Physicochemical characterization of effluent from microbial fuel cell operating with thermochemically modified BaZrO₃/clay–PEM

This study is aimed at determining the physicochemical properties of sewage effluent from microbial fuel cell (MFC). The physicochemical changes were monitored via scanning electron microscopy micrograph and EDS instrumental analysis of the influent in situ and after treatment in an MFC run for 30 days. The cells were constructed using BaZrO₃/Akaso clay (AC) composite functioning as proton exchange membrane (PEM). The PEM performance was further enhanced by heating the BaZrO₃/AC composite to higher temperatures. The Akaso clay material was characterized by FTIR and DSC thermogram analyses at room temperature and heated states. The proton conductivity variation with temperature of BaZrO₃/AC was examined using electrochemical impedance spectroscopy. The activation energy and pre-exponential factor of 5117.93 J kmol⁻¹ and 8.96 kmol s⁻¹, respectively, were obtained for BaZrO₃/clay chemical compounding process. The cell recorded an improved power performance to the tune of 503.23 mW m⁻². The property changes with respect to wastewater quality indices in the effluent before (EBT) and after MFC treatment (EAT) were also presented. The pH of the EAT decreased from 7.90 to 6.88, within the optimum range suitable for crop production. The elemental compositions of sanitary wastewater showed the presence of essential elements (Ca, C, N, K, P) and trace elements (Fe, Ti, Ag, Nb, Ag, Y) in various weight concentrations. The increase in C/N ratio of 3:1 in EBT to 7:1 in EAT shows a relatively higher agricultural value of effluent from MFC operation for improved biochemical processes in plants for improved yield.