Department of Civil and Environmental Engineering, University of Nebraska - Lincoln, Lincoln, NE 68588, USA.
Department of Statistics, University of Nebraska - Lincoln, Lincoln, NE 68583, USA.
Sci Total Environ. 2021 May 10;768:144220. doi: 10.1016/j.scitotenv.2020.144220. Epub 2021 Jan 9.
Proper treatment is necessary to reduce antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) in livestock manure before land application. Conventional stockpiling suffers unreliable removal efficiency, while composting can be complicated and expensive. The objective of this study was to test the feasibility of a novel heat-based technology, i.e., stockpiling manure on conductive concrete slabs, to inactivate ARB and ARGs in beef cattle manure. In this study, two independent bench-scale trials were conducted. In both trials, samples were taken from manure piles on conductive concrete slabs and regular slabs (i.e., heated and unheated piles). In the heated pile of the first trial, 25.9% and 83.5% of the pile volume met the EPA Class A and Class B biosolids standards, respectively. For the heated pile of the second trial, the two values were 43.9% and 74.2%. In both trials, nearly all forms of the total and resistant Escherichia coli and enterococci were significantly lower in the heated piles than in the unheated piles. Besides, significant reduction of ARGs in heated piles was observed in the first trial. Through this proof-of-concept study, the new technology based on conductive concrete slabs offers an alternative manure storage method to conventional stockpiling and composting with respect to reduce ARB and ARGs in manure.
在将畜禽粪便施用于土地之前，需要进行适当的处理以减少其中的抗生素耐药菌（ARB）和抗生素耐药基因（ARGs）。传统的堆肥处理方法去除效率不可靠，而堆肥处理又可能很复杂且昂贵。本研究旨在测试一种新型基于热的技术（即将粪便堆放在导电混凝土板上）在灭活肉牛粪便中 ARB 和 ARGs 的可行性。本研究进行了两个独立的台式试验。在这两个试验中，都从导电混凝土板和常规板（即加热和未加热的堆肥）上的粪便堆中取样。在第一个试验的加热堆中，分别有 25.9%和 83.5%的堆体体积符合 EPA 一级和二级生物固体标准。对于第二个试验的加热堆，这两个值分别为 43.9%和 74.2%。在这两个试验中，加热堆中的总大肠菌和耐抗生素大肠菌及肠球菌的所有形式均明显低于未加热堆。此外，在第一个试验中还观察到加热堆中 ARGs 显著减少。通过这项概念验证研究，基于导电混凝土板的新技术为传统的堆肥处理提供了一种替代的粪便储存方法，可以减少粪便中的 ARB 和 ARGs。
