Up to 95 % reduction of chemical oxygen demand of slaughterhouse effluents using Fenton and photo-Fenton oxidation

Meat industries produce effluents containing high concentrations of organic and inorganic compounds, which must be removed before being discharged or reused. Advanced oxidation processes using Fenton reaction coupled with UV, solar radiation, and electrochemical oxidation are promising methods. Here, we treated the effluent from an anaerobic digester using: (a) the photoelectro-Fenton process, using a system with a Ti-RuO₂ anode and a carbon felt cathode, (b) the solar photo-Fenton process, using a batch reactor and a compound parabolic collector, and (c) a combination of Fenton and solar photo-Fenton processes. The effluent had an initial chemical oxygen demand (COD) of 1159 mgL^?1, and we obtained high removal efficiencies of COD, up to 95 %, using the combination of Fenton and solar photo-Fenton processes.     

Polychlorierte Naphthaline

Measurements show that PCN may occur in industrial waste and residues in the mg/kg range. Investigations were carried out with optimized parameters for GC and MS using two different GC/MS-systems. Chromatograms were obtained for a variety of chlorination degrees using capillary columns of different polarities. It is proposed to quantify PCN using relevant single compounds comparable to the analysis of polychlorinated biphenyls.     

Nitropyridoindoles—Formation,characterization and mutagenicity

Nitration of pyridoindoles (β‐carbolines) was carried out using different nitration methods and structural assignments of these nitro compounds were made using different spectroscopic techniques. The mutagenic activity of these nitro derivatives was studied using Salmonella typhimurium strains TA 98 NR and TA 100 NR in the absence as well as in the presence of S‐9 mix. Only trinitro derivatives were found to be highly mutagenic to strain TA 98 NR.     

土壤-植物根际磷的生物有效性研究进展

探讨土壤-植物根际磷素养分状况及利用机理,提高土壤磷的生物有效性,使土壤中潜在的难溶性磷库活化,提高磷肥利用率,对促进农业生产的持续高效发展和陆地生态系统的良性循环具有重大的现实意义。文章从这一角度出发,论述了根际土壤中根际微生物、根际pH值、根系分泌物、菌根、根际土壤磷酸酶等各种因素对提高土壤磷素利用率的机理。     

两种底质对狐尾藻生长和生理指标的影响

在温室条件下,分别以土壤和沉积物作为底质,模拟研究狐尾藻(Myriophyllum spicatum)生长和生理指标的变化。结果表明:与营养水平相当的沉积物相比,以土壤作为底质的处理,其狐尾藻茎叶生物量降低了87.15%,根系生物量增加了226.54%,根系活力降低了46.46%,超氧化物歧化酶(SOD)和过氧化物酶(POD)活性分别增加了134.20%和119.91%,上覆水和间隙水中活性磷浓度分别增加了146.67%和1382.61%。以土壤为底质,增加该处理水体中磷浓度,抑制狐尾藻生长。     

Introduction of the land snail Cornu aspersum as a bioindicator organism of terrestrial pollution with the use of a suite of biomarkers

The use of organisms in biomonitoring studies allows the determination of the pollution levels, the assessment of the quality of the enviroment and the study of toxic effects of pollutants on the organisms. By studying the responses (biomarkers) of organisms, it is possible to assess the exposure and effects of pollutants. Land gastropods are widely used in relevant studies as they possess several characteristics that make them ideal for use as bioindicators. In the present study we sought to evaluate several biomarkers in the laboratory using snails of the species Cornu aspersum after the exposure to heavy metals (Cd, Hg) and a mixture of polycyclic aromatic hydrocarbons (PAHs) (anthracene, phenanthrene and naphthalene). The biomarkers studied were the following: lysosomic membrane stability using the neutral red retention assay (NRR), the production of reactive oxygen species (ROS) using the compound DCFH-DA and flow cytometry, lipid peroxidation using the TBARs assay that measures the concentration of malondialdehyde (MDA), protein carbonylation (–CO) using ELISA, and single strand breaks of DNA using the comet assay. Our results show significant differences in the responses between the control group and the groups that were exposed to pollutans, enhancing the role of Cornu aspersum as a promising bioindicator organism in terrestrial pollution studies with the use of the biomarkers applied.     

