Combined effect of temperature and illumination on treatment of etching terminal wastewater in single-chamber microbial electrolysis cells

Temperatures and illumination/darkness conditions influenced etching terminal wastewater (ETW) treatment using Serratia marcescens-inoculated single-chamber microbial electrolysis cells (MECs), achieving recalcitrant organics mineralization (6.0- 12.2 mg/L/h) and complete heavy metals removal at 4- 60 degrees C during 24 h operation. A favorable 6 h operation for heavy metals removal and the preferable 24 h for recalcitrant organics mineralization, demonstrated nonsynchronous removal/mineralization of these different components in the ETW. Temperature and illumination combinedly regulated S. marcescens release of more cathodic than anodic extracellular polymer substances (EPS) with a compositional diversity and the more functional cathodic triplet 3 EPS* than active radical HO center dot, converse to the HO center dot over 3 EPS* in darkness, for efficient recalcitrant organics mineralization. These results illustrated the combined influential temperature and illumination via regulating S. marcescens release of different EPS for ETW treatment, providing a new regulating strategy towards efficient treatment of actual industrial wastewaters in single-chamber MECs.