While several studies have investigated the anaerobic digestion of paper-mill sludge (PMS), this technology suffers from nutrient insufficiency, inhibition by aromatic compounds, and low bio-CH4 yield. Hence, PMS was anaerobically co-digested with chicken manure (CM) and supplemented by hydroxyapatite@biochar (HAP@BC) nanocomposite for enhancing 2-chlorotoluene degradation and enriching the methanogenic archaea. Multiple continuous stirred tank reactors (CSTRs) were operated at 12.6 h hydraulic retention time (HRT), using PMS (R1), CM (R2), PMS + CM (R3), PMS + CM+100 mg HAP/L (R4), and PMS + CM+100 mg HAP@BC/L (R5). The maximum bio-CH4 yield of 147.5 ± 9.1 mL/g COD and 2-chlorotoluene removal of 91.2 ± 6.8 % were obtained from R5, experiencing a sufficient C/N ratio of 14.7 and the highest activities of acidogenesis (42.0 %), acetogenesis (37.9 %), and methanogenesis (42.1 %). The abundances of Euryarchaeota, Bacteroidota, and Chloroflexi at the phylum level, and Pseudomonas, and Bacillus at the genus level could highly contribute to the dechlorination mechanism and acetate transformation into CH4. This biomass-to-bioenergy project (10 m3/d capacity) could benefit from pollution reduction, biogas recovery, and carbon credit, giving 5.6 yr payback-period, 3503 USD net present value, and 12.1 % internal rate of return. Because R5 exhibited an efficient techno-economic anaerobic biodegradation performance, future studies are required to optimize its HRT condition and HAP@BC dosage.

中文翻译：

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使用羟基磷灰石@生物炭纳米复合材料对富含2-氯甲苯的造纸厂污泥进行增值以丰富产甲烷群落：一种技术经济方法


虽然有几项研究调查了造纸厂污泥 (PMS) 的厌氧消化，但该技术存在营养不足、芳香族化合物抑制以及生物 CH4 产量低等问题。因此，PMS与鸡粪（CM）进行厌氧共消化，并辅以羟基磷灰石@生物炭（HAP@BC）纳米复合材料，以增强2-氯甲苯降解并富集产甲烷古菌。多个连续搅拌釜反应器 (CSTR) 在 12.6 小时水力停留时间 (HRT) 下运行，使用 PMS (R1)、CM (R2)、PMS + CM (R3)、PMS + CM+100 mg HAP/L (R4) ，和 PMS + CM+100 mg HAP@BC/L (R5)。从 R5 获得了 147.5 ± 9.1 mL/g COD 的最大生物 CH4 产量和 91.2 ± 6.8 % 的 2-氯甲苯去除率，经历了 14.7 的足够 C/N 比和最高的产酸活性 (42.0 %)、产乙酸（37.9%）和产甲烷（42.1%）。门水平上的广古菌门、拟杆菌门和 Chloroflexi 的丰度，以及属水平上的假单胞菌属和芽孢杆菌的丰度，对脱氯机制和乙酸盐转化为 CH4 有很大贡献。该生物质转化为生物能源项目（产能为 10 立方米/天）可受益于污染减少、沼气回收和碳信用额，投资回收期为 5.6 年，净现值为 3503 美元，内部收益率为 12.1%。由于R5表现出高效的技术经济厌氧生物降解性能，未来的研究需要优化其HRT条件和HAP@BC剂量。