35 / 2025-03-31 14:26:39

Enhanced CH4 mitigation in BTF and NH3 interreferences investigation

methane,packing modification,,activated carbon

1. 畜禽集约化养殖与可持续发展 > （4）养殖业的废气和颗粒物减排

Trace CH₄ removal from livestock facilities by biotrickling filters (BTF) remains a significant challenge when using hydrophobic materials as packing, particularly considering microbial adaptation under adverse conditions (such as starvation and low temperatures). Meanwhile, packing surface modification combined with sodium dodecyl benzene sulfonate (SDBS) provides a potential method to solve this problem. In this work, polypropylene plastic (PP) packing was modified by plasma-chemical solution (PP@PC), and rice husk activated carbon (PP@AC), respectively, to improve the CH₄ removal and microbial adaptability. Compared to PP-BTF, the results showed that the CH₄ removal efficiency (RE) increased by 17% on average in PP@AC-BTF with the addition of 25 mg/L SDBS. Additionally, the recovery time was shortened by 5 days in PP@PC-BTF and by 9 days in PP@AC-BTF during the starvation recovery stage. The CH₄ RE enhanced by 18%, and 31% on average in PP@PC-BTF and PP@AC-BTF, respectively at the low temperature of 13 ℃. CH₄ RE in PP@AC-BTF reached over 60% under the empty bed residence time (EBRT) at 5 mins, after the BTF has been in operation for 216 days. PP@AC improved bacterial community structure, CH₄ biodegradation process, and BTF functional stability under harsh factors. PP@AC increased the abundance of methanogenic bacteria and their symbiotic communities (such as Pseudoxanthomonas, Hyphomicrobium, and Hydrogenophaga), while NH₃ disturbance significantly inhibited the growth of Methylosinus. The relative abundance of Methylosinus decreased from 1.5% to 0.1% in PP@AC-BTF biofilm, with NH₃ introduction. Metagenomics results based on KEGG pathways confirmed that the gene expression related to the metabolism of CH₄ and NH₃ was improved in PP@AC-BTF. Bacterial communities can adapt to the harsh environment by biomarkers regulation.