The occurrence of synthetic musks in human breast milk in Sichuan, China

Human breast milk samples collected from mothers (n = 110) who lived in Chengdu, Sichuan Province, southwestern China in 2009 were analyzed to determine the concentrations of 13 musk compounds. Possible relationships between musk concentrations and some personal characteristics were also studied. Only five target analytes were detected in the milk samples analyzed, with median concentration values of 16.5, 11.5, 7.85, <1.5 and <1.4 ng g⁻¹ lipid weight for AHTN (7-acetyl-1,1,3,4,4,6-hexamethyl-1,2,3,4-tetrahydronaphthalene), HHCB (1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta[γ]-2-benzopyran), HHCB-lactone (1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta[γ]-2-benzopyran-1-one), OTNE ([1,2,3,4,5,6,7,8-octahydro-2,3,8,8-tetramethylnaphthalen-2yl]ethan-1-one) and musk ketone (4-tert-butyl-2,6-dimethyl-3,5-dinitroacetophenone, MK), respectively. Mothers who reported high use of hand-cleaning agents, body-cleaning agents, shampoo and hair conditioners, hair dyes and hair gels had significantly elevated milk concentrations of HHCB whereas elevated milk concentrations of AHTN were observed among mothers reporting high use of body-cleaning agents, body lotions, shampoos, hair dyes and hair gels. Younger age showed a significantly positive effect on milk concentrations of both HHCB and AHTN whereas BMI after delivery, the number of children nursed and place of residence (urban or rural) had no significant effect. The estimated median daily intakes of synthetic musks for breast-fed infants were considerably lower than the current provisional tolerable daily intake amounts suggested for adults.     

渤海和黄海北部地区海冰灾害风险评估

海冰灾害是中国海洋灾害的主要灾种之一。渤海和黄海北部地区由于受冬季风带来的寒潮天气影响成为中国最主要的结冰海域。基于灾害风险理论,将研究区海岸带上17个地级市的71个县区作为评价单元,对海冰灾害风险进行评估。选取冰期天数和最大冰厚2个指标,计算致灾因子危险度指数;选取涉海人口密度、海洋经济密度、海洋一产比重等3个指标,计算承灾体脆弱性指数;综合危险度指数与脆弱性指数计算各县区的海冰灾害风险指数,并绘制风险等级图。该风险等级图揭示了海冰灾害风险在渤海和黄海北部地区海岸带上的分布状况,为中国制定海冰灾害风险防范策略提供参考。     

废水中KMnO4对生物处理效果的影响

为减轻和消除含高浓度KMnO4的牛仔服加工废水对生物处理系统的毒害作用,采用模拟序批式活性污泥法,研究KMnO4对活性污泥微生物生长的影响及COD和NH4+-N的降解规律。结果表明,当处理进水COD浓度500 mg/L,NH4+-N浓度23.5 mg/L,污泥浓度为2 000 mg/L时,曝气时间为4 h,KMnO4质量浓度增加对COD和NH4+-N的降解影响很大;同样条件下曝气时间改为8 h,对NH4+-N的降解影响显著减小,但对COD的降解影响减少不多;并且,高浓度KMnO4对NH4+-N去除效果的抑制作用比对COD的大。因此,处理含高浓度KMnO4的废水需要延长一倍曝气时间,可以获得良好的COD和NH4+-N的降解效果。同时,KMnO4对活性污泥的抑制影响较好地吻合非竞争性抑制机理修正莫若特方程的规律。     

丙烯酸废水处理工程实例

采用气浮-动态微电解—水解酸化—接触氧化工艺,对无锡某化工总厂丙烯酸废水原工艺和设备进行了改造,经过调试运行,监测结果表明,进水COD为6 000～10 000 mg/L时,处理出水COD小于60 mg/L。出水达到太湖地区重点工业行业主要水污染物排放标准。     

