摘要

       芬顿调节工艺最近已被用于改善污水污泥的脱水能力。然而，尚不清楚芬顿试剂的调节是否会同时减弱污泥中的抗生素抗性基因（ARG）并提高污泥的脱水能力。在本研究中发现，污泥预酸化在通过 Fenton 试剂调节同时去除 ARGs 和提高污泥脱水能力方面发挥了关键作用。当污水污泥预酸化至 pH = 3.0，然后使用 Fenton 试剂调节时，调节后的污泥中总 ARGs 和总移动成因元素 (MGEs) 的绝对丰度降低了 1.85-2.10 和 2.84-3.12 log单位，分别。此外，污泥毛细管吸入时间（CST）和比过滤阻力（SRF）显着降低，脱水污泥饼中的水分含量（MC）降低至仅60.61-69.95％。调节污泥中 ARGs 和 MGEs 的这种有效衰减导致它们在脱水污泥饼和脱水滤液中被去除。然而，用芬顿试剂对污泥进行调理而没有对污泥进行预酸化，只能提高污泥的脱水能力。在调理处理过程中，去除调理污泥中松散结合的胞外聚合物（EPS）和紧密结合的EPS有助于提高污泥脱水性，污泥微生物细胞的破坏与抗生素耐药性的减弱密切相关。因此，污泥预酸化与芬顿试剂调理相结合，可以同时减弱污水污泥中的抗生素耐药性，提高污泥的脱水能力。

       Fenton conditioning processes have been recently employed to improve the dewaterability of sewage sludge. However, it remains unclear whether the conditioning with Fenton’s reagent would simultaneously attenuate antibiotic resistance genes (ARGs) in sludge and improve sludge dewaterability. It was found in the present study that sludge pre-acidification played a pivotal role in simultaneously removing ARGs and improving sludge dewaterability by conditioning with Fenton’s reagent. When the sewage sludge was pre-acidified to pH = 3.0 and was then conditioned using Fenton’s reagent, the absolute abundances of the total ARGs and the total mobile genic elements (MGEs) in conditioned sludge were reduced by 1.85–2.10 and 2.84–3.12 log units, respectively. Additionally, sludge capillary suction time (CST) and specific resistance to filtration (SRF) were drastically reduced, and the moisture content (MC) in dewatered sludge cake was reduced to only 60.61–69.95%. Such effective attenuation of ARGs and MGEs in conditioned sludge led to their removal in both the dewatered sludge cakes and dewatering filtrate. However, only the improvement of sludge dewaterability was attained by sludge conditioning with Fenton’s reagent but without sludge pre-acidification. During the conditioning treatment, the removal of loosely bound extracellular polymeric substance (EPS) and tightly bound EPS in conditioned sludge contributed to the improvement of sludge dewaterability, and the damage of sludge microbial cells was highly correlated with the attenuation of antibiotic resistance. Thus, sludge pre-acidification combined with conditioning using Fenton’s reagent can be employed to simultaneously attenuate the antibiotic resistance in sewage sludge and improve sludge dewaterability.

https://link.springer.com/article/10.1007/s11356-020-11562-w