低温鸡粪生物质炭的制备及其对土壤理化性质的影响

Low Temperature Preparation of Biochar from Chicken Manure and Its Effect on Soil Physicochemical Properties

低温条件下热裂解制备鸡粪生物质炭,既可以减少炭化过程中矿质元素的损失,又可以固定重金属,还可以缓释营养物质,是鸡粪肥料化利用的一个新途径。试验对300℃下鸡粪生物质炭的制备及其在恒温培养条件下对土壤理化性质的影响进行研究。结果表明:低温制备的鸡粪生物质炭的产率为57.43%,产率较高,孔隙数量较少,pH为9.82,呈碱性,K、Mg、Cu、Zn等矿质元素的含量明显增加。低温炭化过程中通过减少酸溶态和可还原态含量,增加可氧化态含量来固定鸡粪中的Cu和Zn。低温制备的鸡粪生物质炭添加到土壤中后可提高土壤的pH,短期内可增加土壤有效态Cu和Zn的含量,但随着时间的延长对土壤中的Cu和Zn则起到一定的固定作用。这说明低温制备的鸡粪生物质炭能够固定鸡粪中的重金属,缓释营养,但过量使用时可能存在Cu和Zn的短期释放风险。

The preparation of biochar produced from chicken manure by pyrolysis at low temperature can not only reduce the loss of elements and fix heavy metals in the carbonization process,but also slowly release nutrients,which is a new way to fertilize chicken manure.The physicochemical properties of chicken manure biochar prepared at 300℃and its effect on soil properties under incubation at constant temperature were studied.The results showed that the yield of biochar produced from chicken manure was 57.43%,and the pH was 9.82.The contents of K,Mg,Cu and Zn increased significantly and the number of pore was less.Cu and Zn in chicken manure were fixed by reducing acid-soluble and reducible content and increasing oxidizable content during carbonization at low temperature.The biochar could increase soil pH and available Cu and Zn contents in soil in a short time.However,with the extension of time,the biochar could fix available Cu and Zn in soil.The above results show that the biochar can immobilize heavy metals in chicken manure and release nutrients slowly,but there may be short term release risks of Cu and Zn when used in large quantities.