不同酸碱度土壤阳离子交换量的测定研究

为了能够快速准确测定不同酸碱度土壤中的阳离子交换量,弥补现行标准方法的不足,对三氯化六氨合钴浸提-分光光度法中的土壤称样量、pH、浸提时间、浸提温度和离心时间等条件进行了优化。优化后的方法检出限为0.43 cmol^+/kg,测定下限为1.72 cmol^+/kg,方法实验室内精密度为0.2%~1.8%,适用于大批量土壤样品中阳离子交换量的测定。     

分光光度法测定土壤阳离子交换量的方法优化

为了提高土壤阳离子交换量测定的准确度,针对《土壤阳离子交换量的测定三氯化六氨合钴浸提-分光光度法》(HJ 889—2017)标准的不足,对有机质、pH值、浸提时间、离心时间、浸提液过滤等条件进行优化。结果表明,酸性土壤在测试前调节pH值为6.0~8.0,振荡1 h,离心10 min,能够很好地解决测试结果偏低的问题。当有机质质量分数较高,且在380 nm处吸光度很高时,才需要在475 nm处进行吸光度校正。当实际样品基质复杂时,可采用针头过滤的方法,使得测试结果更准确。优化后的方法适用于各种类型土壤的大批量测定。     

褐土类土壤中15种元素可给态含量浸提剂的选择

要解决土壤中各元素可给态含量与人类、动植物的关系,首先要解决与生物有关的各元素含量的浸提剂,即浸提剂选择问题。一种理想的浸提剂应具备:①浸出量与人、动植物生长、发育有关,即相关性好;②浸出量高,便于检出;③通用性好,一次浸提液可作多种元素的测定;④简便易行。根据以上设想,综合国内外有关资料和几年的研究基础,选用了四种浸提剂(纯水、0.10mol/1 HCl、TEA-DTPA、AB-DTPA)进行探索性研究,为今后深入研究背景值的开发、利用和制定污染指标提供依据。     

测定废弃泥浆中的Cr(Ⅵ)的高效浸提方法研究

研究了废弃泥浆中的Cr(VI)提取测定方法并与土壤的浸提方法进行比较。结果表明,用0.1mol/L的KH2PO4为提取剂高速搅拌离心,分离提取液,可简单、快速、准确地测定废弃泥浆中的Cr(VI)。该方法的相对标准偏差为0.6%~2.5%,加标回收率86%~98%。     

AB-DTPA浸提ICP-MS法分析土壤中有效钼的研究

采用AB-DTPA浸提剂和电感耦合等离子体质谱法分析,建立了1种土壤中有效钼的分析方法。将土壤用AB-DTPA在(25±2)℃,(180±10) r/min的振荡频率下浸提8 h,电感耦合等离子体质谱法分析,实验结果表明,检出限为0.000 3 mg/kg,测定下限为0.001 mg/kg。通过对标准物质的测定,土壤有效钼与真值的相对误差在-17.4%～-7.5%,数据测试的准确度较好,加标回收率在90.0%～95.7%,能够满足土壤实际样品的分析测试,同时适用于各种类型土壤的批量检测。     

固体废物浸出液中氰化物测定方法的探讨

用金矿废渣样品进行氰化物的浸提试验，对浸提剂的pH值、浸提次数等条件进行优化。经实际样品验证，确定pH值〉12的碱性水溶液为最佳浸提剂，浸出液中易释放氰化物和总氰化物可用硝酸银滴定法或异烟酸一巴比妥酸分光光度法测定，方法检出限分别为0．25mg／L、0．001mg／L，加标回收率为90．0％～92．0％，测定结果的RSD〈8％。     

ICP—AES光谱法同时测定固体废物浸出液中的多种金属元素

采用翻转振荡方式以水为浸提剂浸提铜渣、尾矿渣、铬渣、铅渣、粉煤灰和电镀污泥试样，过滤后的浸提液经DDTC/CCl4体系萃取富集后，用ICP-AES法同时测定了Cu、Pb、Zn、Cd、Ni、Fe、Mn、Co和V等多种金属元素，方法具有较好的精密度和准确度，宜于推广应用。     

