River bank filtration in Haridwar, India: removal of turbidity, organics and bacteria

Improvement in the quality of river water filtered through a 17-m thick sand-gravel unconfined aquifer at a production well surrounded by surface-water bodies, in Haridwar (India), was studied. Distances between surface water sources and the production well are more than 115 m, and the shortest travel times are 77 and 84 days for monsoon and non-monsoon periods, respectively. During the monsoon period, surface water exhibited increased turbidity by 50–100 times, bacterial count of around 10 times and decreased electrical conductivity of around 0.6 times compared to non-monsoon samples. The quality of abstracted bank filtrate, however, was found not to significantly vary. In non-monsoon months, riverbank filtration resulted in a reduction of turbidity and coliforms by 1 and 3 logs, respectively. For monsoonal months, this increased to more than 2 and 4 logs in turbidity and coliforms reduction, respectively. UV absorbance was also found to be reduced to about 1 log during monsoon season. Results from column studies confirmed that a retention time of around 5 days is adequate to achieve more than 99.9% removal of coliforms.     

Seasonally chemical weathering and CO<Subscript>2</Subscript> consumption flux of Lake Qinghai river system in the northeastern Tibetan Plateau

The major cation and anion compositions of waters from the Lake Qinghai river system (LQRS) in the northeastern Tibetan Plateau were measured. The waters were collected seasonally from five main rivers during pre-monsoon (late May), monsoon (late July), and post-monsoon (middle October). The LQRS waters are all very alkaline and have high concentrations of TDS (total dissolved solids) compared to rivers draining the Himalayas and the southeastern Tibetan Plateau. Seasonal variations in the water chemistry show that, except the Daotang River, the TDS concentration is high in October and low in July in the LQRS waters. The forward models were used to quantify the input of three main rivers (Buha River, Shaliu River, and Hargai River) from rain, halite, carbonates, and silicates. The results suggest that (1) atmospheric input is the first important source for the waters of the Buha River and the Shaliu River, contributing 36–57% of the total dissolved cations, (2) carbonate weathering input and atmospheric input have equal contribution to the Hargai River water, (3) carbonate weathering has higher contribution to these rivers than silicate weathering, and (4) halite is also important source for the Buha River. The Daotang River water is dominated by halite input owing to its underlying old lacustrine sediments. The water compositions of the Heima River are controlled by carbonate weathering and rainfall input in monsoon season, and groundwater input may be important in pre-monsoon and post-monsoon seasons. After being corrected the atmospheric input, average CO₂ drawdown via silicate weathering in the LQRS is 35 × 10³ mol/km² per year, with highest in monsoon season, lower than Himalayas and periphery of Tibetan Plateau rivers but higher than some rivers draining shields.     

Dissolved Boron in the Tapi,Narmada and the Mandovi Estuaries,the Western Coast of India: Evidence for Conservative Behavior

The concentrations of dissolved boron have been measured during different seasons in three estuaries, the Tapi, Narmada and the Mandovi situated on the western coast of India, to investigate its geochemical behavior and inputs from the localized anthropogenic pressures of industrial effluents and sewage discharge. The measured boron concentrations in these estuaries (except the Tapi during non-monsoon) at salinity ≤0.1 fall in a narrow range?～?2–4 μmol/kg (average B?～?2.4?±?0.8 μmol/kg) within the reported wide range?～?0.1–18.6 μmol/kg for global rivers. The much higher estimate of boron concentration in the Tapi River during non-monsoon is attributed to its possible additional supply from the sewage and/or industrial effluents discharged along the river course. During monsoon, the rains seem to be a significant source of dissolved boron to all the three rivers. The distribution of dissolved boron in each estuary exhibits a conservative behavior during the seasons sampled suggestive of no measurable addition or removal of boron in the estuarine region. The orders of magnitude differences in boron concentration between the river waters and seawater, and the conservative behavior of dissolved boron indicate that its major contributor to the estuaries sampled is seawater.     

