TDS Levels Research Articles

Some Physicochemical Parameters of Keana Salt Lake and Domestic Water Sources in the Salt Lake Community, Nasarawa State, Nigeria

Concerns have been raised on levels of some physicochemical parameters in Salt Lake water systems all over the world. In a developing country like Nigeria, Salt Lakes are pertinent domestic water sources in communities where they are found. This study examined the levels of selected physicochemical parameters (Chlorine, pH, Temperature, Total dissolved solids, Electrical conductivity, Total alkalinity, Total hardness, Nitrate, Sulphate and Phosphate) in water samples collected from Keana Salt Lake Nasarawa State, Nigeria and drinking water sources around the Salt Lake, in order to compare them with permissible limits. Water samples were collected in triplicates from five locations (two surface and three underground water sources) and analyzed using standard methods. Analysis of variance (ANOVA) was applied to determine significant differences in concentration (p≤ 0.05) based on sample location. The results are presented as Mean ±standard error values. Results show that Mean concentration levels of TDS and electrical conductivity were above WHO limits in the surface water samples. Chlorine, temperature, alkalinity, total hardness, Nitrate, Sulphate and Phosphate were all within their respective WHO permissible limits. Correlation analyses show that electrical conductivity, Nitrate and TDS were the variable significantly positively correlated among the physicochemical parameters examined in the study. On that note, the study recommends carrying out further research on heavy metals and microbial concentrations of water sources around Keana Salt Lake.

The decolorization effect by Aspergillus sp. 3 on Goldfish opercular beats

Batik effluent had high toxicity to aquatic organisms. Dye decolorization is a process used to reduce color density. Fungi which used for decolorization was Aspergillus sp 3. This study aimed to investigate the ability of fungi on decolorization of 3 kinds of batik effluents (Indigosol Green dye, Indigosol Purple dye, and Naphtol Black dye) and to investigate the ability of fungi on reducing TDS level. The study was also investigated the initial toxicity of batik effluents to Goldfish (Cyprinus carpio). Decolorization was measured by spectrophotometry, the pH value was measured by pH meter, and the TDS value was measured by TDS meter. In addition, the decolorized batik effluent was tested for toxic effect on C. carpio by total opercular beats. Decolorization assay showed that Aspergillus sp. 3 had the ability to decolorized only 2 kinds of batik effluents. The decolorization percentage of Indigosol Purple was 60.015% and Naphtol Black was 56.679%. The pH after treatment decreased from 8.5–9 to 5.3–6. The range of pH value of Indigosol Green, Indigosol Purple, and Naphtol Black 5.3–6. Besides that, Aspergillus sp. 3 also had the ability to reduce the TDS level in the effluent. The TDS level on Indigosol Green, Indigosol Purple, and Naphtol Black as 4,965%, 25,307%, and 15,129%, respectively. Initial toxicity assay of effluent to C. carpio showed that there was a difference of total opercular beats, which exposed by decolorized and before decolorized batik effluent. The total opercular beats of C. carpio on decolorized batik effluents showed high value than before decolorized batik effluents. It can be concluded that Aspergillus sp. 3 had the ability to decolorize and decreasing the initial toxicity of Indigosol Purple batik effluents on C. carpio.

