Bioelectrochemically-assisted anaerobic composting process enhancing compost maturity of dewatered sludge with synchronous electricity generation

Bioelectrochemically-assisted anaerobic composting process (AnC(BE)) with dewatered sludge as the anode fuel was constructed to accelerate composting of dewatered sludge, which could increase the quality of the compost and harvest electric energy in comparison with the traditional anaerobic composting (AnC). Results revealed that the AnC(BE) yielded a voltage of 0.60 +/- 0.02 V, and total COD (TCOD) removal reached 19.8 +/- 0.2% at the end of 35d. The maximum power density was 5.6 W/m(3). At the end of composting, organic matter content (OM) reduction rate increased to 19.5 +/- 0.2% in AnC(BE) and to 12.9 +/- 0.1% in AnC. The fuzzy comprehensive assessment (FCA) result indicated that the membership degree of class I of AnC(BE) compost (0.64) was higher than that of AnC compost (0.44). It was demonstrated that electrogenesis in the AnC(BE) could improve the sludge stabilization degree, accelerate anaerobic composting process and enhance composting maturity with bioelectricity generation. (C) 2015 Elsevier Ltd. All rights reserved.