二氧化氯,亚氯酸根及氯酸根含量在水处理中的分析方法

二氧化氟是一种具有广阔应用前景的饮用水消毒剂，制备和使用时可能产生一系列氯的不同氧化态物质，其中最主要的是ＣｌＯ２、ＣｌＯ２和ＣｌＯ３，本研究用紫外分光光度法分别测定了ＣｌＯ２和ＣｌＯ２的含量，同时用改进的碘量法分别测定溶液中同时存在的ＣｌＯ２、ＣｌＯ２和ＣｌＯ３，并讨论了有关的反应机理，测定的精密度和准确度均满足一般饮用水质分析的需要。     

以N,N—二甲基苯胺为偶联试剂示波极谱法测定水中NO2^——N

研究了ＮＯ２＾－－磺胺重氮盐与Ｎ,Ｎ－二甲基苯胺偶联反应的条件及产物在乙醇,ＮＨ３－ＮＨ４Ｃｌ（ｐＨ＝１０）介质中的极谱行为。二阶导数波高与ＮＯ２＾－－Ｎ浓度在０．０００６－０．０７ｍｇ／Ｌ内呈良好线性关系,回收率为９７％－１０２％,已用于环境水中ＮＯ＾－２－Ｎ的测定。     

离子色谱法测定工业废水中氟硼酸根

应用离子色谱法对Ｆ＾－、Ｃｌ＾－、ＮＯ２＾－、ＰＯ４＾３－与ＢＦ４＾－进行了分离，实现了工业废水中ＢＦ４＾－的测定，具有检测限低、线性范围宽、分析时间短等特点。     

N—苯甲酰苯基羟胺／吡啶偶氮染料配体交换反应萃取分光光度…

在强酸性介质中，ＶＯ＾－３与Ｎ－苯甲酰基羟胺反应生成紫红色络合物，能定量地被ＣＨＣｌ３萃取。萃取液加入２－－５－二乙氨基酚后可发生配体交换反应，并生生成橙红色的Ｖ－５－Ｂｒ－ＰＡＤＡＰ络合物，有机相可直接用于光度测定。     

饮用水中非挥发性有机氯化物的测定

研究了一种测定饮用水中非挥发性有机氯化物（ＮＰＯＣｌ）的方法。水样经氮气气提后，以ＮａＮｏ３溶收抑制Ｃｌ－离子干扰，活性炭吸附后高温的烧，用ＮａＯＨ溶腋作吸收液，氯离子选择电极法测定并换算出ＮＰＯＣｌ值。检测限为０．２×１０~（－６）ｍｏｌ／Ｌ。在１．０×１０~（－６）～２０．０×１０~（－６）ｍｏｌ／Ｌ范围内，回收率为７５．３％。以本法测定自来水源水和末梢水，结果表明自来水厂氯化消毒引起ＮＰＯＣｌ值显著升高。建议ＮＰＯＣｌ值作为自来水水质评价的重要参数。     

重铬酸钾─三氯化钛法测定水中溶解氧

介绍了三氯化钛（ＴｉＣｌ３）与氧反应，以钨酸钠（Ｎａ２ＷＯ４）作指示剂，用重铬酸钾溶液滴定过剩三氯化钛来测定水中溶解氧的方法。本法与碘量法比较，结果表明方法准确、快速，适合于水样中溶解氧的测定     

完全氧化法测定高氯废水的COD_(Cr)

从热力学的角度出发,导出了在ＣＯＤ测定过程中Ｃｌ－ 的完全氧化条件。通过不同浓度的含氯邻苯二甲酸氢钾标准溶液和含氯乙醇标准水样的测定表明, 在所提出的完全氧化条件下,由所测得的表观ＣＯＤ减去Ｃｌ－ 的理论ＣＯＤ便得到水样的真实ＣＯＤ,测定结果与实际吻合较好。最后,对测定过程中的有关问题进行了讨论。     

