The objective of this work is to perform LCAs three wastewater treatement alternatives at battalion-sized (500 soldier) FOBs. Three systems will be explored: traditional wastewater treatment of combined blackwater and graywater streams using activated sludge and anaerobic digestion (the status quo); MXC treatment of blackwater to produce H2O2 for disinfection of blackwater and graywater; a hybrid system of blackwater treatments with MXCs to produce electricity with graywater disinfection using H2O2 produced offsite. Environmental impacts are assessed using Impact 2002+ midpoint and endpoint categories, primarily reported for human health and environmental impacts. Uncertainity analysis is performed using two techniques. First, a pedigree matrix is developed to identify the highest areas of uncertainties in data. Second, a sensitivity analysis is used to explore the effects on endpoint categories from varying transportation distance, the percentage of wastewater that is reused as nonpotable water, and coagulant doses.

The Combined Activated Sludge-Anaerobic Digestion Model (CASADM) quantifies the effects of recycling anaerobic-digester (AD) sludge on the performance of a hybrid activated sludge (AS)-AD system. The model includes nitrification, denitrification, hydrolysis, fermentation, methanogenesis, and production/utilization of soluble microbial products and extracellular polymeric substances (EPS). A CASADM example shows that, while effluent COD and N are not changed much by hybrid operation, the hybrid system gives increased methane production in the AD and decreased sludge wasting, both caused mainly by a negative actual solids retention time in the hybrid AD. Increased retention of biomass and EPS allows for more hydrolysis and conversion to methane in the hybrid AD. However, fermenters and methanogens survive in the AS, allowing significant methane production in the settler and thickener of both systems, and AD sludge recycle makes methane formation greater in the hybrid system.