Fermentation broth of food waste: A sustainable electron donor for perchlorate biodegradation

Microbial reduction has been considered an effective way to remove perchlorate (ClO4-), during which, additional electron donors and carbon sources are required. This work aims to study the potential of fermentation broth of food waste (FBFW) serving as an electron donor for ClO4- biodegradation, and further investigates the variance of the microbial community. The results showed that FBFW without anaerobic inoculum at 96 h (F-96) exhibited the highest ClO4- removal rate of 127.09 mg/L/d, attributed to higher acetate and lower ammonium contents in the F-96 system. In a 5 L continuous stirred-tank reactor (CSTR), with a 217.39 g/m3·d ClO4- loading rate, 100% removal efficiency of ClO4- was achieved, indicating that the application of FBFW in the CSTR showed satisfactory performance for ClO4- degradation. Moreover, the microbial community analysis revealed that Proteobacteria and Dechloromonas contributed positively to ClO4- degradation. Therefore, this study provided a novel approach for the recovery and utilization of food waste, by employing it as a cost-effective electron donor for ClO4- biodegradation.