A sustainable municipal wastewater treatment process for tropical and subtropical regions in developing countries

In this paper, a feasible municipal wastewater treatment process, using the upflow anaerobic sludge blanket (UASB) or the anaerobic baffled reactor (ABR) as an anaerobic pre-treatment system, and the reed bed or the stabilization pond with supporting media as a post-treatment system, is presented and discussed. Results obtained in pilot- and full-scale treatment plants clearly reveal that the anaerobic treatment is indeed a very attractive option for municipal wastewater pre-treatment at temperatures exceeding 20C in tropical and subtropical regions. The UASB system has been commonly employed as an anaerobic pre-treatment system. The ABR provides another potential for the anaerobic pre-treatment. The effluents from the anaerobic treatment system should be post-treated to meet discharge standards. Because of the advantages of the reed bed system when it is employed for tertiary treatment, this system could be considered as a post-treatment system. Another cost-effective system, the stabilization pond packed with attached-growth media, is also a potential post-treatment system.