State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, 100875 Beijing, China.
State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, 100875 Beijing, China.
Waste Manag. 2019 Apr 1;88:160-169. doi: 10.1016/j.wasman.2019.03.039. Epub 2019 Mar 25.
The variations of phosphorus (P) in animal manure during freeze-thaw cycles (FTCs) profoundly influence on non-point source P loss in winter. Therefore, understanding how FTCs influence the physicochemical properties of animal manure and its P availability is crucial. In this study, the freeze-thaw treatment was performed by incubating the pig manure at -20 °C for 12 h and at 18 °C for 12 h. The freeze-only treatment was maintained at -20 °C as a control. In addition, the pig manure was kept at two moisture levels during the FTCs and sampled every five cycles. Six forms of P in the manure were extracted and analyzed. After 30 cycles, the dissolved organic carbon had increased from 10.49 to 13.56 g/kg, and the pH had decreased from 6.25 to 5.77. The particles originally >1000 μm were broken into particles <250 μm. The forms of P in manure shifted from Ca-P, occluded P, and residual P towards NHCl-P, Al-P and Fe-P, resulting in a 23% increase in bioavailable P. These variations were highly coincident with the increase in moisture content and FTC frequency. The proportion of particles <38 μm increased by more than 2% after the FTCs, and the manure P was mainly concentrated in these particles, which might be readily washed away by the melt water. Overall, the study indicated that FTCs could enhance the bioavailability of P in pig manure and the mobility of particle-associated P. These findings are significant for reducing animal manure pollution in freeze-thaw season.
在冻融循环（FTCs）期间，动物粪便中磷（P）的变化会极大地影响冬季非点源 P 流失。因此，了解 FTCs 如何影响动物粪便的物理化学性质及其 P 有效性至关重要。在这项研究中，通过将猪粪在-20°C 下孵育 12 小时，在 18°C 下孵育 12 小时来进行冻融处理。仅冻融处理保持在-20°C 作为对照。此外，在 FTCs 期间，猪粪保持在两个水分水平，并每五个循环采样一次。提取并分析了粪便中的六种形式的 P。经过 30 个循环后，溶解有机碳从 10.49 增加到 13.56 g/kg，pH 值从 6.25 降低到 5.77。原本>1000 µm 的颗粒破碎成<250 µm 的颗粒。粪便中的 P 形态从 Ca-P、闭蓄 P 和残留 P 转变为 NHCl-P、Al-P 和 Fe-P，导致可利用 P 增加了 23%。这些变化与水分含量和 FTC 频率的增加高度一致。经过 FTCs 后，<38 µm 的颗粒比例增加了 2%以上，粪便 P 主要集中在这些颗粒中，这些颗粒可能很容易被融水冲走。总的来说，该研究表明 FTCs 可以提高猪粪中 P 的生物有效性和颗粒相关 P 的迁移性。这些发现对于减少冻融季节动物粪便污染具有重要意义。
