using the wastewater irrigation system. Consequently, this indicated the unsuitable nature of using wastewater as an irrigation source. The study concludes that it is necessary to conduct proper treatments to irrigation water before it is used on crops.