| Tetrabromobisphenol A?TBBPA?is a widely used brominated flame retardants?BFRs?in recent years,accounting for about 60%of the total production of BFRs.It is widely used in plastic products,textiles and Electronic/electrical products.TBBPA is likely to be released during production,use and product disposal into the natural environment.Due to its strong affinity for organic matter,TBBPA tend to be absorbed by soil,sediment,solid particles and accumulated in biota,and disturbed by the environment or human activities will release to the water body.Therefore,the research on the adsorption behavior of TBBPA in water-sediment system can help reveal the environmental behavior characteristics of TBBPA pollution and provide a theoretical basis for potential ecological hazard and health risk assessment.The sediment-water partition coefficient Kd and soluble organic matter affinity coefficient KDOC are important parameters for evaluating the environmental behavior of hydrophobic organic matter,but the traditional method is difficult to eliminate the influence of dissolved organic matter?DOC?in water.Therefore,there are no actual Kd and KDOC values for TBBPA.Based on the research status at home and abroad,this paper establishes and optimizes the solid phase microextraction?SPME?detection method for the free dissolved concentration of TBBPA in water.The adsorption behavior of TBBPA in water and sediment system was studied.The SPME method and the traditional liquid-liquid extraction?LLE?method are used to correct the TBBPA sediment-water partition coefficient Kd,the organic carbon normalization coefficient KOC,the soluble organic matter affinity coefficient KDOC,the free dissolved state and the total dissolved state fdiss were calculated.And the effects of pH,ionic strength,soluble organic matter content and heavy metal content on the adsorption behavior were also explored.The conclusions of this study are as the follows:?1?A DI-SPME–LC-MS/MS based method was developed as a sensitive and simple determination technique to determine TBBPA based on uniform design,and provides good repeatability and high extraction recovery.The optimal extraction parameters for TBBPA was as follows:extraction temperature:40°C,extraction time:20 min,pH value:2,stirring speed:1000rpm,and salt concentration:0.2 M.And only10 mL of sample is needed to determine analytes in aqueous samples such as river water,lake water,and tap water.It may also be employed on a trial basis for the determination of other brominated flame retardants based on similar molecular structures.?2?The adsorption of TBBPA on sediments conforms to the linear model suggesting the sorption process was dominated by partitioning.The freely dissolved concentration and totally dissolved concentration of TBBPA in water were measured by using automatic solid-phase microextraction?SPME?and traditional liquid-liquid extraction?LLE?method respectively,and the adsorption distribution coefficient of the traditional LLE method was corrected.It was found that the traditional LLE method could not eliminate the influence of DOC,and the Kd value of TBBPA could be artificially compressed 1.54 times.The LLE method was corrected by SPME,and the Log KOC of TBBPA in the sediment was 6.05,the Log KDOC was 4.50,and the fdiss was0.56.?3?The results indicated the following:?a?pH greatly affects the mobility of TBBPA in sediment.Under acidic conditions,TBBPA is mainly adsorbed in sediments;under alkaline conditions,TBBPA tends to be released into the sediment solution.?b?The sorbed amount of TBBPA increased with the increase in ionic strength,and the effects of ionic strength on the sorption were possibly caused by formatting neutral ion pairs,screening the negative charge of sediment surface,decreasing the solubility of the compounds by salting out effect and the change of solution pH.?c?HA was sorbed on the soils,which increased the organic matter content of soil and provided more sorption sites for TBBPA.?d?Heavy metals show no direct interference with TBBPA adsorption,though they might indirectly affect the sorption by occupying the adsorption sites of the sediment.The results would provide a better understanding of the transport and fate of TBBPA in the environment. |
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