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1.
A hydrogeochemical survey of springs was carried out in Kirsehir, Turkey and fluoride, heavy metals, and mineral contents
were analyzed. The highest fluoride levels were detected in Mahmutlu with 2.1 ppm. The fluoride content of Pohrenk was, on
average, 1.1 ppm. Consequently, dental fluorosis and dental stains were observed in both villages. Although the fluoride concentrations
were within the suggested limits, dental stains and fluorosis were commonly observed among the villagers especially kids.
The fluoride concentrations of 0.7–1.0 ppm were the lowest in Cevirme, which is to the northwest of fluoride ore. The heavy
metal concentrations of resources around the three villages were compared with and were found lower than WHO’s provisional
guideline values. However, the Fe, Zn, and Cr concentrations in hot springs were much higher than cold springs with as much
as 100 ppb for Fe, 50 ppb for Zn, and 15 ppb for Cr. 相似文献
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GeoJournal - This paper discusses the challenges facing urban water systems in disadvantaged communities (DACs) using Los Angeles County as a case study area. We review issues of water... 相似文献
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A. Siddique S. Saied E. Zahir Z. A. Nayyer N. A. Zaigham 《International Journal of Environmental Science and Technology》2014,11(3):739-746
Trihalomethanes (THMs) are the most abundant disinfection byproducts (DBPs) of the chlorination disinfection. THMs speciation and their geospatial distribution were examined in 58 locations throughout the water distribution network of Karachi city. THMs (CHCl3, CHCl2Br, CHClBr2 and CHBr3) and physico-chemical parameters (pH, TDS, DO, Residual chlorine, temperature and TOC) were determined. CHCl3 was the major THM found in all water samples of 58 locations, which accounted for 91.69 % of the total THMS followed by CHCl2Br (5.69 %), CHClBr2 (1.78 %) and CHBr3 (0.85 %). Total THMs level exceed the maximum contamination level of WHO and USEPA at some locations. Varying nature of correlation from high to low was found within THMs and among the physico-chemical parameters. GIS linked geospatial analysis revealed the association of THMs level with demographical and geological based variations from east to west of Karachi city. Continuous monitoring program and legislation for the contaminant levels were suggested to avoid adverse public health impact of THMs in drinking water supplies. 相似文献
4.
Binbin WANG Baoshan ZHENG 《中国地球化学学报》2006,25(B08):80-80
Background: Fluorine is an important element to human health. Overloading of fluorine may cause dental and/or skeletal fluorosis, while in fluorine deficiency distracts, fluoride drinking water supply or other methods of fluoridation may greatly reduce the ratio of dental caries of local residents. The benefit of drinking water fluoridation has been widely accepted as a public sanitation measure in most western countries, but in China it faces big challenges. Method: Investigation of oral health and fluorine level in drinking water, main food and urine in some big cities of China. Result and conclusion: (1) Fluorine content in drinking water in 70% of the whole research cities is lower than 0.3 mg/L, and in 90% of the research cities, it is lower than 0.5 mg/L. (2) Fluorine concentrations in main foodstuff of respective cities in China were low and did not have too much difference. (3) Drinking water was the main source of fluorine intake for Chinese residents. (4) With the data of the epidemiological research by NCOH in 1995, in the range of fluorine content in drinking water below 1.0 mg/L, the ratio of dental caries and DMFT decreases with the increase of fluorine concentration. The relation between fluorine concentration in drinking water and dental index did not have a good linear relationship. 相似文献
5.
M. Panneer R. Sivakumar M. Senthilkumar 《International Journal of Environmental Science and Technology》2017,14(9):1931-1944
Groundwater is the major source of freshwater in region devoid of surface water resources. Once such region is the Morappur area, Dharmapuri district of Tamilnadu, wherein groundwater is major source of water for all purposes. The area is reported to be severely affected by fluorosis due to excessive Fluoride in groundwater. The area comprises of rocks of Archaean age, namely Charnockite, Epidote Hornblende Gneiss and ultramafic rocks. The area has experienced numerous tectonic disturbances in which numbers of vertical joints have developed and are filled with quartz/feldspathic veins, and highly mineralised. Two aquifer systems have been identified in the area, namely the weathered aquifer and fractured aquifer. In order to understand the factors controlling high Fluoride concentration in groundwater, 149 groundwater samples were collected during pre and post-monsoon period. Analytical results indicate that 35% groundwater samples show Fluoride concentration more than 1.5 ppm (permissible limit). Results indicate that both the aquifer units are affected by high Fluoride and deeper aquifers are more affected. Biotite and Hornblende minerals present in the area and interact with groundwater to release Calcium, Magnesium along with Fluoride. Further chloro-alkaline indices indicate that calcium ions are replaced by sodium due to reverse ion exchange, leading to high concentration of Fluoride along with high concentration of Sodium. Government has taken measures to provide Fluoride-free drinking water from distant surface water sources. However, it is important to follow certain water management methods to improve the groundwater quality. 相似文献
6.
