渤海海域夏季石油烃污染状况及其环境容量估算

根据调查分析了渤海海域石油烃污染状况,建立了渤海石油烃多介质动力学模型,估算了渤海海域石油烃污染物环境容量和剩余环境容量。结果表明,调查海域石油烃平均浓度为(25.7±13.6)mg／rn3,变化范围为4.4~64.8 mg,／m3,其中,莱州湾,渤海湾等近岸海域污染较严重。在一、二类国家海水水质标准下,渤海海域石油烃污染物环境容量(ECo)为29 169 t／a,在三类国家海水水质标准下ECo为177 306 t／a,在四类国家海水水质标准下ECo为298 446 t／a,各海域在一、二类国家海水水质标准下石油烃污染物环境容量分别为,渤海湾5 255 t／a,辽东湾8 869 t／a,莱州湾4 889 t／a,渤海中部10 156 t／a。     

莱州湾石油烃海洋环境容量计算——基于非线性规划的排海通量最优化法

排海通量最优化法是近年来常用于计算海域污染物环境容量的方法。对于石油烃这种非保守物质,本文提出了基于非线性规划的排海通量最优化法(简称非线性规划法)。首先,验证了石油烃点源的线性叠加性;其次,分别选用基于线性规划的排海通量最优化法(简称线性规划法)及非线性规划法,对莱州湾石油烃的环境容量进行计算。结果表明,在I/II类海水水质标准下,线性与非线性规划法计算出的年环境容量分别为6 101.8 t和4 576.1 t。按照线性规划法进行点源的石油烃最优排放规划时,将高估湾内石油烃的自净能力,从而对海域内生态系统造成破坏;非线性规划法则不会出现水质点浓度超标的情况,可对海域的生态环境保护起到更好的指导作用。     

饮用水水源保护区河流水环境容量计算模型

基于河流一维水环境容量计算模型,通过水质控制目标分析,引入了饮用水供水水库的水环境容量决定其保护区内河流水质控制目标的概念,提出以水库的水环境容量为其上游保护区内河流段末的水质控制目标,解决了由于河流与湖库的总磷水质标准不一致、水质标准中没有河流总氮指标以及水环境容量计算中河流与湖库水文设计条件不同步等,导致水源保护区内河流的水质控制目标确定困难的问题,建立了针对饮用水水源保护区内河流水环境容量的计算模型和方法,本模型直接表达了饮用水供水水库与其上游河流水环境容量之间的定最关系,体现了2个水域间的连续性和相互作用关系,为实现饮用水供水水库及其上游河流的污染物总量控制提供了可靠的科学依据,应用本模型,计算了正在建设中的老虎潭水库保护区内河流的水环境容量.结果表明,根据老虎潭水库水环境存量,保护区内河流的总氮水环境容量为65.05 t·a-1,现状总氮年入河量应削减33.86 t;总磷水环境容量为5.05 t·a-1,现状条件下尚有2.23 t·a-的剩余水环境容量,文中所提出的建模方法可以推广至水质控制目标不同情况下的连续水域,尤其适用于下游水域水质控制要求高于上游水域的情况,拓展了水环境容量的研究思路和方法.     

石油烃在胶州湾多介质中迁移-转化模型研究

在分析石油烃主要迁移-转化过程的基础上,根据化学污染物在多介质环境中迁移-转化模型的基本原理,建立了石油烃在胶州湾多介质海洋环境中迁移-转化箱式模型,主要包括大气挥发、浮游植物富集、微生物降解、悬浮颗粒物吸附和水动力交换5个迁移-转化过程.通过模型模拟与验证表明,该模型逻辑结构及动力学方程基本合理,而且所确定的模型参数也基本能够反应胶州湾海域的地域化特征.结合模型灵敏度分析表明,石油烃在胶州湾多介质海洋环境中主要决定于大气挥发、微生物降解和水动力交换等迁移-转化过程.     

山东半岛南部近海海水及动物石油烃污染状况

根据2007年11月对山东半岛南部近海海水和动物体的石油烃污染水平检测结果,分析表层海水及动物体石油烃含量分布特征,评估该海域受石油烃污染程度。结果表明,调查海区表层海水中石油烃含量范围为(0.017~0.069)mg/L,平均含量为0.031 mg/L,鱼类体内石油烃含量范围为(2.24~30.31)×10-6,平均为11.59×10-6;软体类含量范围为(4.19~36.49)×10-6,平均为19.83×10-6;甲壳类含量范围为(8.41~49.07)×10-6,平均为18.47×10-6。海水和动物体石油烃含量分布特征,均呈近岸高、离岸低趋势。虽然调查区域海水和动物体石油烃污染状况为轻度,但日照港和胶州湾海域污染状况却不容忽视。     

