Study On The Distribution Characteristics Of Polycyclic Aromatic Hydrocarbons And Quinolones And Wetland Protetction Measures In Yancheng Coastal Wetland

This study is aiming at 16 kinds of priority polycyclic aromatic hydrocarbons(PAHs)and eight kinds of typical quinolones(QNs)pollution distribution characteristics in surface sediment(0-5cm)of Yancheng Coastal Wetland.Molecular weight ratios,diagnostic ratios and principal component analysis were used to identify the source of PAHs and QNs and the influence factors of distribution characteristics were analyzed,such as organic carbon content in the sediment,sediment particle size and anthropogenic activities.According to the pollution status and wetland protection policies,the wetland protection suggestions and measures were put forward.The content of polycylic aromatics hydrocarbons(PAHs)in surface sediments of Yancheng Coastal Wetland ranged from 2.80-134.66 ng/g,with an average value of18.66 ng/g,which were low level compared to other welands all over the world.The concentration of PAHs in this study area was higher in the middle area and lower in the south and north area.The sites with high PAHs content in the study area were distributed around the downstream of the river and in the developed industrial areas,in which areas the PAHs generally from the upper and middle stream of the river and the industrial processes.The results of source identifying show that PAHs mostly came from petroleum,coal and wood combustion,and other sources.The result of risk assessment showed that the PAHs in Yancheng Coastal Wetland will not harm to the ecosystem in this area at present.The influence of total organic carbon,sediment particle size and human activities on the distribution characteristics were investigated.The results indicated that there was no obvious correlation between sediment particle size and PAHs,positive correlation between total organic carbon and high molecular weight PAHs.In human activities,industrial output value is used to reflect the degree of industrial development,the correlation analysis suggested that there is an obvious positive correlation between industrial output value and HMW PAHs,which indicated that the content of PAHs is higher in the regions with more developed industries.The content of quinolones(QNs)antibiotics in surface sediments of Yancheng Coastal Wetland ranged from 0.33 to 24.79 ng/g,with an average value of 4.53 ng/g.Every kinds of target QNs were detected in sediment samples,among which thedetected rate of Ofloxacin was the highest level of 45.70%,and Ofloxacin detected content were moderate level compared with other areas.Among the 72 sampling sites,the sites with high accumulation were located in Guan river in Xiangshui and the lower content located in Sheyang river near the aquaculture area.The correlation results shows that the antibiotics were mostly from the drainage in the aquaculture area and absorbed into the surface sediments near the river by river runoff.The result of source identifying shows that QNs mainly obtained from aquaculture and livestock breeding.Correlation analysis showed that the sediment grain size and the distribution of Ciprofloxacin had a significant positive correlation(r=0.334,P<0.01),which indicated that the fine particle size of sediment were benifitial to adsorb the Ciprofloxacin.Otherwise,the sediment grain size had relatively significant negative correlations with Sarafloxacin(r=-0.237,P<0.05),which suggested that the more coarse sediment was more conducive to the adsorption of Sarafloxacin,other types of antibiotics and particle size have no obvious correlation.The total organic carbon of sediment was positively correlated with Lomefloxacin and Salafloxacin.The results of risk assessment showed that Ofloxacin presented moderate risk to algae.The ecological risks of the remaining QNs were lower.For sediment-plant distribution characteristics,the PAHs content in plant samples were both higher than that in sediment samples.The enrichment factor results showed that the plant for low molecular weight PAHs have higher concentration effect,and the plants absorb high molecular weight PAHs from sediments was positively correlation with organic carbon content in sediment.The content of QNs in the sediment-plant of Yancheng Coastal Wetland showed that the content rule was not obvious,and there were QNs detected in plants but not in sediments.Meanwhile,the absorption of Piperate in plants were negatively correlated with the total organic carbon in sediments.The distribution of the two target pollutants indicated that the absorption of PAHs by plants had certain rules,which can be further explored,while the absorption of QNs by plants may be affected by a variety of other factors,which requires a comprehensive study.According to the pollution status of PAHs and QNs,this study reviewed the development process of the laws and regulations in Chinese wetland protection.Meanwhile pollution remediation suggestions,resources utilization law were put forward for protection wetland resource and environment scientifically.