生物氧化提金废水中的Fe、As共沉淀

采用Fe、As共沉淀工艺处理强酸性高砷生物氧化提金废水。通过向强酸性高砷生物氧化提金废水中加入浓氨水控制反应液pH,生成FeAsO_4和Fe(OH)_3沉淀,达到Fe、As共沉淀的目的,为后续工艺进一步回收利用Fe、As奠定基础。实验结果表明,在反应液pH为4.5、搅拌转速为500 r/min、反应温度为25℃的条件下,Fe回收率达到99.9%,As回收率为99.8%。处理后废水中As质量浓度小于20μg/L,符合GB3838—2002《地表水环境质量标准》中的Ⅰ,Ⅱ,Ⅲ类水体中As含量标准。     

简论油田企业现行清洁生产

文章阐述了油田企业在开展清洁生产过程中存在的主要问题。针对行业特点,结合企业自身情况,对存在的问题进行了全面分析,提出了解决这些问题的初步对策,为高效地开展清洁生产工作提供科学的参考和借鉴。     

Source profiles of volatile organic compounds associated with solvent use in Beijing,China

Compositions of volatile organic compound (VOC) emissions from painting applications and printing processes were sampled and measured by gas chromatography–mass spectrometry/flame ionization detection (GC–MS/FID) in Beijing. Toluene and C8 aromatics were the most abundant species, accounting for 76% of the total VOCs emitted from paint applications. The major species in printing emissions included heavier alkanes and aromatics, such as n-nonane, n-decane, n-undecane, toluene, and m/p-xylene. Measurements of VOCs obtained from furniture paint emissions in 2003 and 2007 suggest a quick decline in benzene levels associated with formulation changes in furniture paints during these years. A comparison of VOC source profiles for painting and printing between Beijing and other parts of the world showed significant region-specific discrepancies, probably because of different market demands and environmental standards. We conducted the evaluation of the source reactivities for various VOC emission sources. The ozone formation potential (OFP) for unit mass of VOCs source emissions is the highest for paint applications. Substituting solvent-based paints by water-based in Beijing will lead to an OFP reduction of 152,000 tons per year, which is more than 1/4 of the OFPs for VOCs emissions from vehicle exhaust in the city.     

EM菌与化学絮凝剂复配实验研究

通过实验考查EM复壮液分别与无机高分子絮凝剂PAC、PFS复配使用处理高岭土悬浊液絮凝条件和絮凝效果。实验结果表明:EM复壮液与化学絮凝剂复配以后的适用条件为弱酸弱碱性环境。最佳复配比分别为VPAC∶VEM=0.6mL∶2 mL或VPFS∶VEM=1.0 mL∶3.0 mL,前者的絮凝率为91.2%,优于后者的87.6%。同时降低了处理后水中的金属残余量以及絮凝剂的总投加量,降低污水处理的成本,提高了水质。     

铜对活性污泥微生物活性影响研究

通过人工投加铜离子对驯化污泥的破坏性实验,研究了各浓度铜离子对活性污泥氨氮、COD降解的影响及其TTC-脱氢酶活性、氧摄取速率(SOUR)、氨摄取速率(AUR)的影响。结果显示,0~5 mg/L的铜离子对处理系统有机物的去除率影响不大。铜离子浓度与活性污泥的TTC-脱氢酶活性、SOUR以及AUR之间呈现良好的相关性;低浓度的铜离子对TTC-脱氢酶活性和SOUR均有一定的促进作用,而对AUR则会产生一定的抑制作用。当铜离子浓度达到5 mg/L时,其对SOUR、TTC-脱氢酶活性以及AUR的抑制率均超过50%。在此情况下,采用TTC-脱氢酶活性、SOUR以及AUR等指标,能快速有效地表征铜离子对活性污泥微生物的毒害作用。     

数学模拟在污水处理厂节能减排中的应用和发展

在国内外节能减排的大背景下,污水处理厂面临着巨大的提标改造和节能减排压力。基于活性污泥数学模型的数学模拟技术在国内外许多污水处理厂的模拟仿真、运行诊断与工艺优化、升级评估、节能减排等方面得到广泛的应用,文章主要介绍了数学模拟技术在污水处理厂节能减排方面的发展和应用情况,并提出今后国内的主要研究方向。