The Influence Of Tides On The Distribution Characteristics Of Typical Pharmarceuticals And PAHs In Jiuduansha,the South Passage, Yangtze River Estuary

Nowadays, the problems of aquatic environment pollution are focused by most environmental researchers all around the world. And among those problems, the environmental behaviors of Presistent Organic Pollutants (POPs) and Emerging Organic Pollutants(EOPs) and their regulation of transportation and transformation in the natural environment are hot research issues for a long time. These substances are not only ubiquitous around us, but also great threat to the health of aquatic organism and human beings because of their chemical toxicity. The POPs with stable chemical property, high-lipotropy and carcinogenicity could be easily accumulated in the animals bodies and EOPs will be at a toxic concentration towards microbes in the environment due to the so called "pseudo-persistence". So, the main research aim of this thesis is to assess environmental behavior changes of these pollutants in the Jiuduahsha district of Yangtze Estuary according to the tides, including the concentration in different seasons, tides types and depths. Next, the relationship between concentration and environmental factors such as salinity, dissolved organic carbon (DOC) concentration, SPM concentration and particulate organic carbon (POC) will also be discussed. Besides that, the changes of logKoc in the surface (OH) samples,60% full depth (0.6H) samples, and full depth (1.0H) samples during a whole tide period and its relationship with logKow will be analyzed. Finally, the source analysis of PAHs will be conducted to assess the tidal influence on the source of pollutants.The whole-tide samples of this research were collected in Jiuduansha in the South Channel of the Yangtze Estuary in 2014 winer spring tide,2014 winter neap tide,2014 summer spring tide and 2015 winter spring tide, and the experiments on PAHs and pharmaceuticals in different phases were conducted by SPE-UPLC-MS, SPE-GC-MS and ASE-GC-MS. The results showed that the detection rate of pharmeseuticals in water phase in summer was higher than in winter. In terms of concentrations, the winter samples were higher than in summer samples, in which the sulfonamides account for 67.73% and 47.24% in the two seasons and the quinolones were the second part, reaching 46.67% and 31.18%.In the analysis of PAHs in water phase, the detection rates in the two winters and spring-neap tides were similar, and the rates in winter were higher than in summer. The concentrations followed the trend: 2014 winter spring tide> 2015 winter spring tide> 2014 winter neap tide> 2014 summer spring tide.In the composition of PAHs,3 ring compounds contributed most in 2014 winter spring tide,reaching 43.65%.And the others were 2 ring compounds for the rest times. The concentration ratios decreaced according to the growth of rings.In the analysis of PAHs in suspend matters, the detection rates were close, in which most pollutants had 100% rate, while the concentrations had a wide difference. The total concentration in winter was higher than summer, and the 3 rings,4 rings and 5rings in winter were 33.87%,44.22% and 28.15% higher than in winter.Five kinds of pharmaceuticals, including paracetamol (PRCT)、sulfamethazine (SMT)、 sulfamethoxazole (SMX)、ofloxacin (OFC)、erythromycin (ETM) were selected to analyze the tidal influence on such pollutants. Gerenally, concentration of the five substances in all surface, middle and bottom levels in 2014 winter and summer spring tides decreased from flood peak to flood slack and reached the highest level in ebb peak, expect PRCT and SMX increased from flood peak to ebb peak. In winter neap tide, all pollutants increased from flood peak to ebb slack. Analyzing with the environmental factors, SMX and ETM had positive relationship with salinity and had negtive relationship with DOC. The correlationship of SMX (R2>0.7) in the three seasonswith salinity and DOC were obviously higher than ETM.Both two substances had low relationship with SPM.To assess the changes of PAHs in water phase, naphthalene (Nap) of 2 rings, phenanthrene (Phe) of 3 rings, pyrene (Pyr) of 4 rings and benzo[k]fluoranthene (BkF) of 5 rings were selected to discuss. The result showed that the concentration of PAHs at all depths increased according to the growth of ring numbers. The surface concentration of all rings increased from flood peak, and reached highest level at ebb peak and then decreased. In the middle level, the concentration kept unchanged in the period of flood time and reached the top at ebb peak. In the bottom level, the flood slack was the lowest point and increased to the top at ebb peak. The analysis with environmental factors showed that there was negative relationship between salinity and concentrations, in which, interestingly, the slope in 10‰-13‰ in summer and 14‰-18‰ in winter were steep than the other sections, and the relevance increased with ring numbers.The relationship with DOC in summer showed more positive than winter, and the concentrations between 70-90 μmol/L increased slower than concentrations over 90 μmol/L. The relationship with SPM was poor and there was a little positive relationship in summer but there were no relationship in winter.The same subsatances were also selected to analyze the PAHs in suspended matter during 2014 summer spring tide and 2015 winter spring tide. The tidal change in summer increased from the flood peak and reached top at ebb peak. The changes in winter were more obvious than in summer, and it decreased from flood peak to slack and then increased in the surface water. At other depth, the growth from flood peak ended after ebb peak. The relationship between POC showed that all rings had positive relationship in summer and became more obvious with the growth of ring numbers. There was also positive relationship in winter, but some spots with low POC and high PAH concentraion aside from the linear relationship occurred from Phe.The Koc, representing the distributions of pollutants between sedimental and water phases, increased from surface level to bottom level, showing that the PAHs at surface more easily tended to be absorbed on SPM. At the surface and middle level, the concentration grew after the declination from flood tide and reached the top in flood slack and then reached the lowest point after ebb peak. The changes in bottom were quite different from the upper two levels. The highest level occurred in the flood slack, and concentration reached lowest point in ebb peak and then decreased. There was a positive relationship between logKoc and logKow at the three depths.The source analysis showed that the samples of 2014 summer spring tide were due to liquid combustion and the samples of 2014 and 2015 winter were more likely from lumber and coal combustion sources. The sources changed to oil during the flooding period and turned to combustion source during the ebb period in winter. The PCA-MLR showed that the fluid combustion source accounted for 50%-70% during both flood and ebb periods in summer 2014,and the ratio of flood tide was higher than ebb tide. In winter 2015, the lumber and coal sources dominated during ebb tide and diesel and oil sources during flood tide, which corresponded to the former conclusion.