Study On Spatial Heterogeneity Of Polycyclic Aromatic Hydrocarbons In Coal Mining Subsidence Area

Coal mining frequent activities caused the destruction and pollution of the mining area and the surrounding environment.The emergence of coal gangue hills,The sizes of mining subsidence areas becoming bigger and bigger,and the chemical substances in coals and coal gangues,especially the persistent organic pollutants in the environmental medias,pose a great threat to human health.Yangzhuang coal mining subsidence area in Panji and Digou coal mining subsidence area in Xieqiao are located in Huainan City,which is a coal resource city.Those two representative coal mining subsidence areas.The samples were collected on the two soil subsidence areas,and back to the lab for "Soxhlet extraction"extraction of PAHs substances from samples,then through self-administered chromatography sample purification,concentration,purification of the target objects.The GC-MS was used to detect the species and content of PAHs in the samples.Through analysis of datas,combined with field investigation,sampling area environmental records,to explore the study area soil PAHs spatial difference,get the following conclusion:1.Soil samples from the two settlement areas were detected the priority control of the 16 PAHs by US EPA.The total PAHs content in soil of Yangzhuang subsidence area was in the range of 109.00 ng/g dw?6540.62 ng/g dw,and The total PAHs content in soil of digou subsidence area was in the range of 26.55 ng/g dw?1597.87 ng/g dw,.In general,the sigma PAHs content in soils was significantly higher than that of subsidence Yang Di ditch subsidence area.2.In 16 detected PAHs,three kinds of material percentage PAHs in Yangzhuang subsidence area content of the largest in the soil which are phenanthrene,fluoranthene and pyrene.Digou subsidence of three kinds of substances PAHs content in soil maximum percentage which are phenanthrene,naphthalene and fluoranthene.3.Put PAHs in the samples are divided into PAHs low ring number PAHs and high number of cycles of PAHs for analyzing.Yangzhuang sampling displaying that the lowest PAHs content of sampling points is YT12.Low ring number PAHs samples and high ring number PAHs content in other points were essentially flat.Digou subsidence area in soil samples with low PAHs content than the ring number of sigma sigma high ring number PAHs content of this point is high,or flat.4.In the study area,there is a big difference between the five groups of isomers in soil samples,especially in different subsidence areas and different sampling points in the same subsidence area.5.Study on the regional land surface piled coal gangue containing PAHs effect on the PAHs content of the medium is huge.The species and quantity of farmland and non farmland plants in the subsidence area directly affect the content of PAHs in the soil.The PAHs content in the soil environment with strong activity and high viscosity are very little,and it is not PAHs pollution.The organic fertilizer used in the field also has an effect on the content and species of PAHs in the soil.6.Subsidence area traffic and from vehicle exhaust emissions are major sources of PAHs in the soil.Mine wastewater produced by mining operations can also threaten the soil environment,resulting in the increase of PAHs content in soil.7.The soil of low ring number PAHs and soil TOC in Yangzhuang coal mining subsidence had no correlation.There was a significant correlation between PAHs and TOC at 0.05 and 0.1 levels.However,the correlation between the 16 kinds of Yangzhuang coal mining subsidence area PAHs in soil is relatively weak.Relative to the Yangzhuang subsidence area,the correlation between 16 kinds of PAHs and the correlation between the PAHs and the TOC at the level of 0.1 were significantly correlated,and the correlation was very strong in Digou.This has a large area of green land is inseparable from the subsidence area.8.Spatial heterogeneity of PAHs in Digou soil are better than Spatial heterogeneity of PAHs in Yangzhuang soil.The two subsidence areas are affected by the external environment,and the influence of the external environment around the sampling points on the PAHs content in the sampling sites is the main factor.