聚合氯化铝-腐殖酸(PACl-HA)絮体的物理与分形特征研究

采用低温急速冷冻-真空干燥技术制备了PACl-HA絮体的粉末样品,研究了这些样品的物理与分形特征.结果表明,PACl-HA絮体具有无定形结构,主要组成元素为C、O、Al,所含特征官能团保留了絮体组成原料的一些特征;絮体的BET比表面积为130～161 m²·g^-1,BJH累积吸附孔体积为0.38～0.52 cm³·g^-1,BJH脱附平均孔径为7.7～9.6nm,PSD峰值对应孔径8.4～11.2nm.PACl-HA絮体具有自相似性的粗糙表面,呈现多尺度分形特征;图象法和N₂吸附/脱附等温线法确定的表面分形维数Ds分别为2.03～2.26、2.24～2.37,前者的分形尺度大约处于23～390nm之间,主要属于絮体外表面尺度,而后者的分形特征尺度区间的下限大约为0.2nm,属于孔表面尺度;另外,对同一絮体,N₂吸附法和脱附法确定的孔表面分形维数不同.热力学模型计算出的D_s远大于3,与Sahouli等的研究不符.     

High heterogeneity of bacterioplankton community shaped by spatially structured environmental factors in West Lake,a typical urban lake in eastern China

Environmental Science and Pollution Research - Elucidating the bacterioplankton spatial distribution patterns and its determinants is a central topic in ecological research. However, research on...     

A new approach to spatial source apportionment of haze pollution in large scale and its application in China

Long-lasting expansion of haze pollution in China has already presented a stern challenge to regional joint prevention and control. There is an urgent need to enlarge and reconstruct the coverage of joint prevention and control of air pollution in key area. Air quality models can identify and quantify the regional contribution of haze pollution and its key components with the help of numerical simulation, but it is difficult to be applied to larger spatial scale due to the complexity of model parameters. The time series analysis can recognize the existence of spatial interaction of haze pollution between cities, but it has not yet been used to further identify the spatial sources of haze pollution in large scale. Using econometric framework of time series analysis, this paper developed a new approach to perform spatial source apportionment. We applied this approach to calculate the contribution from spatial sources of haze pollution in China, using the monitoring data of particulate matter (PM_2.5) across 161 Chinese cities. This approach overcame the limitation of numerical simulation that the model complexity increases at excess with the expansion of sample range, and could effectively deal with severe large-scale haze episodes.     

Periphyton Developed on Artificial Substrates: Effect of Substrate Type and Incubation Depth

The aim of this study was to assess the effect of substrate type and incubation depth on periphyton that had developed on artificial substrates. Uniform rectangular tiles made out of artificial substrates: glass, ceramic, willow tree and yew tree, were fixed on a floating buoy and deployed at three different depths in a photic zone of the Sava Lake (Belgrade, Serbia). Non-taxonomic attributes in the developed biofilm were estimated week-by-week from the start of the experiment in July, until its end in September 2014. Through assessment of substrate type and depth of incubation effect we concluded that these parameters for the fact influence periphyton development and composition. Glass was preferred by autotrophic component over ceramic and wooden substrates. In general, substrate type effect was diminished by increasing incubation depth. When non-taxonomic parameters are to be used in biomonitoring studies, our results suggest that glass substrate and shallow layer of water column (up to 50 cm) for incubation should be preferred.     

厌氧流化床处理白酒废水运行参数的研究

研究了床层膨胀率、HRT、温度以及有机容积负荷冲击等因素对AFB反应器COD去除率的影响。结果显示:温度为32±2℃,进水COD 6 000 mg/L,pH7.2条件下,AFB反应器处理白酒废水的优化运行参数为床层膨胀率为36%,回流比1∶7,水力停留时间8 h,此时废水COD去除率可达80%左右;同时该反应器在有机容积负荷达到36.1 kg COD/(m3.d)时COD去除率明显下降。     