青藏高原南部和北部暖季气温年代际 变化差异的界线位置*

文章通过对青藏高原北部马兰冰芯中δ¹⁸ O记录(主要反映暖季气温)与近几十年来高原中、南部气象台站暖季气温变化的对比分析,发现在年代际时间尺度上高原北部地区暖季气温变化与南部地区存在明显的差异,其分界线位于32°~33°N附近一带。该位置也是青藏高原地区气候、地理、地质、地球物理等方面存在南北差异的重要分界线。     

拉萨河流域地表径流氢氧同位素空间分布特征

为了探析径流过程中稳定同位素变化特征及其控制因子, 利用2008年拉萨河流域地表径流中δ18O和δD的监测数据以及相关气象和水文资料, 初步研究了流域δ18O和δD的空间分布特征.研究发现: (1)拉萨河流域以大气降水为主要补给来源, 且干流体现了较明显的蒸发效应; (2)河水偏正的d过量参数特征指示了冰雪融水的补给特征; (3)季风降水期间, 拉萨河流域由高程效应和水平距离所造成的δ18O递减率约为0.16‰·(100 m)-1; (4)大循环尺度下, 流域内河水呈现了明显的大陆效应.研究表明高海拔地区地表径流氧氘同位素分布特征能够有效示踪流域水文循环过程, 并提供古高度变化研究的稳定同位素证据.      

Occurrence of nonylphenol an endocrine disrupter in Karun River,Khuzestan Province,Iran

The important Iranian Karun River has never been investigated for the presence of potentially endocrine-disrupting chemicals, nonylphenol (NP). In this study, concentrations of NP were measured in water from Karun River and five wastewater discharge points into this river, collected during April to July 2010. The analytes were extracted by solid-phase extraction, and quantitative analyses were performed by HPLC–FLD. NP was detected in water and wastewater samples with 0.17–1.83 and 15.27–21.79 μg/L, respectively. The results showed that the NP content of aqueous phase of all wastewater samples higher than particulate phase, which were detected in the aqueous and particulate phases with mean concentrations of 12.8 ± 2.4 and 5.2 ± 1.2 μg/L, respectively. These data suggest that the NP levels in Karun river water are likely attributable to untreated municipal wastewaters discharged directly into the river. To our knowledge; this is the first study to evaluate NP concentrations in water and wastewater in Iran.     

Geothermal potential evaluation and development prioritization based on geochemistry of geothermal waters from Kangding area,western Sichuan,China

Kangding geothermal area is located in the western Sichuan, belonging to southeastern margin of Tibetan Plateau. Similar to world-renowned south Tibetan and western Yunnan geothermal belt, western Sichuan has intensive surface thermal manifestations including boiling and hot springs. The emerging temperature of thermal waters ranges from 47 to 79 °C with total dissolved solids lying between 899 and 2550 mg/L. δ²H–δ¹⁸O isotopes indicate a meteoric source for the thermal waters and a significant positive oxygen-18 shift in the southern region. It is suggested that southern thermal waters experienced stronger water–rock interaction and are closer to thermodynamic equilibrium, which is also proved by the water type classification. The reservoir temperature calculated by empirical and theoretical chemical thermometry is 180–225 °C for the north and 225–310 °C for the south. Evidences of hydrogeochemistry, stable isotopes, geothermometry and radiocarbon dating indicate that southern region of Kangding area shows greater geothermal potential than the northern region. In addition, based on the hydrogeochemical modeling of mineral saturation, underlying problem of scaling is likely to occur in the study area. According to the results of reservoir temperature, south Kangding sub-district has greater potential in geothermal power generation and development than northern Kangding. Therefore, further exploration and drilling work should give priority to the south Kangding area.     

青藏高原降水中稳定氧同位素研究进展

稳定氧同位素（δ18O）在冰芯研究中能够很好地反映气候变化,尤其是气温变化的一项重要指标。研究青藏高原降水中δ18O为科学的解释冰芯中δ18O记录具有重要的指示意义。分别介绍了青藏高原季风区、非季风区以及季风区和非季风区的过渡区降水中δ18O研究历史和现状,并对该领域未来的研究趋势进行了展望。     

Investigation on the hydrodynamics of Ganga Alluvial Plain using environmental isotopes: a case study of the Gomati River Basin, northern India

