High TDS Research Articles

Fundamentals of Delineation of Area of Mineral and hot Water Potential in Duyen Hai area, Hung Ha district, Thai Binh Province, Viet Nam for Exploration Purpose

Mineral and hot water is a valuable resource that can be used for nursing and physiotherapy, making bottled water, making beverage and healing, exploiting useful minerals, energy extraction, even cultivation spirulina and other purposes. Hot groundwater was discovered during the 90s of the 20th century in Duyen Hai commune, Hung Ha district, Thai Binh province, but no exploration and evaluation studies were conducted to determine the potential of the mineral and hot water in the area. Spatial distribution of groundwater temperature and the total mineralization in the study area of the mineral and hot water occurrence and its surrounding area has allowed to identify the area of mineral and hot water origin, and that the hot water belongs to average hot water with a temperature of about 49 degrees Celsius. Analyzing the tectonic structure has showed that the mineral and hot water is formed at an area surrounded by three class-2 faults, which have a vertical displacement amplitude of 100 m - 1,000 m and a destructive zone of over 100 m. This is an area with favorable conditions to bring geothermal source and dissolved minerals in surrounding rocks to groundwater in the above aquifers. The approach presented in the paper can be applied to conduct research on potential mineral and hot water in other areas: determine values of some mineral and hot water parameters such as temperature and TDS, compile maps of spatial distribution of the parameters, clarify characteristics of tectonic structure relevant to anomaly of high temperature and TDS.

Isotope and Geochemistry Characterization of Hot Springs and Cold Springs of Sembalun – Rinjani Area, East Lombok, West Nusa Tenggara – Indonesia

The presence of several hot springs in Sembalun – Rinjani, East Lombok, West Nusa Tenggara is an indicator of geothermal potential in the area. This study aims to determine the characteristics of hot springs and cold springs and also the geothermal potential in Sembalun – Rinjani area using isotopes and geochemistry methods. The result of d18O and d2H stable isotopes analysis shows that most of the hot springs are meteoric water. Except for Kalak hot spring, other hot springs are a mixing product of meteoric water and andesitic water, with meteoric water composition between 64 to 87%. While 14C radioisotope suggests that the age of hot springs in the Sembalun area is about 10,000–12,000 years BP, the surrounding cold springs are mostly Modern except Jorong cold spring. The results of gas analysis (He, Ar, and Ne) also suggest the same origin of geothermal fluid, i.e., meteoric water origin. Based on chemical composition, Kalak hot spring is plotted as sulfate type water, while Sebau hot spring is plotted near mature water composition but not representing reservoir fluid due to its relatively low temperature and high Mg content. Na/K geothermometer calculation from Sembalun area shows that subsurface temperature is varied between 111-161 °C, while from Rinjani hot springs indicates higher subsurface temperature, i.e., 250-260 °C. It is estimated that reservoir fluid has high TDS with chloride content up to 4000 mg/L.

Hydrochemical Characteristics, Groundwater Quality and Sources of Solute in the Ramganga Aquifer, Central Ganga Plain, Bareilly District, Uttar Pradesh

Abstract The quality of groundwater is determined in parts of Ramganga basin, Bareilly, UP, India. Spatial variation of all the major ions shows south-eastern increasing trend except chloride and sulphate. Groundwater in the area belongs to the Mg2+-Ca2+-HCO3- cation facies. The monsoonal rainfall changes the ionic abundance order from HCO3->Cl->NO3>SO4-2> F-and Mg2+> Ca2+> K+>Na+ of pre-monsoon to HCO3->Cl-> SO4-2>NO3->F- and Na+> Mg2+> Ca2+> K+ of post-monsoon. Solute acquisition processes indicated that the rock weathering is the major mechanism of ions sources in groundwater. A coupled carbonate and silicate weathering type along with ion exchange processes are responsible for particular groundwater chemistry. Groundwater quality parameters were tested for drinking, irrigation and corrosion purposes. It is found that 8.5%, 26%, 49%, 14% and 3% of the samples fall under the excellent, good, poor, very poor and unsuitable category respectively. SAR, Na%, RSC and Kelly index suggests that groundwater is safe for irrigation purposes. But high TDS of few samples suggested the salinity hazard while using it for irrigation purposes. Low CR values indicated a lower degree of corrosion hazard to the underground metal pipelines in the area.

