Analysis of priority substituted phenols by micellar electrokinetic chromatography

The use of micellar electrokinetic capillary chromatography (MECC) for the separation of eleven substituted phenols listed by the United States Environmental Protection Agency as priority pollutants was demonstrated. The effects of the pH and ionic strength of the buffer, and the length of the separation column on resolution were investigated. The retention characteristics of the eleven phenols in MECC are discussed.     

Direct coupling of supercritical fluid extraction-supercritical fluid chromatography for the determination of selected polycyclic aromatic hydrocarbons in aqueous environmental samples

A rapid and simple method is described for the quantitative determination of polycyclic aromatic hydrocarbons in aqueous environmental samples. A microscale on-line supercritical fluid extraction-supercritical fluid chromatography system using carbon dioxide is employed. The extract is analysed using capillary supercritical fluid chromatography with UV detection. Detection was carried out at 254 nm. An extraction efficiency of as high as 91% was obtained for the PAHs.     

An optimization procedure for the isocratic high-performance liquid chromatographic separations of environmental pollutants

This paper describes the use of the overlapping resolution mapping procedure to optimize the separation of priority pollutants by isocratic, reversed-phase high-performance liquid chromatography. Three classes of pollutants are considered: polycyclic aromatic hydrocarbons, substituted phenols and phthalate esters. The procedure requires only seven chromatographic runs for each set of pollutants before an optimized mobile phase composition is derived which can satisfactorily resolve all the components in the respective mixtures of pollutants. The main advantage of such a systematic scheme to optimize mobile phase compositions is an improvement in method development times compared to conventional techniques. Another benefit is that expenditures on solvents are reduced.     

超临界CO2萃取在环境样品预处理中的应用

阐述了超临界流体萃取的原理和特点，分析了温度、压力、流体流速、改性剂、络合剂等因素对萃取过程的影响，介绍了超临界CO2萃取技术的优点及其在萃取土壤中的有机污染物、非固体介质中的污染物、环境样品中的金属离子等方面的应用，对该技术的应用前景作了展望。     

乙腈盐析萃取HPLC-PDA同时测定水中11种苯胺类化合物

通过对色谱分析和样品萃取条件的选择和优化,建立了同时分析水中11种苯胺类化合物的HPLC方法。样品经乙腈盐析萃取后直接进样分析,采用 ODS色谱柱,以乙腈-水为流动相进行梯度洗脱,用PDA检测。结果表明,11种苯胺类化合物在0.20~100mg/L范围内其浓度和检测信号呈良好的线性关系,方法检出限为0.002~0.007mg/L,地表水和废水样品加标回收率为81.6%~97.4%,相对标准偏差为1.5%~5.5%。     

新疆准东经济技术开发区二氧化碳排放现状与降碳对策研究

通过分析新疆准东经济技术开发区各行业的二氧化碳排放量及排放特征,研究新疆准东经济技术开发区碳达峰碳中和的实现路径。分析结果显示,准东经济技术开发区最主要的二氧化碳排放源是化石燃料燃烧,其对二氧化碳排放量的贡献比例在95.2%以上。能源活动二氧化碳排放量占总排放量的98.5%以上;工业生产过程排放的二氧化碳较少,占比在1.5%以下。新疆准东经济技术开发区主要二氧化碳排放行业是煤电、电解铝、煤化工、硅基新材料。在此基础上,结合各行业特点,提出发展园区循环经济、制定低碳行业标准和培育低碳产业等详细对策。     

Investigation of the use of honey bees and honey bee products to assess heavy metals contamination

Forty-four water samples from eleven sampling points were collected from four highly polluted rivers of northern India once in each four seasons during 1988–1989. The samples were analyzed for phenol, chlorophenols, a few bromophenols and other organics. Phenol was found to be absent in all the analyzed samples. Trichlorophenol and pentachlorophenol were frequently detected. Comparatively, the Ganges river was most polluted at Kannauj followed by Narora, Kachala and Fatehgarh. Maximum phenols were found at Mathura downstream of the Yamuna river followed by Mathura upstream, Okhla, ITO and none at Wazirabad. No phenols were detected in the water of the rivers Hindon and Kali at Ghaziabad and Aligarh, respectively. Some other organic pollutants were also identified by their mass spectra and supported by data from the computerized library, but, not quantified.To whom correspondence should be addressed.     