An investigation using environmental isotopes (δ¹⁸O and δD) was conducted to gain insight into the hydrological processes of the Ganga Alluvial Plain, northern India. River-water, shallow-groundwater and lake-water samples from the Gomati River Basin were analyzed. During the winter season, the δ¹⁸O and δD compositions of the Gomati River water ranged from ?1.67 to ?7.62 ‰ and ?25.08 to ?61.50 ‰, respectively. Deuterium excess values in the river water (+0.3 to ?13 ‰) and the lake water (?20 ‰) indicate the significance of evaporation processes. Monthly variation of δ¹⁸O and δD values of the Gomati River water and the shallow groundwater follows a similar trend, with isotope-depleted peaks for δ¹⁸O and δD synchronized during the monsoon season. The isotopically depleted peak values of the river water (δ¹⁸O?=??8.30 ‰ and δD?=??57.10 ‰) can be used as a proxy record for the isotopic signature of the monsoon precipitation in the Ganga Alluvial Plain.     

Water quality parameters along rivers

Water samples have been collected from a part of Surma River along different points and analyzed for various water quality parameters during dry and monsoon periods. Effects of industrial wastes, municipal sewage, and agricultural runoff on river water quality have been investigated. The study was conducted within the Chattak to Sunamganj portion of Surma River, which is significant due to the presence of two major industries-a paper mill and a cement factory. The other significant feature is the conveyors that travel from India to Chattak. This study involves determination of physical, biological and chemical parameters of surface water at different points. The river was found to be highly turbid in the monsoon season. But BOD and fecal coliform concentration was found higher in the dry season. The water was found slightly acidic. The mean values of parameters were Conductivity 84–805μs; DO: dry- 5.52 mg/L, monsoon-5.72 mg/L; BOD: dry-1 mg/L, monsoon-0.878 mg/L; Total Solid: dry-149.4 mg/L, monsoon- 145.7 mg/L. A model study was also conducted and values of different model parameters were estimated.     

Impacts of Indian summer monsoon and stratospheric intrusion on air pollutants in the inland Tibetan Plateau

Air pollutants can be transported to the pristine regions such as the Tibetan Plateau,by monsoon and stratospheric intrusion.The Tibetan Plateau region has limited local anthropogenic emissions,while this region is influenced strongly by transport of heavy emissions mainly from South Asia.We conducted a comprehensive study on various air pollutants(PM2.5,total gaseous mercury,and surface ozone)at Nam Co Station in the inland Tibetan Plateau.Monthly mean PM2.5 concentration at Nam Co peaked in April before monsoon season,and decreased during the whole monsoon season(June-September).Monthly mean total gaseous mercury concentrations at Nam Co peaked in July and were in high levels during monsoon season.The Indian summer monsoon acted as a facilitator for transporting gaseous pol-lutants(total gaseous mercury)but a suppressor for particulate pollutants(PM2.5)during the monsoon season.Different from both PM2.5 and total gaseous mercury variabilities,surface ozone concentrations at Nam Co are primarily attributed to stratospheric intrusion of ozone and peaked in May.The effects of the Indian summer monsoon and stratospheric intrusion on air pollutants in the inland Tibetan Plateau are complex and require further studies.     

Origin of the enrichment of B and alkali metal elements in the geothermal water in the Tibetan Plateau: Evidence from B and Sr isotopes

Geothermal fields distributed in the southern Tibet Plateau rifts such as Yangbajing - Dangxiong basin, and the Yaluzangbu suture are characterized by intensive hydrothermal activity and high enrichment of trace elements (e.g., Li, Rb, Cs, B and Br) in geothermal springs. However, the origin of these elements and their enrichment mechanisms in those geothermal waters remain unclear. This study presents data for the enriched elements, incompatible elements, and B and Sr isotopes, in the geothermal water in the Tibetan Plateau and compares them with some typical geothermal fields worldwide, in an attempt to provide new insights into the origin and mechanism of the enrichment of these trace elements. The results indicate that all geothermal water samples from the Tibetan Plateau show more negative δ¹¹B values than those from local precipitation and rivers. Considering the wide existence of a high-conductivity zone in the middle or even upper-crust interpreted to correspond to re-melt magmatic fluids in the Tibet, the main sources of the typical chemical composition of geothermal waters in the Tibetan Plateau can be classified into two main types: residual magmatic fluids derived from crustal partial remelting and deep circulated groundwater modified by water–rock interactions. In particular, the possible source of magmatic fluids may play a more significant role for special geochemical compositions of geothermal water in the Tibet. Such resources are beneficial for the development and utilization of the geothermal water itself and also serve as a stable source for feeding the salt lake resources.     