Physico-Chemical and Optical Examination of Water Stored in Copper Vessels

Storage of water in copper vessels is traditionally followed in past and many reports have been published about the antibacterial growth in copper vessel. It is essential to determine the water purity for drinking purposes in daily life through low cost approach. In the present work an attempt has been made to investigate the effect of storage of different drinking water in copper vessel for two week. The corresponding values of pH and TDS meter for different waters were recorded and analyzed. The optical properties such as UV-Vis and Raman studies along with physio-chemical parameters like pH and TDS were analyzed for 3weeks against different water sources kept in copper vessel. The Raman spectra provide information for different water sources. Similarly the UV-Vis spectroscopy provide the peak variation for different waters, however the effect of days and copper concentration analysis are in investigation. The Results obtained in this study reveals that water stored in copper vessel reduces the TDS level of bore water Tirunelveli and maintains its pH at 8.0 after 2 weeks. The bore water in Krishnan kovil (virudhunagar district) shows no variation in TDS after 1 week, but in 2nd week there is sudden decrease in TDS from 1050 to 944ppm and pH level decreases to 8.3 showing alkaline nature. Throughout the experiment we have noticed that the colour of copper vessel changes in case of bore water. For variation in studies we have also studied the pH and TDS of Drinking water at Kalasalingam Academy of Research and Education. There is no change in colour of copper vessel and TDS and pH remains same up to one week, but in second week TDS increases to 100ppm while the pH remain constant at 7.4. These studies will help future researcher for designing of copper vessels and will help them to analyze the Physio-chemical studies of water. Moreover the chemical mechanism and reaction between copper vessel and leaching out of copper into water data base will be generated in future based on UV and Raman studies.

A framework to assess the impact of a hydraulic removing system of contaminate infiltration from a river into an aquifer (case study: Semnan aquifer)

Groundwater resource plays an important role in providing drinking and agricultural water, especially in arid areas. Hence, the inadequate quality of this resource in some areas is a cause of concern, especially for providing drinking water. There are many ways to improve the quality of contaminated aquifers that need to be assessed by considering aquifer condition. A strategy in this study is proposed to remove recharging contamination sources into an aquifer by a hydraulic system. The present study proposes a framework for assessing the performance of a hydraulic removing system of contamination sources in the improvement of aquifers' quality. For this purpose, the flow and TDS concentration of Semnan aquifer, Iran were simulated in using the MODFLOW and MT3D codes in GMS. Quantitative and qualitative modeling were calibrated for 2 years and validation period was 6 months. This study investigates the effect of the hydraulic removing of contamination source on water quality of the aquifer over the next 12 years. Results showed that construction of the hydraulic system would reduce infiltration water with of TDS 13,000 mg/l from Shurab River into the Semnan aquifer. This would improve the quality of the aquifer and reduce TDS levels by 20% in wells around the river over the next 12 years. In addition, the quality improvement index would increase by 6% until the August 2025, indicating improvement of aquifer quality by constructing the hydraulic system. However, complete elimination of this contamination would require a very long time (about 30 years). The proposed framework can be suggested for examining in assessing similar hydraulic removing of contamination source on water quality of aquifers.

Failure Investigation of Evacuated Tube Solar Collector of Water Heater

The instances of failure of solar tube collectors of water heating systems are seldom reported. The investigation of these failures and deep insights of prevention is required to avoid incurring huge costs at breakdown. The solar water heating systems are designed for longevity and requiring less maintenance. In lights of maintaining systems, only collectors are kept dust free for better performance and up-keeping of efficiency. But often the problems like leakages and high TDS levels of water are neglected. These facts at a later stage affect the longevity and working of systems and cause the breakdown of system. Salts accumulation creates blockages in solar tube collectors and entrap water causing pressure rise due to superheating. This leads to cracking failure of tubes. High temperature failure of sealing gasket leads to leakage and corresponding failure of manifold. Salts accumulation may further lead to bursting of collectors, and manifold leakages may cause damage to it by corrosion. Failure of these collectors is not affordable cost wise, and it is as good as replacing parts with the new ones involving high expenses. This report gives a guide on maintenance and precautions by investigating failures of evacuated tube solar collectors.

