不同配比猪粪渣/生活污泥堆肥过程养分及重金属含量变化

Properties of Mixed Pig Manure Residue and Sewage Sludge Composts

【目的】研究不同配比猪粪渣/生活污泥堆肥过程养分及重金属含量变化,开发城市生活污泥堆肥化处置调理剂,实现猪粪渣资源化利用。【方法】以规模化养猪场粪污经固液分离后得到的渣滓为调理剂,与城市生活污泥进行条垛式堆肥,分别设置猪粪渣、生活污泥质量配比6∶10(ZW1处理,C/N=25)和6∶5(ZW2处理,C/N=30)两组不同处理,研究不同物料配比处理堆肥过程温度、C/N、养分含量(全氮、全磷、全钾)、有机质含量和重金属(Cu、Zn、Cd和Pb)含量的变化。【结果】ZW2处理的堆体高温期持续时间长于ZW1处理;两个处理的C/N均逐渐下降并最终趋于一致,且堆肥结束后ZW2处理(C/N=30)的有机碳含量降幅达到28.6%,而ZW1处理(C/N=25)的降幅仅为2.1%,说明猪粪渣中的碳源较容易被微生物分解和转化;堆肥过程中全氮、全磷和全钾随有机碳含量的降低表现为增加的趋势;不同处理的堆肥产品的重金属(Cu、Zn、Cd和Pb)含量在堆肥后均有所提高;堆制58d后,各处理堆肥无害化程度、养分含量和重金属Cd、Pb含量均达到NY525-2012的要求。【结论】猪粪渣可以作为城市生活污泥堆肥的调理剂,且猪粪渣、生活污泥质量配比为6∶5的堆肥效果更优。

【Objective】Waste from pig farms and municipal sewer were mixed and composted to evaluate its utilization as a safe,organic substrate for agricultural applications.【Method】 Manure residue from large pig farms after solid-liquid separation was mixed with municipal sewage sludge for the composting. Two mixing ratios of manure residue∶sewage sludge,i.e.,a low C/N treatment of 6 ∶10 (ZW1) and a high C/N treatment of 6∶5 (ZW2),were applied for the experiment. The changes on temperature,C/N ratio as well as the nutrients (total nitrogen,total phosphorus,total potassium and organic matters) and heavy metals (Cu,Zn,Cd and Pb) contents of the mixtures during the fermentation process were monitored for evaluation.【Result】The thermophilic phase of ZW2 lasted longer than that of ZW1. After composting,the organic carbon content of ZW2 (C/N=30) decreased by 28.6%,while that of ZW1 (C/N=25) merely 2.1%,indicating that the carbon source in pig manure was easily decomposed by microorganisms. As the fermentation progressed,the total nitrogen,phosphorus and potassium increased,and the heavy metals increased in the mixtures. After 58 d of composting,both resulting materials met the national standards for nutrients content and safety on heavy metals.【Conclusion】 The mass ratio of 6:5 (C/N=30) between the pig manure residue and the sewage sludge was considered appropriate for composting to produce an applicable fertilizer.