单柱离子色谱法同时测定地面水中阴离子

单柱离子色谱法同时测定地面水中Ｆ－、Ｃｌ－、ＮＯ－２－Ｎ、ＮＯ－３－Ｎ、ＳＯ２－４阴离子。以２．５ｍＭ苯二甲酸、２．４ｍＭ三羟甲胺缓冲液为淋洗液,在ｐＨ＝４．０,流速为１．５ｍｌ／ｍｉｎ的条件下,测得各阴离子检出限、线性回归方程及相关系数、方法的精密度和准确度。     

重铬酸钾—三氯化钛法测定水中溶解氧

介绍了三氯化钛（ＴｉＣｌ３）与氧反应，以钨酸钠（Ｎａ２ＷＯ４）作指示剂，用重铬酸钾溶液滴定过剩三氯化钛来测定水中溶解氧的方法，本法与碘量法比较，结果表明方法准确，快速，适合于水样中溶解氧的测定。     

石河子市地下水环境背景值

采集并测定了石河子市１９个地下水背景水样，分别确定了该市潜水和承压—自流水中Ｋ＋、Ｎａ＋、Ｃａ２＋、Ｍｇ２＋、Ｃｌ－、ＳＯ、ＨＣＯ、ＮＯ、Ｆ－、总硬度、矿化度、可溶性ＳｉＯ２、ＣＯＤ、ｐＨ、Ｃｕ、Ｐｂ、Ｚｎ、Ｃｄ、Ｍｎ、Ｖ、Ｌｉ、Ｍｏ、Ｓｅ、Ｈｇ、Ｉ、Ａｓ、Ｃｒ＋５、Ｃ６Ｈ５ＯＨ、ＣＮ－、ＡＢＳ的环境背景值．     

Role of halogen(I) cation-transfer mechanisms in water chlorination in the presence of bromide ion

Bromide ion is rapidly converted to HOBr via BrCl by reaction with HOCl. The subsequent slow reactions of (HOCl, OCl-)/(HOBr, OBr-) mixtures are monitored directly by multiwavelength UV-vis absorbance methods and simultaneously by ion chromatographic measurement of ClO2-, ClO3-, and BrO3- (p[H+] 5.6-7.6). A first-order loss of HOCl is observed which is catalyzed by trace concentrations of Br- and BrCl. Chlorite ion forms first and is subsequently oxidized to ClO3-. The loss of HOBr is slower and is second-order in HOBr, so that BrO3- formation takes longer than ClO3- formation. Under the conditions of this work, the relative yield of BrO3- increases with increase in pH. The decomposition of HOCI by bromide proceeds primarily by a series of halogen(I) cation-transfer reactions with subsequent halide release. The presence of HOCI increases the BrO3- yield three-fold from HOBr decay alone.     

Risk assessment of trihalomethanes from tap water in Fortaleza, Brazil

The cancer risks (CR) by oral ingestion, dermal absorption, and inhalation exposure of trihalomethanes (THM) from tap water of ten districts in Fortaleza, Brazil were estimated. The mean levels of THM compounds were obtained in Fortaleza tap water as follow: 63.9 microg L(-1) for chloroform (CHCl(3)), 40.0 microg L(-1) for bromodichloromethane (CHBrCl(2)), and 15.6 microg L(-1) for dibromochloromethane (CHBr(2)Cl). Bromoform (CHBr(3)) was not detected. The mean CR for THMs in tap water is 3.96 x 10(-4). The results indicate that Fortaleza residents have a higher CR by inhalation than dermal absorption and oral ingestion. The CR for CHCl(3) contributes with 68% as compared with the total CR, followed by CHBrCl(2) (21%), and CHBr(2)Cl (11%). The hazard index (HI) is about ten times lower than unity, not indicating non-cancer effects.     

