离子色谱法测定多种水体中碘化物应用研究

利用AS19阴离子交换分离柱,KOH淋洗液自动发生器,抑制型电导检测器,建立了测定多种水体中碘化物的离子色谱法.讨论了干扰及消除、色谱条件的优化,分析方法的线性与检出限、精密度、准确度等,并应用该方法对多种水体中碘化物进行了测定.结果表明:该方法不受水体中其他阴离子干扰,检出限低,线性范围宽,相关系数R2=0.999 9,精密度高,准确度好,操作简便可行,适用于多种水体中碘化物的测定.     

ICP-AES法同时测定废水中的铟、铝研究

钢和铅都是低毒的重金属元素,化学性质相似,都能对环境、人体健康造成不同程度的危害.采用电感耦合等离子体-原子发射光谱法(ICP-AES),研究了同时测定冶炼、矿山、采选、化工等行业排放工业废水中铟和铝的方法.探讨了测定过程中共存离子对铟和铝的干扰问题.实验表明在最佳仪器条件和测定条件下,该方法具有较低的检出限、较高的精密度和准确度,操作简便、快捷.     

应用AFS-2202型双道原子荧光光谱仪联合测定水样中微量As、Se

应用AFS-2202型双道原子荧光光谱法研究了联合测定水样中微量Se、As的方法.研究了酸度、NaBH4 浓度、栽气流速、原子化器高度等条件对检出限及精密度的影响.在优化条件下,对硒、砷的检出限分别位0.16μg/L和0.12μg/L.本方法具有操作简便.快速、基本干扰少、灵敏度高等优点,可用于水样中As、Se的联合测定.     

乙酰丙酮分光光度法测定土壤中甲醛的检出限分析

在环境监测工作中,用乙酰丙酮分光光度法测定土壤中甲醛的含量具有仪器设备简单、操作简便,性能稳定,干扰小,可稳定12h不变等特点。作者采用蒸馏法对土壤进行前处理,用乙酰丙酮比色法测探讨了该方法的检出限。结果表明：乙酰丙酮光度法检测土壤中的甲醛方法最低检出限为1．24mg／kg,蒸馏回收率为55．9％-87．8％。     

气相色谱法测定废水中的甲醇

介绍了采用气相色谱法对含甲醇的化工，化纤废水的测定实验，就方法的准确性，检出限，干扰情况等进行了探讨，获得了较理想的结果，认为采用该法测定废水中甲醇具有快速简便，准确度高，干扰小等优点。     

气相色谱法测定水中三氯甲烷

建立吹扫捕集处理水样,气相色谱法测定水中三氯甲烷的方法,并对吹扫捕集测试条件进行优化。本方法不需使用有机试剂,具有灵敏度高、检出限低、操作简便等优点。当进样量为5m L时,该方法三氯甲烷检出限为0.20μg/L,加标回收率为93.9%~104.8%。     

银硫离子选择电极测定工业废水中的硫化物

本法用Ag/S离子选择电极测定废水中的硫化物,测定浓度范围0.1～1000.0mg/l,方法精密度为4.3％,回收率为P2.5％,检出限为0.1mg/l。大多数离子不干扰测定,该法简便快速,适用于例行监测。     

氢化物-原子荧光法测定贝类中的微量砷

本文研究了氢化物-原子荧光法测定贝类样品中微量砷的试验条件,试验了不同的消解体系、酸介质、预还原剂用量对测定砷的影响及贝类样品常见元素的干扰影响,选择了试验的最佳测定条件。结果表明:方法的检出限为0.20μg/L,相对标准偏差小于3.8%。     

石墨炉原子吸收光谱法直接测定尿锰

以5%的硝酸对尿样进行2.5倍稀释后,优化试验条件,利用石墨炉原于吸收光谱法直接测定尿锰含量.该方法的检出限为0.06μg/L,相对标准偏差(n=9)小于5%,回收率为91%～104%,共存物干扰小.运用结果显示该方法简便、快速,准确度和精密度均达到了分析要求.     

