Efficiency and Mechanisms of Biochar Aerogel-Assisted Biodegradation of Taste and Odor Compounds in a One-Step Membrane Bioreactor for Rural Drinking Water Production

Abstract

In many rural areas, lakes and reservoirs represent common sources for drinking water, but these water bodies are more likely affected by taste and odor (T&O) problems that cause discomfort to consumers. T&O compounds, especially 2-methylisobornol (2-MIB) and geosmin (GSM), are not easily removed using conventional water treatment processes, and this problem is exacerbated in rural areas where treatment systems are often sparser, modest, and outdated compared to typical urban water sources. Herein, a combined process deploying biochar aerogelsupported biofilms and performed in an ultrafiltration (BAB-UF) reactor was evaluated and investigated to treat rural water polluted with 2-MIB and GSM. During a 40-day experiment, the system performance was analyzed at different values of the empty bed contact time (EBCT), while the microbial communities in different BAB-UF reactors were examined extensively. The process proved to be effective in removing 2-MIB and GSM, predominantly through biodegradation. Specifically, using biochar aerogels as suspended fillers in the reactor and an EBCT of roughly 1 h, the removal rate of 2-MIB/GSM was higher than 95%, and the effluent satisfied the requirements for domestic drinking water. Microorganisms with specific functions were enriched in different BAB-UF reactors and governed the transformation process, highlighting the importance of system tuning for achieving the desired biological function and hence product water quality.