SPH study of the evolution of water–water interfaces in dam break flows

Natural Hazards - The mixing process of upstream and downstream waters in the dam break flow could generate significant ecological impact on the downstream reaches and influence the environmental...     

Application of syringe-driven chelate-minicolumn in determination of trace elements in water samples

The direct determination of most trace elements in natural water samples is still very difficult even if the high-sensitivity atomic analytical instrument, such as ICP-MS, is available. The reasons are (1) the natural concentrations of most trace elements…     

Organochlorine pesticides characteristics in water column of strategic drinking water sources in the Yangtze estuary

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.     

Ground water recharge in urban areas — Experience of rain water harvesting

Water consumption is likely to increase substantially in the future on account of rising population, economic growth, and social development. Rapid urbanization and population growth of Allahabad city, has necessitated thinking about the declination in ground water level as well as supply of sufficient quantity of water for future either for drinking purpose or industrial use. In the present study, rainfall recharge of Allahabad city has been computed on GIS platform (ArcInfo). Groundwater recharge potential zones of Allahabad city have also been found out using GIS. Case study of recharge of ground water through roof top rainwater harvesting at Vikas Bhawan (a multistoryed building), Allahabad is discussed. An implementation of this analysis and decision making software is expected to work for sustainable water management.     

Characteristics of isotope in precipitation,river water and lake water in the Manasarovar basin of Qinghai–Tibet Plateau

The stable hydrogen and oxygen of lake, river, rain and snow waters were investigated to understand the water cycle characteristics of the drainage basin of Manasarovar Lake in Tibet. Both δD and δ ¹⁸O of river water are larger than those of lake water and the effect of altitude on both δD and δ ¹⁸O is not very significant. This phenomenon was suggested to occur because Manasarovar basin is located in Qinghai–Tibet Plateau which has low latitude, high altitude, abundant glaciers, thin air and intensive solar radiation, resulting in higher evaporation in lake water.     

Solid–water partitioning of elements in Czech freshwaters

Partitioning of 41 elements between solids and water was studied by filtration and dialysis in situ in Czech freshwaters. Field-based distribution (partition) coefficients, K_D, between suspended particulate matter (SPM) and filtrate (‘dissolved’ fraction) differed by 4 orders of magnitude. The highest K_D values (log K_D>2.0 l/g) were exhibited by Zr, Al, Ce, Pb, La, Ti, Fe, Sm, Th and Cr which are extremely insoluble in near-neutral water or generally poorly soluble (Zr,Ti). The K_Ds decrease with element and DOC loading due to the relative increase of the element in the low molecular fraction. Log K_D mostly increased linearly with pH within a range from 3.5 to 9. K_D^U decreased at pH >6 due to carbonate complexation. The colloidal fraction (>1 kDa <0.4 μm) in a reservoir with a pH of 6.8 was mainly preferred by Fe, Pb, Be, Nb, Y, Al, Ni, U and Zr. When the colloidal fraction is not differentiated from true solution, then incorrect information about partitioning may be obtained and the highest K_D may decrease.     

Oxidative–reductive photodecomposition of perfluorooctanoic acid in water

This article aims to elucidate on usefulness of vacuum ultraviolet (VUV) for photoreductive degradation of perfluorooctanoic acid (PFOA), a representative perfluorinated compound (PFC), in water for the first time. Bench-scale tests were conducted on oxidative and reductive (with aquated electron: e _aq ^? ) mineralization of PFOA using low-pressure UV (LPUV) lamps and potassium iodide. Unlike with 254 nm wavelength (UVC), the reductive mineralization with VUV was very inefficient compared to the corresponding oxidative mineralization. The inefficiency is attributed to low reactivity of e _aq ^? with PFOA and its fluorinated products than that of 185 nm photons. Direct VUV photolysis of PFOA and its products in reductive reaction conditions was not apparent due to a very big difference in reactivity of 185 and 254 nm photons with iodide. The results demonstrated that highly energetic VUV photons are not suitable for photoreductive degradations of PFCs involving e _aq ^? , but they can be best used for oxidative degradations. These findings should serve as an important reference on VUV usage to decompose refractory micropollutants.     

