首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 109 毫秒
1.
应用化学法及吹扫捕集、气相色谱-质谱联用仪(GC-MS),检测Z市农村不同类型饮用水与癌症相关的有机污染物,对污染物的剂量与癌症标化死亡率进行Spearman等级相关分析。该市河水、池塘水、浅井水中部分样品的CODMn、BOD5和NH3-N指标超过地表水环境质量Ⅲ类标准,微生物指标超过生活饮用水卫生标准,检出NH3-N及NO3-N、NO2-N合成致癌物NAD的2类前体物及NDMA等直接致癌物。Z市农村河水、池塘水、浅井水主要受生活排污和农业生产污染,不宜作生活饮用水。不同类型饮用水有机污染物丰水期高于枯水期(P值均小于0.05)。癌症标化死亡率与不同类型饮用水有机污染浓度呈等级正相关(P值均小于0.05),与NO2-N、NDMA、NDEA含量呈剂量-效应关系。直接饮用污染的地表水是造成该市农村癌症高发聚集分布的主要原因之一。  相似文献   

2.
采用硫酸溶液为吸收液,顶空进样气相色谱法测定大气中的吡啶,毛细管柱分离,FID检测器分析。吡啶标准溶液在0~98.3 mg/L范围内线性良好,当采样体积为30 L时,最低检出质量浓度为0.006 mg/m3,标准溶液平行测定的RSD≤3.1%,加标回收率为95.3%~99.6%。  相似文献   

3.
菏泽市地处鲁西南高氟地区,其河流中的高浓度氟化物不仅会通过径流过程影响南四湖水质,还会影响当地水生态平衡及人体健康。通过分析菏泽市主要河流中氟化物的时空分布特征,并结合地下水、土壤及废污水调查结果,探讨了影响河流中氟化物分布的主要因素。结果表明:研究区河流中氟化物的平均浓度在0.98~1.45 mg/L之间,氟化物浓度分布呈现出枯水期>平水期>丰水期、下游>上游、支流>干流的特征。氟化物浓度较高的河流呈现高pH、低钙的特点,水化学组分以Na-HCO3型、Na-SO4型为主。河流中氟化物的浓度主要受蒸发浓缩和岩石风化作用的影响。研究区地下水和土壤中氟化物的背景浓度整体较高。枯水期高氟地下水可能通过直接补给河流对河流水体产生影响,丰水期土壤中的氟也会通过径流过程汇入河流。人类工农业生产过程大量开采利用当地高氟地下水,而高氟废水最终则会进入河流,导致河流中氟化物的含量升高。  相似文献   

4.
采用顶空气相色谱法测定水中的苯胺,对盐类及其用量、顶空温度等条件进行了优化。当加入5 g NaOH,80℃进行顶空时,苯胺在0.02~0.50 mg/L范围内线性良好,方法检出限0.002 mg/L,样品加标平行测定的RSD<5.0%,回收率>95%。方法操作简单,检出限低,适用于水体中苯胺的测定。  相似文献   

5.
研究了陕北主要石油勘探开发地区地表水的水质状况,分析了pH、矿化度(全盐量)、硬度、六价铬、砷、镉、铅、氨氮、挥发酚、石油类、化学需氧量(COD)、氯化物、硫酸盐、硝酸盐氮、总磷、氰化物、氟化物等17个指标,结果显示砷、镉、铅、氟化物、硝酸盐、氰化物、氟化物的Pi值均小于1;挥发酚、总磷、石油类、氨氮、COD、六价铬、硫酸盐、矿化度、氯化物、硬度均超标。研究区东部和西部地表水呈现出不同的污染特征,通过分析不同区域污染物来源,提出了污染防治对策与建议。  相似文献   

