Advanced Wastewater Treatment Design for West Omdurman, Khartoum State, Sudan

Mustafa Ahmed, Prof Ali Mohamed Alouba, Khalid Mustafa Kheiralla

Abstract: In Khartoum State less than 5% of the generated wastewater receives adequate treatment before discharge, while more than 95% is discharged directly or indirectly to surface water and aquifers. In West Omdurman, on-site systems such as septic tanks, cesspits and soakaways are widely used and are a major source of microbiological and chemical contamination of the Nubian and Quaternary aquifers. This paper presents the conceptual design and expected performance of a centralized advanced wastewater treatment plant (WWTP) for West Omdurman, based on the hydrogeological and contamination inventory developed in the PhD study and on standard design criteria. The plant is sized for a design population of 450,000 inhabitants and an average wastewater flow of 60,000 m3/d. The proposed process line comprises bar screening, grit removal, primary clarification, biological treatment using conventional activated sludge with nitrification and denitrification, secondary clarification, rapid sand filtration and ultraviolet (UV) disinfection. Sludge is thickened, stabilized and dewatered prior to land application or controlled disposal. Design calculations give an aeration volume of 20,000 m3 (four basins of 5,000 m3 each), two primary clarifiers of 36 m diameter, four secondary clarifiers of 28 m diameter, a total rapid sand filter area of about 480 m2 and a disinfection contact tank of 1,800 m3. For typical medium-strength municipal wastewater (BOD5 ? 250 mg/L, COD ? 500 mg/L, TSS ? 250 mg/L, TN ? 40 mg/L, TP ? 8 mg/L), the system is expected to achieve effluent concentrations of BOD5 < 20 mg/L, TSS < 20 mg/L, TN 10?15 mg/L and TP 2?3 mg/L, with faecal coliforms < 200 CFU/100 mL after UV disinfection. These values satisfy international guidelines for the reuse of treated wastewater in restricted and many unrestricted irrigation applications and are sufficient to protect the stressed groundwater resources in West Omdurman. The paper also discusses the relative environmental performance of sand filtration, membrane bioreactors (MBR) and ozonation based on life-cycle assessment results from the thesis, highlighting that sand filtration combined with UV disinfection offers a favourable balance between energy use and prevented ecotoxic impacts.

Keywords: wastewater reuse, groundwater protection, Nubian aquifer, West Omdurman, advanced treatment

How to Cite?: Mustafa Ahmed, Prof Ali Mohamed Alouba, Khalid Mustafa Kheiralla, "Advanced Wastewater Treatment Design for West Omdurman, Khartoum State, Sudan", Volume 14 Issue 12, December 2025, International Journal of Science and Research (IJSR), Pages: 171-175, https://www.ijsr.net/getabstract.php?paperid=SR251201044739, DOI: https://dx.doi.org/10.21275/SR251201044739