Analyzing Riyadh Treated Wastewater Parameters for Irrigation Suitability Through Multivariate Statistical Analysis and Water Quality Indices

An alternative irrigation water supply that prioritizes quality standards, promotes sustainable water resource management, and uses ecologically friendly approaches is still being researched. The purpose of this study is to evaluate the thirteen physicochemical properties of Riyadh wastewater treatment plants (WWTPs) over eight years for their potential use in irrigation. Wastewater quality was assessed using the Comprehensive Water Pollution Index (CPI) and the Canadian Wastewater Quality Index (CWQI). Principal component analysis and heatmaps were also used to identify trustworthy parameters. The CWQI results, ranging from 72.95 to 95.55%, showed acceptable variations over eight years, indicating adequate quality. The CPI values varied from 0.19 to 0.77. However, the average CPI was determined to be 0.6, indicating that there had been some slight contamination throughout the study. The first and second components (PC1 and PC2) represented 32.6% of the data, revealing a dominant pattern for a better understanding of the effluent characteristics. The effluent parameters loaded onto PC1 were EC, Ca2++Mg2+, NO3, and COD, whereas NH4, DO, and turbidity were loaded onto PC2. The effluent from the Riyadh WWTPs is appropriate for irrigation, highlighting the necessity of TWW for agriculture and supporting Saudi Arabia’s Green Riyadh Initiative.