农田灌溉水中挥发酚的流动分析-分光光度分析法的建立

主要通过使用流动分析仪对农田灌溉水中的挥发酚进行测定,有效地提高了检测的精密度与准确度。相比传统分光光度计检测法,此法更方便和快捷,大大降低了样品的使用量,节省了人力物力,较好地满足了批量样品测定的要求,值得大力推广和应用。     

Penicillium chrysogenum: Phenol Degradation Abilities and Kinetic Model

Phenol is a typical contaminant of the environment generated by many industries. Several fungi had been reported to degrade phenol as the only source of carbon and energy, but many of them are not useful to apply in soil bioremediation process. In this work, we study the dynamics of phenol degradation by a Penicillium chrysogenum, isolated from soil. Degradation of phenol was studied at room temperature and resting mycelium conditions. High specific degradation rates were obtained. Inhibition was observed on the specific growth rate (30?mg?l¹) and the degradation rate (200?mg?l^?1). Experimental results were fitted to several models during exponential phase, with the Andrews-Haldane model given the best fit. Dynamic mass balance equations for biomass and phenol during the exponential and stationary growth phases were solved and compared very satisfactorily to experimental outcomes. P. chrysogenum degrades phenol completely during the exponential and stationary growth phases. The results obtained are relevant for its practical applications in soil decontamination processes. Model predictions were satisfactory. This is the first work which describes a kinetic model for phenol biodegradation using a filamentous fungus considering both, exponential and stationary phases, and the first one in which a Penicillium isolate is used.     

Organobentonite for Sorption and Degradation of Phenol in the Presence of Heavy Metals

An experimental study was performed to determine the feasibility of usingorganobentonite modified with quarternary ammonium cations (QACs) as a reactive medium in immobilization and biodegradation barriers for mixed contaminants in the subsurface soil. Various factors, including interactions between heavy metals, organic contaminants, and soil microorganisms, were investigated when they coexisted with untreated bentonite and organobentonite. Batch sorption tests for cadmium and lead were conducted to quantify sorption selectivity of these metals on untreated bentonite and organobentonite. Metal concentrations of 50 × 10^-6 M slightly reduced the growth of soil microbes and partially interfered with the biodegradation of phenol. Soil microorganisms tested with untreated bentonite grew after approximately 25 hr of lag period and degraded phenol completely within 350 hr. The results from this study demonstrate that organobentonite could be used as a reactive medium for immobilization and biodegradation of organic contaminants in the presence of heavy metals in the subsurface soil.     

From Media to Molecules: New Approaches to the Detection of Micro-organisms in Water

Present methods for the detection of micro-organisms in the environment are slow, inefficient and often unreliable. Alternative approaches which are reliable and rapid, enabling results to be obtained within one working day, are required. The development of molecular techniques, in particular in situ hybridisation offers the potential for rapid and specific assays. This paper describes the use of oligonucleotide probes targeted against the 16S and 18S ribosomal RNA molecules of Escherichia coli and Cryptosporidium parvum for rapid and specific detection. In situ hybridisations with biotinylated peptide nucleic acid (PNA) probes in combination with the tyramide signal amplification (TSA) system enabled the specific detection of Escherichia coli and Cryptosporidium parvum within 3 hours. The C. parvum assay provided a species-specific alternative to the currently available fluorescent antibody approach.     

Produced Water Surface Spills and the Risk for BTEX and Naphthalene Groundwater Contamination

The widespread use of unconventional drilling involving hydraulic fracturing (“fracking”) has allowed for increased oil-and-gas extraction, produced water generation, and subsequent spills of produced water in Colorado and elsewhere. Produced water contains BTEX (benzene, toluene, ethylbenzene, xylene) and naphthalene, all of which are known to induce varying levels of toxicity upon exposure. When spilled, these contaminants can migrate through the soil and contaminant groundwater. This research modeled the solute transport of BTEX and naphthalene for a range of spill sizes on contrasting soils overlying groundwater at different depths. The results showed that benzene and toluene were expected to reach human health relevant concentration in groundwater because of their high concentrations in produced water, relatively low solid/liquid partition coefficient and low EPA drinking water limits for these contaminants. Peak groundwater concentrations were higher and were reached more rapidly in coarser textured soil. Risk categories of “low,” “medium,” and “high” were established by dividing the EPA drinking water limit for each contaminant into sequential thirds and modeled scenarios were classified into such categories. A quick reference guide was created that allows the user to input specific variables about an area of interest to evaluate that site’s risk of groundwater contamination in the event of a produced water spill. A large fraction of produced water spills occur at hydraulic-fracturing well pads; thus, the results of this research suggest that the surface area selected for a hydraulic-fracturing site should exclude or require extra precaution when considering areas with shallow aquifers and coarsely textured soils.     

