Review of Innovative Approaches of Wastewater Treatment and Management: A Case Study of Benin, Kenya and Zambia in Pursuit of Sustainable Solutions in the Context of the Green Deal

Abstract

One in three people in the African region suffers from water scarcity, this situation is getting worse as a result of population growth. Poor wastewater treatment exacerbates the problem, as only 10% of wastewater in Africa is estimated to be treated before being released into the environment. The major wastewater sources in Africa are agricultural, mining, domestic, and industrial effluents, which include BOD, COD, TSS, NH 4-N, and T-P, heavy metals (like Pb2+, Zn2+, Cu2+), organic compounds, and fecal coliforms. 

Notably, the most widely used treatment method in Kenya is the application of single or combined constructed wetlands and conventional wastewater treatment systems. Whereas, wastewater in Zambia is mostly treated by the use of aerated stabilization ponds. In the case of Benin, the lagoon systems are applied in organic wastewater treatment, while simple and macrophyte lagoon systems are used to treat and recycle domestic wastewater.

The results show that the treated wastewater is low quality, containing significant levels of BOD, COD, TSS, phosphorus, lead, and nitrate. It also exceeded the established regulatory discharge standards, affirming that the treatment methods were not fully effective. The nutrients are not entirely removed by the treatment procedures currently in use. In conclusion, the paper review more cost-effective, sustainable, and innovative technologies to improve wastewater management in Africa, such as the application of iron oxides, zeolites, biochar filters, or membranes. Such an approach will result in lowering environmental pressures in urbanized and rural areas.