河流水环境容量安全边际研究

水环境容量安全边际是污染物总量控制的关键。运用河流二维稳态水质模型,计算大宁河回水区内COD环境容量,并采用一阶误差分析法分析模型关键参数对大宁河COD环境容量影响程度,科学计算大宁河水环境容量安全边际值。结果表明,三峡库区坝前水位175 m时,大宁河回水区内COD环境容量为729.06 t/a;模型参数对环境容量影响顺序为:背景浓度(C0)>混合区长度(x)=水深(h)>流速(u)=扩散系数(E)y>降解系数(K);大宁河回水区内安全边际值为84.06 t/a,占环境容量的11.53%。文章科学地计算大宁河回水区内COD环境容量安全边际,而非人为定性提出,为三峡库区河流水环境容量安全边际确定提供理论依据。     

Pb在胶州湾多介质中迁移-转化模型研究

在分析重金属污染物Pb(II)在胶州湾中主要迁移-转化过程的基础上,根据化学污染物在多介质环境中迁移-转化模型的基本原理,建立了Pb(II)在胶州湾多介质海洋环境中迁移-转化箱式模型,逻辑上主要包括水动力交换、生物富集、有机络合和悬浮颗粒物吸附、沉积等迁移-转化过程.利用1997年和2000年～2004年胶州湾Pb(II)海上监测数据进行模型模拟与验证,模拟结果与监测结果吻合较好,这表明该模型逻辑结构及动力学方程基本合理,同时也说明,模型中所采用的参数基本能够反映胶州湾海域的地域化特征.在此基础上估算了Pb(II)在胶州湾的海洋环境容量.     

基于CMAQ的大气环境容量计算方法及控制策略

利用空气质量模型CMAQ建立了真实条件下基于不同达标率的大气环境容量计算方法,为大气环境质量管理提供了科学依据。采用CMAQ建立研究区域的空气质量模型系统,设置多层嵌套网格(最小网格分辨率3km),获得了2006年1月、4月、7月、10月(四季代表月)的小时污染物浓度值。通过调整研究区域的污染源排放量,并结合空气质量监测数据和环境空气质量标准,建立了不同污染物的达标率与环境容量关系曲线。研究证明,该方法可以确定可吸入颗粒污染物、二氧化硫和二氧化氮在不同达标率下的大气环境容量,并充分反映三种污染物环境容量的季节性变化特征。研究结果不仅有利于环境管理者制定针对研究区域的空气总量控制方案,还有助于构想基于季节性变化的污染控制策略。     

东海赤潮频发区石油烃的季节分布特征

根据2002年4月～2003年3月对东海赤潮高发区表层海水中石油烃污染状况进行的四季现场调查,探讨了该海区石油烃的季节分布特征.结果表明,该海域受到了石油烃的轻度污染,表层海水中石油烃的含量具有明显的时间差异.石油烃的平均浓度夏季最高(0.124 mg/L),春、秋季居中(约0.08 mg/L),冬季最低(0.032 mg/L).并根据调查区域油类污染物排海量及水文情况,对各季节石油烃的水平分布特征进行了初步的分析.     

浅谈辽阳市实施水污染总量控制

本文从辽阳市的水环境状况出发，运用概率稀释模型和水质自净模型分别计算了一定水域的稀释容量和自净容量，从而确定了该水域的容量总量。同时本文提出控制单元的概念，将一城市或地区的水物总量控制划分成若干个单元的一控制，并提出了控制单元内水污染物总量控制分配方法及可操作的工艺程序。     

Toxic effects of acetochlor, methamidophos and their combination on nifH gene in soil

Toxic effects of two agrochemicals on nifH gene in agricultural black soil were investigated using denaturing gradient gel electrophoresis （DGGE） and sequencing approaches in a microcosm experiment. Changes of soil nifH gene diversity and composition were examined following the application of acetochlor, methamidophos and their combination. Acetochlor reduced the nifH gene diversity （both in gene richness and diversity index values） and caused changes in the nifH gene composition. The effects of acetochlor on nifH gene were strengthened as the concentration of acetochlor increased. Cluster analysis of DGGE banding patterns showed that nifH gene composition which had been affected by low concentration of acetochlor （50 mg/kg） recovered firstly. Methamidophos reduced nifH gene richness that except at 4 weeks. The medium concentration of methamidophos （150 mg/kg） caused the most apparent changes in nifH gene diversity at the first week while the high concentration of methamidophos （250 mg/kg） produced prominent effects on nifH gene diversity in the following weeks. Cluster analysis showed that minimal changes of nifH gene composition were found at 1 week and maximal changes at 4 weeks. Toxic effects of acetochlor and methamidophos combination on nifH gene were also apparent. Different nifH genes （bands） responded differently to the impact of agrochemicals： four individual bands were eliminated by the application of the agrochemicals, five bands became predominant by the stimulation of the agrochemicals, and four bands showed strong resistance to the influence of the agrochemicals. Fifteen prominent bands were partially sequenced, yielding 15 different nifH sequences, which were used for phylogenetic reconstructions. All sequences were affiliated with the alpha- and beta-proteobacteria, showing higher similarity to eight different diazotrophic genera.     