Groundwaters from crystalline and metamorphic rocks (hardrocks) and from Quaternary deposits, i.e., alluvial and glacial deposits (softrocks) from the counties of Nord-Trøndelag and Sør-Trøndelag were analyzed for major and minor elements and ions including fluoride. The median concentration of F– in water from the hardrock aquifers is 0.28 mg/l (14.7 eq/l) in contrast to water from softrock aquifers in which it is found to be 0.05 mg/1 (2.6 eq/l). More importantly, ca. 15% of the locations where water was abstracted from hardrock wells contain 1.5 mg/l (78.9 eq/l) F– or more. Thus, 15% of all hardrock wells returned F– results that are at or above the maximum recommended value for drinking water. Of the softrock wells, none are above 1 mg/l. Geologists would normally expect higher F–contents in groundwaters derived from acid rocks, e.g., in granitic or gneissic areas. When comparing the host lithology with the observed F–contents, however, no clear relationship between F– content and lithology is visible. The highest observed F– values actually occur in gneissic host rocks. However, wells drilled in amphibolites/greenstones, mica schists, calcareous rocks, and sedimentary rocks all returned some analytical results above 1.5 mg/l F–. These results suggest that all hardrock wells drilled should be tested for F– and the users informed about the results and advised to take any necessary precautions. When applying the recently proposed Norwegian drinking water limits to our data, 51% of all softrock well waters and 56% of all hardrock well waters are unfit for consumption without prior treatment, although we analyzed only for about half of the proposed elements/parameters. This result seriously questions the concept of fixed action levels—many of them with totally unproven health implications—for so many parameters/elements for hardrock groundwaters. 相似文献
7.
This paper presents the possible alternative removal options for the development of safe drinking water supplies in areas affected by hexavalent chromium. Chromate is a matter of great environmental concern due to its extensive contamination and carcinogenic toxicity. In this study, the conventional adsorption with various types of adsorbent method were used for chromate removal, but only powder carbon steel was compatible with household water treatment and can be designated based on high removal efficiency and affordable cost. Home powder carbon steel with granular activated carbon (PCS–GAC) treatment systems are quite simple. Water needing treatment passes through the cartridge or filter candles contacting PCS–GAC on its way to the faucet. This method is based on the use of powder carbon steel, ML 90 Bombril S.A, as a cleaning agent. Granular activated carbon filters have been employed in home water purification systems essentially for the removal of taste, odor, and color. The effect of pH, redox potential, time, and adsorbate concentration on the uptake carbon steel were observed. The lack of desorption suggests that anion chromium is irreversibly sorbed by the powder carbon steel. 相似文献
8.
V. Campos 《Environmental Geology》2002,42(1):81-82
9.
L. Chen R. M. Liu Q. Huang Y. X. Chen S. H. Gao C. C. Sun Z. Y. Shen 《International Journal of Environmental Science and Technology》2013,10(4):651-664
Nonpoint source pollution generated by agricultural production and city construction has been studied for decades, but very few researches have been conducted on the regional assessment of nonpoint source pollution in the acid rain regions, particularly relating to the control of pollutant in the drinking water source areas. In this study, an integrated framework was applied to estimate nitrogen and phosphorous load in a typical acid rain influenced reservoir, China. The method comprised three separate steps: (1) a watershed model—soil and water assessment tools—was used to estimate nitrogen and phosphorous load from the upper stream watershed; (2) collection of acid rain samples, together with a GIS-based calculation to estimate the atmospheric deposition flux; (3) introduction of a simple export coefficient method. The case study indicated atmospheric deposition accounted for 56.75 % of total nitrogen load during the year, with the highest level of deposition load taking place during the wet season. Maximum phosphorous (93.37 %) was linked to the upstream runoff, originating from the upper watershed. Further analysis by watershed model and export coefficient method indicated forest exported most total nitrogen (27.72 %) and total phosphorous (58.78 %) in the upstream watershed. Results indicated that in the region influenced by acid rain, the nitrogen management should encompass the management of land use practices and the control of acid rain in catchments feeding into drinking water storage areas. It could be inferred that NOX emissions might cause both globe warming and eutrophication in the drinking water sources. This paper could provide a basis for water quality management in such regions. 相似文献
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Encapsulation of limestone waste in concrete after arsenic removal from drinking water 总被引:1,自引:1,他引:0
P. K. Chintalapati A. D. Davis M. R. Hansen J. L. Sorensen David Dixon 《Environmental Earth Sciences》2009,59(1):185-190
Arsenic is one of the many naturally occurring contaminants in drinking water. Although various treatment technologies can
remove arsenic, most suffer from a common problem of disposal of arsenic-enriched waste after treatment. This project focused
on improving a limestone-based disposal technique by encapsulating the arsenic-enriched limestone waste in concrete. The research
work determined the compressive strengths of the concrete cubes prepared using treated limestone after arsenic removal and
determined the amount of leaching from the arsenic-encapsulated concrete. The removal of arsenic was done with batch experiments
using 0.5–1 mm sized Minnekahta Limestone. The efficiency of the limestone in removing arsenic ranged from 85.9 to 95.5%.