Sources and flux of trace elements in river water collected from the Lake Qinghai catchment,NE Tibetan Plateau

River waters play a significant role in supplying naturally- and anthropogenically-derived materials to Lake Qinghai, northeastern Tibetan Plateau. To define the sources and controlling processes for river water chemistry within the Lake Qinghai catchment, high precision ICP-MS trace element concentrations were measured in water samples collected from the Buha River weekly in 2007, and from other major rivers in the post-monsoon (late October 2006) and monsoon (late July 2007) seasons. The distributions of trace elements vary in time and space with distinct seasonal patterns. The primary flux in the Buha River is higher TDS and dissolved Al, B, Cr, Li, Mo, Rb, Sr and U during springtime than those during other seasons and is attributed to the inputs derived from both rock weathering and atmospheric processes. Among these elements, the fluxes of dissolved Cr, B and Rb are strongly influenced by eolian dust input. The fluxes of dissolved Li, Mo, Sr and U are also influenced by weathering processes, reflecting the sensitivity of chemical weathering to monsoon conditions. The anthropogenic sources appear to be the dominant contribution to potentially harmful metals (Ni, Cu, Co, Zn and Pb), with high fluxes at onset of the main discharge pulses due, at least partially, to a runoff washout effect. For other major rivers, except for Ba, concentrations of trace elements are higher in the monsoon than in the post-monsoon season. A total of 38.5 ± 3.1 tons of potentially harmful elements are transported into the lake annually, despite human activities within the catchment being limited. Nearly all river water samples contain dissolved trace elements below the World Health Organization guidelines for drinking water, with the exception of As and B in the Daotang River water samples collected in late July probably mobilized from underlying lacustrine sediments.     

Assessment of naturally occurring arsenic contamination in the groundwater of Sarkisla Plain (Sivas/Turkey)

High arsenic levels in groundwater of the aquifers, belonging to the Pliocene terrestrial layers and Quaternary alluvial sediments, have become a significant problem for the inhabitants living in Sarkisla (Turkey). The main objective of this study was to determine the origin and arsenic contamination mechanisms of the Sarkisla drinking water aquifer systems. The highest arsenic concentrations were found in Pliocene layers and alluvial sediments with concentrations ranging from 2.1 to 155 mg/kg. These rocks are the main aquifers in the study area, and most of the drinking groundwater demand is met by these aquifers. Groundwater from the Pliocene aquifer is mainly Ca-HCO₃ and Ca-SO₄ water type with high EC values reaching up to 3,270 μS/cm, which is due to the sulfate dissolution in some parts of the alluvial aquifer. Stable isotope values showed that the groundwater was of meteoric origin. Tritium values for the groundwater were between 8.31 and 14.06 TU, representing a fast circulation in the aquifer. Arsenic concentrations in the aquifers were between 0.5 and 345 μg/L. The highest arsenic concentrations detected in the Pliocene aquifer system reached up to 345 μg/L with an average value of 60.38 μg/L. The arsenic concentrations of the wells were high, while the springs had lower arsenic concentrations. These springs are located in the upper parts of the study area where the rocks are less weathered. The hydrogeochemical properties demonstrated that the water–rock interaction processes in sulfide-bearing rocks were responsible for the remarkably high groundwater arsenic contamination in the study area. In the study area, the arsenic levels determined in groundwater exceeded the levels recommended by the WHO. Therefore, it is suggested that this water should not be used for drinking purposes and new water sources should be investigated.     