6.
以2016—2020年地表水常规监测结果为依据,发现瑞平塘河自2017年起出现氟化物质量浓度升高现象,2020年其中1个断面氟化物质量浓度平均值达到1.25 mg/L,比2016年高出145%。为此于2021年3—6月,对瑞平塘河流域的氟化物污染状况进行实地调查并开展溯源研究。研究结果显示,2021年氟化物质量浓度超过1.0 mg/L的点位占59.34%,其中超过1.5 mg/L的点位占42.86%,表明大部分河道氟化物质量浓度已经超过水体功能区要求,对生态环境安全构成较大潜在风险。溯源调查结果表明,排除了农业源及矿山源污染的可能,乳胶制品企业排放的废水为瑞平塘河氟化物的污染来源。针对目前该行业的排放标准和环境影响评价均未提及氟化物污染,企业废水处理设施也无除氟工艺单元,缺乏有效的污染防治措施与监管要求等问题。提出,应及时组织开展该区域乳胶制品行业整治提升,增加氟化物处理工艺单元,提升出水水质,确定氟化物排放浓度限值,并对该行业排放标准做进一步研究和完善等建议。  相似文献   

7.
采用温室气体观测卫星(GOSAT) 傅里叶变换光谱仪(FTS)发布的CO2柱浓度L3级别数据集产品,利用TCCON地基站点的CO2柱浓度数据对卫星遥感数据进行验证,分析中国CO2柱浓度时空变化特征及其影响因素。研究结果表明,GOSAT卫星的CO2柱浓度产品精度较高,线性回归的r2为0.99,线性方程斜率为0.98,平均偏差为0.11 mg/L。中国CO2柱浓度呈现逐年增长的趋势,存在12个月的周期性季节性变化。2010、2020年区域年平均CO2柱浓度分别约为389.30、412.62 mg/L,增长了23.32 mg/L,年平均增长率大约为0.58%。中国区域大气CO2柱浓度的月变化存在明显的时空差异,最大值和最小值分别出现在4月和8月,2020年4月和8月的区域平均值分别为415.09、409.13 mg/L。中国区域CO2柱浓度从东部沿海向西部逐级递减,且呈现明显的季节性变化,夏季高值主要集中在东南部沿海地区,冬季高值主要集中在华北地区。  相似文献   

8.
利用双梯度液相色谱仪与固相萃取技术结合,建立了一种在线固相萃取-高效液相色谱同时测定环境水体中甲萘威和百菌清的方法。在取样2.5 mL时,甲萘威和百菌清的检出限分别为0.6 ng/mL和0.4 ng/mL。以20 μg/L标准溶液作为样品溶液,连续进样5针,测定峰面积,计算相对标准偏差(RSD),结果甲萘威的RSD为1.45%,百菌清的RSD为1.20%,符合方法学要求。  相似文献   

9.
气相色谱法测定工业废气中的异丙醇   总被引:1,自引:1,他引:0  
用活性炭吸附管采集吸附工业废气中的异丙醇,经二硫化碳解析后由自动进样器送入气相色谱仪中分离并由FID检测器检测。2 mL二硫化碳解吸溶剂中异丙醇的绝对量为1.57~6.28 mg时,测定结果的相对标准偏差为2.4%~7.6%(n=5);当样品采集量为10 L时,方法检出限为0.3 mg/m3。所用活性炭采样管对异丙醇的吸附效果良好,100 mg活性炭对异丙醇的穿透容量大于15 mg;二硫化碳溶剂对吸附在活性炭中的异丙醇解吸效果较好,异丙醇加标量为3.92~15.70 mg时,解吸效率为93.9%~100.5%。  相似文献   

10.
以硫酸铵-氨水溶液为淋洗液,二苯碳酰二肼为柱后显色剂,采用离子色谱-柱后衍生可见光检测环境空气中六价铬和废气中铬酸雾的含量。通过对分析条件的优化,建立了简便、灵敏、选择性好、准确性高和重现性好的分析气体中六价铬的方法。该方法在Cr6+浓度1.00~600 μg/L之间线性良好,当采集50 L有组织废气和20 L无组织废气时,铬酸雾分析的检出限分别为2.2×10-5和1.1×10-5 mg/m3,采集64 m3环境空气时,Cr6+分析的检出限为7.8×10-9 mg/m3,以浸提后的样品水溶液连续进样得到其相对标准偏差为1.42%(n=8)。利用该法进行环境空气中六价铬和废气中铬酸雾的测定,回收率在80%~105%之间。监测结果显示:环境空气中六价铬含量处于极低状态;五金厂厂界废气中铬酸雾含量极低,约为5 μg/m3;五金厂废气排气筒监测的气体中则含有较高浓度的铬酸雾,其含量已经超过GB 21900—2008中规定的排放限值。  相似文献   