The amount of arsenic adsorbed onto the surface of each gram of limestone ranged from 0.8 to 3.9 μg. Compressive strength
results of concrete cubes prepared by incorporating arsenic-enriched limestone showed typical strength curves at 1, 3, 7 and
28 days. Leaching of arsenic was less than 0.05 mg/L, which is 1/100 of the US Environmental Protection Agency’s standard
for disposal of arsenic in a landfill. Hence, encapsulating the arsenic-enriched limestone in concrete has potential for recycling
the waste material, thereby reducing disposal costs of the limestone-based removal method. 相似文献
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阜阳地区地热水化学特征及同位素分析 总被引:1,自引:0,他引:1
为研究阜阳地区地热形成机制的控制作用,在分析研究区地热地质条件的基础上,利用已有的勘探井水质资料,对研究区地热水的化学特征进行了分析,得出地热流体在垂向、横向上的分布特征,揭示了太古宇五河群风化壳可以构成热储,其较低的总溶解固体(total dissoloved solids,TDS)不同于区域常见的新近系馆陶组、古近系界首组热储。同时,利用大气降水和地热水的稳定同位素资料,研究得出区内地热水的来源主要为大气降水,大气降水经侧向径流补给和蒸发/浓缩作用形成了高TDS地热流体; 利用地热水放射性同位素资料估算了研究区地热水年龄。通过地热水化学、同位素及控热构造等研究,建立了研究区地热资源形成的概念模型,为该地区地热开发利用提供了指导。 相似文献
15.
Recently, there has been considerable interest in categorizing the availability of plant essential nutrients and selected
transition metals in the soil environment so as to predict their effects on ecosystem health and the efficacy of potential
management practices. Researchers desire to isolate important soil properties, determinant biotic activities and fundamental
pedogenic processes that control biogeochemical cycling and are potentially modifiable for the goal of ecosystem sustainability.
In a relative sense, a significant portion of this scientific effort has been directed towards temperate and tropical forest
ecosystems, with relatively less attention given towards understanding the boreal forest ecosystem. Consequently, an investigation
was undertaken near Thompson, Manitoba, to: (1) determine the extent of weathering of the principal soils, (2) employ a selective-sequential
chemical extraction method to categorize the soil-chemical fractions responsible for nutrient availability, and (3) infer
the importance of selected soil forming processes responsible for soil genesis and nutrient availability. Preliminary findings
suggest that nutrient availability is related to the nutrient concentration in the cation exchange fraction and/or to nutrients
sequestered by the organic fraction. The metals in the manganese, noncrystalline and crystalline iron oxide fractions may
be bound so tightly to these oxides that they are largely unavailable to plants; however, they are largely responsible for
buffering the more labile pools against gradually changing vegetational and climatic conditions.