An electrochemical analysis of acute contamination of environmental water and restoring of water quality using taro carbon

Electrochemical techniques were successfully employed to estimate contamination of water of river Buriganga, Bangladesh. A Pt–Cu electrode has been exploited to measure selective nitrate concentration, and corrosion rate of iron has been proposed to indicate relative abundance of dissolved contaminants. In order to evaluate the pollution level, water parameters of river Buriganga have been compared with those obtained from two freshwater streams named Surma and Dawki of the country. An iron strip in contact with Buriganga river water is corroded three times rapidly compared to its contact with Dawki or Surma river water indicates acute contamination of Buriganga river water. The River Buriganga is facing acute pollution from the point of high TDS (0.664–0.694 g/L), low DO (1.47–4.4 mg/L), high COD (197–218 mg/L), high ammonia (270–420 mg/L) and high nitrate concentration (107–157 mg/L). Negative ORP value (− 292 to − 310 mV) of Buriganga river water indicates that the stream contains high level reducing species. Meanwhile, positive ORP value indicates that Dawki (+ 203 to + 209 mV) and Surma (+ 184 to + 205 mV) river water contain oxidizing species. Sediment analysis shows the deposition of disintegrated organic pollutants on the bottom of the River Buriganga. Cost-effective carbon material synthesized from taro stems has been proposed to restore water parameters of filthy water system like Buriganga river.

Major ions and δ34SSO4 in Jiulongjiang River water: Investigating the relationships between natural chemical weathering and human perturbations

The chemical weathering processes become a rising concern in carbon cycling research, because it can increase carbon budgets of lateral transport by rivers and effectively sequestrate atmospheric CO2. Recent studies suggest that the human perturbations can accelerate the chemical weathering, however, the processes of accelerated weathering and its potential environmental effects still remain questions. To examine the mechanism of the human-related accelerated weathering and its influences, the spatial-temporal distributions of the major ions and stable isotope compositions (δ34SSO4) in Jiulongjiang River are measured. The seasonal variations of the riverine solutes results from the hydrologic condition and different mineral dissolution rates of carbonate and silicate minerals. The H2SO4 and HNO3 indeed participate in the mineral dissolution, and increase the riverine C flux. S isotope compositions suggest the riverine H2SO4 is mainly derived from the anthropogenic sewage inputs and oxidation of sulfide, while the statistics and stoichiometry analysis indicating HNO3 are close related to the agricultural activities. On the watershed scale, the areas with high agricultural/urban land use areas (%) have significantly high TDS and DIC values in comparison with that in the areas with high forest covering, indicating the accelerated weathering processes have already been activated by the human perturbations. The assessments of the irrigation water quality suggest that the Jiulongjiang river water is facing the salinity hazard under the accelerated weathering conditions. More attention should be paid to the effect of human perturbations on chemical weathering.

Ion and organic transport in Graphene oxide membranes: Model development to difficult water remediation applications

The role of steric hindrance and charge interactions in governing ionic transport through reduced graphene oxide (rGO) and commercial (DOW-Filmtec NF270) membranes was elucidated by a comprehensive study of experimental and established mathematical analysis based on Nernst-Planck equation. A charge-dominated salt exclusion mechanism was observed for the rGO membranes, which exhibited retention from low (7%) to moderate (70%) extent depending on the nature of ions (5 mM). Swelling of GO (1.2 nm interlayer distance) in water beyond the hydrated diameter of ions was attributed as a primary cause for lowering steric hindrance effects. The influence of parameters affecting charge interactions, such as pH and ionic strength, on the extent of salt rejection was modelled. The potential impact of the membrane's charge density, GO loading and interlayer spacing on salt retention was quantified by performing sensitivity analyses. For a high TDS produced water sample, the rGO membranes partially retained divalent cations (Ca:13%) and exhibited high dissolved oil rejection. The membranes were found to be suitable for the treatment of high TDS water with the goal of selectively removing organic impurities, and thus minimizing the impact of osmotic pressure effect. Performance of the membranes was also investigated for retention of water remediation related organic anions, using perfluoro octanoic (PFOA) acid as a model compound. rGO membranes exhibited a charge-dominated exclusion mechanism for retention (90%) of PFOA (1 ppm).