Microalgal Dynamics in Batch Reactors for Municipal Wastewater Treatment Containing Dairy Sewage Water

This study investigates the microalgal community dynamics associated with changes in municipal wastewater quality and discharges from the dairy industry in central Veracruz, Mexico, using an experimental stabilization-reactors system. Thirty one species of microalgae were recorded and 15 physicochemical variables were measured daily over 25 days in pretreated water. The biomass of microalgal groups displayed significant negative correlations with biochemical oxygen demand (BOD), chemical oxygen demand (COD) and total suspend solids (TSS). Conversely, a significant positive correlation was found with dissolved oxygen, pH and nitrates. Using the Canonical Correspondence Analysis we identified an initial anaerobic phase (Phase I), characterized by high BOD, TSS and COD, ammonium and faecal coliforms. This was followed by a transition phase (Phase II), an initial aerobic phase (Phase III), when water quality improved considerably, and finally an aerobic phase (IV) with a high percent reduction in these parameters and almost complete organic load removal. The most abundant species associated with these phases were Arthrospira jenneri (Cyanophyceae) and Coccomonas sp. (Chlorophyceae) in Phase I; Polytomella sp. (Chlorophyceae) in Phase II; Polytoma tetraolare, Chlamydomonas caeca (Chlorophyceae) and some Cyanophyceae including Geitlerinema, Synechocystis, Cyanobium and Glaucospira in Phase III; Carteria sp. (Chlorophyceae), Lepocynclis ovum and Euglena clavata (Euglenophcyeae) in Phase IV. Maximum richness, diversity, and biomass levels occurred during the aerobic phase. Similar to other wastewater treatment systems the high succession rates decreased with reactor stabilization. These findings provide statistical evidence on the suitability of certain microalgae species as indicators of wastewater stabilization reactor status and effluent quality.     

Identification of Cytotoxicity Intermediate Products and Degradation Pathways for Microcystins Using Low-Frequency Ultrasonic Irradiation

In this study, two microcystins (MCs) were examined. MC-LR and MC-RR were degraded with low frequencies (20, 40, 60, 100, and 200?kHz) of ultrasonic waves. The optimal ultrasonic frequency for treating MCs was 200?kHz. Kinetic reaction results indicated that the degradation reactions of MC-LR and MC-RR from low-frequency ultrasound obeyed the pseudo-first-order kinetic model. The structural characterizations of the intermediate products were identified via liquid chromatography-mass spectrometry, which elucidated the mechanism of the degradation pathways. The main degradation pathways in the LC-MS analysis were Adda and Mdha. The cytotoxic effects on human oral epidermoid carcinoma (KB) cells were evaluated through cell viability assay using 3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide. The inhibitory effect of ??5???g/mL MC-LR on KB cells was significantly enhanced in a dose-dependent manner. Compared with the control, the viability of the KB cells cultured with 15 and 5???g/mL MC-LR was increased by 23?% and 29?%, respectively, after the application of MC-LR and the optimization of the frequencies' ultrasonic irradiated treatment for 48?h. A similar trend was observed in the degradation of ultrasonic irradiated MC-RR. Compared with the control, the viability of the KB cells cultured with 15 and 5???g/mL MC-RR increased by 12?% and 22?%, respectively (P?<?0.05). Results showed that low-frequency ultrasonic irradiation effectively reduced the cytotoxicity of the intermediate products of MCs. Therefore, low-frequency ultrasound is a feasible method for the detoxification of drinking water.     

