Oxidative stress and genotoxicity of 1-methyl-3-octylimidazolium chloride on loach (Misgurnus anguillicaudatus)

This study was a preliminary step to evaluate the acute toxicity of 1-methyl-3-octylimidazolium chloride ([C₈mim]Cl) on loach (Misgurnus anguillicaudatus) by determining the effects on hepatic antioxidant enzyme activities and by the comet assay. The results showed that [C₈mim]Cl had acute toxicity at concentrations above 20 mg L^?1, inducing oxidative stress and genotoxicity on fish liver cells. In respect to enzyme activities, [C₈mim]Cl induced changes in the activities of superoxide dismutase, catalase, and glutathione content the livers of fish exposed at 20–80 mg L^?1. [C₈mim]Cl at the same exposure level caused a remarkable increase in malondialdehyde level. The comet assay indicated that [C₈mim]Cl at 20–80 mg L^?1 induced genotoxicity in liver cells. With increased exposure concentration and time, the two comet parameters trailing rate and tail moment were significantly increased, with significant differences (P < 0.05) observed between control group and each treatment group. The present study shows that ionic liquids can be a threat to the health of aquatic organism when accidentally released to aquatic ecosystems.     

钼冶炼工艺的循环经济探讨

钼是重要的稀有金属之一,主要通过氧化分解辉钼矿来提取。我国普遍使用反射炉、回转窑等焙烧设备生产氧化钼,造成了严重的SO2污染和资源浪费问题。为改变辉钼矿焙烧分解工艺的污染状况,硝酸高压分解、碱性高压氧分解、次氯酸钠分解和电氧化分解等辉钼矿湿法工艺相继被开发出来。但是这工艺往往只关注在如何获取金属钼等资源,而忽视了辉钼矿中占40%的硫资源。从循环经济角度分析了不同辉钼矿分解工艺的物质流向,探讨符合清洁生产和循环经济精神的工艺革新方向,提出了纯氧氧化焙烧和浓硫酸氧化两种新工艺。     

Surface clogging process modeling of suspended solids during urban stormwater aquifer recharge

Aquifer recharge,which uses urban stormwater,is an effective technique to control the negative effects of groundwater overexploitation,while clogging problems in infiltration systems remain the key restricting factor in broadening its practice.Quantitative understanding of the clogging process is still very poor.A laboratory study was conducted to understand surface physical clogging processes,with the primary aim of developing a model for predicting suspended solid clogging processes before aquifer recharge projects start.The experiments investigated the clogging characteristics of different suspended solid sizes in recharge water by using a series of one-dimensional fine quartz sand columns.The results showed that the smaller the suspended particles in recharge water,the farther the distance of movement and the larger the scope of clogging in porous media.Clogging extents in fine sand were 1 cm,for suspended particle size ranging from 0.075 to 0.0385 mm,and 2 cm,for particles less than 0.0385 mm.In addition,clogging development occurred more rapidly for smaller suspended solid particles.It took 48,42,and 36 hr respectively,for large-,medium-,and small-sized particles to reach pre-determined clogging standards.An empirical formula and iteration model for the surface clogging evolution process were derived.The verification results obtained from stormwater recharge into fine sand demonstrated that the model could reflect the real laws of the surface clogging process.     

内配燃料垃圾焚烧飞灰烧结无害化处理实验研究

研究了一种垃圾焚烧飞灰烧结无害化处理的工艺,该工艺是将飞灰与不同比例煤粉混合并添加助熔剂进行造粒烧结。通过对试样进行热流和热重测量,分析了飞灰试样在加热过程中热重变化的规律,并利用XRD、扫描电镜、氮吸附分析仪等仪器分析手段对烧结试样的物相、微观形态和孔隙特性等物理化学性质进行了研究。最后采用电感耦合等离子体发射光谱仪对烧结试样重金属浸出性进行了分析。实验结果为飞灰烧结炉的设计和内配燃料烧结工艺运行参数的制定提供了依据。     

环氧化PVA载体固定漆酶的最佳工艺条件研究

在T=35℃,HAc-NaAc缓冲溶液pH为4的条件下,用环氧化PVA载体对漆酶进行固定化,固定后酶活为游离酶活的95%。用该固定化漆酶处理制浆造纸废水,反复使用6次后,酶活仍保持为初始酶活的45%,且每次COD去除率在40%以上,处理后的废水BOD增大了50%,废水可生化性得到很大提高。     