Spatial and temporal variations of physicochemical and heavy metal pollution in Ramganga River—a tributary of River Ganges,India

The River Ganges being the most sacred river and lifeline to millions of Indians in serving their water requirements is facing excessive threat of pollution. Under various river management and conservation strategies for its protection, the assessment of water quality of its main tributary Ramganga River is lacking. This study focuses on assessment of physicochemical and heavy metal pollution of the Ramganga River by application of multivariate statistical techniques. Sampling of Ramganga River at sixteen sampling sites was carried out in three seasons (summer, monsoon and winter) of 2014. The collected water samples were analyzed for physicochemical parameters and heavy metals. Results from cluster analysis (CA) of the data divided the whole stretch of the river into three clusters as elevation from 1304 to 259 m as less polluted, from 207 to 154 m as moderately polluted and from elevation 154 to 139 m as high-polluted stretches with anthropogenic as main sources of pollution in high-polluted stretch. Principal component analysis of the seasonal dataset resulted in three significant principal components (PC) in each season explaining 72–8% of total variance with strong loadings (>0.75) of PC1 on fluoride (F^?), chloride (Cl^?), sodium (Na⁺), calcium (Ca²⁺), magnesium (Mg²⁺), bicarbonate (HCO₃ ^?), total dissolved solids and electrical conductivity. Temporal variation by one-way ANOVA (Analysis of Variance) showed significant seasonal variation was in the pH, chemical oxygen demand, biochemical oxygen demand, turbidity, HCO₃ ^?, F^?, Zn, cadmium (Cd) and Mn (p < 0.05). Turbidity showed approximately a twofold increase in monsoon season due to rainfall in the catchment area and subsequent flow of runoff into the river. Concentration of HCO₃ ^?, F^? and pH also showed similar increase in monsoon. The concentration of Zn, Cd and Mn showed an increasing trend in summers compared to monsoon and winter season due to dilution effect in the monsoon season and its lasting effect in winters.     

Arsenic mobility in fluvial environment of the Ganga Plain,northern India

In the northern part of the Indian sub-continent, the Gomati River (a tributary of the Ganga River) was selected to study the dynamics of Arsenic (As) mobilization in fluvial environment of the Ganga Plain. It is a 900-km-long, groundwater-fed, low-gradient, alluvial river characterized by monsoon-controlled peaked discharge. Thirty-six water samples were collected from the river and its tributaries at low discharge during winter and summer seasons and were analysed by ICP-MS. Dissolved As and Fe concentrations were found in the range of 1.29–9.62 and 47.84–431.92 μg/L, respectively. Arsenic concentration in the Gomati River water has been detected higher than in its tributaries water and characteristically increases in downstream, attributed to the downstream increasing of Fe₂O₃ content, sedimentary organic carbon and silt-clay content in the river sediments. Significant correlation of determination (r ² = 0.68) was also observed between As and Fe concentrations in the river water. Arsenic concentrations in the river water are likely to follow the seasonal temperature variation and reach the level of World Health Organization’s permissible limit (10 μg/L) for drinking water in summer season. The Gomati River longitudinally develops reducing conditions after the monsoon season that mobilize As into the river water. First, dissolved As enters into pore-water of the river bed sediments by the reductive dissolution of Fe-oxides/hydroxides due to microbial degradation of sedimentary organic matter. Thereafter, it moves upward as well as down slope into the river water column. Anthropogenically induced biogeochemical processes and tropical climatic condition have been considered the responsible factors that favour the release of As in the fluvial environment of the Ganga Plain. The present study can be considered as an environmental alarm for future as groundwater resources of the Ganga–Brahmaputra Delta are seriously affecting the human–environment relationship at present.     

Combined tectonics and climate forcing for the widespread aeolian dust accumulation in the Chinese Loess Plateau since the early late Miocene

Currently mechanisms for the onset of the widespread aeolian dust accumulation in the Chinese Loess Plateau since 8–7 Ma remain elusive. In this study, we compile 11 records of climate (14–7 Ma) and tectonic activity of the Tibetan Plateau and its adjacent areas (15–6 Ma). The results suggest that strong tectonic activity in the northeastern Tibetan Plateau has produced massive debris and dust, which was deposited in the piedmont basins and reworked by weathering and fluviolacustrine erosion. At the same time, global cooling and uplift of the Tibetan Plateau over the period of 14–7 Ma intensified the East Asian winter monsoon and westerly winds (westerlies) while weakening the Asian summer monsoon, which led to the spread of dry land vegetation and aridification in interior China. Sediments in the piedmont basins were then exposed in the aridity and transported by the westerlies to the Chinese Loess Plateau and the North Pacific. We suggest that tectonic activity in the northeastern Tibetan Plateau and shifting global climate together triggered the widespread aeolian dust accumulation in the Chinese Loess Plateau and the North Pacific since 8–7 Ma.     