Measurement of pesticides in surface water and sediment of Caspian Sea, Iran

Background: With development of intensive agriculture in the agricultural regions of the Northern provinces (Caspian Sea coasts), which involves frequent pesticide use in highly mechanized cash-crop cultures. To investigate and provide information on pest…     

Effect of Zob-Ahan effluent water on ground water quality

Even though, application of industrial effluent water may alleviate the irrigation water shortage in dry regions such as Iran, but uncontrolled discharge into environment and agricultural land may cause unirreversible harmful damage to environments. Therefore, application of industrial effluent water should consider the environmental consequences such as soil, ground water and food contamination. In this study the effect application of Zob-Ahan effluent water for irrigation water and seepage from evaporation ponds on the chemical composition of surrounding well-water were seasonally investigated from April to March in 2003. The water from the selected well was sampled and analyzed for pH, EC, nitrate, hardness, TSS, TDS, and cations including Na^＋, Ca^2＋, Mg^2＋, anions including SO4^2-, CO3^2-, HCO3^-, Cl^-, and heavy metals including Pb, Cd, Cu, Fe, Cr, Mn, Co, and Zn . The results were compared with standard levels for ground water resources, irrigation water, and direct human consumption. The result shows that the ground water in the vicinity of effluent water application fields and evaporation ponds is contaminated and the concentrations of NO3, Cl and Fe are higher than standard permissible levels for ground water resources. For irrigation or discharge into absorption well the heavy metal concentrations of Cu, Cr, Co, and Fe are limiting.     

Carbonate equilibrium in the water of the Razdol’naya River

The paper suggests an accurate approach to studying carbonate equilibrium in the water of the Razdol’naya River. The approach involves measuring pH by Pitzer’s scale, using a cell without liquid junction; measuring the total alkalinity by Bruevich’s technique; and using apparent constants of carbonate equilibrium with regard for the organic alkalinity. The Pitzer technique was employed to calculate the apparent constants of carbonate equilibrium in solution that models the riverine water: Ca(HCO₃)₂–NaCl–H₂O within the range of alkalinity of 0–0.005 mol/kg and temperatures of 0–25°C. Carbonate equilibrium in the water of the Razdol’naya River was sampled for studying at eight sites during all four seasons. Although the contents of biogenic compounds in the water are high, they can merely insignificantly affect the acid–base equilibrium, which is controlled in the riverine water by carbonate equilibrium and the concentrations of humic substances, which play the greater role, the greater the discharge of the river. In addition to the production and destruction of organic matter, carbonate equilibrium in the river is also affected by the supply of humic substances with soil waters and total alkalinity with groundwaters. The fluxes of alkalinity and humic substances annually brought by the Razdol’naya River to Amur Bay are evaluated at 1.33 × 10⁹ mol and 9.9 × 10⁶ kgC, respectively. The carbon dioxide export with the Razdol’naya River is equal to the alkalinity flux and does not depend on the weathering mechanisms.     

Environmental pollution status assessment of water and soil in Langfang City

Through systematic sampling and analysis of water and soil in the planning area of Langfang City, employing national environmental quality standards, the qualities of groundwater and surface-water was overall evaluated. On the whole, the quality of deep-level groundwater was better and hazardous substances were not superstandard, F is higher, Fe and Mg was superstandard in several sites. The quality of shallow groundwater was general worse and COD, Fe, Mn, NH4^＋-N, F, total hardness, total dissolved solids etc. overstep drinking water standard; the quality of surface water was worst and many indices were evidently higher, which was very worst in the east of downtown. Main pollution way of water body was lixiviation type of primary pollution groundwater and infiltration type of secondary pollution groundwater. Environmental quality assessment of plough layer soil indicated that it was better in the northwest and worse in the southeast, furthermore from Xiwu, Daguanzhang, Zhougezhuang to Pengzhuang, Dazhaolin and the north of Jingshan railroad, the environmental quality is worst.     

