Mg-AI型水滑石对水溶液中F^-的吸附

采用水热法合成Mg-AI型水滑石（LDHs），研究LDHs及其焙烧产物C-LDHs对水溶液中F^-的吸附行为，并用X射线衍射和热重分析对LDHs，C-LDHs以及吸附F^-后的C-LDHs（R-LDHs）的结构和性质进行了表征．结果表明：LDHs对水溶液中的F^-基本没有吸附，而C-LDHs对F^-有较大的吸附容量，同时，酸性的增强有利于C-LDHs对F^-的吸附．C-LDHs对F^-吸附4h后可达到吸附平衡．通过吸附F^-，C-LDHs的结构由吸附前的混合氧化物固溶体恢复到层状结构，表明C-LDHs对水溶液中F^-的高吸附性能是因为其具有较强的“记忆效应”．     

Geochemistry of soil around a fluoride contaminated area in Nayagarh District,Orissa, India: Factor analytical appraisal

Fluoride contamination in soil was studied in the vicinity of a hot spring in Nayagarh district of Orissa. Both bulk soil from 0 to 30 cm depth and profile soils from 0 to 90 cm depth were analyzed for total fluoride (F_t) and 0.01 M CaCl₂ extractable fluoride (F_ca), major elements, pH, EC and Organic Carbon (OC). High concentrations of both F_t and F_ca were observed in the area surrounding the hot spring and the village of Singhpur. Principal factor analysis (PFA) on the parameters of the bulk soils suggests that two major chemical processes due to three factors, control the soil geochemistry of the area. Factor-1 contributes 37.11% of the total variance and is strongly loaded with Al, Si, Fe, F_tand F_ca, and explains the fluoride enrichment of the soil, whereas the second and the third factors contribute 16.6 and 12.2%, respectively and explain the controlling process of carbonate precipitation and soil alkalinity. Multiple regression analysis of the scores of the factors was performed to derive a fluoride contamination index in soil. The magnitude of the factor effect on the contamination index follows the order of Factor-1 > Factor-2 > Factor-3. The spatial distribution of the contamination index is used to classify the area into highly contaminated, moderately contaminated and uncontaminated zones.     

Distribution and Risk Assessment of Fluoride in Drinking Water in the West Plain Region of Jilin Province, China

The west plain region of Jilin province of northeast China is one of the typical endemic fluorosis areas caused by drinking water for many years. Investigations of hydrogeological and ecoenvironmental conditions as well as endemic fluorosis were conducted in 1998. Results show that the ground water, especially, the water in the unconfined aquifer is the main source of drinking water for local residents. The fluoride concentration in groundwater in the unconfined aquifers is higher than that in the confined aquifer in the west plain of Jilin province. The fluoride concentration in the unconfined aquifer can be used to classify the plain into fluoride deficient area, optimum area and excess area, which trend from west to east. High fluoride (>1.0 mg L(-1)) in drinking water resulted in dental and skeletal fluorosis in local residents (children and pregnant women). There exists a positive correlation between fluoride concentration in the drinking water and the morbidities of endemic fluorosis disease (r1 = 0.781, r2 = 0.872). Health risks associated with fluoride concentration in drinking water are assessed. It has been determined that fluoride concentration in excess of 1.0 mg L(-1) exposes residents to high health risks based on risk identification. The study area is classified into five health risk classes as shown in Figure 4. The risk indexes of this area more than 1.0 are accounted for 68% of the total west plain region.     

