Waste or Gold? Bioelectrochemical Resource Recovery in Source-Separated Urine.

In recent years, source-separated human urine has been highlighted as an effective resource for energy and nutrient recovery. However, even though several technologies exist for resource recovery, they have not been widely implemented. Among these technologies, bioelectrochemical systems (BESs) hold promise as technically and economically interesting alternatives for sustainable resource recovery from source-separated urine. Here, we review the resource recovery performance of BESs, including microbial fuel cells (MFCs) and microbial electrolysis cells (MECs), fed with source-separated urine over the past decade, and suggest an effective path forward toward their widespread implementation.

Evaluating the process performance and potential of a high-rate single airlift bioreactor for simultaneous carbon and nitrogen removal through coupling different pathways from a nitrogen-rich wastewater.

The feasibility of a continuous feed and intermittent discharge airlift bioreactor for simultaneous carbon and nitrogen removal from a low COD/N wastewater was evaluated. The effect of two independent variables, HRT (10-20 h) and NH4+/(NH4++NO3-) ratio (0.25-0.75), on the bioreactor performance was studied. The relatively high anaerobic to aerobic time ratio made an effective contribution to NH4+, NO3-, and TN removal. TN removal was enhanced with increase in HRT and decrease in NH4+/NH4++NO3- and at the optimum condition, 616 mg/L (88%) and 213 mg/L (76%) of sCOD and TN were removed, respectively. The results suggested that the nitrogen removal process was based on a combination of anaerobic ammonium oxidation (Anammox), simultaneous nitrification-denitrification (SND), and presumable dissimilatory nitrate reduction to ammonium (DNRA) mechanisms.