ICP－AES光谱法同时测定团体废物浸出液中的多种金属元素

采用翻转振荡方式以水为浸提剂浸提钢渣、尾矿渣、铬渣、铅渣、粉煤灰和电镀污泥试样，过滤后的浸提液经ＤＤＴＣ／ＣＣｌ４体系萃取富集后，用ＩＣＰ－ＡＥＳ法同时测定了Ｃｕ、Ｐｂ、Ｚｎ、Ｃｄ、Ｎｉ、Ｆｅ、Ｍｎ、Ｃｏ和Ｖ等多种金属元素．方法具有较好的精密度和准确度，宜于推广应用。     

香樟叶片中氟化物监测方法比较

比较了高氯酸、硝酸-氢氧化钾和超纯水3种基质对香樟叶片中氟化物浸提效果以及氟离子选择电极法定量方式之间的差异,同时尝试了离子色谱法。结果表明,间歇超声45 min浸提满足测定要求,标准加入法定量结果更可信。高氯酸基质曲线在不同日期制备的曲线重合度、斜率转化系数和日间偏差不如其他2种基质,但操作简单,浸提效果好,可通过测定前调节p H值和添加总离子强度调节剂改善;硝酸-氢氧化钾浸提效果与高氯酸的相当或更好,精密度好,但操作步骤多;超纯水浸提平均效果是其他2种的80%,叶片氟化物含量较低时与酸浸提效果相近;氟离子选择电极法与离子色谱法对叶片氟化物测定结果差异甚大,原因待查。     

微库仑法和离子色谱法测定土壤中可吸附有机卤素

采用振荡吸附处理土壤样品，用微库仑法和离子色谱法分别测定土壤中的可吸附有机卤素(AOX)。通过优化样品前处理条件以提高AOX的提取效率，上述两种方法检出限分别为15.3 mg/kg和16.3 mg/kg, 4-氯苯酚作为标准物质的加标回收率分别为92.2%～95.0%和77.7%～80.2%。两种方法测定实际土壤样品中AOX,6次测定结果的RSD为5.4%～19.2%。GSS系列标准土壤试验结果表明，振荡吸附处理样品，用微库仑法和离子色谱法在测定样品中AOX时测定结果区别不大，土壤中AOX含量与卤素含量无直接关系。     

The Status of Pesticide Residues in the Drinking Water Sources in Meiliangwan Bay, Taihu Lake of China

The study was carried out to assess the levels of pesticide residues in the water of Meiliangwan Bay, Taihu Lake of China. The most commonly employed organochlorine pesticides (OCPs), organophosphorus pesticides (OPPs) and herbicide atrazine were analyzed. The water samples were collected seasonally from Meiliangwan Bay within a period of one year. The pesticides were analyzed by gas chromatography (GC) with μECD or NPD after solid-phase extraction (SPE), which was confirmed by GC with an ion trap mass spectrometry (MS). The mean concentrations were 1.98 ng/l for lindane, 0.378 ng/l for heptachlor epoxide, 0.367 ng/l for p,p′-DDE, 0.496 ng/l for p,p′-DDD, 1.06 ng/l for p,p′-DDT and 51.6 ng/l for dichlorvos, 39.0 ng/l for demeton, 346 ng/l for dimethoate, 4.12 ng/l for methyl parathion, 11.6 ng/l for malathion, 2.17 ng/l for parathion and 217 ng/l for atrazine. Generally, low concentrations of OCP were found, whereas the concentrations of the OPPs and atrazine in the water of Taihu Lake were relatively high. Heptachlor epoxide and lindane were the two most commonly encountered OCPs while dichlorvos, demeton and dimethoate were found to have much higher concentrations and occurrences than other OPPs.     

Radioactivity, Physical and Chemical Parameters of Underground and Surface Waters in Qua Iboe River Estuary, Nigeria

Radioactivity, physical and chemical parameters of underground boreholes and surface waters in the region of Qua Iboe River Estuary involved in oil production activities were measured. The physical and chemical parameters measured included pH, temperature, turbidity, and concentrations of total dissolved and suspended solids, dissolved oxygen, chemical and biochemical oxygen demand, oils and grease, salinity, hardness (carbonates and bicarbonates), chlorine, sulphide, and metal ions. The work reveals that the radioactivity, physical and chemical parameters determined for both the underground and surface waters are safely below the international permissible limits except that of carbonate (68.6 mg/d – 228.7 mg/l) and bicarbonate (22.9 mg/l – 76.3mg/l) which renders both sources of water hard. The exceedingly high concentration range of hydrogen sulphide (40 mg/l–440 mg/l) in both sources is also beyond the international limit of 0.05mg/l. The ammonium ion concentration (1.40–2.80mg/l) was determined to be slightly higher in both the underground and surface waters than the international limit of 0.5mg/l.     

