Kaijun Wang,Sining Yun,Tian Xing,Bingjie Li,Yasir Abbas,Xinming Liu
The effects of binary and ternary trace elements (TEs) (Fe/Co, Fe/Ni, and Fe/Co/Ni) on the anaerobic digestion (AD) of cattle manure were investigated using kinetic models (first-order, logistic, modified Gompertz, and Coats-Redfern) and experimental measurements. Binary and ternary TEs can significantly improve the biogas production rate and yield potential. The deviation between the predicted and measured data for biogas yield with logistic model (2.1%–5.3%) and modified Gompertz model (0.32%–2.9%) was smaller than that with first-order kinetic model (6.9%–9.9%). The Coats-Redfern model fitting indicated that the activation energy of digestates with trace elements during pyrolysis was reduced by 3.9%–26.2% compared with the control group. Meanwhile, digestates with TEs showed remarkable fertility (5.72%–5.95%). The combination of kinetic models and experimental measurements can effectively quantify the effect of TEs on AD performance and provide an informed choice for industrial production.
Due to the persistence in residue and the emission to environment, antibiotics have become the emerging contaminants. Tetracyclines, as the largest amount of antibiotics in the breeding industry, were investigated in this study. For eliminating the tetracyclines, anaerobic culture was enriched from livestock waste after four generations and FeOn(OH)m modified oyster shell powders (OSPs) were amended into the enrichment culture as auxiliary method. Tetracycline and oxytetracycline were selected as the model compounds. The adsorption models (Langmuir and Freundlich isotherms) of tetracycline and microbes on OSPs were simulated respectively. With the addition of FeOn(OH)m modified OSPs, the transformation efficiency of oxytetracycline achieved 81.5% after 22 days’ incubation, approximately 1.85 times higher than the 4th generation (G-IV) enrichment culture without modified OSPs. Dehydration, demethylation, dehydroxylation and decarboxylation took place under anaerobic condition, inferred from the detected metabolites transformed from oxytetracycline. Genus Methanosarcina and two operational taxonomic units (OTUs) assigned to order Clostridiales , showed an increasing trend on abundance, indicating the contribution to transformation of oxytetracycline. Therefore, the FeOn(OH)m modified OSPs and enrichment culture can accelerate the transformation of oxytetracycline simultaneously, indicating a promising utilization not only for waste water system but also for antibiotic contaminated biomass treatment.
危险品化学品经营许可证（带存储）