Effects of bottom-up and top-down interactions on the productivity of Iyieke Lake, Afikpo North, Ebonyi State, south-east Nigeria

The bottom-up and top-down interactions of the abiotic and biotic components of Iyieke Lake were studied for eleven months covering a pre-flood, flood and post-flood periods. During the study, some water quality parameters were measured while plankton samples were collected for identification in the laboratory using standard method. The results of the water quality parameters measured showed that water temperature was highest (35.00R”C) in February. pH (7.10) and transparency (0.98 m) were highest in August. Highest TDS (28.0 mg/L) and conductivity (56.00 μS/cm) were recorded in March (pre-flood period) while dissolved oxygen level was lowest (4.00 mg/L) in the pre-flood period (February and March). Nitrate (0.18 mg/L) was highest in August (flood period) and phosphate (0.25 mg/L) at the two extreme periods (pre-flood and post flood). The depth of the lake was highest (3.2 m) in August which was the period of inundation. The phytoplankton (Bacillariophyta, Chlorophyta, Cyanobacteria) and zooplankton (Rotifera, Cladocera, Copepoda) of the lake were made of three divisions and taxa each, respectively. Bacillariophyta dominated among the phytoplankton while Rotifera was the most abundant among the zooplankton. The study revealed that nutrients and zooplankton grazing were the major factors that affected phytoplankton abundance and biomass during the study.
 Keywords: Flood; phytoplankton; Iyieke; water quality; zooplankton

In-situ uniaxial drawing of poly-L-lactic acid (PLLA): Following the crystalline morphology development using time-resolved SAXS/WAXS

Simultaneous synchrotron small- and wide-angle X-ray scattering (SAXS/WAXS) was used to follow the crystalline morphology evolution of poly-L- lactic acid (PLLA) during uniaxial deformation at various draw temperatures (Td). The mechanical behaviour of PLLA, was found to be strongly dependent on Td. 2D SAXS/WAXS data taken during the draw showed that at low Tds cavitation and voiding occurred and the initial crystallites underwent ‘overdrawing’ where they slip and are partially destroyed. SEM confirmed that surface voiding and cavitation had occurred at Td = 60 and 65 °C but was absent at higher Tds. During the draw, no long-range macromolecular lamellar structure was seen in the SAXS, but small crystallites of the disordered α′ crystal form of PLLA were observed in the WAXS at all Tds. The PLLA samples were then step annealed in a second processing stage (post-draw) to develop the oriented crystalline lamellar structure and increase the amount of the stable α crystalline form. SAXS/WAXS data showed that a highly oriented lamellar stack macrostructure developed on annealing, with increased crystallite size and crystallinity at all Tds. Furthermore, step annealing drove the crystalline transition in all samples from the disordered α′ crystal form to the stable α crystal form. Therefore, varying pre- and post-processing parameters can significantly influence the mechanical properties, orientation, crystalline morphology and crystal phase transition of the final PLLA material.

Hydrochemical assessment of groundwater in mesozoic sedimentary aquifers in an arid region: a case study from Wadi Nisah in Central Saudi Arabia

Wadi Nisah which lies to the south of Riyadh city is an important source of groundwater supply and agricultural production in the central region of Saudi Arabia. Twenty-nine groundwater samples were collected from wells tapping the shallow alluvial aquifer as well as the Mesozoic Manjur and Dhruma aquifer in western Wadi Nisah. The interpretation of the results of the major ion analysis reveals that geogenic factors mainly rock–water interaction and mineral dissolution control the groundwater chemistry. The samples are characterized by high TDS and EC values. Saturation indices of the groundwater show that minerals dissolution is the primary factor affecting the groundwater composition Piper plot reveals groundwater mixing as Ca + Mg − Cl + SO4 facies, mixed Ca + Mg − Cl + SO4 facies and Na + K + Cl + SO4 facies is present in the study area. Gypsum and dolomite weathering coupled with reverse-ion exchange are responsible for the dominance of alkaline earth elements over alkali elements. Principal component analysis helped in the extraction of three principal components accounting for approximately 78% of the total data variability. The extracted components point mainly towards geogenic influences. However, the third principal component shows the influence of anthropogenic pollution, mainly nitrate pollution from agricultural activity in the area.