酸性染料的臭氧降解与中间产物

以酸性金黄G模拟染料废水为研究对象,观察臭氧氧化过程中染料溶液吸光度和TOC的变化,利用离子色谱仪、红外光谱仪和GC/MS对染料的降解过程进行了分析,并用发光细菌法检测了溶液急性毒性的变化,结果表明,臭氧对染料的降解符合一级反应动力学,反应40 min后染料溶液的脱色率达到99.3%,TOC去除率为35.7%;染料分子中的S有97.8%被转化为SO2-4,分子中的仲胺基部分转化成酰胺基,水解后生成NH+4,最终氧化成NO-3,溶液中有草酸产生;溶液在臭氧化前期由于生成了醛类和酚类物质,使急性毒性首先呈上升趋势,25min后随着氧化的深入,溶液毒性开始逐渐下降,     

利用紫露草微核技术监测滇池水质污染

以蒸馏水和自来水处理作阴性对照,以不同浓度的ＮａＮ３,ＨｇＣｌ２处理作阳性对照,用紫露同核监测法对滇池１１个样点的水样进行了监测评价;结果表明：滇池１１个样点的水样均使使紫露草四分体微核率增加;紫露草微核监测与化学监测结果是基本一致的;将１１个样点的水质污染分为三种程度,重污染,中污染和轻污染。     

Comparison of extraction methods for polycyclic aromatic hydrocarbon determination in sediments

Different sample preparation methods for the determination of polycyclic aromatic hydrocarbons (PAHs) in lake and river sediments were compared and evaluated. Freeze‐dried sediment materials were extracted using Soxhlet extraction, ultrasonic agitation and digestion with various solvents and solvent mixtures. Similarly, clean‐up methods using various types of sorbents for separation of PAHs tested.

The following method gives the best results for the determination of PAHs: freeze‐dried sediment samples were extracted using Soxhlet extractor with dichloromethane (6 hr, dark), extracts were cleanup using Silica gel and a mixture of n‐hexa‐ne‐dichloromethane was used for the elution of PAHs.

This method was used for the determination of 7 selected PAHs in sediment samples from Finnish lakes and Czech streams.     

Cycling in ecosystems: An individual based approach

Cycling index is an important ecological indicator used in ecosystem analysis. The higher the cycling in an ecosystem, the higher the utilization of mass and energy within the system before it is lost due to respiration and other factors. For a stock-flow type ecosystem model at steady state, Finn’s cycling index (FCI) can be computed using simple matrix algebra. However, it is difficult to measure how well this index represents the actual cycling occurring in the system. In this paper, we study cycling in ecological networks using an individual based approach (particle tracking algorithm). This new simulation method provides access to the pathway data of individual particles that flow in the system, therefore one can quantify cycling using this pathway data quite literally. We used particle tracking simulations (PTS) to compute a cycling index using Finn’s idea of flux based cycling. Our simulation based results (using no matrix algebra) agree with Finn’s cycling index, verifying the accuracy of both the PTS, and the original linear algebraic formulation of FCI.     

Spatiotemporal hierarchical modelling of extreme precipitation in Western Australia using anisotropic Gaussian random fields

We discuss an approach for the statistical modelling of extreme precipitation events in South-West Australia over space and time, using a latent spatiotemporal process where precipitation maxima follow a generalised extreme value distribution. Temporal features are captured by modelling trends on the location and scale parameters. Spatial features are captured using anisotropic Gaussian random fields. Site specific explanatory variables are also incorporated. We fit several models using Bayesian inferential methods to precipitation extremes recorded at 36 weather stations around the Western Australian state capital city of Perth over the period 1907–2009. Model choice is performed using the DIC criterion. The best fitting model shows significant non-stationarity over time, with extreme precipitation events becoming less frequent. Extreme precipitation events are stronger at coastal locations, with the intensity decreasing as we head to the higher and drier areas to the North-East.     

Cu2+、Cd2+和Cr6+对斑马鱼联合毒性作用和生物预警的研究

为了研究重金属对水生生物的联合毒性作用,以斑马鱼为受试生物,采用半静态法,在研究Cu2、Cd2和Cr6+对斑马鱼单一毒性的基础上,以获得的Cu2+、Cd2+和Cr6+的96 h-LC50数据,利用等效应曲线法研究了Cu-Cd、Cu-Cr和Cd-Cr的联合毒性作用,并综合分析环境毒理学指标的测定结果,考察利用斑马鱼作为水...     