合理利用城市水资源的几种途径

在水资源日益匮乏的今天,如何最大限度地利用已有的水资源,更好地为人们的生产、生活服务,已成为倍受社会关注的焦点问题。目前,我国面临的水资源短缺状况和水资源的有限性都要求我们另辟蹊径来解决用水问题。本文从节约用水、回收可处理利用的工业废水、减少城市污水排放等方面阐述了在建设节水型社会的大环境下,合理利用城市水资源的几种途径。     

水溶液和芦笋中毒死蜱的辐照降解

为寻求一种能有效降解毒死蜱残留的技术方法,本文采用60Co γ射线辐照水溶液和芦笋中的毒死蜱,并对比了毒死蜱的辐照降解率。结果表明,辐照剂量在0～12kGy时,水溶液中毒死蜱的降解率随剂量的增加而增大,4kGy的辐照可使其降解率达95.5%;芦笋中毒死蜱的辐照降解率偏低,8kGy辐照时降解率最高,达到30.0%。进一步研究表明,芦笋成分Vc、芦丁和总糖等的存在对辐照降解毒死蜱有抑制效应。     

Sonochemical Degradation of Chlorinated Phenolic Compounds in Water: Effects of Physicochemical Properties of the Compounds on Degradation

This study examined a comparative degradation of various chlorinated phenolic compounds including phenol, 4-chlorophenol (4-CP), 2,6-dichlorophenol (2,6-DCP), 2,4,6-trichlorophenol (2,4,6-TCP), 2,3,4,6-tetrachlorophenol (2,3,4,6-TeCP), and pentachlorophenol (PCP) using 28, 580, and 1,000 kHz ultrasonic reactors. The concentration of hydrogen peroxide was also determined in order to investigate the efficacy of different sonochemical reactors for hydroxyl radical production. Clearly, it was observed that the 580 kHz sonochemical reactor had maximum efficacy for hydroxyl radical production. The degradation of all the compounds followed the order; 580 kHz (91?C93%) > 1,000 kHz (84?C86%) > 28 kHz (17?C34%) with an initial concentration of 2.5 mg L^?1 at a reaction time of 40 min with ultrasonic power of 200 ± 3 W and aqueous temperature of 20 ± 1°C in each experiment. Overall, the degradation of those phenolic compounds followed the order, PCP > 2,3,4,6-TeCP > 2,4,6-TCP > 2,6-DCP > 4-CP > phenol at various frequencies in the presence/absence of a radical scavenger (tert-butyl alcohol). It was revealed that the correlations between the compound degradation rates and the physicochemical parameters, R ² = 0.99 for octanol?Cwater partition coefficient, R ² = 0.95 for water solubility, R ² = 0.94 for vapor pressure, and R ² = 0.88 for Henry??s law constant, excluding PCP, were very good in the entire range of each parameter.     

水资源管理模式的变迁与比较研究

研究水资源管理模式对实现水资源可持续利用具有重要意义,人类在开发利用水资源的过程中,经过了供给管理与需求管理、资源化管理与资产化管理、分散管理与集中管理、集成化管理等几个不同的管理模式。在分析比较这些管理模式的产生背景、主要内容和优缺点的基础上,认为水资源管理模式的形成和发展缘自于人类对水资源管理的实践,即如何提高水资源的利用效率和配置效率,水资源管理模式的变迁是一个随经济发展变化的演进过程。     

八棱海棠MdPPO2B基因的克隆及降解苯酚研究

为了探索果树对酚类化合物的修复潜力,从八棱海棠中克隆获得多酚氧化酶基因Md PPO2B,并构建该基因植物超量表达载体,通过转化模式植物拟南芥研究该基因对酚类化合物的修复功能。结果表明,在平板、盆栽、液体3种试验中,不加入苯酚,转基因植株在生长状态和外部形态上和野生型相似;当苯酚浓度分别为0.1 m M和1 m M时,通过植物的根长、叶片鲜重等比较发现,转基因株系比野生型植株对苯酚的耐受性更强,其生长形态较为正常,而野生型植株的生长则受到了明显抑制。由此可见,Md PPO2B转基因植物的PPO活性在植物降解酚类化合物过程中起重要作用;使用果树来源的多酚氧化酶基因用于有机污染物修复,对环境治理具有较好的应用前景。     

实现水土保持产业化的途径——以四川省宁南县为列

水土保持产业是指一项基础性产业，水土保持产业化是水土保持事业在市场经济条件下的必然选择，以四川省宁南县实现水土保持产业化发展的途径为例，探讨了在市场经济条件下如何实现水土保持产业化，并提出了笔者对我国水土保持产业化发展的几点看法。     

Characterization of Burkholderia sp. XTB‐5 for Phenol Degradation and Plant Growth Promotion and Its Application in Bioremediation of Contaminated Soil

