液氨中油的红外分光光度法测定及其组分特性研究

介绍了用红外分光光度法测定液氨中油的分析方法，样品经三氯三氟乙烷或四氯化碳萃取后测定总萃取物，随后将萃取液通过氟里硅土吸附柱分离非极性的碳氢油和烃的极性衍生物，并测定碳氢油，烃的极性衍生物由总萃取物与碳氢油含量之差间接求得。     

液氮中油的红外分光光度法测定及其组分特性研究

介绍了用红外分光光度法测定液氨中油的分析方法。样品经三氯三氟乙烷或四氯化碳萃取后测定总萃取物，随后将萃取液通过氟罗里硅土吸附柱分离非极性的碳氢油和烃的极性衍生物，并测定碳氢油，烃的极性衍生物由总萃取物与碳氢油含量之差间接求得。用本方法测定了镇海炼化公司氨回收的精制液氨及大化肥装置的液氨中油的含量，并对油组分特性进行了分析。     

红外光度法测定低浓度水样中的石油类和动植物油研究

文章对如何提高低浓度样品测量的准确度进行了探讨.在测量低浓度的水样时,在萃取过程中除了四氯化碳会对水样中的油份进行萃取,水对四氯化碳中的极性物质也进行反萃取,当样品中含油浓度很低时,由于四氯化碳含极性物质可能大于油分含量,从而出现负值.因此测定低浓度水样中的石油类和动植物油是一项精细的工作,在实际工作中应该尽量采取下文所述的方法避免这种情况,只有做好了测量的各个环节,才能保证测量结果的精确可靠.     

四氯化碳的回收利用

文章介绍了用碱液反萃取四氯化碳中的碘的技术，使含碘四氯化碳得以净化及循环使用，其效果良好，有实际应用价值。     

用改进法测定水中的石油类

通过对现行国标《水质石油类和动植物油的测定红外光度法》（GB16488-1996）方法中的萃取、吸附预处理过程进行改进,通过对比实验得出萃取过程采用一次萃取,前处理吸附过程采用分液漏斗代替玻璃层析柱制备硅酸镁层析柱,并辅助真空泵加速,处理效果对测定结果无影响,采取改进方法可大大节约分析时间;四氯化碳（CCl4）毒性较大,大量使用对实验室人员和环境影响较大,实验证明用氯化四氟乙烯（S-316）替代四氯化碳（CCl4）作为萃取剂,实验室前期处理过程以及实际萃取效果与用四氯化碳作为萃取剂无差别,测定结果符合国家标准的要求,氯化四氟乙烯（S-316）的应用可以减少对臭氧层的破坏,可以作为该方法较理性的萃取剂。     

岩石中微量铍的萃取比色测定

<正> 至今已提出了不少直接比色测定铍的方法,但用于测定岩石中的微量铍(低至0.0001％)仍有困难。原用四氯化碳萃取铍的乙酰丙酮络合物需两次萃取才能定量回收。我们改用氯仿代替四氯化碳一次萃取即能定量回收,大大碱化了分析流程,缩短了分析时间。分析0.000n％的样品相对误差在±30％以下。     

火焰原子吸收光谱法测定水中铜、铅、镉

在ｐＨ＝３．０以吡咯烷二硫代氨荃甲酸按为螫合剂，四氯化碳为萃取剂富集水中微量的铜铅、镉，继而用硝酸－过氧化氢混合液反萃取至水相，用火焰原子吸收光谱法进行测定，方法简便、灵敏准确。四氯化碳可回收利用。     

四氯乙烯替代四氯化碳作为油类萃取剂的研究

油类萃取剂四氯化碳对人体毒性较大，且对大气臭氧层有着严重的破坏作用。实验尝试用低毒的四氯乙烯替代四氯化碳作为油测定的萃取剂。经两者在检出限、线性、精密度、质控样品测定，以及萃取效率试验、加标回收试验的比较。结果表明：改进方法代替标准方法基本可行。四氯乙烯较之其他替代品具有一定的优越性。     

