Research Center for Environmental Quality Management, Graduate School of Engineering, Kyoto University, 1-2 Yumihama, Otsu, Shiga 520-0811, Japan.
Research Center for Environmental Quality Management, Graduate School of Engineering, Kyoto University, 1-2 Yumihama, Otsu, Shiga 520-0811, Japan.
Waste Manag. 2024 Jun 30;183:123-131. doi: 10.1016/j.wasman.2024.05.006. Epub 2024 May 13.
In this study, the reduction in the abundance of antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARGs) and the fertilizer potential of liquid products from hydrothermally treated cattle manure were investigated. Hydrothermal treatment (HTT) was conducted under different reaction temperatures (125, 150, 175 and 200 °C) and retention times (60, 90 and 120 min). The total organic carbon (TOC) and total nitrogen (TN) of the liquid product increased with increasing reaction temperature. The germination index (GI), a measure of the percentage of germination, exceeded 90 % at 125, 150, and 175 °C in diluted samples, while it decreased to 18 % at 200 °C. Although a longer retention time contributed to an increase in TOC of liquid products, it did not increase the GI values. The liquid product should be diluted or adjusted before use as fertilizer to prevent phytotoxicity. In our analysis of ARB and ARGs, E. coli and antibiotic-resistant E. coli were completely reduced after HTT, except for the operating conditions of 125 °C and 60 min. Although both a higher reaction temperature and longer retention time tended to be better for the reduction of ARGs and intI1, it was found that the longer retention time is much more effective than the higher reaction temperature. The reduction of target ARGs and intI1 was 2.9-log under175 °C and 120 min. Comprehensively considering the fertilizer potential of liquid product and the reduction of ARB and ARGs, 175 °C of reaction temperature and 120 min of retention time of operating conditions for HTT were recommended.
本研究旨在探讨水热处理牛粪便液体产物中抗生素抗性细菌（ARB）和抗生素抗性基因（ARGs）丰度的降低情况，以及其作为肥料的潜力。水热处理（HTT）在不同的反应温度（125、150、175 和 200°C）和保留时间（60、90 和 120 分钟）下进行。液体产物的总有机碳（TOC）和总氮（TN）随反应温度的升高而增加。稀释样品中，发芽指数（GI，衡量发芽率的百分比）在 125、150 和 175°C 时超过 90%，而在 200°C 时降至 18%。虽然较长的保留时间有助于增加液体产物的 TOC，但不会增加 GI 值。在用作肥料之前，液体产物应稀释或调整，以防止植物毒性。在我们对 ARB 和 ARGs 的分析中，除了 125°C 和 60 分钟的操作条件外，HTT 后大肠杆菌和耐药大肠杆菌完全减少。虽然较高的反应温度和较长的保留时间都有利于 ARGs 和 intI1 的减少，但发现较长的保留时间比较高的反应温度更有效。在 175°C 和 120 分钟的条件下，目标 ARGs 和 intI1 的减少量分别为 2.9 个对数。综合考虑液体产物的肥料潜力和 ARB 和 ARGs 的减少情况，推荐使用 175°C 的反应温度和 120 分钟的保留时间作为 HTT 的操作条件。
