银钛共负载型光催化材料降解甲基橙废水

以膨胀珍珠岩为载体,采用溶胶凝胶法对其进行负载,制备出不同类型的光催化材料（TiO2．EP、Ag＋-TiO2-EP）,并在模拟日光条件下,研究其对甲基橙溶液的降解效果。结果表明,浸渍3次且担载0．04％Ag＋的负载型TiO2光催化活性最高,在光催化剂用量为0．3g,20mL初始浓度为10mg／L甲基橙溶液光照4h后降解率可达81．6％,且甲基橙的光催化降解服从一级动力学方程。回收3次后仍有较强的活性,其2h降解率为24．8％。     

响应曲面法优化C/Fe-Bi2WO6光催化降解氧氟沙星

通过两步法制备C/Fe-Bi2WO6,利用SEM、XRD和EDS等表征手段,对所制备的样品的形貌及微观结构进行了表征。对氧氟沙星(OFLX)模拟废水进行降解实验,通过单因素实验确定主要影响因素和水平后,利用响应曲面法(RSM)对C/Fe-Bi2WO6的光催化降解的主要影响因素进行优化。通过分析实验结果,建立了C/Fe-Bi2WO6光催化降解氧氟沙星的二次多项式模型,预测处理最佳实验条件为:pH为6.45,H2O2的浓度为208.36 mg/L,C/Fe-Bi2WO6浓度0.55 g/L和氧氟沙星浓度为7.62 mg/L。在最佳条件下进行验证实验,发现实验去除率与预测去除率具有良好的一致性,相对误差为2.3%。     

对啶虫脒污染土壤的生物修复作用简

啶虫脒属于一种新型的氯化烟碱类杀虫剂,被认为是替代有机磷农药的重要品种之一,在世界范围内已经得到了广泛的应用,其在环境中的残留备受关注,利用微生物修复异源污染物是一种有效的措施。在实验室条件下,研究了高效降解菌D-2（噬染料菌属,Pigmentiphaga sp.）对被啶虫脒污染土壤的修复作用及其影响因素。结果表明,降解菌株在未灭菌土壤中的降解效果要略好于灭菌土壤,在土壤外源添加降解菌2×10⁸ cfu/g,温度20~40℃,弱碱性（pH 7.5）的条件下,该菌株能有效降解土壤中1~200 mg/kg的啶虫脒。啶虫脒施用对土壤种群结构有一定的影响,可以刺激细菌和真菌的生长,从而使土壤微生物群落结构发生改变,而降解菌的施用可缓解啶虫脒对土壤微生物的影响,修复受污染土壤。因此,人工接种降解菌D-2可提高土壤中啶虫脒的降解率,有效降低其在土壤中的残留。     

Simultaneous determination of malachite green, enrofloxacin and ciprofloxacin in fish farming water and fish feed by liquid chromatography with solid-phase extraction

An effective and sensitive method for simultaneous analysis of malachite green (MG), enrofloxacin (ENFLX) and ciprofloxacin (CPFLX) by liquid chromatography-diode array detection with solid-phase extraction (SPE) is developed. The conditions of SPE and LC were investigated and optimised. The effective separation of these compounds was achieved using a ZY1104 C18 column (250 × 4.6 mm, 5 μm) with 20 mM tetrabutyl ammonium bromide (pH 3.0)-acetonitrile as mobile phase and gradient elution. The diode array detection was used at 278 nm for ENFLX and CPFLX and at 613 nm for MG. Under the optimal conditions, the method LOD values of MG, ENFLX and CPFLX were 0.01, 0.07 and 0.10 μg L(?-1) for fish farming water samples and 1.5, 10.5 and 15 μg kg(?-1) for fish feed samples, respectively. The relative recoveries of the three analytes were achieved to be 76.7-82.3% with the RSDs (n = 5) of 3.2-4.6% for spiked fish farming water samples and 78.8-93.7% with the RSDs (n = 5) of 3.1-4.8% for spiked fish feed samples.     

