摘要

     碱处理在发展中国家广泛应用于减少污泥中的病原菌，保证污泥在农业上的安全使用。本研究的目的是探讨碱处理活性污泥（was）和上流式厌氧污泥床（UASB）污泥对细菌群落、病原菌（活蠕虫卵和沙门氏菌属）和抗生素抗性基因（ARG）的影响。通过采用变性凝胶梯度电泳（DGGE）技术，以16s rDNA基因为靶点来检测细菌群落结构。应用聚合酶链反应（PCR）来检测多个ARG的存在。碱处理是通过在污水污泥中添加熟石灰（Ca（OH）2）来进行的。在处理2、24、48和72小时之前和之后采集样本。碱处理显著改变了污泥中的细菌群落结构，在24小时后UASB污泥中的细菌轮廓变化比WAS更明显。一些细菌在极端pH条件下（pH > 12）仍然存在，如WAS样品中的稻瘟菌和脱氯单胞菌，UASB污泥样品中的地发菌和土杆菌。污泥经过24小时的碱化处理后，其病原菌和指标值均符合卫生法律规定，具有应用于农业生产的潜力。必须强调的是，那些目前卫生法规中没有的但在碱处理后的污泥样品中检测到的ARG可能是对人类健康的一个威胁。

     Alkaline treatment is widely used to reduce pathogens in sewage sludge in developing countries and guarantee that it is safe for use in agriculture. The aim of this study was to investigate the effect of alkaline treatment applied to waste-activated (WAS) and Upflow Anaerobic Sludge Blanket (UASB)-sludge on the bacterial community, pathogens (viable helminths eggs and Salmonella spp), and antibiotic resistance genes (ARG). The bacterial community structure was examined through denaturing gel gradient electrophoresis (DGGE), targeting 16S rRNA genes. Polymerase chain reaction (PCR) was applied to evaluate the presence of several ARGs. The conducted alkaline experiment consisted of adding hydrated lime (Ca(OH)₂) to sewage sludges. Samples were taken before and after 2, 24, 48, and 72 hours of treatment. Alkaline treatment changed considerably the bacterial community structure and after 24 hours, shifts in bacterial profiles were more pronounced in the UASB sludge sample than in WAS. Some bacteria remained under extreme pH conditions (pH > 12), such as Azospira oryzae and Dechloromonas denitrificans in the WAS samples, and Geothrix and Geobacter in the UASB sludge samples. The values of pathogens and indicators in the sludge after 24 hours of alkaline treatment meet sanitary law regulations and thus the sludges could have the potential to agricultural distribution. It is important to highlight that ARG, which are not currently present in sanitary regulations, were detected in the sludge samples after the alkaline treatment, which could be a concern for human health.

     https://iahr.tandfonline.com/doi/abs/10.1080/09593330.2018.1505960#.Xmch7fR5vak