用二乙基氨荒酸钠萃取和电热原子吸收测定天然水中每升毫微克量的痕量金属

本文描述了测定淡水和天然水中痕量金属Cd、Co、Ca、Fe、Ni和Pb的方法。用二乙基氨荒酸盐把金属从500ml样品中萃取到四氯化碳中去,再将萃取物蒸发至于,残渣用0.1ml浓硝酸矿化,将矿化物适度稀释厉用石墨炉子吸收光度计测量。检测限分别为:Cd10pg;Co150pg;Cu125pg;Fe100pg;Ni250pg;pb100pg。此萃取矿化法几乎无任何干扰,如痕量元素是它们的500倍,Na,K,Ca和Mg是它们的一百万倍时都不干扰它们的测定。此方法成功地用于测定去离子水,河水和海水中这六种金属。     

油类分析中四氯化碳的回收利用

环境监测分析中四氯化碳用作水中油类萃取剂,多年来已有几种回收利用含油四氯化碳的研究方法。文章运用旋转蒸发(常压)法进行废液回收,对标准样品的测定结果令人满意,并验证了该方法在环境监测分析工作中的环境效益和经济效益。     

Experimental investigation of the effect of sediment transport patterns on the adsorption of cadmium ions onto sediment particles

The mechanism of flow turbulence, sediment supply conditions, and sediment transport patterns that affect the adsorption of cadmium ions onto sediment particles in natural waters are experimentally simulated and studied in this study both in batch reactors and in a turbulence simulation tank. By changing the agitation conditions, the sediment transport in batch reactors can be categorized into bottom sediment-dominated sediment and suspended sediment-dominated sediment. It is found that the adsorption rate of bottom sediment is much less than that of suspended sediment, but the sediment transport pattern does not affect the final (equilibrium) concentration of dissolved cadmium. This result indicates that the parameters of an adsorption isotherm are the same regardless of the sediment transport pattern. In the turbulence simulation tank, the turbulence is generated by harmonic grid-stirred motions, and the turbulence intensity is quantified in terms of eddy diffusivity, which is equal to 9.84F(F is the harmonic vibration frequency) and is comparable to natural surface water conditions.When the turbulence intensity of flow is low and sediment particles stay as bottom sediment, the adsorption rate is significantly low, and the adsorption quantity compared with that of suspended sediment is negligible in the 6 h duration of the experiment. This result greatly favors the simplification of the numerical modeling of heavy metal pollutant transformation in natural rivers. When the turbulence intensity is high but bottom sediment persists, the rate and extent of descent of the dissolved cadmium concentration in the tank noticeably increase, and the time that is required to reach adsorption equilibrium also increases considerably due to the continuous exchange that occurs between the suspended sediment and the bottom sediment.A comparison of the results of the experiments in the batch reactor and those in the turbulence simulation tank reveals that the adsorption ability of the sediment, and in particular the adsorption rate, is greatly over-estimated in the batch reactor.     

Adsorption of phenolic compounds from aqueous solutions by aminated hypercrosslinked polymers

Two novel polymers （NJ-1 and N J-2） were synthesized by chemically modified a hypercrosslinked polymer NJ-0 with dimethylamine and trimethylamine, respectively. The comparison of the adsorption properties of the three polymers toward phenol, resorcin and phloroglucin was made. The study focused on the static equilibrium adsorption behaviors and the adsorption thermodynamics. Freundlich equation was found to fit the adsorption results well. The effect of amino groups introduced onto the surface of the resin and the structure of phenolic compounds on the adsorption were also studied. The hydrogen-bonding interaction and electrostatic interaction could happen between the amino groups and the adsorbates. The adsorption impetus increased as quantity of hydroxyl groups increased, but the adsorption capacity decreased due to the drop of the matching degree of the aperture of resins and the diameter of adsorbate molecules.     

