| Fire retardants were used widely in consumer products such as electronic circuitry, furniture, textiles, polyurethane foam, thermoplastics, construction materials and other products to control fire accident, halogenated flame retardants (HFRs) account for a large proportion, at the same time, some studies suggest that environmental problems of halogenated flame retardants was underestimated.The research focused on the23kinds of novel brominated flame retardants (NBFRs),13kinds of polybrominated diphenyl ether (PBDEs) and2kinds of Dechlorane Plus (DPs) were investigated as the objects, By using the method of soxhlet extraction and liquid-liquid extraction to explore the fate and removal of halogenated flame retardants in two sets of process at the waste water treatment plant (WWTP). The maximum concentration of halogenated flame retardants was392ng/L in the influent, and107ng/L in the effluent. The concentration of DBDPE, PBDE209and DP were86.1ng/L,214ng/L and2.32ng/L, respectively in the influent,. DBDPE was predominant with71.4ng/L, followed by PBDE209with27.5ng/L and DPs withl.14ng/L in the effluent. The concentration of NBFRs increased gradually from July of2012to October of2013, ranged from30.3ng/L to131ng/L, about4times increased. The concentration of PBDEs were from2.82ng/L to216ng/L, the average growth is200times. The concentration of NBFRs was increased year by year in sludge from201##to2014and up to1080ng/g.dw in January of2014. However the highest concentration of PBDEs was549ng/g.dw in July of2012and the highest concentration of DPs was24.2ng/g.dw in January of2013. Air samples were combined gas phase with particle phase, NBFRs were influenced by the season in the gas phase, the highest concentration were785pg/m3at the A/O pool in October, while in WWTP entry areas and urban areas, NBFRs were,280pg/m3and194pg/m3, respectively. In the particle phase, the concentrations increased with time, the concentration at A/O pool was834pg/m3in July of2013,639pg/m3in WWTP entry areas and186pg/m3in the urban area. The PBDEs level in the gas phase among the A/O pool, WWTP entry areas and urban areas were ranged from1.58pg/m3to19.1pg/m3. the PBDEs concentration was about576pg/m3in urban area,794pg/m3in A/0pool, and557pg/m3in WWTP entry areas in July of2013. In all soil sampling, The concentration of soil sample in WWTP entry was higher than others soil sampling sites, the highest concentration of DBDPE was about754ng/g (DW), followed by PBDE209with53.4ng/g (DW) WWTP entry.In order to investigate the biodegradable of halogenated flame retardant, the anaerobic sludge method was used, the removal rate of the NFRs ranged from57.9%to80.1%in12h, it is up to81%in72h, for high bromine individual PBDEs congener, the removal rate can reach up to93.4%in72h, but for the low bromine PBDEs was relatively low to71.2%at the same time.This study shows, Total amount of67.9kg HFRs entered into WWTP through inflow, and about10.9kg flowed out to the Songhua River, The removal rate of halogenated flame retardants was high in both two set of process, about83.1%-96.5%for PBDEs,75.9%-91.9%for NBFRs and44.9%-91.3%for DPs. High removal rate is due to sludge adsorption. the trend of halogenated flame retardants in the WWTP include:volatile, sludge adsorption and biodegradation. Monitoring data show that PBDEs was degraded by sludge accounted for51%, NBFRs were adsorbed by sludge is78%, Use the multimedia fugacity model of the WWTP to simulate the fate of halogenated flame retardants, and the results show that the sludge adsorption accounted for the main part, and NBFRs fit better to the detection results. |
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