Application of multivariate statistical techniques in the assessment of groundwater quality in seawater intrusion area in Bafra Plain, Turkey

Multivariate statistical techniques such as cluster analysis and principal component analysis were performed on 28 groundwater wells in Bafra Plain. Cluster analysis results show that the groundwater in the study area is classified into three groups (A, B, and C), and factor analysis indicates that groundwater is composed of 89.64 % of total variance of 12 variables and is mainly affected by three factors. Factor 1 (seawater salinization) includes concentrations of electrical conductivity, TDS, Cl^?, Na⁺, and sodium adsorption ratio, factor 2 (mixing water) includes δ¹⁸O, δD, and T, and factor 3 (fresh) includes Ca²⁺. For determination of the source of water, Ca/Cl, Cl/HCO₃, Mg/Cl, and Ca/Na as initials and Mg/Ca and SO₄/Cl as molar rates which were identified, the rates had been found to be very useful. Cluster analysis was made by using these rates and the waters were classified in two groups (group 1 and group 2). First group waters were affected by seawater, and the second group were very less affected by freshwater or seawater. According to the comparison of two different parameters, group 1 comprised group A and group B-2, -3, and -4 from the same wells, and group 2 comprised group B-1 and group C from the same well. As a result of this study, it could be said that multivariate statistical methods gave very useful results for the determination of the source.     

Chemical characteristics of groundwater and assessment of groundwater quality in Varaha River Basin, Visakhapatnam District, Andhra Pradesh, India

Study on chemical characteristics of groundwater and impacts of groundwater quality on human health, plant growth, and industrial sector is essential to control and improve the water quality in every part of the country. The area of the Varaha River Basin is chosen for the present study, where the Precambrian Eastern Ghats underlain the Recent sediments. Groundwater quality is of mostly brackish and very hard, caused by the sources of geogenic, anthropogenic, and marine origin. The resulting groundwater is characterized by Na(+)?>?Mg(2+)?>?Ca(2+)?:?[Formula: see text]?>?Cl(-)?>?[Formula: see text], Na(+)?>?Mg(2+)?>?Ca(2+)?:?[Formula: see text]?>?Cl(-)?>?[Formula: see text]?>?[Formula: see text], Na(+)?>?Mg(2+)?>?Ca(2+)?:?[Formula: see text]?>?Cl(-), and Na(+)?>?Mg(2+)?>?Ca(2+)?:?Cl(-)?>?[Formula: see text]?>?[Formula: see text] facies, following the topographical and water flow-path conditions. The genetic geochemical evolution of groundwater ([Formula: see text] and Cl(-)-[Formula: see text] types under major group of [Formula: see text]) and the hydrogeochemical signatures (Na(+)/Cl(-), >1 and [Formula: see text]/Cl(-), <1) indicate that the groundwater is of originally fresh quality, but is subsequently modified to brackish by the influences of anthropogenic and marine sources, which also supported by the statistical analysis. The concentrations of total dissolved solids (TDS), TH, Mg(2+), Na(+), K(+), [Formula: see text], Cl(-), [Formula: see text], and F(-) are above the recommended limits prescribed for drinking water in many locations. The quality of groundwater is of mostly moderate in comparison with the salinity hazard versus sodium hazard, the total salt concentration versus percent sodium, the residual sodium carbonate, and the magnesium hazard, but is of mostly suitable with respect to the permeability index for irrigation. The higher concentrations of TDS, TH, [Formula: see text], Cl(-), and [Formula: see text] in the groundwater cause the undesirable effects of incrustation and corrosion in many locations. Appropriate management measures are, therefore, suggested to improve the groundwater quality.     

Statistical approaches for hydrogeochemical characterization of groundwater in West Delhi, India