Composition analysis of colored dissolved organic matter in Taihu Lake based on three dimension excitation-emission fluorescence matrix and PARAFAC model, and the potential application in water quality monitoring

Taihu Lake is one of the five biggest lakes in China. Surface water samples from 26 sampling sites of Taihu Lake were collected. Furthermore wet chemical analysis （CODCr and BOD5） and measurement of three dimensional excitation-emission matrix （3DEEM） spectra in the laboratory have been conducted. Using parallel factor analysis （PARAFAC） model, three components of colored dissolved organic matter （CDOM） have been identified successfully, based on the analysis of 3DEEM data. The characteristics of the three components also have been described by comparing them to some components of CDOM, identified in earlier researches. Meanwhile, spatial variations of concentration for the three components in Taihu Lake have been analyzed, and the result indicates that the concentration of component 1 depends more on the situation of wastewater pollution and can be used as the indicator of wastewater pollution. The relationship between the concentrations of the three components and results of the wet chemical analysis show that none of the three components can be used as indicators of gross organic matter in water. However, the concentrations of all the three components have obvious linear relationships with the BOD5 value, especially for component 1 （r = 0.72878）. Finally, the potential applications of the composition analysis based on 3DEEM and PARAFAC model in water quality monitoring have been illuminated.     

Transformation of mercury speciation through the SCR system in power plants

Coal-fired utility boilers are now identified as the largest source of mercury in the United States. There is speculation that the installation of selective catalytic reduction （SCR） system for reduction of NOx can also prompt the oxidation and removal of mercury. In this paper, tests at six full-scale power plants with similar type of the SCR systems are conducted to investigate the effect of the SCR on the transformation of mercury speciation. The results show that the SCR system can achieve more than 70%-80% oxidation of elemental mercury and enhance the mercury removal ability in these units. The oxidation of elemental mercury in the SCR system strongly depends on the coal properties and the operation conditions of the SCR systems. The content of chloride in the coal is the key factor for the oxidization process and the maximum oxidation of elemental mercury is found when chloride content changes from 400 to 600 ppm. The sulfur content is no significant impact on oxidation of elemental mercury.     

汽车排气尾流中微粒分布及其变化特性的研究

根据微粒核化、凝并及凝结模型对汽车排气尾流中微粒分布的变化特性进行了分析.结果表明,微粒的核化增加了排气尾流中超细微粒的数量;微粒的凝并和凝结将改变排气尾流中的微粒分布.在核化、凝并及凝结过程同时存在时,核化对微粒分布的影响相对较小,微粒分布的变化主要受凝并和凝结的作用.在排气管出口处,微粒的核化、凝并及凝结过程比较剧烈,微粒分布变化较大;随着距排气管出口距离的增加,微粒演变逐渐减弱.研究工作可以为汽车排放控制策略的确定以及汽车微粒对人体健康影响的研究提供依据.     

Effect of copper on the degradation of pesticides cypermethrin and cyhalothrin

The influence of coexisting copper (Cu) ion on the degradation of pesticides pyrethroid cypermethrin and cyhalothrin in soil and photodegradation in water system were studied.Serial concentrations of the pesticides with the addition of copper ion were spiked in the soil and incubated for a regular period of time,the analysis of the extracts from the soil was carried out using gas chromatography (GC).The photodegradation of pyrethroids in water system was conducted under UV irradiation.The effect of Cu~(2 ) on the pesticides degradation was measured with half life (t_(0.5)) of degradation.It was found that a negative correlation between the degradation of the pyrethroid pesticides in soil and Cu addition was observed.But Cu~(2 ) could accelerate photodegradation of the pyrethroids in water.The t_(0.5) for cyhalothrin extended from 6.7 to 6.8 d while for cypermethrin extended from 8.1 to 10.9 d with the presence of copper ion in soil.As for photodegradation,t_(0.5) for cyhalothrin reduced from 173.3 to 115.5 rain and for cypermethrin from 115.5 to 99.0 min.The results suggested that copper influenced the degradation of the pesticides in soil by affecting the activity of microorganisms.However, it had catalyst tendency for photodegradation in water system.The difference for the degradation efficiency of pyrethroid isomers in soil was also observed.Copper could obviously accelerate the degradation of some special isomers.     