A comparative study of particle size distribution from two oxygenated fuels and diesel fuel

Oxygenated fuels are known to reduce particulate matter (PM) emissions from diesel engines. In this study, 100% soy methyl ester (SME) biodiesel fuel (B100) and a blend of 10% acetal denoted by A-diesel with diesel fuel were tested as oxygenated fuels. Particle size and number distributions from a diesel engine fueled with oxygenated fuels and base diesel fuel were measured using an Electrical Low Pressure Impactor (ELPI). Measurements were made at ten steady-state operational modes of various loads at two engine speeds. It was found that the geometric mean diameters of particles from SME and Adiesel were lower than that from base diesel fuel. Compared to diesel fuel, SME emitted more ultra-fine particles at rated speed while emitting less ultra-fine particles at maximum speed. Ultra-fine particle number concentrations of A-diesel were much higher than those of base diesel fuel at most test modes.     

Combined effects of cadmium and fluoranthene on germination, growth and photosynthesis of soybean seedlings

The single and combinational effects of cadmium (Cd) and fluoranthene (FLT) on germination, growth and photosynthesis of soybean seedlings were investigated. Exposure to 5, 10, or 15 mg Cd/L or 1, 5, or 10 mg FLT/L individually or in combination significantly decreased germination vigor (3 days) and final germination rate of soybean seeds, except at 1 and 5 mg FLT/L. The results of two-way ANOVA analysis and the Bliss independence model showed that at lower concentrations of FLT (1 mg/L), the interaction between Cd and FLT on germination was antagonistic, whereas the interaction was synergistic when the concentration of FLT was 5 or 10 mg/L and the concentration of Cd was 15 mg/L. Growth, expressed as dry weight, length of shoot and root, leaf area, and photosynthesis, expressed as net photosynthetic rate, intercellular CO2 concentration, chlorophyll contents and fluorescence of soybean seedlings were also reduced by exposure to 5 or 10 mg Cd/L or 1 or 5 mg FLT/L, singly or jointly. Significant antagonistic effects of exposure to 5 or 10 mg Cd/L or 1 or 5 mg FLT/L on shoot growth and photosynthesis were observed, whereas synergy and antagonism of Cd and FLT were both observed for root growth.     

房地产项目中地下停车场汽车尾气对环境的影响分析

房地产开发项目的地下停车场集中排放的汽车尾气对环境产生影响,分析了地下停车场有害物的种类及危害,介绍了地下停车场的设计要点,汽车污染的控制.     

Raman spectroscopy of diesel and gasoline engine-out soot using different laser power

We studied engine-out soot samples collected from a heavy-duty direct-injection diesel engine and port-fuel injection gasoline spark-ignition engine. The two types of soot samples were characterized using Raman spectroscopy with different laser powers. A Matlab program using least-square-method with trust-region-reflective algorithm was developed for curve fitting. A DOE (design of experiments) method was used to avoid local convergence. The method was used for two-band fitting and three-band fitting. The fitting results were used to determine the intensity ratio of D (for “Defect” or “Disorder”) and G (for “Graphite”) Raman bands. It is found that high laser power may cause oxidation of soot sample, which gives higher D/G intensity ratio. Diesel soot has consistently higher amorphous/graphitic carbon ratio, and thus higher oxidation reactivity, compared to gasoline soot, which is reflected by the higher D/G intensity ratio in Raman spectra measured under the same laser power.     

流态变化对污水管网沉积污染物分布及转化的影响

为探明城市污水汇流管网流速变化对沉积层污染物及生物菌群演替的影响,通过控制污水管道中试系统中干管、支管流速,模拟了不同汇流条件下城市污水管网系统运行状态,探究了不同汇流条件下沉积层碳、氮、硫类污染物的分布特征以及微生物种群结构的分布规律.结果表明,在不同汇流条件下,COD、TN、NH3-N、NO3-N、硫酸盐含量沿沉积...     

双酚类化合物的毒理学效应及微生物降解机制的研究进展

双酚类化合物作为重要的有机化工原料,广泛应用于各行各业。然而双酚类化合物是一类内分泌干扰物,毒性评价结果表明其与许多疾病发病率的升高密切相关。伴随双酚类化合物的大量使用,诸多环境样品中都检测出双酚类化合物。由于双酚类化合物的结构稳定,很难在自然界中被完全降解,会不断累积,对生态安全和人体健康产生危害,亟待有效修复。有机污染物的物理化学修复方法易对环境造成二次污染,微生物降解因其获取容易、无二次污染等特点成为双酚类化合物修复的有效途径。本文总结概述了几种典型双酚类化合物的毒性评价及微生物降解机制。