Improved defluoridation and energy production using dimethyl sulfoxide modified carbon cloth as bioanode in microbial desalination cell

In the present study, carbon cloth (CC) was functionalized using dimethyl sulfoxide (DMSO) and employed as an excellent bioanode for improving defluoridation efficiency, wastewater treatment, and power output from a microbial desalination cell (MDC). The Raman spectroscopy and X-ray photoelectron spectroscopy (XPS) analysis of DMSO modified carbon cloth (CC_DMSO) confirmed the functionalization of CC_DMSO, and the water drop contact angle of 0° ensured its superior hydrophilicity. The presence of -COOH (carboxyl), S[bond, double bond]O (sulfoxide) and O-C[bond, double bond]O (carbonyl) functional groups on CC_DMSO aids in enhancing the performance of the MDC. Besides, cyclic voltametric and electrochemical impedance analysis revealed that CC_DMSO had an excellent electrochemical performance with low charge transfer resistance. Replacing CC with CC_DMSO as anode in MDC, the time required for 3,10 and 20 mg/L of initial fluoride (F^-) concentrations in the middle chamber was reduced from 24 ± 0.75 to 17 ± 0.37, 72 ± 1 to 48 ± 0.70, and 120 ± 0.5 to 96 ± 0.53 h, respectively to meet the prescribed standards (1.5 mg/L). Furthermore, using CC_DMSO, the anode chamber of MDC exhibited a maximum of 83% substrate degradation, and simultaneously, the power output is increased by 2-2.8 times. CC_DMSO improved the power production from 0.009 ± 0.003, 1.394 ± 0.06 and 1.423 ± 0.15 mW/m² to 0.020 ± 0.07, 2.748 ± 0.22 and 3.245 ± 0.16 mW/m², respectively, for initial F^- concentrations of 3,10, and 20 mg/L. Modifying CC with DMSO thus proved to be an efficient and simple methodology for enhancing the overall performance of MDC.

Enhanced methane production in microbial electrolysis cell coupled anaerobic digestion system with MXene accelerants

Accelerants can improve the anaerobic performance of a microbial electrolysis cell coupled anaerobic digestion (MEC-AD). MAX phase titanium aluminum carbide (MAX), multilayer Ti₃C₂T_X MXene (ML-MXene) and few-layer Ti₃C₂T_X MXene (FL-MXene) were utilized as accelerants for MEC-AD to promote CH₄ production and CO₂ reduction at a voltage of 0.6 V. The highest CH₄ yield (358.7 mL/g VS) and the lowest CO₂ yield (57.4 mL/g VS) relative to the control group (170.6 and 125.1 mL/g VS) were obtained in MEC-AD with ML-MXene (0.035 wt%). The digestates of MEC-AD with 0.035 wt% ML-MXene have superior thermal stability (40.9%) and total nutrient content (42.1 g/kg). The ML-MXene enhanced the abundances of Methanosarcina and Methanobacterium. This work highlights the possible role of MXene in promoting methanogenesis. These important findings provide a novel avenue for the development of MXene accelerants for MEC-AD systems.