Identification of Crucial Characteristics of Activated Carbon in Anaerobic Treatment of Crotonaldehyde Wastewater for Enhancement of Methane Production

Abstract

Crotonaldehyde wastewater is a typical high-concentration aldehyde-containing wastewater in the petrochemical industry, which adversely affect the metabolic functions of anaerobic microorganisms. This study assessed the influence of activated carbons of different materials on the anaerobic treatment performance of crotonaldehyde wastewater, and identified the crucial material characteristics. The results indicated that the specific methanogenic activities of anaerobic granular sludge in the wood activated carbon (W-AC), coconut shell activated carbon (CS-AC), and coal activated carbon (C-AC) group were 11.47, 9.97, and 6.50 mL CH4/(g VSS·d), which were 3.28, 2.84, and 1.86 times that of the control group, respectively. The cumulative methane yield at 72 hours for different test groups was also W-AC > CS-AC > C-AC > control group. The W-AC group exhibited significantly higher aldehyde removal efficiency than the other groups, attributed to its superior electron exchange capacity compared with CS-AC and C-AC, thereby enhancing redox mediation in microbial electron transfer processes. In addition, the introduction of the W-AC facilitated the formation of a spatial distribution structure consisting of activated carbon/bacteria, bacteria/archaea, and archaea from the outside to the inside of AGS. This study demonstrated that dosing activated carbon was an efficient strategy to intensify the anaerobic treatment of crotonaldehyde wastewater.

Keywords: crotonaldehyde wastewater, Activated carbon, surface functional group, electron exchange capacity, anaerobic granular sludge