病死猪炭及其改性对重金属污染土壤的修复机理研究

Pyrolysis is a new technology for the safe treatment of the dead animals from piggery. The resulting biochar derived from deceased pigs (BDFDP) is rich in phosphorus, calcium and other minerals, which makes it a good candidate for alternative phosphorus fertilizer as well as for remediation of soils contaminated with heavy metals. However, there is little information on the efficacy of using BDFDP for adsorption and stabilization of heavy metals in contaminated soils. More research is warranted for better understanding of the interaction between the BDFDP and heavy metals and associated mechanisms. In this proposed study, the untreated and modified BDFDP materials will be characterized with Fourier transformation infra-red spectrophotometry (FTIR), solid-state 13C-NMR spectroscopy, scanning electron microscopy (SEM) as well as other physical and chemical analyses. The effects of the age of deceased pigs as a feedstock and physic-chemical modification techniques on the properties of the BDFDP will be assessed. Laboratory studies will be conducted to investigate the effects of soil properties, and application rates of amendments on the effectiveness of adsorption of typical heavy metals by soils amended with BDFDP and activated carbon. The impacts of BDFDP application on the availability of multiple heavy metals for plant uptake will be carried out in a greenhouse pot experiment. Results will be analyzed to identify the main factors affecting the bioavailability of the heavy metals. The proposed study will provide fundamental information for effective in situ remediation of soils contaminated with heavy metals thereby enhancing environmental quality and promoting safe food production.

病死猪炭是以畜禽养殖业中产生的病死猪为原料，经高温热解后得到的一种新型生物质炭，它具有孔隙度大，磷、钙等矿物质含量高的特点。病死猪炭输入土壤被认为是修复重金属污染土壤并改善土壤肥力的新技术，但其对不同重金属的吸附机理以及对重金属生物有效性的影响机理尚缺乏深入系统研究。本项目拟以病死猪炭为试验材料，通过红外光谱、固态13C核磁共振波谱、电镜扫描等技术表征病死猪炭的理化性质，分析猪的成长时期和改性方法对病死猪炭理化性质的影响；通过吸附-解吸附试验对比病死猪炭和活性炭在不同类型土壤中对典型重金属离子的吸附效果的影响，并探明其吸附机理；通过盆栽试验研究添加病死猪炭、改性病死猪炭以及活性炭对不同类型重金属复合污染土壤中重金属生物有效性的影响，探明修复重金属复合污染土壤的影响因子。本项目将为重金属复合污染土壤的修复提供理论支撑和科学依据，同时也为提高我国生态环境质量和粮食安全提供保障。

病死猪炭是以畜禽养殖业中产生的病死猪为原料，经高温热解后得到的一种新型生物质炭，它具有孔隙度大，磷、钙等矿物质含量高的特点。病死猪炭输入土壤被认为是修复重金属污染土壤并改善土壤肥力的新技术，但其对不同重金属的吸附机理以及对重金属生物有效性的影响机理尚缺乏深入系统研究。本项目以病死猪炭为试验材料，通过电镜扫描，红外光谱，能量散射X射线谱，X射线衍射等技术表征病死猪炭的理化性质，分析猪的成长时期和改性方法对病死猪炭理化性质的影响。通过吸附实验，研究猪炭及超声改性猪炭对水溶液中Cd2+和Pb2+的吸附效果，并研究不同施炭土壤及其老化对重金属-PAEs复合溶液中污染物吸附效果的影响。通过盆栽实验，研究了猪炭及其酸化改性对复合污染土壤中重金属有效性及其形态分布的影响，并研究了Pb胁迫下猪炭，法国梧桐炭及其超声改性对土壤-作物系统中重金属转移和空心菜生长的影响。并通过培养实验，并对比研究了常规化学和猪炭及其酸化对土壤磷含量及形态转化的影响。结果表明，不同生长期病死猪制备的猪炭的性质存在较大差异；超声改性猪炭对溶液中Cd2+和Pb2+的吸附具有更明显的效果；施用猪炭对重金属-PAEs复合污染土壤中Cd2+和Zn2+的吸附效果较法国梧桐炭更加明显，并且经老化处理后的土壤其吸附性能增强；施用猪炭和酸化猪炭可以显著降低土壤中有效态Pb和Zn的含量，且猪炭经酸化改性后对土壤中Pb的吸附效果更明显，且可以明显促进蔬菜作物的产量；此外，施用猪炭和酸化猪炭均可以显著提高活性磷的含量并促进作物对氮素的利用率。在农业生产中，将猪炭经酸化处理后用于替代磷肥的施用具有潜在的可行性。该项目的顺利实施，为猪炭在缓解土壤重金属污染，提高土壤肥力和促进作物生长发面的应用提供了理论支撑和科学依据，同时也为提高我国生态环境质量和粮食安全做出了贡献。