Application of a Larval Medaka Assay to Evaluate the Fish Safety Level in Sagami River, Japan

Physico-chemical characteristics of some river and hand-dug well waters used for drinking and domestic purposes in the oil rich Niger Delta area of Nigeria were assessed using standard methods. The concentrations of the parameters in the river water samples ranged in the following order: pH (5.6–6.9), temperature (26.90–28.60°C), turbidity (23–63 NTU), electrical conductivity (52–184 μs/cm), DO (5.4–7.2 mg/l), BOD (21–57 mg/l), TDS (6.0–217 mg/l), PO₄ ³⁻ (0.19–1.72 mg/l), SO₄ ²⁻ (25–36.8 mg/l), NO₃ ⁻ (20.3–28 mg/l), Fe (6.07–15.71 mg/l), Zn (0.04–0.24 mg/l), Pb (0.01–0.17 mg/l), Ni (0.01–0.13 mg/l), Vn (0.01–0.20 mg/l) and Hg (0.001–0.002 mg/l). The concentrations of these parameters in the hand-dug well water ranged in the following order: pH (5.7–6.8) temperature (26–30°C), turbidity (134–171 NTU), electrical conductivity (160–340 μs/cm), DO (5.4–6.4 mg/l), BOD (13–34 mg/l), TDS (110–190 mg/l), PO₄ ³⁻ (0.84–1.84 mg/l), SO₄ ²⁻ (10.6–28.1 mg/l), NO₃ ⁻ (11.3–23 mg/l), Fe (13.17–16.31 mg/l), Ni (0.01–0.02 mg/l), Vn (0.01–0.04 mg/l) and Hg (0.001–0.004 mg/l). The concentrations of BOD, turbidity, NO₃ ⁻ and Fe in the water samples were above WHO and FMENV permissible limits for safe drinking water. The results suggest that the use of such waters for drinking and domestic purposes pose a serious threat to the health of the users and calls for the intervention of government agencies.     

Residual fate and persistence of endosulfan (50 WDG) in Bengal gram (Cicer arietinum)

A detailed study has been presented on heavy metal content of the Iture Estuary. Waters of the Sorowie and Kakum rivers that supply water into the Estuary were investigated to ascertain heavy metal pollution levels due to anthropogenic activities. Concentration s of Cd, Zn, Se and Pb were measured. The study shows pre-occupying pollution levels that constitute a threat to both terrestrial and aquatic ecosystems. The abundance of metals in the Estuary is in the order Zn > Pb > Cd > Se. The level of Cd in the Iture Estuary ranged between 0.011 mg/l and 0.041 mg/l while Se was in the range 0.018 mg/l to 0.029 mg/l, Pb 0.020 mg/l to 0.075 mg/l and Zn 0.040 to 2.45 mg/l. The impact of contaminated water from the Sorowie River on the Iture Estuary was outstanding and the study points out the importance of the Sorowie River as a primary pollution source to the Iture Estuary. The pollution of the Iture Estuary was found to be connected to human activities in its catchments.     

Distribution of heavy metals in surface water of Ranipet industrial area in Tamil Nadu, India