Distribution of mercury species in water and sediments in Caohai Lake, Guizhou Province

Caohai Lake which is situated in Guizhou Province, has suffered drain project many times since 1958.The main mercury contamination includes industry waste water, litter and waste residue from refine zinc furnace and so on. The water and sediment samples which were collected from Caohai Lake in different seasons using metal clean protocols. Study sites were selected at the upper and down reaches and the tributaries of this lake, respectively. Total mercury （THg）, reactive mercury （RHg） and dissolved mercury （DHg） concentrations were measured by trap pre-concentration and CVAFS detection methods, and the concentrations of particulate mercury （PHg） are equal to difference of THg and DHg. Total methylmercury （MeH） and dissolved methylmercury （DMeHg） concentrations were measured by GC-CVAFS detection method. Mercury in sediment was measured by AAS method. The results in autumn were obtained as follows： the average concentrations of total mercury, reactive mercury,     

Interstellar water in meteorites?

D/H ratios of two meteorites (Renazzo CR and Semarkona LL3), which are known to exhibit the largest departures from the terrestrial hydrogen isotopic ratios, have been determined with the CRPG Nancy ion microprobe. Correlations between the D/H ratios and the chemical compositions (H2O, K, Si, C/H) of plausible hydrogen carriers were observed. From these correlations, it is possible to show that, contrary to previous interpretations, phyllosilicates are the carriers of the deuterium-rich hydrogen in Semarkona and Renazzo: 870 x 10(-6) > or = D/H > or = 670 x 10(-6) (+4600 > or = deltaD > or = 3300%) and > or = 320 x 10(-6) (deltaD > or = 1050%), respectively. Hydrogen is also present in the chondrules of these two deuterium-rich meteorites. The large differences in D/H ratios between matrix (up to 700 x 10(-6), deltaD up to +3500%) and chondrules (from 120 x 10(-6) (deltaD = -230%) to 230 x 10(-6) (deltaD = +475%)) show that hydrogen in chondrules cannot originate from the matrix by simple contamination or diffusion processes. The high D/H ratios measured in water-bearing minerals could not have been produced thermally within a dense solar nebula. Chemical reactions (i.e., involving ions or radicals), taking place in interstellar space or in the outer regions of the nebula at 110-140K are presently the only conceivable mechanisms capable of yielding such isotopic enrichments. Water in these meteorites should no longer be considered as a simple product of nebular condensation under equilibrium thermodynamic conditions at T > or = 160K.     

Community perceptions of forest–water relationships in the Blue Nile Basin of Ethiopia

Community perception of forest–water relationship was gathered using participatory rural appraisal tools in four watersheds of the Blue Nile River Basin in Ethiopia. These were compared and contrasted with the observational records of forest cover and water flow. Upstream and downstream communities were assessed separately to check for differences in perception based on location within a watershed. The key result of the study was that people in the study watersheds had a range of perceptions about the forest–water relationship which were watershed specific. The perceptions were generally consistent with observational evidence from the same watersheds. This study highlighted the need for locale-specific approaches to land and water management in the Basin, as well as the potential value of using community perceptions to complement the observational records which can have spatial and temporal limitations.     

Assessment of changes in the area of the water conservation forest in the Qilian Mountains of China’s Gansu province, and the effects on water conservation

The Qilian Mountains water conservation forest in Gansu province is an important ecological barrier surrounding the oasis in China’s Hexi Corridor. The water they provide is the basis for the existence and sustainable socioeconomic development of those oases. As a result of unsustainable use of the water conservation forest until the 1980s, the oasis ecosystems of the Hexi region were seriously damaged, and the oasis areas experienced deterioration of their ecological environment. In this paper, Landsat images were used to monitor the temporal and spatial changes in area of water conservation in Qilian Mountains of China’s Gansu province and to assess the effect on water conservation by analyzed relationship between water conservation forest area, climatic data and hydrological data. The results showed that the forest covered 15.1% of the study area in 2007 and has followed different trends during the study period. From 1978 to 1990, the forest area decreased; however, from 1990 to 2007, the forest area increased, with a faster rate of increase from 1990 to 2000, and the rate of increase averaged 2,733.89 ha per year since 1990. The water conservation forest appears to play an important role in flood control, runoff regulation, the prevention of soil erosion, and water conservation; and these benefits increase with an increasing area of forest.     