Rare-earth elements and isotopic geochemistry of thermal waters of the Okhotsk sea shore, Far East of Russia

New data on hydrogeochemistry of thermal waters of the Okhotsk sea-shore (Ulskiy, Annensky Tumnin, Talaya, Paratunka, Dagi and Lesogorsky) is presented in the paper. Sikhote-Alin ridge thermal waters with crystalline host rocks refer to sulfate-hydrocarbonate or hydrocarbonate sodium fresh waters with elevated silicon content (up to 41 ppm), lowest TDS (<0.3 g/L), alkaline (9.1<pH<9.3). Thermal waters of Talaya and Paratunka refer to sedimentary basins, resulting in presence of sulfate and chlorine in main ions, higher TDS (1-1.2 g/L), lower pH (∼8.6) values and reducing conditions (-82>Eh>-157 mV). Geological conditions were proved by shapes of REE patterns (positive Eu-anomaly for sedimentary basins). Stable water isotopes led us to divide roughly studied waters into two groups, using peculiarities of moisture source for water recharge areas. First group: Tumin, Annensky and Talaya with more “continental” climate as for mainland thermal waters, forming isotopically lighter water and second group: Ulskiy, Paratunka, Dagi and Lesogorsky, with “marine” climate of Sakhalin and Kamchatka, forming isotopically heavier water.

Water quality of an Indian tributary affected by various industrial effluents- a case study

Industrialization and urbanization are modern need and trends. Such trends affect the natural ecosystem of rivers. Indian rivers face such problems in a high ratio. The aim of this study is to investigate the cause and amount of pollution in a tributary river Krishni. Pre-monsoon sampling of Krishni river water was performed as per APHA standard. Water samples were collected from different sites of Krishni river. Physiochemical parameters as well as trace elements concentrations have been analysed and results were compared with BIS-2012, WHO-2017 and EPA-2001 recommendations. The presence of high BOD, COD, TDS and others physiochemical parameters along with heavy metals reveals that tributary is highly polluted owing to industrial and domestic discharge either directly or through drains. High values of these parameters are harmful for the ecological health of the river because it makes survival of aquatic flora and fauna at risk. On the basis of the results obtained by the present study, it was concluded that level of the pollution in river Krishni is at alarming phase, where if strong action for the rejuvenation of river not takes place, river becomes a dead pool.

Impact Assessment of Groundwater Quality using WQI and Geospatial tools: A Case Study of Islamkot, Tharparkar, Pakistan

Groundwater is the only source of fresh water in the Thar Desert which is located in an arid region of Pakistan with dense population and spreads over 19,638km2. Low rainfall, low groundwater recharge, high evaporation and absence of perennial streams are the general reasons for water scarcity. Being the single water source for drinking, domestic and industrial uses, and livestock activities, this source is highly overexploited. Realizing the gravity of the situation, this paper presents a groundwater quality evaluation of Islamkot, Tharparkar, using Water Quality Index (WQI) and Geospatial tools. 40 samples were collected from dug wells. The TDS of 28 samples was found higher than 3000mg/L and 12 samples ranged from 1500 to 3000mg/L. Many (28) samples were not further analyzed due to their very high TDS which made the water unfit for drinking. Twelve samples with TDS ranging from 1500 to 3000 mg/L were further analyzed. The analyzed results revealed the average values of pH, EC, TDS, salinity, chloride, total alkalinity, fluoride, and arsenic. The results did not meet NEQS and WHO guidelines. Pearson correlation analysis was conducted among parameters. Further, groundwater quality was assessed by WQI and indicated that water quality varied from very poor to unsuitable for drinking. The consumption of polluted groundwater has been the main cause of prevalent waterborne diseases and poses a very high risk for public health