流动注射—化学发光法测定大气二氧化硫

本文对大气二氧化硫的流动注射—化学发光法测定进行了研究.基于鲁米诺—碘—二氧化硫无机偶合化学发光反应,建立了测定大气二氧化硫的新方法.采用了流动注射气体扩散在线分离技术,使得经典的化学发光测定的选择性大大提高.对鲁米诺—碘这一化学发光体系有很强催化作用的金属离子及其它酸化后不挥发的物质均不影响本体系的测定.方法具有简单、快速、选择性好的特点.已用于大气环境监测分析,结果较满意.     

Voltammetric trace determination of mercury using plant refuse modified carbon paste electrodes

Citrus limon peel (kitchen waste) and Leucaena leucocephala seeds (agricultural waste) were used as a modifier for fabrication of modified carbon paste electrode for determination of mercury in aqueous sample using differential pulse anodic stripping voltammetry. Mercury was adsorbed on electrode surface at open circuit and anodic stripping voltammetric scan was run from ?0.5 to 0.5 V. Various electrochemical parameters including amount of modifier, supporting electrolyte, accumulating solvent, pH of the accumulating solvent, and accumulation time were investigated. The effect of presence of other metal ions and surfactants was also studied. In comparison C. limon peel proved to be a better modifier than L. leucocephala seed biomass. This was justified by electrode characterization using cyclic voltammetry that indicated decrease in resistance of electrode when C. limon peel was used as modifier and increase when modifier was L. leucocephala seeds. Maximum current response was obtained using 5 % C. limon peel biomass, hydrochloric acid as supporting electrolyte, acetate buffer of pH 6 as an accumulating solvent, 10-min accumulation time, and scan rate of 50 mV/s. Linear calibration curves were obtained in the concentration range 100 to 1,000 μg L^?1 of mercury for accumulation time of 10 min with limit of detection of 57.75 μg L^?1 and limit of quantification of 192.48 μg L^?1. This technique does not use mercury as electrode material and, therefore, has a positive environmental benefit.     

Catalytic hydrogenation of polyaromatic hydrocarbon (PAH) compounds in supercritical carbon dioxide over supported palladium

A series of supported palladium catalysts were evaluated for their ability to mediate the complete hydrogenation of polycyclic aromatic hydrocarbon (PAH) compounds. Benzo[a]pyrene (B[a]P) or phenanthrene (Phe) in hexane was merged with a hydrogen-carbon dioxide [5% (w/w) H(2)/CO(2)] stream and transferred to a flow through mini-reactor (capacity ca. 1 g) that was maintained at 90 degrees C under a back-pressure of 20.68 MPa. Effluent from the reactor trapped in hexane was monitored/quantified by gas chromatography-mass spectrometry. Catalyst formulations supported on iron powder, high density polyethylene (HDPE) or gamma-alumina were prepared and compared in terms of hydrogenation activity as measured by the quantity of substrate per unit time that could be perhydrogenated to toxicologically innocuous products. Both of the Pd preparations supported on gamma-alumina were more efficient than a commercial Pd(0) (5% w/w) on gamma-Al(2)O(3) formulation or preparations supported on HDPE or the iron powder. Bimetallic mixtures with Pd increased the hydrogenation activity when co-deposited with Cu or Ni but not with Ag or Co. However, increases in hydrogenation activity by increasing the loading of Pd (or bimetallic mixture) on this surface were limited. Despite using supercritical carbon dioxide (scCO(2)) to swell the surfaces of the polymer, the deposition of nanoparticles within the polyethylene formulation was appreciably less active than either the oxidic or the Fe(0) formulations.     

低碳经济背景下克拉玛依市的发展现状分析

克拉玛依是一座典型的资源型城市,正处于工业化、城市化快速发展的阶段,能源消费和CO2排放持续增长将成为克拉玛依经济发展的硬约束。本文以2002—2013年克拉玛依市统计年鉴中的产业结构、人口、能源消费和经济数据为基础,分析了克拉玛依市的产业结构、能源消费、CO2排放情况,提出了发展低碳城市的思考。     

Simultaneous determination of selected endocrine disrupter compounds in wastewater samples in ultra trace levels using HPLC-ES-MS/MS

