宁东能源工业基地表层土壤粒径分布、养分、重金属含量与大气降尘的关联性

Correlation Between Particle Size Distribution,Nutrient and Heavy Metals Content of Topsoil in Ningdong Energy Industrial Base and Atmospheric Dustfall

[目的]研究宁东能源工业基地大气降尘携带的营养物质、重金属与土壤养分、重金属含量之间的关联性,为该区域的土壤利用和环境保护提供科学依据。[方法]本研究在宁东能源工业基地马莲台电厂主导风向下风向采集不同距离的表层土壤和大气降尘样品,分析土壤和降尘样品的粒径组成、分形维数以及6种重金属(Zn,Cu,Cd,Cr,Pb,Ni)的空间分布特征及其潜在生态风险;利用Pearson相关性分析法对表土与大气降尘中重金属含量的相关性进行探讨。[结果]①宁东能源工业基地大气降尘的成分来源复杂,包括了自然源和人为源降尘。其中自然源降尘主要来自于境内沙尘,主要成分为石英、方解石、斜长石、绿泥石和高岭石等。人为源降尘则主要源自燃煤烟尘,主要成分涉及Ag,Cr,Pb,Co,Mn,As,Cu和二硫化硅以及多环芳烃化合物(PHAs)等。②大气降尘和表土的粒径分布曲线在不同距离上均呈非正态性及双峰和多峰分布,说明大气降尘和表土颗粒组成具有多源性。③大气降尘和表土综合潜在生态风险指数表明,距离污染源越远降尘中重金属的生态风险指数越大,而土壤中重金属的生态风险指数越小。Pearson相关分析分析表明,表土与大气降尘中Cr和Cu两种重金属元素具有一定的正相关性。④大气降尘携带的营养物质沉降到地表改变了土壤的养分供给,尤其是有机质的增加量最为显著。[结论]宁东能源工业基地大气降尘成分复杂,对土壤组成有显著影响,且增加了其潜在生态风险指数,尽管其颗粒粒径组成、分布、养分、重金属含量与大气降尘的关联性相对较弱,但其累积效应仍然值得关注。

[Objective]The relationships between nutrients and heavy metal content of soil and atmospheric dustfall in Ningdong energy industrial base were studied in order to provide a scientific support for soil utilization and environmental protection in this area.[Methods]To examine the distribution characteristics and the potential ecological risk of heavy metals in both topsoil and atmospheric dustfall,soil and atmospheric dustfall samples of different distances in the leeward of near Maliantai thermal power plant in Ningdong energy industrial base were collected.The contents of 6 kinds of heavy metals(Zn,Cu,Cd,Cr,Pb,Ni)in the both topsoil and atmospheric dustfall samples were measured in the laboratory.The comprehensive potential ecological risk of these heavy metals was evaluated using the potential ecological risk index,and the fractal dimensions of soils,and their relevance with that of atmospheric dustfall were also analyzed.[Results]①the composition of atmospheric dustfall was complex,which included the dustfalls of natural resources and artificial resources.The dustfall of natural resources was mainly from domestic sand dust,and the main components of which were Quartz,Calcite,Plagioclase,Chlorite and Kaolinite,etc.The dustfall of artificial resources was mainly from flue gas,and the main components of which were related to Ag,Co,Mn,Cr,Pb,As,Cu,Silicon disulfide and some polycyclic aromatic hydrocarbons(PHAs),etc.②The particle size distribution curves of atmospheric dustfall and topsoil demonstrated abnormal and bimodal and multi-peak distribution status at various distances,which indicated that the compositions of atmospheric dustfall and topsoil were from multiple sources.③The comprehensive potential ecological risk index of both atmospheric dustfall and topsoil indicated that the index of atmospheric dustfall increased with the distance from source of pollution,while the index of topsoil decreased with the distance increasing from thermal power plant.Pearson correlation coefficients showed that Cr and Cu in the atmospheric dustfall were positively related to the Cr and Cu in soil.④Nutrients carried by atmospheric dustfall deposited into the topsoil changed soil nutrients supply,of which the soil organic matter was the most significant.[Conclusion]The composition of atmospheric dustfall was complex,which significantly changed the soil constitution,and increased the potential ecological risk index.Though,the correlation of particle size distribution,nutrient and heavy metals content between the topsoil and atmospheric dustfall were relatively weak,the cumulative effect deserved more attention in the future.