论大学生思想政治工作进网络之紧迫性

在对大学生利用网络的情况进行调查的基础上，总结出学生使用网络的现实基本状况，并分析学生上网存在的问题，指出学院的思想政治工作进网络的紧迫性。     

A Bayesian strategy for combining predictions from empirical and process-based models

We present a strategy for using an empirical forest growth model to reduce uncertainty in predictions made with a physiological process-based forest ecosystem model. The uncertainty reduction is carried out via Bayesian melding, in which information from prior knowledge and a deterministic computer model is conditioned on a likelihood function. We used predictions from an empirical forest growth model G-HAT in place of field observations of aboveground net primary productivity (ANPP) in a deciduous temperate forest ecosystem. Using Bayesian melding, priors for the inputs of the process-based forest ecosystem PnET-II were propagated through the model, and likelihoods for the PnET-II output ANPP were calculated using the G-HAT predictions. Posterior distributions for ANPP and many PnET-II inputs obtained using the G-HAT predictions largely matched posteriors obtained using field data. Since empirical growth models are often more readily available than extensive field data sets, the method represents a potential gain in efficiency for reducing the uncertainty of process-based model predictions when reliable empirical models are available but high-quality data are not.     

O3/UV降解喹啉过程中的毒性变化

利用发光细菌新鲜菌悬液进行毒性测试，研究了O3／UV降解喹啉过程中的毒性变化．研究表明，在选取的浓度范围内，无论是HgCl2还是喹啉，发光细菌发光抑制率(或相对发光量)与物质浓度的对数均呈线性关系．采用处于对数生长期初期的发光细菌进行毒性测试时的灵敏度和最低检测限都很理想，适合于毒性测试．O3／UV降解喹啉时，体系毒性出现先迅速上升并保持一段时间随后缓慢下降然后又缓慢上升的现象．O3／UV降解喹啉过程中产生了毒性更强的中间产物，这些产物是导致体系毒性上升的主要因素。     

固定化微生物脱氮技术进展

:氮污染已日益严重 ,但现有的生物脱氮技术存在许多问题。因此世界各国研究者纷纷研究改进技术 ,硝化细菌和反硝化细菌固定化生物脱氮是其中一个主要的研究方向。文章综述了固定化微生物脱氮技术的研究进展 ,包括固定介质、主要的固定化方法和技术以及固定化微生物在废水生物脱氮方面的应用。     

Electrochemical determination of methyl parathion using a modified electrode

Electrochemical studies of pesticides using various electrode systems attain prominence in recent years because of their application in trace determinations. Cyclic voltammetric studies of methyl parathion on a glassy carbon electrode at various pH in 50% aqueous ethanol medium were carried out. Influence of pH led to the selection of pH 1.0 as the best pH for the electroanalysis of methyl parathion. The number of electrons transferred was determined using controlled potential coulometry. On the basis of the results a probable reduction mechanism was proposed. Cyclic voltammetric studies of methyl parathion using polypyrrole deposited and sodium montmorillonite clay modified electrodes in the presence of cetyl trimethyl ammonium bromide were carried out. The clay-modified electrode and the reduction peak around ?0.2?V were selected for stripping analysis owing to their maximum current response. The experimental parameters were optimized using the differential pulse stripping mode. A calibration plot was made. The determination limit and standard deviations were arrived. The applicability of the method was also verified in a sample soil analysis.     

Nanomaterials for water cleaning and desalination,energy production,disinfection, agriculture and green chemistry

Nanomaterials may help to solve issues such as water availability, clean energy generation, control of drug-resistant microorganisms and food safety. Here we review innovative approaches to solve these issues using nanotechnology. The major topics discussed are wastewater treatment using carbon-based, metal-based and polymeric nanoadsorbents for removing organic and metal contaminants; nanophotocatalysis for microbial control; desalination of seawater using nanomembranes; energy conversion and storage using solar cells and hydrogen-sorbents nanostructures; antimicrobial properties of nanomaterials; smart delivery systems; biocompatible nanomaterials such as nanolignocellulosis and starches-based materials, and methods to decrease the toxicity of nanomaterials. Significantly, here it is reviewed two ways to palliate nanomaterials toxicity: (a) controlling physicochemical factors affecting this toxicity in order to dispose of more safe nanomaterials, and (b) harnessing greener synthesis of them to bring down the environmental impact of toxic reagents, wastes and byproducts. All these current challenges are reviewed at the present article in an effort to evaluate environmental implications of nanomaterials technology by means of a complete, reliable and critical vision.