分散式养猪场粪污/秸秆混合发酵沼渣制备缓释肥及缓释性能研究

Study on the Preparation of Sustained-release Fertilizer Through Biogas Residue of Excrement/Straw Mixed Fermentation from Dispersed Pig Farm and Its Sustained-release Performance

针对分散式养猪场粪污/秸秆混合发酵沼渣污染物产生量大、养分易流失等特点,本文以沼渣为原料,沸石为载体,聚乙烯醇为包膜材料,不添加沸石制备复混包膜肥Ⅰ,不同MAP、沸石与沼渣质量比制备Ⅱ(1∶4∶25)和Ⅲ(1∶25∶25),对3种复混肥缓释性能进行了探讨,并与市售普通复合肥肥效释放进行对比。结果表明,3种复混肥总磷、总氮初期养分溶出率均低于15%,微分溶出率均小于1%,28 d内累计养分溶出率低于80%,符合《中国缓释肥料(GB/T 23348-2009)》缓释肥评价要求;在静水中总磷累积溶出率表现为:Ⅲ>Ⅰ>Ⅱ,1~20 d内总氮累积溶出率大小为:Ⅰ>Ⅲ>Ⅱ,20~60 d内总氮累积溶出率大小为:Ⅰ>Ⅱ>Ⅲ;在进行土柱淋溶养分溶出试验研究中,总磷、总氮溶出率大小为Ⅰ>Ⅲ>Ⅱ;60 d内复混肥Ⅰ、Ⅱ、Ⅲ在静水中总磷、总氮的溶出率均符合Elovich动力学模型,显著性水平均为P<0.01。研究结果可为分散式养猪场粪污/秸秆混合发酵沼渣资源化利用及制备沸石缓释肥配比提供参考。

The distributed pig excrement/straw mixed fermentation residue produced a large amount of pollutants,including nutrient,phosphorus,and other contaminants.In this study,biogas residue was used as raw material and zeolite as carrier,polyvinyl alcohol was employed as coating material to prepare mixed coated fertilizer.The compound fertilizerⅠwas as control and did not contain zeolite.The ratios of MAP,zeolite and biogas residue were 1:4:25 and 1:25:25 for prepared compound fertilizerⅡandⅢrespectively.The sustained-release properties of three kinds of compound fertilizers were discussed and compared with common commercial fertilizers.The results showed that the dissolution rates of total phosphorus and nitrogen in prepared compound fertilizers were less than 15%,the differential dissolution rates were less than 1%,and the cumulative nutrient dissolution rate within 28 d was less than 80%.These results indicated the prepared samples met the requirement of slow release fertilizer in China(GB/T 23348-2009).The accumulation dissolution rate of total phosphorus in static water wasⅢ>Ⅰ>Ⅱ.The accumulation dissolution rate of total nitrogen at 1~20 d and 20~60 d periods were showing asⅠ>Ⅲ>Ⅱ,andⅠ>Ⅱ>Ⅲ,respectively.In the experiment on leaching nutrient leaching of soil column,the total phosphorus and total nitrogen dissolution rates from three compound fertilizers wereⅠ>Ⅲ>Ⅱ.The dissolution rate of total phosphorus and nitrogen in compound water ofⅠ,ⅡandⅢwithin 60 d was agreed with Elovich kinetic model,and the significance level was P<0.01.The results could provide a reference for the resource utilization and preparation of zeolite sustained-release fertilizer from the dispersive pig manure/straw mixed fermentation.