An analytical procedure for the simultaneous determination of six selected endocrine disrupter compounds (EDCs: diltiazem, progesterone, benzyl butyl phthalate (BBP), estrone, carbamazepine (Cbz), acetaminophen) was developed by liquid chromatography electrospray ionization tandem mass spectrometry (HPLC-ES-MS/MS). All of the parameters for HPLC and ES-MS/MS systems including mobile phase composition, flow rate, and sample injection volume were optimized to obtain not only the best separation of species interested but also low detection limits. Reverse phase chromatography coupled to ES-MS/MS was used for the separation and detection of EDCs. Formic acid (0.10% ) and 5.0 mM ammonium formate were selected as mobile phase composition in gradient elution. Detection limits for diltiazem, progesterone, BBP, estrone, Cbz, and acetaminophen were found to be 0.13, 0.12, 0.04, 0.13, 0.12, and 0.05 ng/mL, respectively. Influent and effluents from three different wastewater treatment plants located in Ankara, i.e., rotating flat-sheet membrane unit, pilot type flat-sheet membrane unit located at METU Campus and samples from Ankara central wastewater treatment plant were analyzed for their EDCs contents under the optimum conditions.     

Monitoring of aminophenol isomers in surface water samples using a new HPLC method

A new HPLC method was developed for the simultaneous determination of aminophenol isomers by means of a mixed-mode stationary phase containing both SCX and C18 moieties. All factors influencing the separation were discussed and optimized. The chromatographic conditions for the separation of aminophenols are the stationary phase duet SCX/C18, the mobile phase of aqueous phosphate buffer (pH 4.85):methanol?=?85:15 (v/v) delivered with a flow rate of 1 mL/min and a detection at 285 nm. The method proposed was validated in terms of linearity, limits of detection and quantification, accuracy and precision. The HPLC method elaborated here was applied with good results on river water samples. In order to survey the quality of surface rivers entered in treatment plants which deliver water for Bucharest, two major rivers were included in a monitoring program which last more than 1 year.     

Mathematical models for accurate prediction of atmospheric visibility with particular reference to the seasonal and environmental patterns in Hong Kong

Atmospheric visibility impairment has gained increasing concern as it is associated with the existence of a number of aerosols as well as common air pollutants and produces unfavorable conditions for observation, dispersion, and transportation. This study analyzed the atmospheric visibility data measured in urban and suburban Hong Kong (two selected stations) with respect to time-matched mass concentrations of common air pollutants including nitrogen dioxide (NO(2)), nitrogen monoxide (NO), respirable suspended particulates (PM(10)), sulfur dioxide (SO(2)), carbon monoxide (CO), and meteorological parameters including air temperature, relative humidity, and wind speed. No significant difference in atmospheric visibility was reported between the two measurement locations (p > or = 0.6, t test); and good atmospheric visibility was observed more frequently in summer and autumn than in winter and spring (p < 0.01, t test). It was also found that atmospheric visibility increased with temperature but decreased with the concentrations of SO(2), CO, PM(10), NO, and NO(2). The results showed that atmospheric visibility was season dependent and would have significant correlations with temperature, the mass concentrations of PM(10) and NO(2), and the air pollution index API (correlation coefficients mid R: R mid R: > or = 0.7, p < or = 0.0001, t test). Mathematical expressions catering to the seasonal variations of atmospheric visibility were thus proposed. By comparison, the proposed visibility prediction models were more accurate than some existing regional models. In addition to improving visibility prediction accuracy, this study would be useful for understanding the context of low atmospheric visibility, exploring possible remedial measures, and evaluating the impact of air pollution and atmospheric visibility impairment in this region.     

Environmental impact of biomethanogenesis

The environmental impact of biomethanogenesis is related to its ecological role, accumulation and effect as a greenhouse gas, and application in anaerobic digestion for conversion of biomass and wastes to methane and compost. Biological formation of methane is the process by which bacteria decompose organic matter using carbon dioxide as an electron acceptor in the absence of dioxygen or other electron acceptors. This microbial activity is responsible for carbon recycling in anaerobic environments, including wetlands, rice fields, intestines of animals sediments, and manures. The mixed consortium of microorganisms involved includes a unique group of bacteria, the methanogens, which may be considered to be in a separate kingdom based on genetic and phylogenetic variance from all other life forms. Because methane is a significant and increasing greenhouse gas, its source fluxes and their potential reduction are of concern. Biomethanogenesis may be harnessed for reduction of wastes and conversion of renewable resources to significant quantities of substitute natural gas which could mitigate carbon dioxide and other pollutants related to use of fossil fuels.     