Season-induced variation in water table depth and selected chemical parameters of groundwater in Lagos Coastal Plain Sand Aquifer, Nigeria

In-situ measurement of depth to aquifer and water table was undertaken in 45 protected dug wells over two seasons. Samples were also analyzed for pH, EC, TDS, Ca, Cl, K, HCO 3 , CO 3 , SO 4 , Mg, K, and Na using universally accepted laboratory techniques. The study was aimed at examining seasonal variations in the chemistry of groundwater in the Lagos Coastal Plain Sand aquifer and its potability using the WHO standards. The study area covered parts of the Lagos Metropolis and the entire settlements of Ikorodu, Epe, and Badagry. The sample locations were mapped with ArcMap 9.3 software while the data were analyzed using descriptive statistics, paired sample T-test, correlation and multivariate statistical techniques using SPSS software 17.0 version. The result shows that about 60% of the samples had pH below the WHO minimum standard of 6.5 in both the dry and wet seasons. Mean EC and TDS levels were excessively high at Igando in both seasons. Some major ions, calcium, magnesium, potassium and sodium, and chloride exceeded the WHO limit at Oko-Oba, Ilogbo, Shomolu and Shogunle in the dry season. They were also excessively high in the wet season at Igando, Oko-Oba, Odo-Onosa, Ilogbo, Shomolu, and Shogunle. Correlation analysis shows that a significant relationship exists between the parameters at p<0.05 with the exception of Mg 2+ and K + in both seasons. The result of the paired sample T-test also shows significant variations among pH, Ca 2+ , HCO 3 - and Mg 2+ with higher mean values in the dry than the wet season except for pH. Factor analysis identified salinity and anthropogenic activities as the two major sources of pollution. These account for about 74.48% and 84.21% of the total variances in dry and wet seasons, respectively. Consequently, protection of the recharge areas of the aquifer from environmental pollution and formulation and enforcement of appropriate policies that will stem the rate of indiscriminate groundwater exploitation and prevention of saline water intrusion in the coastal settlements are recommended. Keywords: Aquifer; Coastal Plain Sand; Groundwater; Lagos; Seasonal variations, Water quality parameters

Investigação de indicativos de qualidade da água em trechos dos rios urbanos Lucaia e Jaguaribe em Salvador, Bahia, Brasil.

The need to use water resources forced the urban agglomerates to grow along the rivers, but the increasing urban occupation increased the problems of water management in the cities, especially in relation to the release of domestic effluents and the drainage of rainwater. The present work aimed to evaluate physical-chemical and microbiological variables in water samples collected in urban rivers located in Salvador-Bahia. Collected at two distinct points of the Lucaia and Jaguaribe rivers, in the rainy and in the dry period, they showed that both physico-chemical and microbiological parameters, in most cases, presented values ​​above those indicated in current legislation, especially the second point of the Lucaia river that presented levels of EC, TDS, chloride and hardness superior to the other points investigated. The comparison of these results with INEMA Monitora program data indicate that these rivers are impacted by inadequate discharges of domestic effluents during the period investigated.

Impact of drinking water salinity on children's education: Empirical evidence from coastal Bangladesh

This study examines the impact of drinking water salinity on children's education using a unique and rich dataset collected from eight southwest coastal districts of Bangladesh. Salinity concentration in drinking water is measured at the household level using water samples from households' primary source of drinking water during the summer, wet and dry season of 20014−15. A third of the deep tube-well water samples was found to be slightly (1000 < TDS < 2000 mg/l) to moderately (TDS ≥ 2000 mg/l) saline. Linking the child-level data on educational outcome to water salinity (i.e. TDS level), the study reveals a statistically significant negative effect of excessive salinity on grade advancement for 7–12 year old children. More specifically, exposure to excessive drinking water salinity (TDS > 1000 mg/l) decreases the grade advancement likelihood of 7–12 year old children by 6.7 percentage points. The results remain robust to alternative model and econometric specifications. The adverse effect of salinity on grade advancement does not vary significantly across the gender of the child while poverty, as expected, exacerbates the effect. Impaired cognitive development due to early childhood exposure appears to be the most plausible channel through which the negative effects of excessive sodium consumption permeate to young children's educational deficit. Additionally, poor health of the adults and elevated medical expenditure play a small yet significant mediating role.

