Laboratory of Resource Recovery in Sanitation Systems Group - RReSSa, Department of Environmental Engineering, Federal University of Santa Catarina, Technological Center, Florianopolis 88040-610, Santa Catarina, Brazil.
Laboratory of Resource Recovery in Sanitation Systems Group - RReSSa, Department of Environmental Engineering, Federal University of Santa Catarina, Technological Center, Florianopolis 88040-610, Santa Catarina, Brazil.
Sci Total Environ. 2024 Jun 10;928:172375. doi: 10.1016/j.scitotenv.2024.172375. Epub 2024 Apr 9.
Using waste from sewage systems, particularly human excreta, could save resources and increase soil fertility, contributing to nutrient management. However, because of the pathogenic content in human feces, this resource can pose health risks to farmers and consumers. Therefore, this work analyzed the behavior of the microorganisms: Escherichia coli ATCC13706 and human adenovirus (HAdV-2) in the soil and the internal part of the plant tissue during the vegetative stage after applying spiked composted human feces as biofertilizer. In a greenhouse, we simulated the application of the biofertilizer in lettuce cultivation by spiking three concentrations of E. coli (6.58, 7.31, and 8.01 log CFU.g) and HAdV-2 (3.81, 3.97, and 5.92 log PFU.g). As a result, we achieved faster decay in soil at higher concentrations of E. coli. We estimated linear decay rates of -0.07279, -0.09092, and -0.115 days, corresponding to Ts of 13.7, 11.0, and 8.6 days from higher to smaller concentrations of E. coli, respectively. The estimated periods for the inactivation of 4 logarithmic units of E. coli bacteria in soil are longer than the cultivation period of lettuce for all concentrations studied. Concerning the bacterial contamination in plants, we found E. coli in the internal part of the leaves at the highest concentration tested during the first three weeks of the experiment. Furthermore, HAdV-2 was found in roots at a stable concentration of 2-2.3 log PFU.g in five of the six samples analyzed. Therefore, bacterial infection could pose a risk, even if fresh greens are washed before consumption, especially for short-term cultures. Regarding viral infection, a positive result in the roots after disinfection may pose a risk to root and tubercule vegetables. These discoveries highlight the importance of conducting comprehensive evaluations of hygiene practices in incorporating organic amendments in crops, explicitly aiming to minimize the risk of post-contamination.
利用污水系统（尤其是人类排泄物）中的废物可以节约资源，提高土壤肥力，促进养分管理。然而，由于人类粪便中存在病原体，因此这种资源可能对农民和消费者的健康构成威胁。因此，这项工作分析了微生物（大肠杆菌 ATCC13706 和人类腺病毒（HAdV-2）在向土壤和植物组织内部施用人造粪便作为生物肥料后的营养阶段的行为。在温室中，我们通过向生菜种植中添加三种浓度的大肠杆菌（6.58、7.31 和 8.01 log CFU.g）和 HAdV-2（3.81、3.97 和 5.92 log PFU.g）来模拟生物肥料的应用。结果，我们在更高浓度的大肠杆菌中实现了更快的土壤衰减。我们估计线性衰减率分别为-0.07279、-0.09092 和-0.115 天，对应于大肠杆菌浓度从高到低的 Ts 分别为 13.7、11.0 和 8.6 天。在所有研究浓度下，估计土壤中大肠杆菌减少 4 个对数单位的时间都比生菜的种植时间长。关于植物中的细菌污染，我们在实验的前三个星期发现了内部叶片中的大肠杆菌，在最高浓度下存在污染。此外，在六个分析样本中的五个样本中，HAdV-2 在根部以 2-2.3 log PFU.g 的稳定浓度存在。因此，即使在食用前清洗新鲜蔬菜，细菌感染也可能构成风险，尤其是对于短期培养的植物。关于病毒感染，在消毒后根部呈阳性结果可能对根和块茎类蔬菜构成风险。这些发现强调了在将有机肥料纳入作物种植中，对卫生措施进行全面评估的重要性，特别是旨在尽量减少后续污染风险。
