The effect of electrodialytic treatment and Na2H2EDTA addition on methanogenic activity of copper-amended anaerobic granular sludge: Treatment costs and energy consumption

摘要

The effect of electrodialytic treatment in terms of a current density, pH and Na_2H_2EDTA addition on the methanogenic activity of copper-amended anaerobic granular sludge taken from the UASB reactor from paper mill was evaluated. Moreover, the specific energy consumption and simplified operational and treatment costs were calculated. Addition of Na_2H_2EDTA (at pH7.7) to copper-amended sludge resulted in the highest microbial activity (62mgCH_4-CODgVSS~(-1)day~(-1)) suggesting that Na_2H_2EDTA decreased the toxic effects of copper on the methanogenic activity of the anaerobic granular sludge. The highest methane production (159 %) was also observed upon Na_2H_2EDTA addition and simultaneous electricity application (pH7.7). The energy consumption during the treatment was 560, 840, 1400 and 1680kWhm~(-3) at current densities of 0.23, 0.34, 0.57 and 0.69mAcm~(-2), respectively. This corresponded to a treatment costs in terms of electricity expenditure from 39.2 to 117.6? per cubic meter of sludge.