A key issue when researching land degradation is the pollution of soils. For bioremediation of contaminated soil, Burkholderia sp. XTB‐5 cells were obtained from soil and grown on mineral salt medium with initial phenol concentrations of 650 mg L⁻¹ and 850 mg L⁻¹, which were found to degrade more than 98% of phenol content in less than 4 days. About 90% of phenol content (with initial concentration of 250 mg kg⁻¹ soil) was removed from soil inoculated with XTB‐5 cells in 6 days. More than 90% of phenol content was removed within 20 days after co‐introduction of XTB‐5 cells and plants to sterilized soil in a greenhouse or to natural soil in field trials. But under the same conditions, individual introduction of plants to sterilized soil in the greenhouse reduced phenol content by about 50% and introduction to natural soil in field trials reduced phenol content by about 38%, suggesting that phytoremediation of phenol is often inefficient and microorganisms can efficiently degrade this pollutant. In addition, strain XTB‐5 was found to solubilize phosphate and produce 1‐Aminocyclopropane‐1‐Carboxylate (ACC) deaminase and siderophore. Strain XTB‐5 promoted plant growth in both phenol‐absent and phenol‐spiked soil under greenhouse and field conditions. Considering that ACC deaminase is beneficial to plant growth under adverse environmental conditions, plant growth promotion by XTB‐5 in phenol‐contaminated soil is not only due to XTB‐5 cell‐degradation of phenol and reduced phytotoxicity but also to production of ACC deaminase. Hence, Burkholderia sp. XTB‐5 presents an attractive microorganism for phytoremediation of contaminated soil and agronomic application. Copyright © 2016 John Wiley & Sons, Ltd.     

杭州市水资源承载力评价及提升路径

[目的]评价浙江省杭州市的水资源承载力,分析不同区域出现超载问题的原因,并研究破解超载问题的对策和提升承载力的路径。[方法]在国家试行的水资源承载能力评价方法的基础上,提出兼顾水量、水质并考虑上游来水情况的承载力评价方法和超载成因分析指标体系,对杭州市8个评价单元(包括主城区和7个县、市、区)的水资源承载力进行评价并分析超载成因。[结果]近3a(2013—2015年)杭州市水资源承载力趋向改善,超载和临界超载单元数量逐年下降,从7个下降到2个。超载和临界超载问题主要是由于快速城市化导致的用水总量区域差异拉大,现代都市生活方式对水资源需求明显增大,平原河网地区环境自净能力不足,部分流域上游县市水资源利用效率偏低等原因造成的。[结论]建议针对水资源超载区域和主要问题,从保障、整治、限制、监管4个方面完善水资源管理政策和措施。     

鲁山县水土保持综合治理开发途径研究

该文以鲁山县１９９２－１９９６年不土保持综合治理开发项目区为依托,通过水土保持坡面,沟道工程及林草配置防护建设和水土资源开发利用。商品基地建设等途径进行了探索性试验研究和效益分析,阐明水土保持是山区发展的生命线,是国土整治,江河治理的根本,对促进山区经济持续发展战略目标的实现具有十分重要的意义。     

UV Light-Assisted Degradation of Methyl Orange,Methylene Blue,Phenol, Salicylic Acid,and Rhodamine B: Photolysis Versus Photocatalyis

Methyl orange (MO), methylene blue (MB), phenol (F), salicylic acid (SA), and rhodamine B (ROD) were used as substrates during the photodegradation experiments in the absence and in the presence of nanostructured Ag/titania-silica. The catalyst was characterized by scanning electron microscopy (SEM), scanning transmission electron microscope high-angle annular dark field (STEM-HAADF), stereological analysis, nitrogen adsorption-desorption, and X-ray photoelectron spectroscopy (XPS) measurements. The results were fitted on pseudo-first and pseudo-second kinetic order models. The film diffusion was also determined. The photolysis degrades MO and F to a greater extent than the photocatalysis. The degradation of SA occurred at the same rate either by photolysis or by photocatalysis. MB was best removed by photocatalysis. With regard to the photocatalysis, the highest rates of film diffusion were obtained for MB, F, and ROD, meaning that these molecules crossed the film to arrive at the catalyst surface more rapidly than the others. For MO and MB, the results followed the pseudo-first-order kinetic model while for SA, F, and ROD, the pseudo-second-order kinetic model was more appropriate.