Characteristics of Piezometric heads and determination of fresh water–salt water interface in the coastal zone near Beihai,China

Changes in hydraulic heads with space and time and evolution of the location of fresh water–salt water interface are important for groundwater development in coastal aquifers. Measurements of piezometric heads at 11 well clusters consisting of three piezometric wells of different depths with a 5-day interval for 15 months show that the piezometric heads at nearly all the wells near the northwestern coast in Beihai decrease with increasing depth and increase with increasing distance from the coast. Changes in piezometric heads at the wells during the measurement period were caused by seasonal precipitation and induced by the tide. The depth of the sharp interface between fresh water–salt water can be estimated based on measurements of piezometric heads at a piezometric well tapping at a point in the salt water zone below the interface and measurements of the water table at the same well. The calculations of the interface for well H5 range from 40 to 80 m below sea level in the measurement period, which are believed to be more reasonable than those estimated with the Ghyben–Herzberg relation. An erratum to this article can be found at     

Catalytic ozonation of phenol in water with natural brucite and magnesia

Catalytic ozonation has attracted much attention in treatment of wastewater for its mild conditions. Phenol and its ramifications are common components in a wide variety of wastewaters including those from coal conversion processes, coking plants, petroleum refineries and several chemical industries. In this paper, natural brucite and magnesia have been successfully used in catalytic ozonation of phenol. And the mechanisms of catalysis were also investigated. From Figs. 1 and 2, it can be found that both brucite and magnesia have remarkable catalysis on degradation of phenol and removal of Chemical Oxygen Demand （COD）. The pH of solutions on the process of ozonation alone, catalytic ozonation with brucites and with magnesia were 6.35-2.76, 10.18-8.52 and 10.58-10.83, respectively. It can be concluded that alkali environment plays a critical role for catalytic ozonation of phenol. We also found that the alkaline minerals reacted on the surface with oxalic acid and other low molecular-weight acids which are intermediate products in ozonation, but those intermediate products could be mineralized into carbon dioxide completely with enough ozonation time.     

Research on surface water environment planning of urban forest conservation in Jiufeng of Wuhan

Conservation of Urban Forest Site in Jiufeng is constructed as an ecotourism function urban forest conservation combining mountain and vegetation resource around. According to fieldwork, the conservation is located in the outskirts of the city where non-point pollution is dominant. In order to master the source intensity and its distribution, data from Quickbird remote sensing in 2004 and field collection are adopted to establish the environment database including data layers of districts, land use, map, soil map, DEM, water and road systems, soil property and economy. Traditional quantitative analysis of non-point pollution intensity has encountered with the following difficulties： （1） Large area of vegetation landscape reconstruction will create tremendous ecological benefits, but calculation of pollution decrease brought by reconstruction is difficult to achieve. （2） In conservation reconstruction will be implemented in the residential are step by step, i.e., of moving, repairing and centralization, which is a complex project with wide time span, leading to inaccurate prediction. （3） Construction of the conservation will speed up the development of local tourism, thus if a single society index is chosen to predict the pollution intensity, the development trend of the region could not be figured out completely. Consequently acreage of different planning land use is counted and models of urban and rural areas respectively help to compute unit pollution load. In the urban area, the pollution load of the same land use is regarded as the function of population density, clean frequency and precipitation, while in the rural area, SCS model, universal soil loss equation （USLE） and pollution transfer model are applied to compute unit pollution load of TN and TP. The results of total pollution load are TN 179.706 kg/a and TP 33.814 kg/a. For impracticability of routine planning measures, the project applies measures of distribution controlling against water erosion and soil loss and concentrated-dispersive controlling to lighten non-point pollution brought by living sewage.     

The role of water resources in the evolution of the Israeli–Lebanese border

The current location of the border between Lebanon and Palestine, today's Israel, is a product of various competing forces. The Zionist Organization aspired to include the entire Galilee region up to the lower reaches of the Litani River (also known as the Kassimiyah River) within Palestine. The river itself was the desired northern border of the country. The Zionists supported their position by employing instrumental arguments that were largely related to the availability of water resources. On the other hand, residents of the upper Galilee, today's southern Lebanon, demanded that they be included with Lebanon. They used their trade links with Beirut, and cultural and familial ties with other parts of Lebanon to support their position. These instrumental and expressive arguments appear to have assisted in the demarcation of the border between Lebanon and Palestine. Currently, access to the water resources, not necessarily control over them, is likely to influence negotiations between Israel and Lebanon over the future of the Israeli-occupied security zone in southern Lebanon.