资源化利用冲施猪粪水高温堆肥研究

Research on resource utilization of pig slurry via high-temperature composting

为有效处理采用水泡粪养殖模式的养猪企业粪污处理提供新的途径,评估辅料中添加不同量猪粪水对猪粪高温堆肥的影响,以期建立利用冲施猪粪水无害肥料化高效堆肥工艺.通过工厂堆肥,以蘑菇渣、砻糠和木屑为原料混匀建堆,堆体顶部挖槽,分7次添加不同量的猪粪水,研究添加不同量猪粪水高温堆肥过程中堆体温度、含水量、p H值、EC、C/N、铵态氮含量、硝态氮含量、水溶性有机碳含量、木质素含量、纤维素含量半纤维素含量、发芽指数和养分等理化指标的变化.结果表明,相比每次添加0.5t猪粪水(Z1)和每次添加1t猪粪水(Z2)的处理,每次添加2t猪粪水(Z3)的处理高温期温度最高,降温后熟阶段降温速率也最大;堆肥过程中各处理p H值变化基本一致,均是先降低再升高最后降低趋于稳定;各处理堆体在堆肥过程中,C/N均呈现逐步减小的趋势,并最终保持稳定,根据终点C/N与初始C/N的比值,至堆肥结束时,Z1、Z2处理未腐熟,Z3处理基本腐熟;各处理铵态氮含量逐渐下降,硝态氮含量逐渐增加;堆肥结束时,Z2和Z3处理类酪氨酸类物质和类色氨酸类物质减少至消失,胡敏酸类、富里酸类等物质成为DOM的主体部分,基本腐熟,而Z1处理未腐熟..相比Z1和Z2处理,Z3处理在堆肥过程中木质素、纤维素和半纤维素降解速率更快;堆肥过程中,各处理发芽指数(GI)不断增大,至堆肥结束时,Z1、Z2、Z3处理的发芽指数分别为72%、84%和101%,Z2和Z3处理腐熟,且Z3处理堆肥腐熟所需时间更短(第43d GI为85%).各处理有机质含量均下降,全氮、全磷、全钾含量在堆肥结束时比堆肥初始均有所增加.分次将猪粪水注入蘑菇渣、砻糠和木屑混合物进行高温堆肥可以有效解决规模化养猪厂猪粪水难处理的问题.

Effects of different amounts of pig slurry added in auxiliary materials on the composting efficiency were investigated for establishing an efficient composting technology to recycle huge amount of pig slurry in large-scale pig farms. Three treatments were arranged in the factory to investigate the effect of different amounts of pig slurry addition in the mixture of mushroom dregs, rice chaff and sawdust on the composting efficiency by monitoring the variations of physicochemical indexes including stack temperature, p H value, EC, C/N, moisture content, ammonium nitrogen, nitrate nitrogen, germination index, lignin content, cellulose content, hemicellulose content, water-soluble carbon content and nutrients during composting process. The highest composting temperature was observed in stack Z3 and its temperature dropped faster than stack Z1 and Z2 at the end of composting. The p H decreased at beginning and then increased during the composting. In the end, it dropped and reached stabilization stage. The C/N values of all treatments decreased gradually during the composting process. The ratio of the end C/N to the initial of stack Z3 was 0.59 indicating it was matured at the end of composting. The ammonium and nitrate content decreased and then increased gradually, respectively. The tyrosine and tryptophan like substances disappeared in Z2 and Z3, while the humic acids and fulvic acids became the main component of the DOM after composting. Compared to Z1 and Z2, Z3 showed a greater degradation rate of lignin, cellulose and hemicellulose during composting. Germination index of each treatment increased during composting process. At the end of composting, the germination indices of Z1, Z2 and Z3 were 72%, 84% and 101%, respectively. The organic matter of all treatments decreased while the total N, P and K increased during the composting process. The addition of pig slurry to the mixture of mushroom residue, rice hulls and sawdust led to effective high-temperature-composting, which could be a novel strategy to deal with the huge amount of pig slurry in pig farms.