| Valorization of paper-mill sludge laden 2-chlorotoluene using hydroxyapatite@biochar nano-composite to enrich methanogenic population: A techno-economic approach |
| Paper ID : 1044-ISCH |
| Authors |
|
Rania Mohamed Hafez * Rania M. Hafez
master student at National Research Centre (NRC) |
| Abstract |
| While several studies have investigated the anaerobic digestion of paper-mill sludge (PMS), this technology suffers from nutrient insufficiency, aromatic compounds inhibition, and low bio-CH4 yield. Hence, PMS was anaerobically co-digested with chicken manure (CM) and supplemented by hydroxyapatite (HAP) @biochar (BC) nanocomposite for enhancing 2-chlorotoluene degradation and enriching the methanogenic archaea. A continuous stirred tank reactors (CSTRs) were operated at 12.6 h., retention time and supplied by PMS (R_1), CM (R_2), PMS+CM (R_3) (1:1 w/w), PMS+CM+100 mg HAP/L (R_4), and PMS+CM+100 mg HAP@BC/L (R_5). The maximum bio-CH4 productivity of 147.47±9.10 mL/g COD removed and 2-chlorotoluene removal efficiency of 91.2±6.8% were obtained from R_5, owing to the sufficient C/N ratio of 14.7, with the highest activities of acidogenesis (42.0%), acetogenesis (37.9%), and methanogenesis (42.1%). The abundance of Euryarchaeota, Bacteroidota, and Chloroflexi at the phylum level, and Pseudomonas, and Bacillus at the genus level could highly contribute to dechlorination of 2-chlorotoluene and acetate transformation into CH4. These results could gain benefits from pollution reduction, biogas recovery, and carbon credit, giving a payback-period of 5.5 yr, NPV of 3712 USD, and IRR of 12.8%. Hence, adding HAP@BC to PMS+CM would maintain an efficient techno-economic anaerobic biodegradation performance with enriched methanogenic archaea and dechloroniation-degrading microbes. |
| Keywords |
| Anaerobic co-digestion; Microbial community; Nutrient-rich nanocomposite; Paper-mill sludge; Technology profitability |
| Status: Abstract Accepted (Poster Presentation) |