Ranipet industrial area is about 120 km from Chennai on Chennai-Bangalore highway and is a chronic polluted area identified by Central Pollution Control Board of India. It is one of the biggest exporting centers of tanned leather in India. The total number of industries located in and around Ranipet town are 240 tanneries along with ceramic, refractory, boiler auxiliaries plant, and chromium chemicals. Studies were carried out to find out the contamination of surface water bodies due to industrial effluents. The results reveal that the surface water in the area is highly contaminated showing very high concentrations of some of the heavy/toxic metals like Cadmium ranging from 0.2 to 401.4 μg/l (average of 51.1 μg/l), Chromium 2.4–1,308.6 (average of 247.2 μg/l), Copper 2.1–535.5 μg/l (average of 95.5 μg/l), Nickel 1.6–147.0 μg/l (average of 36.7 μg/l), Lead 6.4–2,034.4 μg/l (average of 467.8 μg/l) and Zinc 20.8–12,718.0 μg/l (average of 3,760.4 μg/l). The concentration levels of these metals are much above the permissible limits in surface water and are health hazards especially for the people working in the tannery industries. It was observed that the people in the area are seriously affected and suffering from occupational diseases such as asthma, chromium ulcers and skin diseases. Distribution of metals, their contents at different locations, and their effects on human health are discussed in this paper.     

SEASONAL INFLUENCES OF THE ORGANIC POLLUTION MONITORING OF THE NEW CALABAR RIVER, NIGERIA

Monitoring of the New Calabar River water was conductedmonthly for a period of one year to ascertain seasonalinfluences and industrial effluent discharges on the organicpollution status of the river. Dissolved oxygen (DO) levelsranged between 3.4 and 9.1 mg/l and 4.4–9.0 mg/l for therainy and dry seasons respectively. Total dissolved solids(TDS) levels ranged between 6.5 and 4013.9 mg/l for the rainyseason and 4.32–619.5 mg/l for the dry season. The ranges forthe organic pollutant parameters were: biochemical oxygendemand, 0.25–4.20 mg/l and 0.15–4.95 mg/l; COD, 10–1000mg/l and 15–100 mg/l; oil and grease, 0.00001–5000 g/l and0.00001–800 g/l; anionic surfactants, 2.0–30 gMBAS/l and 0.1–2.0 g MBAS/l for the rainy and dryseasons respectively. The ranges for the same parameters forthe industrial effluent were: DO, 2.1–3.9 mg/l and 6.5–10.8mg/l; BCD, 0.35–1.4 mg/l and 2.3–2.7 mg/l; COD, 508 mg/l and20–576 mg/l; oil and grase, 0.07–50 g/l and0.048–25.0 g/l; and anionic surfactants, 4.0–7.3g MBAS/l and 0,2–17.0 g MBAS/l for the rainyand dry seasons respectively. These results indicate thatseasonal changes as well as industrial effluent dischargesinfluenced the organic load of the river.     

Influence of Mining Activities in the North of Potosi, Bolivia on the Water Quality of the Chayanta River, and its Consequences

Mining activity in the North of Potosi (Siglo XX mine, Ingenio Catavi-Siglo XX, Pucro mine and Colquechaca mine) produces minewater containing high concentrations of heavy metals such as As (0.02-34 mg/l), Cd (45-11,600 microg/l), Cu (0.35-32 mg/l), Fe (42-1,010 mg/l), Pb(33-3,130 microg/l), Ni(20-4,320 microg/l), and Zn (1.1-485 mg/l), that exceed considerably the limit values. The rivers in the North of Potosi (Katiri and Pongoma) that do not receive minewater contain clear water with rather low heavy metal concentrations. These rivers and also other rivers contaminated with minewater, are tributaries of the Chayanta River that transports water with a high concentration of heavy metals such as As (6-24 microg/l), Cd (260-2,620 microg/l), Cu (205-812 microg/l), Pb(10-21 microg/l) and Ni(110-332 microg/l). These elements result from mining activity, as indicated by a comparison with rivers not contaminated by minewater discharges. Water of the Chayanta River, used all year long by the population of Quila Quila, (a village situated at about 75 km from the mining centers), for the irrigation of crops such as potato, maize and broad bean, contains heavy metal concentrations exceeding for several elements the guidelines for irrigation. As drinking water the population of Quila Quila consumes spring water with a generally acceptable heavy metal concentration, as well as infiltrated water of Chayanta River (which is also used in animal drinking troughs) with a high concentration of Cd (23-63 microg/l), exceeding the limit value for drinking water. The metal concentration is significantly lower in the infiltrated water than in the water of Chayanta River. Some technological solutions are suggested to improve the quality of the water used. Surveys carried out on inhabitants of the region, showed that many people present health problems, probably to be attributed to the bad quality of the water they consume and use for irrigation.     