Physico-Chemical Analysis in Surface Waters around the Closed Gaborone Sanitary Landfill in Botswana

The aim of the study was to ascertain the pollution levels in water sources in the areas surrounding the closed Gaborone landfill site. The study focused on the physico – chemical analysis of surface water resources around the closed Gaborone landfill site. The specific objectives were to determine the properties of surface water around the landfill and compare them along a transect with the water sources upslope and downslope of the landfill. Furthermore, the probable impacts of the wastes on water resources are highlighted and the levels of heavy metal contamination in surface waters around the closed Gaborone landfill are shown, in addition to compare the findings in this study with set standards (WHO, USEPA, FAO, EU, USSR and BOBS) and other yardsticks from previous studies. Due to scarcity of water resources and poor drainage water levels, five (5) existing surface water samples were collected offsite along a spatial gradient transect while the sampling interval was based on the length of the slope below the landfill. Field sampling and laboratory analysis of surface water resources was done so as to ascertain physico – chemical and heavy metal pollution levels. The findings of the investigations show that physical parameters such as pH, Electrical Conductivity, turbidity, TDS and TCU levels at the closed Gaborone landfill are above the drinking water standards BOS 32: 2000, WHO (2004) and USEPA (1991) limits and there is a general decline in pH, EC, TSS, TVS, TSD and TCU with increasing distance from the landfill site. While the chemical properties show that alkalinity, nitrates, phosphates, sulphates, chlorides, calcium, magnesium, chromium, and ammonia levels for the closed Gaborone landfill are higher than BOS 32: 2000, WHO (2004) and USEPA (1991) limits indicating toxicity. The general trend patterns show that there is a general decline in alkalinity, BOD5, sulphates, phosphates, nitrates, magnesium, calcium and chromium levels with increasing distance from the closed Gaborone landfill while chlorides levels are increasing. There was a significant decline in alkalinity, EC, sulphates, and calcium with increasing distance at P = 0.05. On the other hand, BOD5 levels can be classified as clean to moderately polluted. Overall, sanitary landfills have a far-reaching impact on the surrounding water resources and if left unmonitored increased pollution levels could lead to compromised drinking water quality, public health deterioration and descending environmental eminence.

Assessment of water quality of lakes used for recreational purposes in abandoned mines of Linden, Guyana

ABSTRACT The open pit method is often the easiest and the most inexpensive form of mining. Bauxite mining, which commenced in 1916 in Linden, Guyana, has left many abandoned pits upon closure of mining activities; subsequently pit lakes have been formed. Globally, Acid Mine Drainage (AMD) is a common water quality problem for pit lakes. However, the pit lakes in Linden are used for recreational activities. In this study, the water quality of three lakes in Linden (NE Kara Kara, Kara Kara and Lucky Spot) were analysed for their physico-chemical characteristics. The morphological and aesthetic features were also examined. The study showed that all three lakes are acidic, with mean pH values of 3.4, 3.1 and 4.7, which are not within the allowable range for recreational waters. Mean concentrations of Al (23.06 mg/l), Fe (10.56 mg/l) and Mn (2.4 mg/l) exceeded acceptable limits; nevertheless, TDS levels measured were within the acceptable limits. In terms of aesthetic quality, NE Kara Kara and Kara Kara pit lakes were free from any form of waste and debris. For the pit lakes to be considered suitable for recreational purposes, treatment of the lakes’ waters is recommended.

