Upgrade of waste stabilization ponds to improve effluents for reuse purposes

• DOI: 10.2166/h2oj.2023.063
• Publication Date: 2023-06-08T17:08:16Z
• Authors: Jochen Sinn; Shelesh Agrawal; Laura Orschler; Selina Schubert; Susanne Lackner
• Keywords: Fodder; Facultative lagoon; Stabilization pond

Abstract Waste stabilization pond (WSP) systems exist in many countries affected by climate change causing increasing demand for irrigation water. There is little long-term experience with WSP Africa, and thus, this study provides a comprehensive investigation of Namibia. One its treatment trains was upgraded mechanical anaerobic pre-treatment, post-treatment compared to second train without upgrades. The pre-treatment showed positive results on COD, TSS partially pathogen removal. E. coli were reduced the new EU reuse standard 1,000 MPN/100 mL fodder irrigation, P. aeruginosa stagnated Enterococci levels increased. main reduction happened during baffled facultative pond. In contrast, only 5% algae-based chlorophyll-a. Among top 20 genera, Pseudomonas most dominant. With different upgrades, hygiene requirements especially restricted can be reached. At same time, high total tCOD TN effluent values did not meet standards. But as mainly consists algae, adding biomass fertilizer barren soil, it raised question if all parameters set standards are applicable or should adapted their specific purpose.