固废基土壤调理剂的制备及其矿区生态修复效果

我国煤矸石产量大,利用率偏低,大量堆积没有得到合理利用,造成了土地资源浪费和严重的环境污染。以煤矸石为主要原料,通过添加铝粉发泡养护得到多孔材料,再将其与废弃有机质以及含碳辅料发酵制成固废基土壤调理剂。对比探究喷播固废基土壤调理剂(SWSC)、丛枝菌根真菌(AMF)和固废基土壤调理剂耦合菌根真菌(SWSC+AMF)的土壤理化性质以及对矿区典型植物生长的影响,研究不同处理下植物中重金属的累积量。结果表明:固废基土壤调理剂的优选配方为:当煤矸石和水泥掺比为85%∶15%时,制备的多孔材料性能最优;优选鸡粪和风化煤作为有机质和含碳辅料;当多孔颗粒、鸡粪与风化煤的质量配比为4∶2∶4时,制备的固废基土壤剂调理剂最优。对土壤调理剂的制备及应用全流程进行重金属安全性评价,重金属含量均低于国家标准中重金属的限定值。喷播SWSC+AMF的土壤中有机质含量为35.24 mg/kg,速效钾含量为261 mg/kg,有效磷含量为278 mg/kg,碱性磷酸酶含量可达到293.07 mg/kg,且喷播SWSC+AMF对披碱草的株高和根长生成具有促进作用,可有效减少对披碱草中重金属Cd、Pb、Ni的累积,同时对改善土壤结构,提升土壤肥力方面有积极作用。

PREPARATION OF SOLID WASTE-BASED SOIL CONDITIONERS AND THEIR ECOLOGICAL REMEDIATION EFFECTS ON THE MINING AREA

In China, the output of coal gangue is large, and the utilization rate is low. A large amount of accumulation has not been reasonably utilized, resulting in the wasting of land resources and environmental pollution. In this paper, coal gangue was used as the main raw material, and porous materials were obtained by adding aluminum powder for foaming and curing, and then fermented with waste organic matter and carbon-containing auxiliary materials to make solid waste-based soil conditioners. The soil physicochemical properties of spraying solid waste-based soil conditioner (SWSC), arbuscular mycorrhizal fungi (AMF) and solid waste-based soil conditioner coupled with mycorrhizal fungi (SWSC+AMF), and their effects on the growth of typical plants in the mining area were compared. The accumulation of heavy metals in plants under different treatments was compared. A proportion of gangue and cement at 85%∶15% was best for making the porous material. Chicken manure and weathered coal were selected as organic matter and carbon excipients. When the ratio of porous particles, chicken manure and weathered coal was 4∶2∶4, the prepared solid waste-based soil conditioner was the best. When the mass ratio of porous particles, chicken manure and weathered coal was 4∶2∶4, the prepared solid waste-based soil agent conditioner was the best. The whole process of preparation and application of soil conditioners was evaluated for heavy metal safety, and the heavy metal content met the limit values in the corresponding national standards. The content of organic matter in the soil sprayed with SWSC+AMF was 35.2 mg/kg, the content of available potassium and available phosphorus was 261 mg/kg and 278 mg/kg, and the content of alkaline phosphatase could reach 293.07 mg/kg. Moreover, spraying SWSC+AMF could promote the growth of plant height and root length, which can effectively reduce the accumulation of Cd, Pb and Ni element in Elymus grass, and improve soil structure and fertility.