Oxidation Ditches for Recycling and Reusing Wastewater Are Critical for Long-Term Sustainability—A Case Study

Abstract

Because the cost of operation and maintenance is lower than those of chemical treatments, the aerobic biological oxidation method used to treat wastewater is very effective. An oxidation ditch can be classified as progressive aeration-activated sludge capable of removing organic pollutants and also nitrogen and phosphorus. The overall goal of this research is to analyse influent, effluent, and operating data over a seven-year period (2014–2020) to better understand process performance, identify knowledge gaps, and suggest potential improvements for the operating efficiency of the wastewater treatment plant (WWTP) in Bishah Governorate, which works with oxidation ditch technology. An examination of historical influent, effluent, and operational data shows that the Bishah WWTP has consistently met the national and international guidelines for wastewater reuse in restricted and unrestricted irrigation. The effluent ratio of the biodegradable organic material (BOD5)/chemical oxygen demand (COD) values ranged from 0.3 to 0.51 with an average of 0.41. Significant Pearson correlation coefficients (bivariate) between physico-chemicals merit, especially in total coliforms form, BOD5 and ammonia. It could be concluded that the operational performance of a wastewater treatment plant with an oxidation ditch in Bishah is working well according to national and international standards.