Parametric statistical approaches, correlations and multiple linear regressions were used to develop models for the interpretation of hydrogeochemical parameters in the Western part of Delhi state, India. The hydrogeochemical parameters indicated that the groundwater quality is not safe for consumption. The water is moderately saline and the salinity level is increasing over time. There is also the problem of nitrate pollution. The correlation between electrical conductivity (EC) and other water quality parameters except potassium (K(+)), nitrate (NO(3)(-)) and bicarbonate (HCO(3)(-)) is significantly positive and Ca(++)+ Mg(++)/Na(+)+ K(+) is significantly negative. In predicting EC, the multiple R(2) values of 0.996 and 0.985 indicate that 99.6% and 98.5% variability in the observed EC could be ascribed to the combined effect of Na(+), HCO(3)(-), Cl(-), SO(4)(--), NO(3)(-) and Ca(++)+ Mg(++) for the year of 2005 and 2006 respectively. Out of 99.6% of the variability in EC in 2005, 51.2% was due to Cl(-) alone, and 8.5%, 12.5%, 6.1%, 14.7% and 6.7% were due to Na(+), HCO(3)(-), SO(4)(--), NO(3)(-) and Ca(++) + Mg(++). Similarly in 2006, out of 98.5% of the variability in EC, 48.5% was due to Cl(-) alone, and 10.4%, 12.7%, 5.3%, 17.2% and 4.4% were due to Na(+), HCO(3)(-), SO(4)(--), NO(3)(-) and Ca(++)+ Mg(++). The analysis shows that a good correlation exists between EC, Cl(-) and SO(4)(--) either individually or in combination with other ions and the multiple regression models can predict EC at 5% level of significance.     

Hydrochemical Identification of Groundwater Resources and Their Changes under the Impacts of Human Activity in the Chah Basin in Western Iran

Chemical properties and pollution of water resources were studied in the Chah basin that is located in the Hamadan province, western Iran. Water quality was characterized according to its major constituents and the geological features of the area. Chemical analysis results indicate that groundwaters show wide concentration ranges in major inorganic ions, reflecting complex hydrochemical processes. Groundwater in the studied area is, for the most part, weakly to moderately mineralized and dominated by the calcium (Ca(2+)) and bicarbonate (HCO3-) ions. Within the basin, three different hydrogeochemical facies have been identified: Ca-HCO(3), Ca-SO(4) and Mg-HCO(3). The predominant water type of groundwater samples is the Ca-HCO(3) facies in the recharge area and has a tendency toward Mg-HCO(3) and Ca-SO(4) facies along the direction of water flow. The samples were classified into four groups based on chloride (Cl(-)) and nitrate (NO3-) concentrations and the processes that control water chemistry has been discussed. The results explained the importance of cation exchange, mineral weathering, and anthropogenic activities on groundwater chemistry. It was indicated that cation exchange and Cl-salt inputs are the major process controlling the water chemistry of the low Cl(-) and high [NO3-] (group 2) and high Cl(-) and [NO3-] (group 4). Groundwaters low in NO3- and high in Cl(-) (group 3) and low in NO3- and Cl(-) (group 1) are mainly affected by cation exchange and mineral dissolution. Pollution of groundwaters appeared to be affected by the application of fertilizers, irrigation practice, and solubility of mineral phases and discharge of domestic sewage. Measuring and predicting the mass loading of pollutant to groundwater from specific agricultural systems seems to be useful aids in controlling pollutions in groundwater.     

Effects of temperature and soil moisture on methyl halide and chloroform fluxes from drained peatland pasture soils

A series of laboratory-based incubations using a stable isotope tracer technique was applied to measure the net and gross fluxes of CH(3)Cl and CH(3)Br as well as the net fluxes of CHCl(3) from surface soils of the Sacramento-San Joaquin Delta of California. Annually averaged flux measurements show that these mineral/oxidized peat soils are a net source of CH(3)Cl (140 ± 266 nmol m(-2) d(-1)) and CHCl(3) (258 ± 288 nmol m(-2) d(-1)), and a net sink of CH(3)Br (-2.3 ± 4.5 nmol m(-2) d(-1)). Gross CH(3)Cl and CH(3)Br fluxes are strongly influenced by both soil moisture and temperature: gross production rates of CH(3)Cl and CH(3)Br are linearly correlated with temperature, whereas gross consumption rates exhibit Gaussian relationships with maximum consumption at soil moisture levels between 20 and 30% volumetric water content (VWC) and a temperature range of 25 to 35 °C. Although soil moisture and soil temperature strongly affect consumption rates, the range of gross consumption rates overall is limited (-506 ± 176 nmol m(-2) d(-1) for CH(3)Cl and -12 ± 4 nmol m(-2) d(-1) for CH(3)Br) and is similar to rates reported in previous studies. CHCl(3) fluxes are not correlated with methyl halide fluxes, temperature, or soil moisture. The annual emission rates of CHCl(3) from the Sacramento-San Joaquin Delta are found to be a potentially significant local source of this compound.     