Arsenic uptake by arbuscular mycorrhizal maize （Zea mays L.） grown in an arsenic-contaminated soil with added phosphorus

The effects of arbuscular mycorrhizal (AM) fungus (Glomus mosseae) and phosphorus (P) addition (100 mg/kg soil) on arsenic (As) uptake by maize plants (Zea mays L.) from an As-contaminated soil were examined in a glasshouse experiment.Non-mycorrhizal and zero-P addition controls were included.Plant biomass and concentrations and uptake of As,P,and other nutrients,AM colonization,root lengths,and hyphal length densities were determined.The results indicated that addition of P significantly inhibited root colonization and development of extraradical mycelium.Root length and dry weight both increased markedly with mycorrhizal colonization under the zero-P treatments,but shoot and root biomass of AM plants was depressed by P application.AM fungal inoculation decreased shoot As concentrations when no P was added,and shoot and root As concentrations of AM plants increased 2.6 and 1.4 times with P addition,respectively.Shoot and root uptake of P,Mn,Cu,and Zn increased,but shoot Fe uptake decreased by 44.6%,with inoculation, when P was added.P addition reduced shoot P,Fe,Mn,Cu,and Zn uptake of AM plants,but increased root Fe and Mn uptake of the nonmycorrhizal ones.AM colonization therefore appeared to enhance plant tolerance to As in low P soil,and have some potential for the phytostabilization of As-contaminated soil,however,P application may introduce additional environmental risk by increasing soil As mobility.     

Degradation of metabolites accumulated of benzo[a]pyrene by coupling Penicillium Chrysogenum with KMnO4

Several main metabolites of benzo[a]pyrene （BaP） formed by Penicillium chrysogenum, Benzo[a]pyrene-1,6-quinone （BP 1,6- quinone）, trans-7,8-dihydroxy-7,8-dihydrobenzo[a]pyrene （BP 7,8-diol）, 3-hydroxybenzo[a]pyrene （3-OHBP）, were identified by high-performance liquid chromatography （HPLC）. The three metabolites were liable to be accumulated and were hardly further metabolized because of their toxicity to microorganisms. However, their further degradation was essential for the complete degradation of BaP. To enhance their degradation, two methods, degradation by coupling Penicillium chrysogenum with KMnO4 and degradation only by Penicillium chrysogenum, were compared; Meanwhile, the parameters of degradation in the superior method were optimized. The results showed that （1） the method of coupling Penicillium chrysogenum with KMnO4 was better and was the first method to be used in the degradation of BaP and its metabolites; （2） the metabolite, BP 1,6-quinone was the most liable to be accumulated in pure cultures; （3） the effect of degradation was the best when the concentration of KMnO4 in the cultures was 0.01% （w/v）, concentration of the three compounds was 5 mg/L and pH was 6.2. Based on the experimental results, a novel concept with regard to the bioremediation of BaP-contaminated environment was discussed, considering the influence on environmental toxicity of the accumulated metabolites.     

Impact of atrazine and nitrogen fertilizers on the sorption of chlorotoluron in soil and model sorbents

Sorption of chlorotoluron in ammonium sulfate, urea and atrazine multi-solutes system was investigated by batch experiments. The results showed application of nitrogen fertilizers to the soil could affect the behavior of chlorotoluron. At the same concentration of N, sorption of chlorotoluron decreased as the concentration of atrazine increased on the day 0 and 6 in soil, respectively. The sorption of chlorotoluron increased from 0 to 6 d when soils were preincubated with deionized water, ammonium sulfate and urea solution for 6 d. That indicated incubation time was one of the most important factors for the sorption of chlorotoluron in nitrogen fertilizers treatments. The individual sorption isotherms of chlorotoluron in rubbery polymer and silica were strictly linear in single solute system, but there were competition sorption between pesticides or between pesticides and nitrogen fertilizers. That indicated the sorption taken place by concurrent solid-phase dissolution mechanism and sorption on the interface of water-organic matter or water-mineral matter.     