Effects of drill cuttings discharge on meiofauna communities of a shelf break site in the southwest Atlantic

The present study investigates the effects of drill cutting discharges on the structure of meiofauna communities in an area of the shelf break at Campos Basin, Southeast Brazil. Drilling activities were operated, in a first phase, with water-based fluid and, in a second phase, with synthetic fluid paraffin-based (NAF-III). A total of 135 samples taken at a pre-drilling situation (MS1) and two post-drilling moments (MS2 and MS3—3 and 22 months post-drilling, respectively) were analyzed. Effects on meiofauna were dependent on two main factors: 1—the impact received during drilling operation, if water-based or synthetic/water-based drilling fluid and 2—the background state, if it already presented signs of previous drilling activities or not. Based on univariate and multivariate analysis, there were evidences that the most affected area after drilling was those under the influence of synthetic-based fluid and that already had signs of previous drillings activities. The region impacted only by water-based fluid was less affected and the only one that completely recovered after 22 months. Nematodes and copepods had different responses to the impact. While copepods flourish in the impacted area and recovered 22 months after drilling, nematodes were adversely affected shortly after drilling and the community structure only recovered where hydrocarbons had been depleted.     

Analysis of Urban Atmospheric Pollution Data in the Bologna Area

Pollutant concentrations relative to the years 1993-1995 measured in the Bologna urban area by a network of automatic stations (S.A.R.A. Sistema Automatico di Rilevamento Ambientale) are analysed to estimate the typical behaviour of the pollutants, especially with regard to periodicities and meteorological dependencies and to attempt prediction for the pollutant daily concentration up to a few days using a statistically based model.The results obtained show the presence of a very significant weekly periodicity for all the analysed pollutants. A yearly periodicity has been found only for the primary pollutants analysed.The statistical prediction, using an ARMA model with meteorological variables as transfer functions, shows good predicting capabilities up to one day for carbon monoxide (CO) and sulphur dioxide (SO2) and up to two days for nitrogen dioxide (NO2).     

固相萃取-高效液相色谱法测定废水中的酚类化合物

建立了Supelclean ENVI-Chrom P柱固相萃取-高效液相色谱法测定废水中11种酚类化合物的分析方法,并对固相萃取条件和液相色谱条件进行了讨论。该方法分离效果良好,净化效果明显,方法检出限为2×10-3~2×10-2mg/L,平行分析(n=6)的RSD为2.7%~16.4%,废水加标回收率除2,4-二硝基酚偏低以外,其他化合物的回收率为61.4%~115.8%。     

便携式气相色谱法快速测定恶臭气体样品中的硫化物

建立一种利用便携式气相色谱仪快速、简便地测定恶臭气体样品中硫化物的方法,对硫化氢、甲硫醇、甲硫醚及二硫化碳能实现良好分离,光离子化检测器PID可实现甲硫醇、甲硫醚、二硫化碳的快速定性、定量分析,还能避免高浓度二氧化硫对测定的干扰,检出限分别为0.05、0.03、0.02ppm,精密度好,相对标准偏差RSD分别小于11.6%、7.89%和2.14%,经实际应用,效果良好。     

On the optimal control of carbon dioxide emissions: an application of FUND

This paper presents the Climate Framework for Uncertainty, Negotiation and Distribution (FUND), an integrated assessment model of climate change, and discusses selected results. FUND is a nine‐region model of the world economy and its interactions with climate, running in time steps of one year from 1990 to 2200. The model consists of scenarios for economy and population, which are perturbed by climate change and greenhouse gas emission reduction policy. Each region optimizes its net present welfare. Policy variables are energy and carbon efficiency improvement, and sequestering carbon dioxide in forests. It is found that reducing conventional air pollution is a major reason to abate carbon dioxide emissions. Climate change is an additional reason to abate emissions. Reducing and changing energy use is preferred as an option over sequestering carbon. Under non‐cooperation, free riding as well as assurance behaviour is observed in the model. The scope for joint implementation is limited. Under cooperation, optimal emission abatement is (slightly) higher than under non‐cooperation, but the global coalition is not self‐enforcing while side payments are insufficient. Optimal emission control under non‐cooperation is less than currently discussed under the Framework Convention on Climate Change, but higher than observed in practice. This revised version was published online in July 2006 with corrections to the Cover Date.