REVIEW PAPER ON TREATMENT OF INDUSTRIAL AND DOMESTIC WASTEWATERS USING UASB REACTORS INTEGRATED INTO CONSTRUCTED WETLANDS FOR SUSTAINABLE REUSE

Abstract

The successful use of anaerobic technologies, especially up-flow sludge blanket (UASB) reactors for the treatment of raw domestic sewage and industrial wastewaters in tropical and subtropical countries opened the opportunity to substitute the aerobic processes with anaerobic reactors in removal of organic matter. Proper management of domestic and industrial wastewaters in developing nations is negligible. Even cost effective integrated green technologies like anaerobic reactor with constructed wetland technologies are not applied. Hence the objective of the present review was to assess the pollutant removal efficiency of the up flow anaerobic sludge blanket (UASB) reactor coupled with a constructed wetland (CW) in treating these wastewaters and their capability to produce quality water for sustainable reuse. To achieve the objectives, the review was organized using reputable journals, articles, and review papers. The interpretation of the result of each document was done using tables, bar graphs, Pie chart and lines. The results were reorganized again by calculating average flow rate, hydraulic loading rate, and percentage removal efficiencies. Most research results revealed that use of UASB-CW integrated treatment system is a promising technology in wastewater treatment and able to complying the effluent discharge standards Globally, the following abatement efficiencies ranged from 79.2-93.9%, 89.2-92.9%, 87.2-96.3%, 22.6-96.9%, 33-85.9%, and 97.9-99.99% were achieved for Chemical oxygen demand (COD), Biological oxygen demand (BOD), Total suspended solid (TSS), Total Kjeldhal Nitrogen (TKN), Total phosphorus (TP) and fecal Coliforms (FC), respectively using UASB-CW treatment systems. UASB-CW technologies are effectively integrated treatment systems and can be used for resource scarce developing countries. Since, both treatment technologies are cost-effective, easy operation and maintenance and capable of meeting effluent standards Hence, the indiscriminate disposal of wastewaters and their environmental impacts in Ethiopia can be resolved using these low-cost combined treatment technologies.