Distribution and ecological effect of mercury in Laogang landfill, Shanghai, China

Laogang landfill near Shanghai is the largest landfill in China, and receives about 10000 t of daily garbage per day, Samples of topsoil and plants were analyzed to evaluate mercury pollution from the landfill. For topsoil samples, there were significant correlations among total mercury （HgT）, combinative mercury （Hgc） and gaseous mercury （HgG）, and content of total organic carbon （TOC）, but, no significantly relationship was found between Hg content and filling time. Hg content changes in vertical profiles with time showed that the average Hgv of profiles 1992, 1996, and 2000 was similar, but their average HgG was quite different. HgT was significantly correlated with Hgc in profile 1992 and 2000, and Hgv was significantly correlated with Hg6 in profile 1996. HgG/Hgv ratio in profile samples decreased in the order of （HgG,/HgT）1992〉（HgG/HgT）1996〉〉（HgG/HgT）2000. A simple outline of Hg release in landfill could be drawn： with increasing of filling time, degradation undergoes different biodegradation, accordingly, gaseous mercury goes through small, more, and small proportion to total mercury. Distribution of Hg in plants was inhomogeneous, following the order of leaf〉root〉stem. The highest value of leaf may be associated with higher atmospheric Hg from landfill. Ligneous plants （e.g. Phyllostachys glanca, Prunus salicina and Ligustrum lucidum） are capable of enriching more Hg than herbaceous plants.     

EDTA-enhanced phytoremediation of lead contaminated soil by Bidens maximowicziana

Phytoremediation is a potential cleanup technology for the removal of heavy metals from contaminated soils.Bidens maximowicziana is a new Pb hyperaccumulator,which not only has remarkable tolerance to Pb but also extraordinary accumulation capacity for Pb.The maximum Pb concentration was 1509.3 mg/kg in roots and 2164.7 mg/kg in overground tissues.The Pb distribution order in the B. maximowicziana was:leaf>stem>root.The effect of amendments on phytoremediation was also studied.The mobility of soil Pb and the Pb concentrations in plants were both increased by EDTA application.Compared with CK(control check),EDTA application promoted translocation of Pb to overground parts of the plant.The Pb concentrations in overground parts of plants was increased from 24.23-680.56 mg/kg to 29.07-1905.57 mg/kg.This research demonstrated that B.maximowicziana appeared to be suitable for phytoremediation of Pb contaminated soil,especially,combination with EDTA.     

Decomposition of alachlor by ozonation and its mechanism

Decomposition and corresponding mechanism of alachlor, an endocrine disruptor in water by ozonation were investigated. Results showed that alachlor could not be completely mineralized by ozone alone. Many intermediates and final products were formed during the process, including aromatic compounds, aliphatic carboxylic acids, and inorganic ions. In evoluting these products, some of them with weak polarity were qualitatively identified by GC-MS. The information of inorganic ions suggested that the dechlorination was the first and the fastest step in the ozonation of alachlor.     

Enzymatic oxidation of aqueous pentachlorophenol

The influence of the nonionic surfactant Tween 80 on pentachlorophenol （PCP） oxidation catalyzed by horseradish peroxidase was studied. The surfactant was tested at concentrations below and above its critical micelle concentration （CMC）. Enhancement of PCP removal was observed at sub-CMCs. The presence of Tween 80 in the reaction mixture reduced enzyme inactivation which occurred through a combination of free radical attack and sorption by precipitated products. A simple first-order model was able to simulate time profiles for enzyme inactivation in the presence or absence of Tween 80. At supra-CMCs, the surfactant caused noticeable reductions in PCP removal, presumably through micelle partitioning of PCP which precluded the hydrophobic PCP molecule from interacting with the enzyme.     

Potential of plant polyphenol oxidases in the decolorization and removal of textile and non-textile dyes

In this study an effort has been made to use plant polyphenol oxidases; potato （Solanum tuberosum） and brinjal （Solanum melongena）, for the treatment of various important dyes used in textile and other industries. The ammonium sulphate fractionated enzyme preparations were used to treat a number of dyes under various experimental conditions. Majority of the treated dyes were maximally decolorized at pH 3.0. Some of the dyes were quickly decolorized whereas others were marginally decolorized. The initial first hour was sufficient for the maximum decolorization of dyes. The rate of decolorization was quite slow on long treatment of dyes. Enhancement in the dye decolorization was noticed on increasing the concentration of enzymes. The complex mixtures of dyes were treated with both preparations of polyphenol oxidases in the buffers of varying pH values. Potato polyphenol oxidase was significantly more effective in decolorizing the dyes to higher extent as compared to the enzyme obtained from brinjal polyphenol oxidase. Decolorization of dyes and their mixtures, followed by the formation of an insoluble precipitate, which could be easily removed simply by centrifugation.     

Removal of heavy metals from sewage sludge by low costing chemical method and recycling in agriculture

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