The leaching of additive-derived flame retardants (FRs) from plastics in avian digestive fluids: The significant risk of highly lipophilic FRs

The exposure to plastic debris and associated pollutants for wildlife is of urgent concern,but little attention has been paid on the transfer of plastic additives from plastic debris to organisms. In the present study, the leaching of incorporated flame retardants(FRs),including polybrominated diphenyl ethers(PBDEs), alternative brominated FRs(AFRs), and phosphate flame retardants(PFRs), from different sizes of recycled acrylonitrile-butadienestyrene(ABS) polymer were investigated in avian digestive fluids. The impact of co-ingested sediment on the leaching of additive-derived FRs in digestive fluids was also explored. In the recycled ABS, BDE 209(715 μg/g) and 1, 2-bis(2,4,6-tribromophenoxy) ethane(BTBPE,1766 μg/g) had the highest concentrations among all target FRs. The leaching proportions of FRs were higher in finer sizes of ABS. The leaching proportions of FRs from recycled ABS increased with elevated logK OWof FRs. In the tests with coexisted ABS and sediment, hexato deca-BDEs, BTBPE, and decabromodiphenyl ethane(DBDPE) migrated from ABS to sediment, which resulted in the less bioaccessible fractions of these FRs in gut fluids. More lipophilic chemicals tended to be adsorbed by sediment from ABS. The results suggest the migration of additive-derived FRs from plastics to other indigestible materials in digestive fluids. The findings in this study provide insights into the transfer of additive-derived FRs from plastics to birds, and indicate the significant contribution of FR-incorporated plastics to bioaccumulation of highly lipophilic FRs.     

Electrochemical detoxification of four phosphorothioate obsolete pesticides stocks

The phosphorothioate pesticides are widely used for crop production and fruit tree treatment, but their disposal causes serious environmental problems. Four commercial phosphorothioate pesticides (Demeton-S-methyl, Metamidophos, Fenthion and Diazinon) were treated by an electrolysis system using Ti/Pt as anode and stainless steel 304 as cathode. A number of experiments were run in a laboratory scale pilot plant and the results are presented. For Fenthion the achieved reduction was over 60%, while for Demeton-S-methyl, Metamidophos and Diazinon was more than 50%. Diazinon had the lowest energy demand. The COD/BOD5 ratio was improved considerably after electrolysis for all four pesticides examined. As a conclusion, electrochemical oxidation could be used as a pretreatment method of the pesticides detoxification.     

山体绕流和尾流区气态污染物输送扩散规律的研究

采用瞬时烟线仪与迪沙(DISA)热线风速仪相结合的方法探测了山体的绕流区和尾流区结构。试验结果表明,山体的绕流和尾流对低架源排放的气态污染物扩散影响甚大,山体绕流可改变烟流的地面浓度分布.结果还表明,我们所用的探测流向的方法较为有效和准确.     

H2O2对载银TiO2光催化降解Aroclor1260的影响

光催化氧化法降解水中有机污染物是近来发展较为迅速的废水处理技术，以锐钛型载银TiO2为催化剂，在发射光谱波长为254nm，功率的15W紫外灯照射下，考察不同H2O2浓度对Aroclor1260的光催化降解的影响，结果表明：低浓度的H2O2对Aroclor1260的光催化降解有促进作用，而当H2O2的浓度高于30mol/l时，光催化降解受到抑制，而且这种影响对不同PCB单体化合物的效果基本一致。     

城市污水净化的环境效益与环境影响分析

对佛山城市污水净化系统的环境响应和效益预测原则，城市污水净系统正式运转将对佛山水道化纤厂至人民桥段及佛山涌水质有明显改善，其社会效益十分显著，但净化系统的建设交将带来以恶臭、卫生防疫和噪声等方面为主的不利环境影响。因此在城市环境建设中应尽量减少城市污水净化的负面影响，充分发挥其环境效应和社会效益，为城市环境综合整治创造良好的条件。     

三种激光雷达监测污染物分布和输送对比

利用3种不同型号激光雷达在广州番禺大气成分观测站开展外场同步对比观测实验.通过全球地基气溶胶监测网（AERONET）气溶胶光学厚度（AOD）产品验证了3种激光雷达原始信号反演消光系数的可靠性.同时对比探讨了激光雷达低层反演能见度产品与能见度仪的相关性;对比美国国家环境预报中心全球同化系统模式（NCEP-GDAS）模拟结果讨论了激光雷达对混合层高度反演的有效性.最后利用个例分析揭示不同天气型下污染物可能的外源输送和本地积累.量化分析结果表明：3部激光雷达反演的能见度与能见度仪的相关系数均达到0.7以上,混合层高度均与NCEP-GDAS模式计算的混合层高度具有一定的可比性.与模拟结果相比,白天混合层高度在霾天气时相对较低,更能有效的揭示霾天气,亦可反映夜间间歇性湍流特性.应用分析表明：3部激光雷达均能较为一致的监测污染物的输送和本地的累积.外来输送主要以弱冷空气输送型为例,分析个例（2014年11月21~22日、24~25日）表明：后一过程（24~25日）由于夜间混合层高度（MLH）低,导致上层的粒子无法下传,污染物聚集在0.8km,且快速过境了,而前一过程（21~22日）整层输送,导致了近地层相对高的PM_2.5浓度;本地累积主要以冷高出海型为例（2014年11月25日20：00~27日20：00）,逆温与低的地表通风系数共同造成了前一时段（25日20：00~26日20：00）的消光明显高于后一时段（26日20：00~27日20：00）.     

铁炭微电解-Fe2+/K2S2O8降解甲基橙

针对偶氮类有机物废水具有色度大,难降解的特点,以对二甲基氨基偶氮苯磺酸钠(甲基橙)为模拟研究对象,对水体系中铁炭微电解-Fe2+/K2S2O8降解甲基橙的方法进行了研究。通过正交实验确定出该方法各因素的影响程度,进一步通过单因素影响实验确定该方法的最佳条件是:铁炭微电解填料、FeSO4和K2S2O8投加量分别为300 g/L、1.3mmol/L和0.7 mmol/L,初始pH值为7.0。在最佳条件下,甲基橙COD和色度去除率分别能达到64.7%和68.2%。