This study investigated the behaviour of pathogens and microbial indicators during dewatering of sludge from an upflow anaerobic sludge blanket (UASB) reactor treating real domestic wastewater under tropical conditions. The sludge was dewatered in air-drying beds during wet and dry seasons and was monitored for 90 days. Culture-based methods, direct microscopy identification and quantitative polymerase chain reaction assays, were used to evaluate pathogenic and microbiological indicator microorganisms in the sludge. Thermotolerant coliforms and coliphages (somatic and male F-specific) were monitored as bacterial and viral indicators, respectively. Pathogenic organisms monitored included Salmonella spp., Salmonella Typhimurium, Salmonella Enteritidis, pathogenic Escherichia coli strains (intimin-coding genes), Campylobacter jejuni, Cryptosporidium spp., adenovirus, and viable helminths eggs. Results revealed that microbial indicators did not show a significant variation between the dry and wet seasons, as it was verified for some pathogens. During the 90 days of sludge dewatering, the air-drying bed was able to remove microbial indicators and the pathogenic organisms E. coli, S. Typhimurium, and Cryptosporidium spp. (when present). Pathogenic C. jejuni, S. Enteriditis, and adenovirus decreased 0.5–1.7, 0.3–0.4, and 2.6–4.8 log units, respectively. These results highlight the potential of air-drying beds as a simple and low-cost process for sludge dewatering and hygienisation.

这项研究调查了在热带条件下，用于处理实际生活污水的上流厌氧污泥覆盖（UASB）反应器中污泥脱水过程中的病原体和微生物指标。在潮湿和干燥季节，污泥在风干床中脱水，并进行90天监测。基于培养的方法，直接显微镜鉴定和定量聚合酶链反应测定法被用于评估污泥中的致病性和微生物指示微生物。耐热大肠菌群和大肠菌群（体细胞和雄性F特异性）分别作为细菌和病毒指标进行监测。监测的病原生物包括沙门氏菌，鼠伤寒沙门氏菌，沙门氏菌肠炎，致病性大肠杆菌菌株（内膜蛋白编码基因），空肠弯曲菌，隐孢子虫属，腺病毒和蠕虫卵。结果表明，对于某些病原体，微生物指标在干燥季节和潮湿季节之间没有显示出明显的变化。在污泥脱水的90天中，风干床能够去除微生物指示剂和病原性微生物E. coli，S。鼠伤寒和隐孢子虫属。（如果有）。致病空肠弯曲杆菌，小号。肠炎和腺病毒分别减少了0.5–1.7、0.3–0.4和2.6–4.8对数单位。这些结果突显了风干床作为污泥脱水和卫生化的简单且低成本过程的潜力。