College of Engineering, China Agricultural University, Beijing 100083, PR China.
Department of Civil and Environmental Engineering, Virginia Tech, Arlington, VA 22202, USA.
Chemosphere. 2024 Oct;366:143475. doi: 10.1016/j.chemosphere.2024.143475. Epub 2024 Oct 4.
Antibiotics in animal manure pose significant risks to the environment and health. While anaerobic digestion (AD) is commonly used for pig manure treatment, its efficiency in antibiotic removal has been considerably limited. This study investigated the impact of hydrothermal pretreatment (HTP) on sulfadiazine (SDZ) removal in a two-stage AD system. Results indicated that the HTP process reduced SDZ concentration by 40.61%. Furthermore, the SDZ removal efficiency of the AD system coupling HTP increased from 50.90% to 65.04% compared to the untreated system. Biogas yield was also improved by 26.17% while maintaining system stability. Changes induced by HTP in the microbial communities revealed that Firmicutes, Bacteroidetes, Caldatribacteriota, and Proteobacteria emerged as the primary bacterial phyla. Following HTP, the relative abundance of Prevotella, which exhibited a strong negative correlation with SDZ concentration, increased significantly by 25-fold in the acidogenic stage. Proteiniphilum, Syntrophomonas and Sedimentibacter showed notable increases in the methanogenic stage after HTP. The N-heterocyclic metabolism carried out by Prevotella might have been the predominant SDZ degradation pathway in the acidogenic stage, while the benzene ring metabolism and hydroxylation by the Proteiniphilum emerged as the primary degradation pathways in the methanogenic stages. Furthermore, biodegradation intermediates were proven to be less toxic than SDZ itself, indicating that the HTP-enhanced two-stage AD process could be a viable way to lower the environmental risks associated with SDZ. The findings from this study provide valuable insights for removing SDZ from the environment via two-stage AD.
动物粪便中的抗生素对环境和健康构成重大风险。虽然厌氧消化（AD）常用于猪粪处理，但它去除抗生素的效率受到了很大限制。本研究探讨了水热预处理（HTP）对两段式 AD 系统中磺胺嘧啶（SDZ）去除的影响。结果表明，HTP 工艺将 SDZ 浓度降低了 40.61%。此外，与未处理系统相比，耦合 HTP 的 AD 系统的 SDZ 去除效率从 50.90%提高到 65.04%。沼气产量也提高了 26.17%，同时保持了系统的稳定性。HTP 对微生物群落的变化表明，厚壁菌门、拟杆菌门、Caldatribacteriota 和变形菌门成为主要的细菌门。经过 HTP 后，与 SDZ 浓度呈强烈负相关的普雷沃氏菌（Prevotella）的相对丰度在产酸阶段显著增加了 25 倍。HTP 后，产甲烷阶段的蛋白菌（Proteiniphilum）、同型产乙酸菌（Syntrophomonas）和沉积杆菌（Sedimentibacter）的丰度明显增加。普雷沃氏菌（Prevotella）进行的 N-杂环代谢可能是产酸阶段 SDZ 降解的主要途径，而蛋白菌（Proteiniphilum）的苯环代谢和羟化作用则成为产甲烷阶段的主要降解途径。此外，生物降解中间体的毒性比 SDZ 本身要低，这表明 HTP 增强的两段式 AD 工艺可能是降低 SDZ 环境风险的一种可行方法。本研究为通过两段式 AD 去除环境中的 SDZ 提供了有价值的见解。