石墨炉原子吸收光谱法直接测定尿锰

以5％的硝酸对尿样进行2．5倍稀释后,优化试验条件,利用石墨炉原于吸收光谱法直接测定尿锰含量。该方法的检出限为0．06μg／L,相对标准偏差（n=9）小于5％,回收率为91％～104％,共存物干扰小。运用结果显示该方法简便、快速,准确度和精密度均达到了分析要求。     

Distribution and ecological effect of mercury in Laogang landfill, Shanghai, China

Laogang landfill near Shanghai is the largest landfill in China, and receives about 10000 t of daily garbage per day, Samples of topsoil and plants were analyzed to evaluate mercury pollution from the landfill. For topsoil samples, there were significant correlations among total mercury （HgT）, combinative mercury （Hgc） and gaseous mercury （HgG）, and content of total organic carbon （TOC）, but, no significantly relationship was found between Hg content and filling time. Hg content changes in vertical profiles with time showed that the average Hgv of profiles 1992, 1996, and 2000 was similar, but their average HgG was quite different. HgT was significantly correlated with Hgc in profile 1992 and 2000, and Hgv was significantly correlated with Hg6 in profile 1996. HgG/Hgv ratio in profile samples decreased in the order of （HgG,/HgT）1992〉（HgG/HgT）1996〉〉（HgG/HgT）2000. A simple outline of Hg release in landfill could be drawn： with increasing of filling time, degradation undergoes different biodegradation, accordingly, gaseous mercury goes through small, more, and small proportion to total mercury. Distribution of Hg in plants was inhomogeneous, following the order of leaf〉root〉stem. The highest value of leaf may be associated with higher atmospheric Hg from landfill. Ligneous plants （e.g. Phyllostachys glanca, Prunus salicina and Ligustrum lucidum） are capable of enriching more Hg than herbaceous plants.     

EDTA-enhanced phytoremediation of lead contaminated soil by Bidens maximowicziana

Phytoremediation is a potential cleanup technology for the removal of heavy metals from contaminated soils.Bidens maximowicziana is a new Pb hyperaccumulator,which not only has remarkable tolerance to Pb but also extraordinary accumulation capacity for Pb.The maximum Pb concentration was 1509.3 mg/kg in roots and 2164.7 mg/kg in overground tissues.The Pb distribution order in the B. maximowicziana was:leaf>stem>root.The effect of amendments on phytoremediation was also studied.The mobility of soil Pb and the Pb concentrations in plants were both increased by EDTA application.Compared with CK(control check),EDTA application promoted translocation of Pb to overground parts of the plant.The Pb concentrations in overground parts of plants was increased from 24.23-680.56 mg/kg to 29.07-1905.57 mg/kg.This research demonstrated that B.maximowicziana appeared to be suitable for phytoremediation of Pb contaminated soil,especially,combination with EDTA.     

Decomposition of alachlor by ozonation and its mechanism

Decomposition and corresponding mechanism of alachlor, an endocrine disruptor in water by ozonation were investigated. Results showed that alachlor could not be completely mineralized by ozone alone. Many intermediates and final products were formed during the process, including aromatic compounds, aliphatic carboxylic acids, and inorganic ions. In evoluting these products, some of them with weak polarity were qualitatively identified by GC-MS. The information of inorganic ions suggested that the dechlorination was the first and the fastest step in the ozonation of alachlor.     

Enzymatic oxidation of aqueous pentachlorophenol

The influence of the nonionic surfactant Tween 80 on pentachlorophenol （PCP） oxidation catalyzed by horseradish peroxidase was studied. The surfactant was tested at concentrations below and above its critical micelle concentration （CMC）. Enhancement of PCP removal was observed at sub-CMCs. The presence of Tween 80 in the reaction mixture reduced enzyme inactivation which occurred through a combination of free radical attack and sorption by precipitated products. A simple first-order model was able to simulate time profiles for enzyme inactivation in the presence or absence of Tween 80. At supra-CMCs, the surfactant caused noticeable reductions in PCP removal, presumably through micelle partitioning of PCP which precluded the hydrophobic PCP molecule from interacting with the enzyme.     

基于综合水质标识指数和对应分析法的校园河道水质评价

以三峡大学的校园河道求索溪为研究对象,利用综合水质标识指数法确定求索溪水质类别,分析其水质时空变化规律,并利用对应分析法得出求索溪中不同监测点的主要污染因子.研究结果表明:求索溪整体的综合水质标识指数为7.423,整体水质为劣V类(地表水环境质量标准GB 3838-2002)且黑臭.从时间变化来看,求索溪4月份的水质最差,5月份次之,4、5月份所有监测点的水质都劣于V类且黑臭;8月份水质最好,水质为Ⅳ类;从空间分布来看,8个监测点综合水质标识指数均超过6.0,水质为劣V类,其中6号监测点的水质相对最好,监测点3号的水质相对最差;对应分析法得出求索溪的整体水体污染程度受总氮因子的影响最大,其次为总磷.该研究拟为求索溪及类似校园河道的水环境治理研究提供基础依据和参考.     