Received: 31 October 1996 · Accepted: 21 May 1997 相似文献
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Drinking water from Japan (Toyama, Kumamoto, Osaka, and Tokyo Prefecture) and France (Volvic water) was evaluated for taste and health properties using an index based on major and trace mineral content and organoleptic components. Although various reports point to calcium (Ca2+) as a key ingredient imparting good taste and magnesium (Mg2+) and sulfate (SO4 2?) as causing unpleasant taste in drinking water, recent sensory threshold experiments have indicated that other major ions and minerals directly or indirectly contribute to good taste, including potassium (K), silica (SiO2), and phosphorous (P). The present study examined major and trace constituents in water to accurately quantify water taste, flavor, and health effects in good-tasting (Volvic, Toyama, and Kumamoto water) and average-tasting water (Osaka and Tokyo water). Trace metal, volatile organic carbon, non-purgeable organic carbon and total inorganic carbon levels were evaluated as parameters influencing the sensory properties of the drinking water. All of the representative good-tasting water contained higher amounts of tasty minerals (Ca2+, K+, SiO2) and lower amounts of unsavory, rough (Mg2+ and SO4 2?), and bitter (Cl?) minerals. Stiff diagrams of the water samples indicated that good-tasting water was generally bicarbonate (HCO3 ?) type. Seasonal variations in physicochemical parameters did not change the order of abundance of cations and anions but did affect the concentration of various ions present in the water. Trace metals also affected water flavor. Mn facilitates acetaldehyde formation and Fe is associated with polyphenolic oxidation and formation of organoleptic flavor constituents. Trihalomethanes (THMs) may also cause unpleasant drinking water flavors or odors. THMs concentrations for all samples were below 5.7 μg/L, meeting the safety and taste requirements for good drinking water. The Japanese samples were compared against Volvic water, which was used as a standard for good-tasting water. Total dissolved solids concentrations were below 300 mg/L for all specimens, in compliance with World Health Organization guidelines. The results are discussed on the basis of the balance between inorganic major ions and trace minerals and THMs concentration thresholds. 相似文献
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T. S. Imo T. Oomori M. Toshihiko F. Tamaki 《International Journal of Environmental Science and Technology》2007,4(4):421-426
The purpose of this study was to assess exposure of four trihalomethanes (chloroform, bromodichloromethane, dibromochloromethane and bromoform) in drinking water of Okinawa Island and Samoa. Trihalomethanes compounds were determined in the drinking water samples that were collected from the selected consumption sites and treatment plants of both Okinawa and Samoa in 2003–2004. The Chatan and Nishihara Water Treatment Plants (Okinawa) uses both ozonation and chlorination for primary and secondary disinfection. For Samoa Water Treatment Plants only chlorination is used as primary disinfection. Results showed that the mean concentration of trihalomethanes from treatment plants in Okinawa ranged from 0.30 ± 1.81 ?g/L to 11 ± 2.68 ?g/L and from the consumption sites ranged from 2.08 ± 0.32?g/L to 19.39 ± 100 ?g/L. In comparison, the mean concentration of trihalomethanes from the treatment plants in Samoa ranged from 226 ± 81.2 ?g/L to 267 ± 92.3 ?g/L and from the consumption sites were in the ranges 212 ± 101 ?g/L to 387 ± 125 ?g/L. Brominated compounds were commonly seen in all samples collected in Okinawa. Among the trihalomethanes compounds, chloroform was the common detected trihalomethanes in the samples collected from Samoa. The trihalomethanes levels in all samples collected in Okinawa and Samoa were generally below the guideline values in Japan, but some samples displayed levels which exceeded the level of Japan Water Quality and WHO Standards for chlorinated and brominated compounds. 相似文献
20.
Qinghui HUANG Jianhua LI Jianfu ZHAO Ran XU Li XIE 《中国地球化学学报》2006,25(B08):181-182
Biandansha, Qingcaosha and Meimaosha sands located respectively in the upper, middle and lower reaches of the Yangtze (Changjiang River) estuary are regarded as strategic drinking water sources of Shanghai City. In the coming decade, the Qingcaosha Reservoir will first be built and gradually take the place of present water sources in the Huangpu River. However, there is little report on the occurrence of persistent organic pollutants (POPs) such as organochlorine pesticides (OCPs) in those strategic water sources. Water samples collected from those strategic water sources were filtered in-situ by Whatman GF/F filters in April 20-23, 2006. Pesticides in the filtrates were enriched on ENVI-18 solid phase extraction (SPE) tubes. OCPs eluted from SPE tubes were determined by GC-μECD method with a mixed standard solution of 20 OCPs compounds. Pentachloronitrobenzene was added as internal standard. Total concentrations of OCPs varied between 15.1 and 83.1 ng/L in water samples from Shanghai strategic water sources. A half of twenty objective OCPs compounds including DDTs were not detected. In Qingcaosha waters, there were six compounds such as a-HCH, dieldrin, endrin, endrin ketone, β-endosulfan and endosulfan sulfate. Total concentrations of these OCPs ranged from 15.1 to 31.6 ng/L and averaged 19.9 ng/L. OCPs had higher concentrations at low water tide than at high water tide, and in bottom water than in surface water. In Biandansha and Meimaosha waters, lindane (T-HCH) of 9.0 ng/L and γ-chlordane of 8.8 ng/L were found, respectively. There was no significant difference between total OCPs concentrations in surface water from Biandansha and Qingcaosha, which are much lower than those in the downstream Meimaosha waters. 相似文献