Hydrochemical characteristics of the groundwater in Trans-Yamuna Alluvial aquifer, Palwal District, Haryana, India

Hydrochemical processes have been evaluated for the groundwater regime in Trans-Yamuna alluvial aquifer, Palwal District, Haryana. The groundwater belongs to the Na+–Mg+2 and Cl−–SO4−2 facies, and solute acquisition processes indicated that the rock weathering/evaporation is a major mechanism that characterizes the hydrochemistry. It is also indicated that dissolution and reverse ion exchange processes are playing a major role in determining the groundwater chemistry in the study area. The varied climate in Ganga plains is responsible for the importance of different hydrogeochemical processes that impact on hydrochemistry of groundwater. Groundwater quality parameters were tested for drinking and irrigation purposes. Water quality index shows that 13%, 31%, 34% and 21% fall in good, poor, very poor and unsuitable water category, respectively, for drinking purposes. On the basis of SAR and Na%, the groundwater indicated that it is safe for irrigation purposes. But high TDS of few samples suggested the salinity hazard while using it for irrigation purposes for a longer period.

Pengaruh Kualitas Produk dan Direct Marketing terhadap Keputusan Pembelian Air Minum Ziva Ro di Desa Banjarwati Kecamatan Paciran Kabupaten Lamongan

The community in Paciran sub-district is 102,548 people. Paciran sub-district also includes industrial districts, both home industries and large industries. The need for clean water is increasing, especially those who live in areas adjacent to large factories such as in the Paciran sub-district, so that the water content is polluted by wastes from these large industries, so that the water quality in the Paciran area is especially unfit for consumption. directly because it depends on the very high TDS and PH substances. This shows that ZIVA RO drinking water is an important instrument for one of the drinking water industries in the Paciran area that uses a reverse osmosis process. This is what makes product quality and direct marketing influencing purchasing decisions. From this background, the problems obtained are: first, how is the influence of product quality on ZIVA RO drinking water decisions in Banjarwati Village, Paciran District, Lamongan Regency, second, how is the influence of direct marketing on ZIVA RO drinking water purchasing decisions in Banjarwati Village, Paciran District, Regency Lamongan. The type of research used is quantitative research, the sampling technique used is the independent sampling technique, with the number of respondents as many as 100 people, the data analysis technique used is using reliability and validity tests, correlation analysis tests, coefficients of determination, multiple linear regression analysis and , hypothesis testing. The results showed that the product quality variable did not have a significant positive effect on purchasing decisions of -0.697 &gt; 1.984 with a significant level of t less than 0.05, namely 0.487&gt; 005. Direct marketing from the results of this study direct marketing has no significant effect on purchasing decisions obtained by 1.091 &gt; 1.984. With tingakat t less than 0.05 that is 0.278&gt; 0.005.

Multi-tracer (δ18O, δD, 3H, CFCs and SF6) investigation of groundwater recharge and apparent age at the Bamenda Highlands along the Cameroon volcanic line

The Bamenda Highlands contains numerous dilute and soda springs of unknown hydrological provenance. These dilute springs are a vital source of drinking water to the inhabitants. As a contribution to water management, this study investigated the spring water recharge, residence time and sub-surface circulation using δ18O, δD, 3H, CFCs, SF6 and TDS. A plot of both water types along the local meteoric water line indicated the meteoric origin and rapid recharge following precipitation. Dilute springs with a δ18O altitude effect of 0.27/100 m suggested recharge at different elevations. The CFC-12, CFC-11 and CFC-113 dating (complemented by 3H) showed reasonable young apparent ages of dilute springs ranging from 21 to > 52 (mean/median of 25) years and old soda springs (> 52 years). SF6 concentrations in dilute springs revealed exceptionally young ages relative to CFCs modelled ages suggesting a terrigenous enrichment of the former. Thus, groundwater dating with SF6 is unreliable in the area. Besides the old apparent ages of soda springs, their highly depleted δ18O and high TDS (mean of 1396 mg/l) indicated palaeo-recharge and high water–rock interaction, respectively. In contrast, the low TDS of dilute springs (< 140 mg/l) indicated low-water interaction. Most dilute springs showed exponential mixing models indicating heterogeneous recharge under unconfined aquifer conditions. Conversely, the old soda springs displayed piston flow and binary mixing models. The meteoric recharge and similar residence time of the shallow dilute springs suggested natural resilience to short-term changes in climatic conditions. Thus, low shallow groundwater abstraction is sustainable at the Bamenda Highlands.