11.
The aim of this study was to estimate the risk for caries and fluorosis in a desertification area, applying the calcium/fluoride concentration ratio of underground water and the quality of water in a selected geographical region. This study was performed in the municipality of São João do Rio do Peixe, located in the tropical semiarid lands of Brazil. A total of 111 groundwater samples were collected. Fluoride concentration varied from 0.11 to 9.33 mg/L. Thirty percent of all samples analyzed showed values above 1.5 mg/L, while 64 % were above the ideal limit of 0.7 mg/L. Mean calcium concentration was 47.6 mg/L, and 14.4 % of all samples presented values above the WHO acceptable limits. The proportional value of calcium/fluoride in water showed that only 12 % of the samples were suitable for dental caries prevention with minimal risk for dental fluorosis. Mapping of the fluoride distribution indicated that approximately 2,465 people could be affected by dental fluorosis and 1,057 people might be affected by skeletal fluorosis. It can be concluded that, in addition to fluoride, many water parameters were not suitable for the drinking water. Mapping out calcium/fluoride ratio may indicate areas of water suitability for caries control, whereas the fluoride concentration solely can indicate the areas with the risk for fluorosis. This approach can be relevant for health authorities for identifying communities where dental caries or dental fluorosis is prevalent.  相似文献   

12.
为考察遂宁市辖区内集中式饮用水水源地污染物钡的分布特征和健康风险水平,通过电感耦合等离子体原子发射光谱法对研究区域内市级、县级和乡镇级所有在用的56个集中式饮用水水源地钡的浓度进行分析检测,借助空间分析与统计分析的结果,探讨了其空间分布和浓度差异,并利用环境健康风险评价模型,对不同类型水源地钡的健康风险进行了评价。结果表明,38个地表水水源地钡的浓度范围为0.065~0.180 mg/L,均值为0.110 mg/L;18个地下水水源地钡的浓度范围为0.027~0.370 mg/L,均值为0.130 mg/L。地表水与地下水水源地间钡的浓度差异具有统计学意义(P0.05),钡的空间分布也存在不同程度的差异性。各水源地中的钡经饮用和皮肤暴露两种途径对成人和儿童所引起的非致癌风险值为1.34×10~(-8)~1.62×10~(-8),远低于推荐的最大可接受风险水平(1.0×10~(-6)),各水源地因污染物钡导致的非致癌风险极低。  相似文献   

13.
Fluoride concentration in groundwater sources used as major drinking water source in rural area of block Nawa (Nagaur District), Rajasthan was examined and the toxic effects by intake of excess fluoride on rural habitants were studied. In block 13, habitations (30%) were found to have fluoride concentration more than 1.5 mg/l (viz. maximum desirable limit of Indian drinking water standards IS 10500, 1999). In five habitations (11%), fluoride concentration in groundwater is at toxic level (viz. above 3.0 mg/l). The maximum fluoride concentration in the block is 5.91 mg/l from Sirsi village. As per the desirable and maximum permissible limit for fluoride in drinking water, determined by World Health Organization or by Bureau of Indian Standards, the groundwater of about 13 habitations of the studied sites is unfit for drinking purposes. Due to the higher fluoride level in drinking water, several cases of dental and skeletal fluorosis have appeared at alarming rate in this region. There is an instant need to take ameliorative steps in this region to prevent the population from fluorosis. Groundwater sources of block Nawa can be used for drinking after an effective treatment in absence of other safe source. The evaluation of various defluoridation methods on the basis of social and economical structure of India reveals that the clay pot chip, activated alumina adsorption, and Nalgonda techniques are the most promising.  相似文献   