Morphology and composition of particles emitted from a port fuel injection gasoline vehicle under real-world driving test cycles

Traffic vehicles, many of which are powered by port fuel injection (PFI) engines, are major sources of particulate matter in the urban atmosphere. We studied particles from the emission of a commercial PFI-engine vehicle when it was running under the states of cold start, hot start, hot stabilized running, idle and acceleration, using a transmission electron microscope and an energy-dispersive X-ray detector. Results showed that the particles were mainly composed of organic, soot, and Ca-rich particles, with a small amount of S-rich and metal-containing particles, and displayed a unimodal size distribution with the peak at 600?nm. The emissions were highest under the cold start running state, followed by the hot start, hot stabilized, acceleration, and idle running states. Organic particles under the hot start and hot stabilized running states were higher than those of other running states. Soot particles were highest under the cold start running state. Under the idle running state, the relative number fraction of Ca-rich particles was high although their absolute number was low. These results indicate that PFI-engine vehicles emit substantial primary particles, which favor the formation of secondary aerosols via providing reaction sites and reaction catalysts, as well as supplying soot, organic, mineral and metal particles in the size range of the accumulation mode. In addition, the contents of Ca, P, and Zn in organic particles may serve as fingerprints for source apportionment of particles from PFI-engine vehicles.     

A laboratory study on migration of K+ in a two-layer landfill liner system.

Contaminant transport through the clay liner and the underIying secondary leachate drain layer (SLDL) in landfills was studied through a laboratory test, and analysis method on the transport of K+ in a two-layer soil system. The soils used for this study were Ariake clay and the underlying layer, Shirasu soil from the Kyushu region of Japan, representing the clay liner material and SLDL material, respectively. The effective diffusion coefficients (De) of the selected target chemical species, potassium (K+) for the Ariake clay and Shirasu soil were back-calculated using a computer program, and it was found that values of De derived from this study were consistent with those previously published. The hypothesis that the mechanical dispersion process can be negligible has been proved to be reasonable based on both the observation that the predicted values fit the experimental data and the analyses of two dimensionless parameters. Parametric analysis showed the transport of K+ through the soils is controlled by advection-diffusion rather than diffusion only, whereas at low Darcy velocity (i.e. < or = 10(-9) m s(-1)), transport of K+ would be controlled by diffusion. The test results and parametric analysis may be applied in design of landfill liners and SLDLs, particularly in coastal areas.     

湖北省湖泊水环境化学特征及其与人类活动的关系

通过对湖北省近３０个湖泊水环境化学的分析，探讨了湖北省湖泊水质状况和湖水的化学稳定性，指出远离工业区和居民生活区的湖泊水质一般较好，城区或城效型湖泊在不同程度上受到了工业废水和生活污水的影响。控制，消除湖泊污染是今后经济、社会和环境建设不可忽视的重要工作。     

Metal accumulation in intertidal litter through decomposing leaf blades, sheaths and stems of Phragmites australis

Metal contents of decomposing leaf blades, leaf sheaths and stems of common reed (Phragmites australis) were monitored by a litter bag method on the sediment of an intertidal brackish marsh in the Scheldt estuary (The Netherlands). On monthly intervals, two litter bags were retrieved from the marsh during 9 months for both leaf blades and sheaths and during 16 months for stems. All samples were dried, weighed and analysed for ash and Cd, Cu, Cr, Ni, Pb and Zn contents. Most concentrations increased considerably during the decomposition. Generally, also a very important net metal inflow into the litter bags could be observed. The inflow was highest for leaf blades. High correlations between ash contents and metal concentrations for leaf blades suggest that the increase of leaf blade metal contents can be due to physicochemical sorption of dissolved metals and an important infiltration of mud particles, which were not removed by rinsing the leaf blades with distilled water preceding the analyses. For stems, smaller amounts of inflowing ash and even outflowing ash amounts were found, which suggests that inflow of inorganic particles is not the major factor determining metal accumulation by stems on medium term. Ergosterol concentrations in stem tissue however proved to be correlated with metal contents, which suggests a significant role of fungal litter colonizers in metal accumulation. For leaf sheaths, the effects of physicochemical sorption, infiltration of mud particles and incorporation by microbial litter colonizers do not seem to be as pronounced as for stems and leaf blades.