固定污染源排气中氟化物监测方法研究

采用直接蒸镏法对固定污染源中固态氟化物样品进行处理，使用离子色谱或离子选择电极对样品进行测定，结果表明：其测定范围、精密度、准确度，均能满足环境监测的要求。     

工厂的氟污染对蔬菜含氟量的影响

上海某厂生产氟利昂和氢氟酸等化工产品,排放的废水、废气中含有大量氟化物。该厂排放的废气中氟化氢的量相当于全市氟化氢总排放量的50％左右。     

杭嘉湖蚕桑区大气氟化物排放标准制定研究

文章按照《制定地方大气污染物排放标准的技术方法》建立了蚕桑区大气氟化物允许排放速率牟模型，根据蚕桑区氟污染特征，污染危害特征和污染气象特征确定模型参数，提出了浙江省杭嘉湖蚕桑区大气氟化物排放标准，并分析了标准的经济和技术可行性。     

纳米氢氧化镁改性PVDF超滤膜的制备与表征

通过相转化法制备了纳米PVDF/Mg(OH)_2共混超滤膜,研究了负载Mg(OH)_2对PVDF膜结构和性能的影响。以牛血清蛋白(BSA)为模拟污染物进行超滤试验,测试膜的纯水通量和截留率;测定膜表面和水之间的接触角,进而定量分析比较膜表面的亲水性;利用微机电子控制万能试验机测试膜的机械性能;通过扫描电镜(SEM)、原子力显微镜(AFM)、X射线衍射仪(XRD)等方法表征膜表面特征。结果表明,添加纳米Mg(OH)_2的改性膜保持了原有膜的晶型结构,证明纳米Mg(OH)_2与PVDF材料有很好的相容效果。当纳米Mg(OH)_2添加量为0.8%(质量分数)时,改性效果达到最优。此时,接触角从73.1°降至59.6°,纯水通量为333.37 L/(m~2·h),较未改性前提高了126.3%,膜的拉伸最大力为6.8 N,断裂伸长率为16.2%,较未改性膜的机械性能有明显提高,膜的抗污染性也显著提高。     

Forecast optimal fluoride concentration data in drinking water according to the ambient temperature in Golestan,Iran

Controlling fluoride concentrations in drinking water at optimal levels could be effective in preventing certain negative health effects in humans. This study investigated optimal fluoride concentrations in potable water in Golestan province, according the ambient temperatures in the province. The study used data on fluoride concentrations in drinking water supplied by the Water and Wastewater Company of Golestan Province. The annual mean maximum temperatures were extracted from a website that recorded daily ambient temperature. The optimal value of fluoride in drinking water for each county of Golestan province was calculated by the Galgan and Vermillion formula. The results show that all of the counties should contain fluoride concentrations ranging from 0.73 to 0.766 milligrams per liter (mg/L) according to the calculation formula, while fluoride concentrations were instead reported to range between 0.23 and 0.53 mg/L by the Water and Wastewater company. In addition, according to World Health Organization (WHO) recommendations, the concentrations of fluoride in potable in all of the cities in Golestan province fall below the WHO standard. In conclusion, we suggest that the fluoride concentrations in Golestan province's drinking water should be taken into account by the appropriate authorities and that optimal fluoride concentrations in drinking water according to ambient temperatures be set to avoiding negative health impacts.     

Speciation analysis of aluminium in plant parts of Betula pendula and in soil

The research presents the first results of aluminium speciation analysis in aqueous extracts of individual plant parts of Betula pendula and soil samples, using High Performance Ion Chromatography with Diode Array Detection(HPIC-DAD). The applied method allowed us to carry out a full speciation analysis of aluminium in the form of predominant aluminium–fluoride complexes: AlF_((x = 2,3,4))~((3-x))(first analytical signal), AlF~(2+)(second analytical signal) and Al~(3+)(third analytical signal) in samples of lateral roots, tap roots, twigs, stem, leaf and soil collected under roots of B. pendula. Concentrations of aluminium and its complexes were determined for two types of environment characterised by different degree of human impact:contaminated site of the Chemical Plant in Luboń and protected area of the Wielkopolski National Park. For all the analysed samples of B. pendula and soil, AlF_((x = 2,3,4))~((3-x))had the largest contribution, followed by Al~(3+)and AlF~(2+). Significant differences in concentration and contribution of Al–F complexes and Al~(3+)form, depending on the place of sampling(different anthropogenic pressure) and plant part of B. pendula were observed. Based on the obtained results, it was found that transport of aluminium is "blocked" by lateral roots, and is closely related to Al content of soil.