Characterization, treatment and releases of eight polybrominated diphenyl ethers （PBDEs） congeners and sixteen polycyclic aromatic hydrocarbons （PAHs） in wastewater were evaluated along the treatment processes of ...Characterization, treatment and releases of eight polybrominated diphenyl ethers （PBDEs） congeners and sixteen polycyclic aromatic hydrocarbons （PAHs） in wastewater were evaluated along the treatment processes of a typical secondary treatment municipal sewage treatment plant （STP） （in Hefei City） situated the beside Nanfei River, East China. The findings showed that the average concentrations of the total PBDEs in raw wastewater and treated effluent were 188.578 and 36.884 ng/L respectively. Brominated diphenyl ether （BDE） 209 congener, the predominant PBDE in the STP and Nanfei River, could be related to the discharge of car-industry-derived wastes. For PAHs, the average concentrations in raw wastewater and treated effluent were 5758.8 and 2240.4 ng/L respectively, with naphthalene, benzo[a]pyrene and indeno[1,2,3-c,d]pyrene being detected at the highest concentrations. PAHs mainly originate from the combustion of biomass/coal and petroleum. The STP reduced about 80% of the PBDEs and 61% of the PAHs, which were eliminated mainly by sedimentation processes. The removal rates of PBDEs/PAHs increased with the increase of their solid-water partitioning coefficients. Accordingly, the STP＇s effluent, containing some PBDE congeners （e.g., BDE 47, 99 and 209, etc.） and low-molecular-weight PAHs, could be an important contributor of these contaminants＇ input to Nanfei River. It resulted in a significant increase of PBDE/PAH concentrations and PAH toxicological risk in the river water downstream. About 4.040 kg/yr of PBDEs and 245.324 kg/yr of PAHs could be released into the Nanfei River. The current conventional wastewater treatment processes should be improved to remove the relatively low-molecular-weight PBDEs/PAHs more effectively.展开更多
为了解城镇污水处理厂不同提标改造要求对成本的影响程度,围绕水环境质量改善目标,提出城镇污水处理厂排放限值的分级体系设计.在排放浓度分级方面,梳理现行国家和地方城镇污水处理厂排放标准,将其主要水污染物的排放浓度限值分为四级,...为了解城镇污水处理厂不同提标改造要求对成本的影响程度,围绕水环境质量改善目标,提出城镇污水处理厂排放限值的分级体系设计.在排放浓度分级方面,梳理现行国家和地方城镇污水处理厂排放标准,将其主要水污染物的排放浓度限值分为四级,按照从宽到严的顺序,分别为GB 18918—2002《城镇污水处理厂污染物排放标准》一级A标准(四级)、GB 3838—2002《地表水环境质量标准》中准Ⅴ类水质标准(三级)、准Ⅳ类水质标准(二级)和准Ⅲ类水质标准(一级)的浓度水平,并对从四级分别提高到三级、二级和一级排放限值进行技术经济评估.结果表明:对于一座设计规模为10×10^(4) t/d的城镇污水处理厂,由四级分别提高到三级、二级和一级,需增加的成本和占地面积逐步提高.当排放限值从四级提高到一级时,成本与占地面积增加最多,其中投资成本增加1.1×10^(8)~1.4×10^(8)元,运行成本增加1.6~1.8元t,土地占用面积增加2000 m 2.以某中等城市为例,提标到最严格的一级限值最高需要增加投资成本24.4×10^(8)~31.1×10^(8)元,新增运行成本13.0×10^(8)~14.6×10^(8)元a,增加占地面积6.8×10^(4) m 2.研究显示,城镇污水处理厂出水可直接与水质改善目标相衔接,且将大幅度增加污水处理厂的成本.展开更多
基金supported by the Mega-projects of Science Research for Water Environment Improvement(No.2009ZX07106-001,2012ZX07101-002)the National Natural Science Foundation of China(No.40901248)the China Basic Research Program(No.2008CB418206)
文摘Characterization, treatment and releases of eight polybrominated diphenyl ethers （PBDEs） congeners and sixteen polycyclic aromatic hydrocarbons （PAHs） in wastewater were evaluated along the treatment processes of a typical secondary treatment municipal sewage treatment plant （STP） （in Hefei City） situated the beside Nanfei River, East China. The findings showed that the average concentrations of the total PBDEs in raw wastewater and treated effluent were 188.578 and 36.884 ng/L respectively. Brominated diphenyl ether （BDE） 209 congener, the predominant PBDE in the STP and Nanfei River, could be related to the discharge of car-industry-derived wastes. For PAHs, the average concentrations in raw wastewater and treated effluent were 5758.8 and 2240.4 ng/L respectively, with naphthalene, benzo[a]pyrene and indeno[1,2,3-c,d]pyrene being detected at the highest concentrations. PAHs mainly originate from the combustion of biomass/coal and petroleum. The STP reduced about 80% of the PBDEs and 61% of the PAHs, which were eliminated mainly by sedimentation processes. The removal rates of PBDEs/PAHs increased with the increase of their solid-water partitioning coefficients. Accordingly, the STP＇s effluent, containing some PBDE congeners （e.g., BDE 47, 99 and 209, etc.） and low-molecular-weight PAHs, could be an important contributor of these contaminants＇ input to Nanfei River. It resulted in a significant increase of PBDE/PAH concentrations and PAH toxicological risk in the river water downstream. About 4.040 kg/yr of PBDEs and 245.324 kg/yr of PAHs could be released into the Nanfei River. The current conventional wastewater treatment processes should be improved to remove the relatively low-molecular-weight PBDEs/PAHs more effectively.
文摘为了解城镇污水处理厂不同提标改造要求对成本的影响程度,围绕水环境质量改善目标,提出城镇污水处理厂排放限值的分级体系设计.在排放浓度分级方面,梳理现行国家和地方城镇污水处理厂排放标准,将其主要水污染物的排放浓度限值分为四级,按照从宽到严的顺序,分别为GB 18918—2002《城镇污水处理厂污染物排放标准》一级A标准(四级)、GB 3838—2002《地表水环境质量标准》中准Ⅴ类水质标准(三级)、准Ⅳ类水质标准(二级)和准Ⅲ类水质标准(一级)的浓度水平,并对从四级分别提高到三级、二级和一级排放限值进行技术经济评估.结果表明:对于一座设计规模为10×10^(4) t/d的城镇污水处理厂,由四级分别提高到三级、二级和一级,需增加的成本和占地面积逐步提高.当排放限值从四级提高到一级时,成本与占地面积增加最多,其中投资成本增加1.1×10^(8)~1.4×10^(8)元,运行成本增加1.6~1.8元t,土地占用面积增加2000 m 2.以某中等城市为例,提标到最严格的一级限值最高需要增加投资成本24.4×10^(8)~31.1×10^(8)元,新增运行成本13.0×10^(8)~14.6×10^(8)元a,增加占地面积6.8×10^(4) m 2.研究显示,城镇污水处理厂出水可直接与水质改善目标相衔接,且将大幅度增加污水处理厂的成本.
