Water scarcity is a growing global concern, particularly in decentralized and rural areas where novel methods of decentralized high-strength wastewater treatment must be developed. One such technology is a combined electrochemical process of electrocoagulation (EC) and electrodialysis (ED). This study analyzed the viability of this process by performing pilot-scale testing, life cycle assessment (LCA), and techno-economic assessment (TEA) on the treatment of three different high-strength blackwaters: sewage sludge, port-o-john, and latrine. The process was the most viable in the treatment of sewage-sludge blackwater achieving a COD reduction of ~96% (to 75.3 ± 25.8 mg/L) and a NH3-N reduction of ~97% (to 3.9 ± 1.3 mg/L) with a treatment cost of 39.6 $/m3 treated water. The process was least viable for the port-o-john blackwater as its high pollutant loading and pH causing a COD and NH3-N reduction of ~90% (to 245 ± 136) and ~65% (to 156 ± 9.54) respectively with a cost of 39.8 $/m3 treated water. The latrine blackwater had a COD and NH3-N reduction of ~88% (to 201 ± 40.7) and ~70% (to 78.6 ± 7.5) respectively with a cost of 40.4 $/m3 treated water. The decrease in NH3-N removal for the port-o-john and latrine blackwater is likely due to their high pH. This also had negative impacts on their LCA. Sewage sludge, port-o-john, and latrine blackwater had negative global warming potentials (-2.42, -2.11, and -1.59 metric tons CO2-eq/year) due to their low energy demand and compatibility with solar powered operation, however; they had high water eutrophication potentials of 5.33, 71.18, and 54.83 kg N eq/year respectively. Overall, the EC-ED process represents a low-carbon, decentralized alternative to conventional wastewater treatment, but nutrient leakage remains a concern especially for highly concentrated wastewaters. Additional studies are needed to further develop it as a circular sanitation process by improving its nutrient recovery to complement its energy and climate advantages.
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