Global concerns, including a lack of water and energy, need sustainable wastewater management. Municipal sewage (MS) is frequently dumped untreated into river bodies. Also, MS sludge (MSS), a by-product of the MS treatment process, causes landfilling issues when disposed of conventionally. This study concentrated on the anaerobic treatment of MS using Acti-zyme, an enzyme bio-catalyst, to co-harvest biogas and biosolids as value-added products. The possibility of using this technology on a broad scale was assessed using a techno-economic study. For the techno-economic analysis, an MS plant in Zimbabwe with a 19.6 ML/day capacity, a 60% operational efficiency, and a 20-year life lifetime were considered. Contaminants were removed from MS patients by >60% following treatment with Acti-zyme. When treatment conditions were ideal, biogas comprising 78% bio-methane and bio-solids containing 8.0, 5.0, and 1.0% of NPK, respectively, were produced. An annual nett financial advantage of US$5.7 million and a nett energy output of 1.4 MWh were anticipated. The project will need to commence with a $22 million US investment. It was calculated that the positive net present value would be US$1.2 million, with an internal rate of return of 17.6% and a payback period of 5.9 years. 183 MWh must be produced to achieve breakeven. It is feasible to treat MS using Acti-zyme, which co-harvests biogas and biosolids as valuable added products, according to the techno-economic analysis (Manyuchi, Ikhu-Omoregbe and Oyekola, 2020).