B,As, and F contamination of river water due to wastewater discharge of the Yangbajing geothermal power plant,Tibet, China

Thermal waters from the Yangbajing geothermal field, Tibet, contain high concentrations of B, As, and F, up to 119, 5.7 and 19.6 mg/L, respectively. In this paper, the distribution of B, As, and F in the aquatic environment at Yangbajing was surveyed. The results show that most river water samples collected downstream of the Zangbo River have comparatively higher concentrations of B, As, and F (up to 3.82, 0.27 and 1.85 mg/L, respectively), indicating that the wastewater discharge of the geothermal power plant at Yangbajing has resulted in B, As, and F contamination in the river. Although the concentrations of B, As, and F of the Zangbo river waters decline downstream of the wastewater discharge site due to dilution effect and sorption onto bottom sediments, the sample from the conjunction of the Zangbo River and the Yangbajing River has higher contents of B, As, and F as compared with their predicted values obtained using our regression analysis models. The differences between actual and calculated contents of B, As, and F can be attributed to the contribution from upstream of the Yangbajing River. Water quality deterioration of the river has induced health problems among dwellers living in and downstream of Yangbajing. Effective measures, such as decontamination of wastewater and reinjection into the geothermal field, should be taken to protect the environment at Yangbajing.     

玛曲高原区潜水水化学和氢氧同位素特征

玛曲高原区地下水是黄河的重要补给水源,然而其水化学特征及形成机理认识还十分有限。通过采集玛曲潜水、河水和黄河河道沉积物,系统研究了玛曲高原区地下水水化学、同位素特征以及水文地球化学过程。结果表明:河水和潜水的溶解性总固体含量低,分别为72~195 mg/L和207~459 mg/L,水化学成分以Ca2+和HCO3-为主,水样中砷浓度为0.46~17.7μg/L。氢氧同位素结果表明,地下水和河水补给来源为当地大气降水,河水相对潜水富集δ18O和δD。河水水化学组成主要受蒸发浓缩作用的影响,而潜水主要受碳酸盐岩溶解作用的影响。潜水水样SI白云石小于0的占68%,表明潜水中白云石处于不饱和状态。某些潜水砷含量超标的原因可能是沉积物铁锰氧化物矿物的还原性溶解,而砷的来源可能是玛曲河道和浅层松散沉积物中吸附态砷。研究成果有助于揭示黄河上游玛曲段地下水的来源及地下水化学成分的形成机理。     

Characteristics of the geothermal water in Changbai Mountain volcanic region,northeast of China

Geothermal water is plentiful in Changbai Mountain region, northeastern China, due to the volcanic activities and widespread faults. For the exploration of geothermal resources, this study uses quartz and cation geothermometer to estimate the temperatures of the geothermal reservoir and uses the tubular models to evaluate the thermal gradient. The hydrogeochemical characteristics of the geothermal resources were also evaluated by hydrogeochemical analysis. The results showed that the geothermal reservoir temperatures of the four major thermal springs in Changbai Mountain region range from 72 to 169 °C. The average geothermal reservoir temperatures of Jinjiang hot springs, Changbai hot springs I, Xianrenqiao hot springs, and Changbai hot springs II are 129.25, 169, 89, and 73.67 °C, respectively. The geothermal gradient values of the four major thermal springs have different characteristics. The geothermal gradient values of Jinjiang hot springs and Changbai hot springs I are 4.6 and 3.1 °C/100 m, respectively. The geothermal gradient values of Xianrenqiao thermal springs and Changbai thermal springs II are both lower than 1.5 °C/100 m, with the values of 1.1 and 1.4 °C/100 m. And the geothermal gradients are influenced by Changbai Mountain Tianchi volcano. In addition, the water chemical analyses showed that the geothermal water types are HCO₃-Na with higher concentrations of Na⁺, Cl^?, SO₄ ^2?, TDS, and HCO₃ ^? than the non-thermal waters, which suggested a deep and long water cycle of the thermal water, and therefore a sufficient water-rock interaction.