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 ℃ 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 3EPS* than active radical HO•, converse to the HO• over 3EPS* 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.