Rancang Bangun Sistem Pengolah Air Bersih Standar WHO dan Kemenkes Bagi Warga Dusun Sinan - Desa Gawerejo - Kecamatan Karangbinangun - Kabupaten Lamongan Jawa Timur

Sinan Village is located in Karangbinangun Subdistrict, Lamongan city, which is experiencing a shortage of clean water. The main source of water for the people in that village is originated from river water of Bengawan Solo branches which is mixed with pond water and is collected in a pond. The results of the pH, turbidity and TDS tests that have been carried out show that the Bengawan Solo water does not meet WHO's clean water standards and the standard from Ministry of Health. In this study, the design of the river and pond water filtration control system in the reservoir was carried out. The designed filtration system consists of the deposition stage and filtering stage. Deposition stage is carried out by using alum as a purifying medium and aims to simplify the screening phase. While the screening stage is carried out using stone, sand, charcoal and palm fiber which aims to increase the pH value and reduce the value of turbidity and TDS. The system is designed in a modular manner between each filtration stage to fascillitate the maintenance process of the system and flushing the remaining deposits produced by the filtration process. Testing result of this system is done by varying the variables of volume and height of sand used and it is known that the difference in sand volume used has a significant effect on the levels of TDS, Turbidity, and pH of the resulting clean water.

Mineralization process of spring in carbonate coastal aquifer in the massif Bokkoya (Central Rif, Morocco)

The study focuses on the monitoring of physico-chemical parameters and major chemistry elements in water from six springs and sinks during two seasons, rainy and dry. Samples taken in the coastal karst aquifer massif Bokkoya Al-Hoceima, were analyzed for their chemical quality and to quantify their state of anthropogenic and / or natural contamination, scientific and practical interest, because local population used to supply drinking water. The waters of the internal Rif region are highly mineralized and marked by a chloride-sodium or sodium-sulfated facies to connect mainly to a process of marine intrusion and dissolution of evaporitic minerals included in the on-site rocks. This mineralization of marine origin is partly due to the intensive exploitation of groundwater but also to landslides, that are known in the area, and which accelerate the phenomenon of saltwater intrusion in the coastal karstic aquifer. The salinity of this water presente levels of salinization C3 and C4 as classified by Wilcox log and water of the Bokkoya massif were qualified as very hard. The comparison of hydrochemical results to the quality standards for drinking water set by the World Health Organization shows that the majority of the water withdrawal is not suitable for consumption, especially because of the high levels of EC, TDS and Cl - related to marine intrusion, together with the urban pollution factor which increases the content of NO - 3 in waters.

Physico Chemical and Microbial Analysis of Different Sources of Water collected from Indora, Himachal Pradesh, India

Life could not be imagining without the presence of water on this earth. An ecosystem is very dependent on the quality of water. Regular water quality monitoring is very essential of a region. In the study area, no study has been yet done on the quality of drinking water and productivity level of Beas river near Arni University, Himachal Pradesh, India. The main aim of this study was to determine the water quality of three different sources of water like hand pump water, tap water, and Beas river water. For this, we have collected total twenty-six samples in the month of May 2018 and analysed for pH, TDS, EC, DO, alkalinity, phenolphthalein alkalinity, total hardness, calcium hardness, chloride, sulfate, phosphate, nitrate, carbonate, bicarbonate, E. coli, and productivity level by standard methods. The entire analysed parameters showed the lower level than the permissible guideline of the WHO except for the presence of E. coli and higher level of alkalinity. The productivity level of Beas river was indicating that trophic index belonged to the ultra-oligotrophic. From the findings, it might be concluded that hand pump water, tap water, and Beas river water was drinkable except the presence of E. coli and higher level of alkalinity in tap water and river water. However, in the case of the productivity level of Beas river was indicating the very low accumulation of dissolved nutrient salts, and a lower rate of algae growth as the productivity level belonged to the ultra-oligotrophic. Further extensive study on the water minerals and heavy metals level in all the water sources are required in this study area.