Effects of chitosan on growth of an aquatic plant (Hydrilla verticillata) in polluted waters with different chemical oxygen demands

Effects of chitosan on a submersed plant, Hydrilla verticillata, were investigated. Results indicated that H. venicillata could prevent ultrastructure phytotoxicities and oxidativereaction from polluted water with high chemical oxygen demand (COD). Superoxide dismutase (SOD) activity and malondialdehyde (MDA) contents in H. verticillata treated with 0.1% chitosan in wastewater increased with high COD (980 mg/L) and decreased with low COD (63 mg/L), respectively. Ultrastructural analysis showed that the stroma and grana of chloroplast basically remained normal. However, plant cells from the control experiment (untreated with chitosan) were vacuolated and the cell interval increased. The relict of protoplast moved to the center, with cells tending to disjoint. Our findings indicate that wastewater with high COD concentration can cause a substantial damage to submersed plant, nevertheless, chitosan probably could alleviate the membrane lipid peroxidization and ultrastructure phytotoxicities, and protect plant cells from stress of high COD concentration polluted water.     

Removal of cadmium using MnO2 loaded D301 resin

MnO2 loaded weak basic anion exchange resin D301 （Anion exchange resin, macroreticular weak basic styrene） as adsorbent has been prepared and applied to the removal of cadmium. The adsorption characteristics have been investigated with respect to effect of pH, equilibrium isotherms, removal kinetic data, and interference of the coexisting ions. The results indicated that the Cd^2＋ could be efficiently removed using MnO2 loaded D301 resin in the pH range of 3-8 from aqueous solutions with the co-existence of high concentration of alkali and alkaline-earth metals ions. The saturate adsorption capacity of the Cd^2＋ was 77.88 mg/g. The adsorption process followed the pseudo first-order kinetics. The equilibrium data obtained in this study accorded excellently with the Langmuir adsorption isotherm.     

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.     

Penetration analysis of elements and bioleaching treatment of spent refractory for recycling

Acidithiobacillus ferrooxidans ATCC23270 and Acidithiobacillus thiooxidans TM-32 were used for bioleaching of spent refractories of aluminium and copper melting furnaces for their recycling.Firstly,penetration of elements into aluminium melting furnace refractory was investigated and it was found that up to 7 cm from surface was contaminated.Comparison on leaching efficiency by the strains ATCC23270 and TM-32 found that the strain ATCC23270 could treat larger amount of the refractories than the strain TM-32 could do.In the experiment of bioleaching of spent refractory aluminium melting furnace by the strain ATCC23270,high leaching efficiency were obtained on Al,Si,and Ca,and extremely low leaching performance was,however,shown on the rest of elements i.e.,Na,Mn,and Zn.Under the strain TM-32 use,relatively high leaching performance was recognized on Al,Si,Ca,Na,Mn,and Zn.In the experiment of bioleaching for spent refractory copper melting furnace,almost the same leaching trends were shown on Cu,Zn,Al,and Si under the strains ACTT23270 and TM-32 uses.     

Simultaneous removal of ammonium and phosphate by zeolite synthesized from coal fly ash as influenced by acid treatment

Zeolite synthesized from fly ash （ZFA） without modification is not efficient for the purification of NH4＋ and phosphate at low concentrations that occur in real effluents, despite the high potential removal capacity. To develop an effective technique to enhance the removal efficiency of ammonium and phosphate at low concentrations, ZFA was modified with acid treatment and the simultaneous removal of ammonium and phosphate in a wide range of concentration was investigated. It was seen that when compared with untreated ZFA, only the treatment by 0.01 mol/L of H2SO4 significantly improved the removal efficiency of ammonium at low initial concentrations. The behavior was well explained by the pH effect. Treatment by more concentrated H2SO4 led to the deterioration of the ZFA structure and a decrease in the cation exchange capacity. Treatment by 0.01 mol/L H2SO4 improved the removal efficiency of phosphate by ZFA at all initial P concentrations, while the treatment by concentrated H2SO4 （≥0.9 mol/L） resulted in a limited maximum phosphate immobilization capacity （PIC）. It was concluded that through a previous mild acid treatment （e.g. 0.01 mol/L of H2SO4）, ZFA can be used in the simultaneous removal of NH4＋ and P at low concentrations simulating real effluent.