Composting is considered to be a primary treatment method for livestock manure and rice straw, and high degree of maturity is a prerequisite for safe land application of the composting products. In this study pilot-scale experiments were carried out to characterize the co-composting process of livestock manure with rice straw, as well as to establish a maturity evaluation index system for the composts obtained. Two pilot composting piles with different feedstocks were conducted for 3 months: (1) swine manure and rice straw (SM–RS); and (2) dairy manure and rice straw (DM–RS). During the composting process, parameters including temperature, moisture, pH, total organic carbon (TOC), organic matter (OM), different forms of nitrogen (total, ammonia and nitrate), and humification index (humic acid and fulvic acid) were monitored in addition to germination index (GI), plant growth index (PGI) and Solvita maturity index. OM loss followed the first-order kinetic model in both piles, and a slightly faster OM mineralization was achieved in the SM–RS pile. Also, the SM–RS pile exhibited slightly better performance than the DM–RS according to the evolutions of temperature, OM degradation, GI and PGI. The C/N ratio, GI and PGI could be included in the maturity evaluation index system in which GI > 120% and PGI > 1.00 signal mature co-composts.
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机译:堆肥被认为是用于牲畜粪便和稻草的主要处理方法,并且高度成熟是堆肥产品在土地上安全使用的前提。在这项研究中,进行了中试规模的实验,以表征牲畜粪便与稻草的共同堆肥过程,并为获得的堆肥建立了成熟度评价指标体系。进行了两个不同原料的中试堆肥,历时3个月:(1)猪粪和稻草(SM–RS); (2)奶牛粪和稻草(DM–RS)。在堆肥过程中,监测包括温度,湿度,pH,总有机碳(TOC),有机物(OM),不同形式的氮(总氮,氨和硝酸盐)和腐殖化指数(腐殖酸和富里酸)在内的参数。除了发芽指数(GI),植物生长指数(PGI)和Solvita成熟度指数。在两个桩中,OM损失均遵循一阶动力学模型,而在SM–RS桩中,OM矿化速度略快。而且,根据温度,OM降解,GI和PGI的变化,SM-RS桩表现出比DM-RS更好的性能。 C / N比,GI和PGI可以包括在GI> 120%和PGI> 1.00表示成熟共同构成的成熟度评估指标体系中。
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