Langford Katherine H, Scrimshaw Mark D, Birkett Jason W, Lester John N
Environmental Processes and Water Technology Group, Department of Environmental Science and Technology, Faculty of Life Sciences, Imperial College London, London SW7 2AZ, United Kingdom.
Chemosphere. 2005 Dec;61(9):1221-30. doi: 10.1016/j.chemosphere.2005.04.043. Epub 2005 Jun 13.
Polybrominated diphenyl ethers and nonylphenol polyethoxylates have been reported to be estrogenic and may enter the aquatic environment through the discharge of treated sewage effluent. Therefore, their fate during wastewater treatment processes is an important factor in determining their environmental impact. Batch tests with activated sludge from a Husmann apparatus were used to determine the effects of physico-chemical properties and sludge characteristics on the partitioning of polybrominated diphenyl ether flame retardants and nonylphenol polyethoxylate surfactants during biological wastewater treatment. Hydrophobic compounds, those with high logK(ow) values, were sorbed more rapidly and to a greater extent to the solid phase than more soluble compounds. For these hydrophobic compounds sorption may become an increasingly important removal mechanism as sludge age and therefore solids content increase. The initial rate of partitioning was greatest for the most hydrophobic compounds but all rates diminished with time as a result of progressive saturation of sorbent binding sites, a reduction of sorbate availability and as a consequence of the system reaching equilibrium. The sorption of polybrominated diphenyl ethers fit Freundlich adsorption isotherms demonstrating generally increasing adsorption capacity and efficiency with increasing hydrophobic nature. A correlation between increasing logK(ow) and increasing organic matter content was also observed for both polybrominated diphenyl ethers and nonylphenol polyethoxylates indicating the organic content of mixed liquor will also be influential in removing compounds during wastewater treatment.
据报道，多溴二苯醚和壬基酚聚乙氧基化物具有雌激素活性，可能通过处理后的污水排放进入水生环境。因此，它们在废水处理过程中的归宿是决定其环境影响的一个重要因素。使用来自胡斯曼装置的活性污泥进行批次试验，以确定物理化学性质和污泥特性对多溴二苯醚阻燃剂和壬基酚聚乙氧基化物表面活性剂在生物废水处理过程中分配的影响。疏水性化合物，即具有高logK(ow)值的化合物，比更易溶的化合物更快且更大程度地吸附到固相上。对于这些疏水性化合物，随着污泥龄以及因此固体含量的增加，吸附可能成为越来越重要的去除机制。对于疏水性最强的化合物，分配的初始速率最大，但由于吸附剂结合位点逐渐饱和、吸附质可用性降低以及系统达到平衡，所有速率都会随时间而降低。多溴二苯醚的吸附符合弗罗因德利希吸附等温线，表明随着疏水性增加，吸附容量和效率总体上会提高。对于多溴二苯醚和壬基酚聚乙氧基化物，还观察到logK(ow)增加与有机物含量增加之间存在相关性，这表明混合液的有机含量在废水处理过程中对去除化合物也有影响。