14.
The study aimed to assess the quality and health aspects of water intended for human and livestock consumption in two rural districts of the Rift Valley of Ethiopia. The study involved two parts: the first consisted of a questionnaire survey and farmers’ group discussions, complemented by secondary health data, and the second part determined the chemical (total dissolved solids, pH, manganese, hexa-valent chromium, fluoride) and microbiological quality of different water sources during dry and wet seasons. The result showed a lack of sustainable access to safe water in the communities. Industrial pollution and mismanagement of water sources by human and livestock was found to be a source of potential health risk. Potentially linked human health problems like malaria, diarrhoea and gastrointestinal parasites were common in the districts. Overall, 76 % of the assessed water sources (n?=?25) failed to comply with World Health Organization guidelines for human drinking water, for at least one assessed parameter, mostly irrespective of the season. The non-compliance was mainly attributed to Escherichia coli contamination and/or high fluoride concentration. At least 20 % of the water samples were also found to be unfit for livestock consumption based on assessed chemical parameters in both dry and wet seasons. To minimize the health risk associated with mismanagement and poor quality of water sources in the area, targeted action in the protection of surface water sources should be given priority.  相似文献   

15.
Fluoride Content in Drinking Water Supplies of Riyadh, Saudi Arabia   总被引:2,自引:0,他引:2  
Groundwater supplies about 34% ofthe total water demand for the capital city of SaudiArabia, Riyadh. The other 66% is desalinatedseawater. The fluoride level in Riyadh drinking watersupplies was evaluated. Samples were collected fromselected wells, treatment plants, desalinatedseawater, distribution network and 19 locally producedand imported bottled water. The fluoride level in theinfluent to the seven groundwater treatment plants andtheir final product water were in the range of 0.63–1.6 and 0.23–1.1 mg/L, respectively. Blending of theplants product water with the desalinated seawaterresulted in the fluoride level ranging from 0.01–0.5 mg/Lin the distribution network. Ninety percent of thesamples collected from the distribution network hadfluoride levels less than or equal to the calculatedweighted average value of 0.24 mg/L. The locallyproduced bottled waters as compared to 8 imported oneshave shown fluoride levels in the range of 0.2–0.83and 0.04–0.2 mg/L, respectively. In general, thefluoride level in Riyadh drinking water supplies isbelow the optimum recommended level of 0.7 to1.2 mg/L. It is therefore recommended thatfluoridation be considered in water treatment plants.  相似文献   

16.
This study was carried out to assess the fluoride concentration in groundwater in some villages of northern Rajasthan, India, where groundwater is the main source of drinking water. Water samples collected form deep aquifer based hand-pumps were analysed for fluoride content. Fluoride in presently studied sites was recorded in the ranges of 4.78 and 1.01 mg/l. The average fluoride concentration for this region was recorded 2.82 mg/l. As per the desirable and maximum permissible limit for fluoride in drinking water, determined by WHO or by Bureau of Indian Standards, the groundwater of about 95 of the studied sites is unfit for drinking purposes. Due to the higher fluoride level in drinking water several cases of dental and skeletal fluorosis have appeared at alarming rate in this region. The middle and eastern parts of the Hanumangarh, a northern most district of the state, can be classified as higher risk area for fluorosis; due to relatively high concentrations of fluoride (3-4 mg/l) in groundwater of this region. After evaluating the data of this study it is concluded that there is an instant need to take ameliorative steps in this region to prevent the population from fluorosis.  相似文献   

