With the rapid growth of industrialization, treating oily wastewater has emerged as a critical global issue in environmental remediation. Electrocoagulation (EC) has proven its high efficiency and environmental sustainability for treating several types of wastewaters. Although traditional EC technology offers efficient treatment for oily wastewater, its large-scale implementation faces obstacles such as expensive electrode materials, complex manufacturing processes, and high energy consumption. 

Prof. Abudukeremu Kadier and Peng-Cheng Ma’s group at the Xinjiang Technical Institute of Physics and Chemistry (XTIPC), of Chinese Academy of Sciences (CAS), have successfully designed a highly conductive basalt fabric (BF) composite material, using multi-walled carbon nanotubes (CNTs) and silver nanowires (AgNWs) coating, and have used it as a cathode in a solar-powered electrocoagulation (SPEC) process for oily wastewater treatment. The composite CNT/AgNws coating not only significantly enhanced the BF conductivity (1.66 x 10⁴ S/m) but also improved its mechanical stability and endowed it with outstanding anti-bacterial activity against E. coli and S. aureus bacteria. 

Experimental results revealed that under optimized conditions, the SPEC process with the BF-CNT/AgNWs cathode achieved a chemical oxygen demand (COD) removal efficiency of 90.28% for simulated oil-water emulsions, with remarkably low energy consumption (1.28 kWh·kg-1COD) and minimal electrode consumption (0.35 kg·m-3). Moreover, due to the utilization of solar-powered energy, the overall cost was reduced by eliminating the electricity fees. 

The related research findings were recently published as a Research Article in the Journal of Environmental Management, entitled “A solar-powered electrocoagulation process with a novel CNT/silver nanowire coated basalt fabric cathode for effective oil/water separation: From fundamentals to application”.  

Figure 1: (A) Fabrication of the BF-CNT/AgNWs composite cathode material; (B) Experimental setup of the solar-powered electrocoagulation (SPEC) system; (C) Comparative analysis of oil-water emulsions before and after SPEC treatment; (D) Antibacterial performance evaluation of the BF-CNT/AgNWs composite cathode material.