Microbial biodiesel production: novel method of utilizing sago wastewater for lipid production using oleaginous yeast, Candida tropicalis ASY1

A study was undertaken to determine the physico-chemical characteristicsof sago wastewater (SWW) from various sago industries in Salem andNamakkal districts of India. Besides, different SWW (raw wastewater,aerobic wastewater, treated wastewater and starch wastewater) from withinthe industry were evaluated. The results concluded that effluents from thisregion are whitish and greyish brown in color with majority supra-colloidalor settable suspended solids with high TS, TSS, and TDS. The ammoniacal,nitrate, and nitrite nitrogen ranged from 2.7 to 6.5, 4.5 to 19.1, and 0.4to 2.8 mg.L-1. The total nitrogen content of SWW samples was ranged from180- 650 mg.L-1. The phosphate level of SWW was very high (640-1096 mg.L-1). The COD and BOD content of SWW from all the industries ranged from2560 to 3200 mg.L-1 and 34000 to 76000 mg.L-1 indicates its high organicnature. SWW effluents are acidic in nature (pH 4.3-5.2). The free cyanide(CN) content was ranged from 1.2 to 5.2 mg.L-1. The treated wastewater hadneutral pH (pH - 6.2), and had a reduced level of EC, starch content, TSS,COD and BOD.

Probiotic Technology- A Novel Approach in scouring of Textiles

Today's scouring process is chemically based and highly alkaline. Due to the unspecific nature of chemical processes, not only the impurities but also the cellulose is attacked, leading to damage in strength properties. Furthermore, current processes cause environmental problems due to high COD, BOD and TDS content in the effluents. A wide range of studies have been carried out on bio-preparation of cotton in the preceding 10-12 years. This paper deals with application of probiotic scouring on cotton and analyzing the effectiveness of probiotic scouring over conventional scouring & testing the properties of pro-scoured cotton knitted substrates. It was found that that in probiotic scouring of cotton degradation of pectic substances is one of the most essential processes. Probiotic degradation of pectic accelerates the removal of waxy materials from the cotton primary wall, thus produces highly water absorptive cotton. Using probiotics, decreases the TS, TDS, COD, BOD thereby reducing both effluent load and preparation costs. 100% bio-degradable Scouring agent, sets new standards in pre-treatment for cotton significantly

Assessment of Groundwater Quality in Coastal Region a Case Study of Qayyumabad, Karachi, Pakistan

The aim of present study is to assess groundwater quality of Qayyumabad area for drinking purpose. Groundwater samples (n = 20) were collected from wellbores from variable depths (12-300 feet) occurring on both banks of the Malir River near study area. Water quality was assessed through estimation of physical parameters including, pH, Eh, TDS, EC, hardness, temperature, aesthetic character (taste, color and odor) and chemical parameters including major cations (Na, K, Ca, Mg), anions (Cl, NO3, SO4, HCO3) and minor/trace elements (Fe, As). Data revealed that groundwater of study area has very high TDS content (range: 805-40340 mg/l) and positive Eh (-180 to +125 mV), suggesting the recent recharge. The pH varies in the range of 6.55-7.75 which comply with WHO limit (6.5-8.5) for drinking water. Major solutes varied in the order of Na (mean: 2587 mg/l) > Mg (433mg/l) > Ca (231mg/l) > K (91 mg/l) while anions in the order of Cl (mean: 3385 mg/l) > SO4 (mean: 580 mg/l) > HCO3 (mean: 343 mg/l) > NO3 (11.43 mg/l). Both arsenic and iron contents occur within the WHO permissible limits except two samples which showed elevated Fe (4950 ppb) and As (100 ppb) respectively. These results suggest that groundwater in study area is unfit for drinking purpose. Principal component analysis (PCA) explained four factors where F1 suggests the salts leaching mechanism and F2 indicated anoxia prevalence due to organic matter decomposition. On the other hand, F3 confirmed water rock interaction and F4 supported the prevalence arsenic release associated with anoxia.