17.
The ground water quality of District Nainital (Uttarakhand, India) has been assessed to see the suitability of ground water for drinking and irrigation applications. This is a two-part series paper and this paper examines the suitability of ground water including spring water for drinking purposes. Forty ground water samples (including 28 spring samples) were collected during pre- and post-monsoon seasons and analyzed for various water quality constituents. The hydrochemical and bacteriological data was analyzed with reference to BIS and WHO standards and their hydrochemical facies were determined. The concentration of total dissolved solids exceeds the desirable limit of 500 mg/L in about 10% of the samples, alkalinity values exceed the desirable limit of 200 mg/L in about 30% of the samples, and total hardness values exceed the desirable limit of 300 mg/L in 15% of the samples. However, no sample crosses the maximum permissible limit for TDS, alkalinity, hardness, calcium, magnesium, chloride, sulfate, nitrate, and fluoride. The concentration of chloride, sulfate, nitrate, and fluoride are well within the desirable limit at all the locations. The bacteriological analysis of the samples does not show any sign of bacterial contamination in hand pump and tube-well water samples. However, in the case of spring water samples, six samples exceed the permissible limit of ten coliforms per 100 ml of sample. It is recommended that water drawn from such sources should be properly disinfected before being used for drinking and other domestic applications. Among the metal ions, the concentration of iron and lead exceeds the permissible limit at one location whereas the concentration of nickel exceeds the permissible limit in 60 and 32.5% of the samples during pre- and post-monsoon seasons, respectively. The grouping of samples according to their hydrochemical facies indicates that majority of the samples fall in Ca–Mg–HCO3 hydrochemical facies.  相似文献   

18.
Characterization of Rain and Roof Drainage Water Quality in Xanthi, Greece   总被引:1,自引:0,他引:1  
Thirteen field campaigns were undertaken in the period from December 2, 2002 until September 1, 2004 to collect water samples in order to characterize the quality of rainfall and roof drainage in the city of Xanthi, a typical provincial city in Greece. In each campaign, water samples were collected from 10 representative sites in the city (in total 130 samples), representing areas of distinct land use and human activities (i.e., traffic volume, residence density and industrial activity). The water samples were analyzed according to drinking water criteria for total coliform (not detected), temperature (range: 0.9–20°C), pH (range: 3.6–11.4), alkalinity (range: 0–21.5 mg CaCO3/L), nitrate (range: 0–2456 μg/L), ammonium (range: 0–2628 μg/L), sulfate (range: 0–0.5 mg/L), calcium (range: 259.1–3064 μeq/L), magnesium (range: 0.8–488.8 μeq/L), potassium (range: 0.0–110.6 μeq/L) and dissolved heavy metals (Fe, range: 0.01–0.18 mg/L; Mn, range: 0.01–0.09 mg/L; Zn, range: 0.01–0.54 mg/L; Cu, Cr and Ni, not detected). Pollutant concentrations were generally higher in roof drainage than in rainwater, but both were lower than drinking water standards. Dissolved heavy metal concentrations were generally higher in the areas of intensive human activities, such as roads with high traffic volume and densely populated residential areas. The satisfactory quality of rainwater, which results from this analysis, makes its use as grey water possible.  相似文献   

19.
A study was undertaken to estimate fluoride content in thegroundwater in certain parts of rural Eritrea, North-East Africa,along the River Anseba. Standard procedure was adopted for fluoride detection. Results indicate elevated concentration offluoride in groundwater. The highest concentration was found tobe 3.73 mg L-1, well above the safety level for consumption.Geological basis for the high concentration of high fluoride hasbeen established; it is presumed to be the pegmatite intrusion hosted by a granitic batholith. Extensive dental fluorosis has been observed in the population exposed to drinking water of highfluoride content.  相似文献   

20.
通过全国多家实验室的大量监测数据,研究分析了离子选择电极法测定水中氟化物的质量控制指标。研究表明,在0.5~4.5 mg/L范围内同一标准样品多次测定的质量控制指标为:室内相对标准偏差(RSD)≤4.0%,室间相对标准偏差(RSD’)≤8.0%,相对误差(RE)≤±10.0%。在0.06~7.0 mg/L范围内实际样品平行双样测定质量控制指标为:相对偏差(RD)≤5.0%。加标回收率范围为90%~110%。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号