活性炭吸附和脱附-等离子体氧化净化有机废气的研究

根据滑动弧放电等离子体适于降解高浓度有机物废气的特性,结合活性炭吸附法,提出了吸附器的吸附浓缩和热脱附-等离子体氧化净化有机废气的方法。在活性炭吸附过程中,最初2 h内甲苯净化率达到100%,随着时间的增加净化率下降;在热脱附滑动弧放电等离子体净化过程中,甲苯降解效率最高为97.3%。将滑动弧放电等离子体反应器出口气相产物收集进行FT-IR检测,发现放电后有CO2、CO、H2O和NO2产生,并分析了甲苯的降解机理。     

秦皇岛地热能梯级利用状况与前景分析

在对秦皇岛地热能资源现状和开发利用调查的基础上,对秦皇岛地区的地热资源分布特征进行了分类,通过对相应的地热资源利用现状进行调查,掌握了地热能利用的现状以及存在的种种问题和不足。为了更加合理高效地利用地热能资源,进行开发利用前景分析,制定了地热能综合梯级利用的规划建议。     

Assessment of low-level metal contamination using the Mediterranean mussel gills as the indicator tissue

Purpose  

The aim of this study was to compare the level of metal contamination in two bays in the middle part of the Eastern Adriatic coastal zone in Croatia using the gills of mussels Mytilus galloprovincialis as indicator tissue. Despite the existing sources of contamination, previous studies with caged mussels only indicated moderate metal contamination of the Kaštela Bay, contrary to the Trogir Bay in which marina and shipyard present a probable source of Cu- and Zn-contamination.     

Sulfate and glutathione enhanced arsenic accumulation by arsenic hyperaccumulator Pteris vittata L.

This experiment examined the effects of sulfate (S) and reduced glutathione (GSH) on arsenic uptake by arsenic hyperaccumulator Pteris vittata after exposing to arsenate (0, 15 or 30 mg As L⁻¹) with sulfate (6.4, 12.8 or 25.6 mg S L⁻¹) or GSH (0, 0.4 or 0.8 mM) for 2-wk. Total arsenic, S and GSH concentrations in plant biomass and arsenic speciation in the growth media and plant biomass were determined. While both S (18-85%) and GSH (77-89%) significantly increased arsenic uptake in P. vittata, GSH also increased arsenic translocation by 61-85% at 0.4 mM (p < 0.05). Sulfate and GSH did not impact plant biomass or arsenic speciation in the media and biomass. The S-induced arsenic accumulation by P. vittata was partially attributed to increased plant GSH (21-31%), an important non-enzymatic antioxidant countering oxidative stress. This experiment demonstrated that S and GSH can effectively enhance arsenic uptake and translocation by P. vittata.     

Biodegradation of methyl red by Bacillus sp. strain UN2: decolorization capacity,metabolites characterization,and enzyme analysis

Azo dyes are recalcitrant and refractory pollutants that constitute a significant menace to the environment. The present study is focused on exploring the capability of Bacillus sp. strain UN2 for application in methyl red (MR) degradation. Effects of physicochemical parameters (pH of medium, temperature, initial concentration of dye, and composition of the medium) were studied in detail. The suitable pH and temperature range for MR degradation by strain UN2 were respectively 7.0–9.0 and 30–40 °C, and the optimal pH value and temperature were respectively 8.0 and 35 °C. Mg²⁺ and Mn²⁺ (1 mM) were found to significantly accelerate the MR removal rate, while the enhancement by either Fe³⁺ or Fe²⁺ was slight. Under the optimal degradation conditions, strain UN2 exhibited greater than 98 % degradation of the toxic azo dye MR (100 ppm) within 30 min. Analysis of samples from decolorized culture flasks confirmed biodegradation of MR into two prime metabolites: N,N′dimethyl-p-phenyle-nediamine and 2-aminobenzoic acid. A study of the enzymes responsible for the biodegradation of MR, in the control and cells obtained during (10 min) and after (30 min) degradation, showed a significant increase in the activities of azoreductase, laccase, and NADH-DCIP reductase. Furthermore, a phytotoxicity analysis demonstrated that the germination inhibition was almost eliminated for both the plants Triticum aestivum and Sorghum bicolor by MR metabolites at 100 mg/L concentration, yet the germination inhibition of parent dye was significant. Consequently, the high efficiency of MR degradation enables this strain to be a potential candidate for bioremediation of wastewater containing MR.