Meta分析固液分离技术对养殖废弃物分离效率及气体排放的影响

Efficiency and Gas Emission Assessment of Various Solid-liquid Separation Technologies for Animal Slurry:A Meta Analysis

固液分离技术被广泛应用于养殖场畜禽粪污的管理,笔者选取36篇已发表的文章进行了全面的Meta分析,以评估不同分离技术的分离效率及其对气体排放的影响。结果表明,螺旋挤压及离心技术是应用最普遍的2种技术,且离心技术具有更高的分离效率(E X-SF);粪污各指标分离效率随干物质含量的增加而增加;结合干物质分离效率和去除效率的频率分布特征,将分离技术按效率进行了分类,高效率组中固体组分的鲜重(FM)、干物质(DM)、挥发性固体(VS)、总氮(TN)、总铵态氮(TAN)、总磷(TP)及总钾(TK)含量的分离效率分别是低效率组的2.5、1.9、1.6、3.1、5.2、2.3及3.1倍;固液分离技术显著降低了甲烷(CH 4)(34.4%~67.9%)及温室气体(GHG)(38.9%~60.7%)的排放,且高效率组相较于低效率组具有更高的气体减排潜力。研究对实际生产中预测不同分离技术的效率及环境影响提供了理论依据,并对粪污分离后的安全利用具有重要参考价值。

Solid-liquid separation technology is widely used in animal farms to manage slurry.To evaluate the distribution of components in slurry under the application of different solid-liquid separation technologies,36 published articles were screened for comprehensive meta-analysis.The results of data analysis show that the separation efficiency(E X-SF)of slurry was positively correlated with dry matter content of raw slurry.Centrifuge and screw press are the two most widely used separation technologies in practical production.With the same dry matter content of raw slurry,the E X-SF of centrifuge is higher than that of screw press.The efficiencies of different separation technologies are classified according to the removal efficiency and separation efficiency.The E X-SF of FM,DM,VS,TN,TAN,TP and TK in solids of the high efficiency group are 2.5,1.9,1.6,3.1,5.2,2.3 and 3.1 times as high as that of the low efficiency group,respectively.After solid-liquid separation,the CH 4 and GHG emissions of the slurry were significantly reduced by 34.4%-67.9%and 38.9%-60.7%,respectively.The high efficiency group has higher potential of gas emission reduction than the low efficiency group.This study also provides theoretical basis for the prediction of the efficiency and environmental impact of different liquid and solid components separation technologies in storage and field application,which has important reference value for the accurate evaluation and safe utilization of separated slurry in China.