Assessment of the Water Quality of Troia for the Multipurpose Usages

The aim of this study was to determine the origin and quality of waters in Troia. For this purpose total of 25 water samples including 2 springs, 14 surfaces and 9 groundwaters, were collected at eight different times. Global positioning system (GPS) was used to determine to coordinates of sampling points. The concentration of 6 minor elements (B, Cu, F, Fe, Pb and Zn), 9 major anions and cations (Na(+), Ca(2+), K(+), Mg(2+), SO(4)(2-), PO(4)(3-), HCO(3)(-), Cl(-) and, CO(3)(2-)) were determined by spectrometric, colorimetric and volumetric methods. Water pH, EC, DO, ORP and TDS were measured in situ using probes. The data showed that the concentrations of most of minor elements were below the EPA and TSE limits except Pb which ranged between 0.001 and 4.832 mg L(-1). Statistically significant relationships (P<0.01 and r>0.70) were observed between Fe and Cu, Cu and K(+), Cu and Ca(2+), B and Na(+), Na(+) and K(+). Assessing the water based on irrigation using Wilcox model showed that some well waters were not suitable for irrigation. Troia water was found to be highly corrosive and the average corrosion coefficients varied from 0.5 to 4.6. According to the Piper and Schoeller diagrams results, the water in Troia was classified as mixed water type.     

Assessment of groundwater corrosiveness for unconfined aquifer system at Kalpakkam

Groundwater samples from the shallow unconfined aquifer were collected from fifteen borewells in Kalpakkam nuclear plant site and were analysed for various physico-chemical parameters. The pH, temperature, salinity, TDS and EC were measured in the field. The borewell samples were analysed in the laboratory for Ca(2+), Mg(2+), Na(+), Cl(-), [Formula: see text], [Formula: see text], [Formula: see text] and [Formula: see text]. The Piper Trilinear diagram showed that majority of the borewell samples fall in Na - Cl +SO(4) type and Na - CO(3)+HCO(3) type. The Cl: HCO3 ratio of some borewell samples are categorized under injuriously contaminated to highly injurious type. The higher salinity levels encountered in some borewells emphasized the need for better understanding of groundwater corrosiveness. Accordingly, the Langeliar saturation Index (SI), Aggressivity index (AI) and Larson ratio (LnR) were evaluated for assessing the corrosive nature of the groundwater. The saline water incursion in the southern part of the study area increased the ionic concentration of Cl(-) and [Formula: see text] that made the groundwater corrosive.     

Dry deposition study by using dry deposition plate and water surface sampler in Shalu, central Taiwan

This study presents the chemical composition of dry deposition by using dry deposition plate and water surfaces sampler during daytime and nighttime sampling periods at a near highway traffic sampling site. In addition, the characterization for mass and water soluble species of total suspended particulate (TSP), PM2.5 and PM10 were also studied at this sampling site during August 22 to October 31 of 2006 around central Taiwan. The samples collected were analyzed by using Ion Chromatography (DIONEX 100) for the ionic species analysis. Results of the particulate dry deposition fluxes are higher in the water surfaces sampler than that of the dry deposition plate. In other words, the results also indicated that water surface can absorb more ambient dry deposition inorganic pollutants than that of dry deposition plate in this study. The results obtained in this study indicated that the ionic species of Cl(-), NO3(-) and SO4(2-) occupied about average 60-70% downward flux out of total ionic species for either dry deposition plate or water surfaces sampler during August to October of 2006 at this near highway traffic sampling site.