Carbon-neutral potential in treatment of N, N-dimethylformamide-containing industrial wastewater: Comparative investigation of energy conservation, carbon reduction and expenditure between UASB and Fenton process

Abstract

The methanogenic degradation of N, N-dimethylformamide (DMF) is a sustainable and low-carbon technology for the treatment of high-strength industrial wastewater. Compared with the state-of-the-art chemical degradation method like Fenton, the UASB process exhibited its promising superiority in bio-energy recovery, economic profit gaining and carbon emission reduction. The lab-scale UASB obtained high DMF removal efficiency of over 98 % with methane recovered as bio-energy at a limited organic loading rate (OLR) of 4.2 COD kg/m3/d. Compared with the Fenton process, the UASB process is demonstrated more suitable to the carbon-neutral treatment of high-strength DMF-containing wastewater: The Fenton process is suitable to the relative low COD concentration below 1500 mg/L; The UASB was capable of covering all electricity consumption when COD > 3586 mg/L; The UASB also achieved zero CO2 emission when COD > 5720 mg/L; The UASB process obtains net profit when COD > 3616 mg/L. This study provided clear evidence of the promising potential and remarkable feasibility of bio-energy production in carbon-neutral treatment of DMF-containing wastewater.