The early warning of aquatic organophosphorus pesticide contamination by on-line monitoring behavioral changes of Daphnia magna

In this paper, the movement behavior of Daphnia magna was studied as a bio-indicator of organophosphorous pesticide (OP) contamination, using an on-line bio-monitoring method, the Multispecies Freshwater Biomonitor. A static test of acute toxicity test revealed the 24-h and 48-h LC(50) values (95% confidence limit) for Daphnia magna to be respectively 0.45 microg/l and 0.21 microg/l for dipterex 3.80 microg/l and 0.90 microg/l for malathion, and 1.25 microg/l and 0.38 microg/l for parathion. The behavior strength of Daphnia magna was a sensitive indicator of sublethal OP stress and resulted in significant concentration-response relationships for the three OPs. Increasing OP concentration will result in more intensive behavioral responses of Daphnia magna and shorter response time, which could be described by the Stepwise Stress Model (SSM). Therefore movement behavior can be effectively applied in early warning of environment quality by on-line bio-monitoring. The intensive changes in behavior strength of Daphnia magna over a short time follow the SSM concept and can be used as an indicator of early stress response to OP accidental contamination.     

Survey of the occurrence of residues of methyl tertiary butyl ether (MTBE) in Dutch drinking water sources and drinking water

An indicative survey has been carried out in The Netherlands investigating the presence of methyl tertiary butyl ether (MTBE) in drinking water and the corresponding sources. In total, 71 different sites used for the preparation of drinking water in The Netherlands were sampled in two successive seasons in 2001 involving the analysis of 156 samples. (ground water (n = 88), surface water (n = 17), bank filtrate water (n = 6) and drinking water (n = 45)). To combine high sample throughput with high selectivity and sensitivity, off-line purge and trap for sampling and gas chromatography mass spectrometry equipped with an automated thermal desorption sampler (TDS-GC-MS) was selected as the preferred analytical methodology. The developed procedure enabled the analysis of at least 40 samples per day and provided a limit of quantification of 2 ng l(-1). In the first period 63 samples of raw water were analyzed. Concentrations ranged between < 10 ng l(-1) and 420 ng l(-1) with a median concentration below 10 ng l(-1). The second period was focused at the re-sampling of positive locations (MTBE > 10 ng l(-1)) and a few additional drinking water utilities of which both the raw and drinking water of the utilities were analyzed. The median concentration of MTBE in the selected set of drinking water samples was 20 ng l(-1) (n = 45). At one location MTBE was found at a level of 2900 ng l(-1) caused by point source contamination of the ground water (11 900 ng l(-1)). Special attention has been paid to the quality of the results by analyzing all samples in duplicate and the analysis of control samples during each series of analyses.     

Assessment of temporal variations of water quality in inland water bodies using atmospheric corrected satellite remotely sensed image data

The spatial distribution of silicate, ammonium, nitrate, nitrite, phosphate, chlorophyll a and dissolved oxygen in Obidos lagoon was obtained by surveying five sites in eight campaigns, between October 2004 and October 2006. A confined inner branch of the lagoon showed higher availability of ammonium (1.2-81 micromol l(-1)), phosphate (1.9-17 micromol l(-1)), silicate (0.85-86 micromol l(-1)) and chlorophyll a (0.30-18 microg l(-1)) than other sites (0.47-25 micromol l(-1), 0.10-3.9 micromol l(-1), 0.47-25 micromol l(-1), 0.25-11 microg l(-1), respectively). According to several trophic classification tools, that branch is considered eutrophic to polytrophic, emphasising its deteriorated conditions, while the rest of the lagoon is of better quality. In autumn/winter nutrients were inversely correlated to salinity (r > 0.93) reflecting the freshwater inputs enriched in nitrogen and phosphorous compounds to the inner branch. In warmer periods, dissolved oxygen concentrations dropped during the night, and sediments of the branch become an important source of ammonium and phosphate. The low DIN:P ratio (median = 10) obtained in the branch, which suggests an excess of phosphate, that increased in warmer periods and changed the limiting nutrient in the entire lagoon. These results emphasize the spatial heterogeneity of water quality in Obidos lagoon, its seasonal variability, and the importance of recognising these distributions before defining homogenous water body on the scope of Water Framework Directive.