Inorganic chemicals in domestic water of the United Arab Emirates

The concentration of selected inorganic chemicals was determined for 396 samples of bottled water, desalinated water, and groundwater used for drinking and domestic purposes in the United Arab Emirates (UAE). The objective of this study was to compare the concentrations of inorganic chemicals in different domestic water types used in the UAE with the World Health Organization (WHO) limits for drinking water. Results of the present study revealed a wide variation in the concentrations of major, minor, and trace inorganic chemicals in domestic water of the UAE. For example, the bottled water sold for drinking is depleted in major ions and the total dissolved solids (TDS) in some brands do not exceed 100 mg/l. On the other hand, some of the domestic water used may contain as much as 3,000 mg/l TDS, which is above the WHO recommended limit for drinking water (500–1,500 mg/l TDS). Similarly, while bottled water is almost free of trace ions and minor constituents, some natural groundwater may have concentrations higher than the WHO recommended limits for drinking water. The cause of this variation is related to the different water sources and the large number of companies producing and distributing drinking and domestic water. Moreover, it is clear that the current controls on domestic water quality in some areas, namely conformance of pH and electrical conductivity measurements with prescribed ranges of values, are currently inadequate. These two parameters are not enough to judge if water is suitable for drinking or not and some consumers may receive domestic water of uncertain quality.     

金属材料在盐湖卤水中的耐蚀性

通过现场暴露试验获得了12种典型金属材料在盐湖卤水中暴露181d、415d和810d的腐蚀结果,讨论了它们在卤水中的耐蚀性。TH200、QT500-5、Q235和16Mn在盐湖卤水中的耐蚀性较好。QT500-5的耐蚀性好于TH200。304、316L和430不锈钢在盐湖卤水中发生较轻的点蚀和缝隙腐蚀,耐蚀性较好;其耐蚀顺序为316L>304>430。T2、QSi3-1在盐湖卤水中有好的耐蚀性。L6、6066和LC4(BL)在盐湖卤水中发生严重的点蚀和缝隙腐蚀,耐蚀性差。     

喹啉季铵盐絮凝-缓蚀剂FNQ-C的制备及其性能研究

本文研究了天然高分子改性喹啉季铵盐型阳离子絮凝-缓蚀剂FNQ-C的制备,确定了其最佳制备反应条件;考察了FNQ-C在模拟循环冷却水中的絮凝、缓蚀性能.絮凝实验表明FNQ-C的絮凝净水效果优于国产阳离子聚丙烯酰胺絮凝剂PAM-C,挂片腐蚀实验表明FNQ-C的缓蚀性能与国产商品缓蚀剂EDTMP相当.实验亦证实FNQ-C的缓蚀用药量与其絮凝净化用药量相容,可以一次投药同步满足絮凝、缓蚀两种水质要求.     

雨生红球藻3个株系的生长及对光盐反应初探

对雨生红球藻3个株系（No.3、No.712和No.797)的生长、对诱导虾青素形成的光盐因子的反应进行了比较,结果表明：No.3、No.712和No.797的生长速率分别为0．128d^-1,0.137d^-1和0.144d^-1;外加盐的量较大（4gL^-1)时导致雨生红球藻细胞数的减少,而外加盐浓度较低（2gL^-1)时,细胞数的反应因株系和光照的不同而有所差异;盐和强光照均导致静细胞比例显著增加;盐的加入仅在弱光照下诱导雨生红球藻3个株系的虾青素累积,在强光照下却导致件株系虾青素含量的下降,强光照下不外加盐时No.3、NO.712和No.797藻液的虾青素含量无显著差异,分别为2.15、2.77和2．45mg L^-1。图1表2参12     

福建省沿海地区海盐和大气污染物反应的致酸作用

本文着重研究福建省沿海地区盐和大气污染物反应的致酸作用,从源排放估算、致酸前体物观测、大气气溶胶组成分析、降水离子特征分析四个层次进行讨论,结果表明ＨＣｌ人为排放源仅占ＳＯ２,ＮＯｓ的４％;大气中活性氯;ＨＣｌ最大浓度为４．２３μｇ／ｍ＾－３,Ｃｌ２最大浓度为３．９７μｇ．ｍ＾－３,气溶胶中Ｃｌ＾－／Ｎａ＾＋比和降水中Ｃｌ／Ｎａ＾＋比背离,降水中过量氯与Ｈ浓度呈现正相关,过量氯对Ｈ浓度最大贡献达３     

Inorganic arsenic and trace elements in Ghanaian grain staples

A total of 549 samples of rice, maize, wheat, sorghum and millet were obtained from markets in Ghana, the EU, US and Asia. Analysis of the samples, originating from 21 countries in 5 continents, helped to establish global mean trace element concentrations in grains; thus placing the Ghanaian data within a global context. Ghanaian rice was generally low in potentially toxic elements, but high in essential nutrient elements. Arsenic concentrations in rice from US (0.22 mg/kg) and Thailand (0.15 mg/kg) were higher than in Ghanaian rice (0.11 mg/kg). Percentage inorganic arsenic content of the latter (83%) was, however, higher than for US (42%) and Thai rice (67%). Total arsenic concentration in Ghanaian maize, sorghum and millet samples (0.01 mg/kg) was an order of magnitude lower than in Ghanaian rice, indicating that a shift from rice-centric to multigrain diets could help reduce health risks posed by dietary exposure to inorganic As.     

Salting our landscape: an integrated catchment model using readily accessible data to assess emerging road salt contamination to streams

A new integrated catchment model for salinity has been developed to assess the transport of road salt from upland areas in watersheds to streams using readily accessible landscape, hydrologic, and meteorological data together with reported salt applications. We used Fishkill Creek (NY) as a representative watershed to test the model. Results showed good agreement between modeled and measured stream water chloride concentrations. These results suggest that a dominant mode of catchment simulation that does not entail complex deterministic modeling is an appropriate method to model salinization and to assess effects of future applications of road salt to streams. We heuristically increased and decreased salt applications by 100% and results showed that stream chloride concentrations increased by 13% and decreased by 7%, respectively. The model suggests that future management of salt application can reduce environmental concentrations, albeit over some time.     

乙基橙褪色光度法测定加碘盐中微量碘（Ⅴ）

提出了在盐酸介质中,在溴化钾催化作用下,碘酸根氧化乙基橙褪色吸光光度法测定碘的新方法。结果表明,最大吸收波长为５１０ｎｍ时,碘（Ⅴ）浓度在０～１．６ｍｇ／Ｌ内呈线性关系,表观摩尔吸光系数为４．４×１０４,方法用于加碘盐中碘（Ⅴ）的测定,结果满意。     

利用浑浊度推算含沙量方法的限制性与适用性研究

通过对利用浑浊度与含沙量的相关关系来推算含沙量的方法的研究,发现此方法有两个限制因子,一是泥沙粒径,二是水中盐等其他杂质。研究结果表明,浊度法对于低含沙量、粒径小的水样测量精度高。     

钻井水溶开采地面沉降的机理分析与控制对策措施研究

本文通过对某矿钻井水溶开采的溶腔稳定性、覆岩稳定性和地表移动变形分析计算,探讨了该矿产生溶腔失稳和地面沉降的机理,并提出了控制溶腔失稳和地面沉降的对策措施,对钻井水溶开采矿山有一定的借鉴价值。