Simultaneous preconcentration of cadmium and lead in water samples with silica gel and determination by flame atomic absorption spectrometry

A new method that utilizes pretreated silica gel as an adsorbent has been developed for simultaneous preconcentration of trace Cd(II) and Pb(II) prior to the measurement by flame atomic absorption spectrometry. The effects of pH, the shaking time, the elution condition and the coexisting ions on the separation/preconcentration conditions of analytes were investigated. Under optimized conditions, the static adsorption capacity of Cd(II) and Pb(II) were 45.5 and 27.1mg/g, the relative standard deviations were 3.2% and 1.7% (for n = 11), and the limits of detection obtained were 4.25 and 0.60 ng/mL, respectively. The method was validated by analyzing the certified reference materials GBW 07304a (stream sediment) and successfully applied to the analysis of various treated wastewater samples with satisfactory results.     

Waste oyster shell as a kind of active filler to treat the combined wastewater at an estuary

Estuaries have been described as one of the most difficult environments on Earth. It is difficult to know how to treat the combined wastewater in tidal rivers at the estuary, where the situation is very different from ordinary fresh water rivers. Waste oyster shell was used as the active filler in this study in a bio-contact oxidation tank to treat the combined wastewater at the Fengtang Tidal River. With a middle-experimental scale of 360 ma/day, the average removal efficiency of COD, BOD, NH3-N, TP and TSS was 80.05%, 85.02%, 86.59%, 50.58% and 85.32%, respectively, in this bio-contact oxidation process. The living microbes in the biofilms on the waste oyster shell in this bio-contact oxidation tank, which were mainly composed of zoogloea, protozoa and micro-metazoa species, revealed that waste oyster shell as the filler was suitable material for combined wastewater degradation. This treatment method using waste oyster shell as active filler was then applied in a mangrove demonstration area for water quality improvement near the experiment area, with a treatment volume of 5 × 10^3 m^3/day. Another project was also successfully applied in a constructed wetland, with a wastewater treatment volume of 1 ×10^3 m^3/day. This technology is therefore feasible and can easily be applied on a larger scale,     

曝气生物滤池去除邻苯二甲酸丁基苄酯的效果

采用陶粒滤料曝气生物滤池(BAF)处理邻苯二甲酸丁基苄酯(BBP)模拟废水,考察了空床接触时间(EBCT)、温度对BBP的去除效果的影响;运用气质联用仪(GC-MS)分析了BBP在曝气生物滤池内降解的中间产物并推测其可能的降解途径。结果表明,当温度为25℃,空床接触时间(EBCT)为8 h时,BAF对BBP的降解效果良好,去除率达到95.7%;BAF对BBP的去除率随着温度的升高和EBCT的增加而增大,EBCT为去除效果的主要影响因素。BAF出水中检测到邻苯二甲酸二丁酯(DBP)、邻苯二甲酸二甲酯(DMP)以及邻苯二甲酸(PA)等降解产物,据此推测邻苯二甲酸丁基苄酯的生物降解途径可能为BBP的苯环先断裂生成邻苯二甲酸二丁酯,而后断裂一个酯键形成单酯,接着再断裂另一酯键形成邻苯二甲酸,最终分解成二氧化碳和水。     

生化尾水垂直流-水平潜流组合湿地净化研究

采用垂直上升流-水平潜流组合人工湿地装置,对处理污水处理厂生化尾水进行深度处理,选用陶粒、沸石和砾石3种填料,美人蕉、再力花和菖蒲3种植物配置成6种不同的组合.8个月的试验结果表明,水力负荷为0.5 m3/(m2·d),试验装置对NH3-N和TP的去除效果较好,NH3-N平均去除率在69.3％以上,6组试验装置中4组的TP平均去除率在50％以上;COD,N03--N和TN去除效果较差,平均去除率分别在12.5％～ 15.1％,-1.8％ ～ 9.6％和6.3％～ 17.9％之间.以陶粒为填料种植美人蕉的组合湿地装置脱氮除磷效果最好,NH3-N,TN,N03--N,TP的平均去除率分别达到80.9％,17.9％,9.6％,77.5％.     

双水相浮选-HPLC法测定水中氯硝柳胺

文章建立了双水相浮选-高效液相色谱法来测定环境水中氯硝柳胺的含量。选择丙酮为亲水有机溶剂,40%(NH4)2SO4溶液为分相剂。当pH为3.0,氮气流速为20 min/mL,浮选时间为30 min时,萃取率达93.4%。该方法具有高效、绿色环保以及低成本等优点,是一种测定水样中氯硝柳胺含量的新方法。     

汽车排气污染防治现状及对策分析

随着汽车保有量的剧增,汽车尾气已逐步成为城市环境空气污染的主要来源之一,本文依据我国对机动车污染防治实施的政策及措施,结合近年来现状,对汽车排气污染防治的思路、政策及措施等方面做了分析探讨。     

崩塌落石冲击荷载作用下埋地管道的安全评价

野外调查人员在进行崩塌落石灾害的风险分析和评价时,由于没有科学的判别依据,往往只能根据以往经验主观加以判断。本文在前人研究成果和野外调查资料分析的基础上,探讨了崩塌落石冲击力的计算方法,并运用LS-DYNA显式动力学分析软件建立了崩塌落石冲击荷载作用下埋地管道的三维有限元模型,进行了数值模拟,研究了某些因素对埋地管道安全的影响规律,得出一些具有实用性的曲线或公式,可供评价实际问题时查询应用,以为埋地管道的安全运营及崩塌落石的防护设计提供决策依据。     

石油污染盐碱化土壤修复技术的研究进展

油田周围普遍存在着土壤盐碱化和石油污染的双重问题,石油污染盐碱化土壤的修复是亟需解决的环境瓶颈问题。本文在分析石油污染盐碱化土壤特性的基础上,介绍了适用于盐碱地土壤修复的技术,包括微生物修复、植物-微生物联合修复以及物理/化学修复技术的研究进展,并对该领域今后的研究方向与重点进行了展望。     

青藏高原北部库赛湖沉积柱中长链烯酮的分布特征及古环境意义

长链烯酮不饱和度指标U37K或U37K′已被广泛应用于古海洋表层水温的重建,但用于恢复湖泊古温度的研究则相对很少。本文以青藏高原北部咸水湖泊库赛湖作为研究对象,对湖心一个5m沉积柱中的长链烯酮进行了测定分析,并通过分子生物学手段确定了其母源。结果表明该沉积柱的大部分层位存在长链烯酮,其C37/C38<1;DNA测序结果表明库赛湖中的定鞭藻为Isochrysis属,为长链烯酮的母源。根据已发表文献中的湖泊环境中长链烯酮不饱和度指标U37K与温度的经验公式估算出的古湖水温度接近于实测的现代夏季水温,且与甘油二烷基甘油四醚(Glycerol Dialkyl Glycerol Tetraethers,GDGT)重建的库赛湖古湖水温度范围基本一致。但是,用长链烯酮恢复的古湖水温度总体上稍高于由GDGT计算出的温度且波动更为强烈,这可能与这两种脂类的母源生物在湖中的栖息层位不同有关。     

我国大气灰霾污染特征及污染控制建议——以2013年1月大气灰霾污染过程为例

本文以中国环境科学研究院观测站监测结果为基础对2013年1月大气灰霾污染过程的特征及成因进行了深入分析,揭示我国针对重污染应急工作存在的问题和改善城市及区域大气环境面临的严峻挑战,进一步提出了我国城市及区域应对重污染过程及推动空气质量达标的对策建议。