北京市交通路口大气颗粒物污染特征研究(Ⅱ)——大气颗粒物中非烃类化合物污染特征

研究了北京市交通路口大气颗粒物中非烃类化合物的污染特征.通过对2000年6月采集的大气颗粒物样品的分析,研究了北京市崇文门路口大气颗粒物中非烃类化合物的污染状况.结果表明:交通排放是大气颗粒物中非烃类化合物的重要来源之一;总体上非烃类化合物主要富集在粒径较小的粒子中,细粒子中的非烃类化合物应主要来源于机动车尾气排放;白天ρ(非烃类化合物)随机动车流量的增加而增加,夜晚机动车流量减小,但ρ(非烃类化合物)却高于白天,显示出大型柴油车的主要影响和贡献;非烃类化合物的污染主要表现为酞酸酯和苯酚类化合物的污染.并对交通路口大气颗粒物中酞酸酯的来源进行了探讨.      

Bioconcentration kinetics of PCBs in various parts of the lifecycle of the tadpoles Xenopus laevis

Polychlorinated biphenyls （PCBs） in Xenopus laevis have been reported only for a few congeners. Additionally, there is very little information on the ability of Xenopus laevis to bioconcentrate PCBs. To address these issues, the tadpole Xenopus laevis was exposed to Aroclor 1254 mixtures in water at room temperature for 110 d followed by an additional 110 d of nonspiked PCBs in the water for the control group. During the whole process, bioconcentration factors （BCFs） of PCBs ranged from 1180 to 15670. For most PCB congeners, the highest and lowest bioconcentrations of the kinetic curves were found to be remarkably simultaneous, respectively. All 141 PCB congeners under the same experimental conditions had no linear correlation on the lgBCF versus lgKow relationship. The relationship between lgBCFs and lgKow followed a parabolic pattern indicative of selective bioconcentration, suggesting that the kinetic curves of the PCB congeners observed in the lifecycle of the tadpoles may be concentrated due to the amphibian special species and internal metabolism. In contrast, lgBCFs for PCBs were inversely related to lgKow, suggesting that a metabolism of the higher Kow PCB congeners occurred. These results support the author＇s conclusion that the tadpole Xenopus laevis plays major roles in the bioconcentration of PCB congeners, and demonstrated that the exposure kinetic curves of PCB congeners are complex. Besides the amphibian metamorphous development, the lifecycle of the tadpole Xenopus laevis also may be of importance in determining the bioconcentration of PCB congeners.     

基于电子鼻土壤与地下水污染修复现场TVOC和恶臭的评估

根据上海某土壤与地下水污染修复现场情况,应用自主研发的电子鼻系统(iSA-M1)分别对未修复及修复过程中的土壤和地下水、修复场地上空及周边空气中的VOCs和恶臭类气体进行检测.结合前期研究所得TPI和OPI公式,求得各点的值,并将其用图表示.结果表明:①修复后TVOC和恶臭的浓度总体呈下降趋势;②在土壤和地下水修复过程中,VOCs和恶臭的挥发受气象要素和作业的影响,其浓度在总体下降的过程中伴随着阶段性上升现象;③结合GIS技术,电子鼻能初步用于评估土壤和地下水修复现场造成的空间污染情况及对周围居民产生的影响.但造成影响程度的具体细化分级还需要进一步研究.     

Effect of coagulation pretreatment on the fouling of ultrafiltration membrane

The purpose of this study is to understand the effect and mechanism of preventing membrane fouling, by coagulation pretreatment, in terms of fractional component and molecular weight of natural organic matter （NOM）. A relatively higher molecular weight （MW） of hydrophobic compounds was responsible for a rapid decline in the ultrafiltration flux. Coagulation could effectively remove the hydrophobic organics, resulting in the increase of flux. It was found that a lower MW of neutral hydrophilic compounds, which could remove inadequately by coagulation, was responsible for the slow declining flux. The fluxes in the filtration of coagulated water and supernatant water were compared and the results showed that a lower MW of neutral hydrophilic compounds remained in the supernatant water after coagulation could be rejected by a membrane, resulting in fouling. It was also found that the coagulated flocs could absorb neutral hydrophilic compounds effectively. Therefore, with the coagulated flocs formed on the membrane surface, the flux decline could be improved.