Hydrogeology And Hydrochemistry Of Shallow Groundwater And Surface Water And Potential Water Pollution In Gadung District, Buol, Central Sulawesi

Inhabitants of Gadung District depend on Labuton River and shallow groundwater as their water resources. But issue of river pollution caused by gold mining activities operated for decades around upstream area of Labuton River becomes challenge for their water demands. In the other hand, shallow groundwater from dug wells has low resistance for contaminants from urban activities around downstream area. This study aims to analyze characteristics of hydrochemistry and to identify pollution cases in research area. In order to recognize flow path of shallow groundwater water table in research area have been measured.EC, pH, and TDS from water samples (13 samples from Labuton River and 16 samples from groundwater) has been measured. Na+, K+, Ca2+, Mg2+, F-, Cl-, NO3-, SO42-concentrations of the samples measured using Ion Chromatograph. HCO3-concentrations of the samples measured using Alkalinity Checker. Hydrochemistry Labuton River which is dominantly associated with Dolokapa Formation is controlled by rock weathering process. It is indicated by TDS 50 - 200 mg/L and total cationic charge 428,7 - 2973,8 μeq/L. Labuton River and shallow groundwater in research area has hydrofacies Mg+HCO3 type generally, but Mg+SO4 type is shown along ± 5.2 km of water flow of Labuton River from mining area to the downstream zone which is categorized as MIW (Mining Influenced Water). MIW in Labuton River has high concentration of SO42- (9.27 to 35.12 - 36.03 mg/L), high TDS value (100 to 140 - 160 mg/L), and low pH (6.3 to 5.4 - 5.6) from its original water. Labuton River water is polluted by contaminant from mining activity along ± 2.8 km water flow indicated by pH 5.4 - 5.6. Groundwater in some part of study area is polluted by urban contaminant indicated by concentration NO3-> 3 mg/L (3.33 - 19.43 mg/L).

Hydrochemical characteristics of travertine-depositing hot springs in western of Yunnan, China

The hydrochemical characteristics of 15 travertine-depositing hot springs and 7 hot springs that do not deposit travertine in western Yunnan of China are compared to obtain a better understanding of the hydrochemical factors affecting deposition of travertine from hot springs. The analyses of hydrochemical characteristics of the hot springs include the concentrations of Ca and HCO3, the percentage compositions of Ca among cations and HCO3 among anions, the milliequivalent ratio of Ca to HCO3 (γCa/γHCO3), the partial pressure of carbon dioxide (pCO2), saturation index (SI) and hydrochemical types of the water samples. All the travertine-depositing hot springs contain high concentrations of CO2, Ca and HCO3. Their partial pressures of CO2 (0.03–0.76 atm) are much higher than that of atmosphere (0.03% atm) and the values of pH range from 5.9 to 7.7. Hydrochemical investigations show that water samples in the travertine-depositing hot springs have relatively high TDS (higher than 590 mg/L) and they are mainly of HCO3–Ca type. The concentrations of Ca and HCO3 are higher than 55 mg/L and 300 mg/L, respectively, and the values of γCa/γHCO3 are in the range of 0.1–2. The saturation index values of calcite (SIc) are almost positive. By comparison, the concentrations of Ca and HCO3 in the hot springs that do not deposit travertine are relatively low, the range of value of γCa/γHCO3 is mostly lower than 1 and the hydrochemical types vary greatly. In addition, the concentrations of CO2, Ca and HCO3 decrease along the flow path of the travertine-depositing Nanni hot spring.