Abstract:

2,4-Dichlorophenol (2,4-DCP), a typical chlorophenol compound, was used as the target pollutant. Bovine bone char was used as a carrier to load the HD bacterial strain, thereby producing solid engineered bacterial agents to degrade 2,4-DCP in contaminated soils. The succession and changes of microbial communities in soil and earthworm guts under the stress of 2,4-DCP were revealed using high-throughput sequencing. The results showed that when the bovine bone char, with a particle size range of 160—250μm, was pyrolyzed for 4h, the viable bacteria count was the highest, reaching 2.42×10⁹cfu/g. When the concentration of 2,4-DCP in the soil was 15mg/kg, the effect of solid engineered bacterial agent combined with earthworm remediation group was significantly higher than that of the blank control group and the earthworm-only group. Scanning electron microscopy images showed that strain HD could be stably loaded into the surface voids of bovine bone char, and the surface of the solid engineered bacterial agent showed a porous honeycomb structure. The results of microbial sequencing showed that the input of earthworms and solid engineered bacterial agent could increase the total number and diversity of soil microorganisms. This study aims to provide theoretical and practical references for the development of bioremediation techniques for organic polluted soils.

Key words: 2,4-dichlorophenol, earthworm, kinetics, immobilization, biotechnology

摘要：

以典型氯酚类化合物2,4-二氯苯酚（2,4-DCP）为目标污染物，牛骨炭作为载体负载HD菌株制备固体工程菌剂，对污染土壤中的2,4-DCP进行降解实验，利用高通量测序揭示2,4-DCP胁迫下的土壤与蚯蚓肠道微生物群落演替、变化。结果表明：牛骨炭粒径160~250μm、热解4h时，牛骨炭负载的活菌数最多，达2.42×10⁹cfu/g；当土壤中2,4-DCP浓度为15mg/kg时，协同修复组效果显著高于空白对照组和蚯蚓修复组；扫描电镜图表明，HD菌株可稳定负载于牛骨炭的表面空隙中，且固体工程菌剂表面呈多孔蜂窝状结构；微生物测序结果表明蚯蚓、固体工程菌剂的投入均可增加土壤微生物总数和多样性。本研究旨在为有机污染土壤生物修复技术发展提供理论与应用参考。

关键词: 2,4-二氯苯酚, 蚯蚓, 动力学, 固定化, 生物技术