Multivariate analysis of the dominant and sub-dominant epipelic diatoms and water quality data from South African rivers

Data are presented on the distribution of the dominant and sub-dominant epipelic diatoms found in South African rivers from different regions of the country. A multivariate analysis identified 36 diatom species that were associated with different levels ofTDS, PO 4 , NH 4 and SiO 2 . Three groups of rivers were identified. Group I consisted of sites with high PO 4 and SiO 2 which corresponded to Durban Metropolitan Area sites, Kruger National Park rivers, the rivers in the Johannesburg Metropolitan Area and the Orange River. In these rivers 12 diatom species were identified that might indicate those water quality characteristics. Group II included stations where the water quality had high TDS and NH 4 values which were associated with most stations in the Swartkops River in the Eastern Cape. The indicators in this group comprised 12 diatom species. Group III were from sampling stations where the water had low levels of minerals, i.e. the upper reaches of the Gamtoos River and the Swartkops River in the Eastern Cape, the Olifants River in the Northern Cape, rivers sampled in KwaZulu-Natal and the Northern Cape. At these sites, 13 diatom species were found as dominants in this better water quality. Water quality data collected during this study showed that over 50% of the river systems display some degree of eutrophication and thus efforts should be made to reduce inputs of nutrients and pollutants to those rivers.

Greywater Treatment Using Single and Combined Adsorbents for Landscape Irrigation

Greywater reuse can be considered as an additional supply of water not only to protect water resources but also to reduce water shortage. Thus, the aim of this research is to examine the feasibility of three adsorbents (activated carbon (AC), Iranian natural zeolite (Z) and stabilized nano zero-valent iron (nZVI)) in single and combined forms to treat greywater for reuse in landscape irrigation. For this purpose, greywater samples were collected from student hostel of Fasa University and analyzed in a batch mode experiment. Also, the adsorption of COD was studied in terms of kinetic, isotherm and thermodynamic models. The results indicated that among the seven treatments, the combination of AC, Z and nZVI had the best performance in greywater treatment. 85.75% removal of COD, 91.81% of TDS and 98.1% of turbidity were achieved by triple combined treatment. In double combined adsorbents, the highest adsorption rate of COD, TDS and turbidity was accomplished when AC+nZVI, AC+Z and nZVI+Z were used, respectively. The results also indicate that single adsorbents alone are not adequate to guarantee a sufficient reduction of COD, TDS and turbidity. Kinetics of COD removal by all treatments obeyed to pseudo-second-order model and the Freundlich isotherm closely fitted the experimental data. The COD data demonstrated that the sorption process is spontaneous and endothermic. The results indicated that the triple combined adsorbents were able to reduce the COD, TDS, turbidity and pH level to the required reuse in landscape irrigation and the results were satisfactory according to Iranian standards.

GIS-Hydrogeochemical Model of the Yaound&amp;#233; Fractured Rock Aquifer, Cameroon: Aquifer Setting, Seasonal Variations in Groundwater-Rock Interaction and Water Quality

This study of the gneiss-fractured-rock aquifer in Yaoundé capital of Cameroon determines: the aquifer setting-flow systems, the aquifer type, seasonal variations in rock-water interactions, evolution of the hydrogeochemical processes, physicochemical parameters and the suitability for domestic-agro-industrial use of the groundwater. Physicochemical field tests were carried out on 445 wells during four seasons for EC, pH, TDS, Temperature and static water level from July 2016 to May 2017. 90 well samples were analyzed 45 samples per season: wet/dry. 38 borewell logs were used together with structural data to determine the aquifer setting. The field physico-chemical and laboratory analysis data of well samples were mounted unto various GIS software platforms: Global mapper, AqQa, Aquachem, Rockworks, Logplot7, Surfer and ArcGIS, to get indices/parameters/figures, by use of Durov’s, Piper’s and Gibbs diagrams, Water quality index WQI, USSL ratio, Sodium Absorption ratio SAR, Percent sodium %Na, Kelly Ratio KR, Magnesium Absorption Ratio MAR, Total Hardness TH, Residual Sodium Carbonate RSC and Permeability Index PI that were determined. The process of groundwater ions acquisition is three-fold: by recharge through atmospheric precipitation, by ion exchange/simple dissolution between the rock-groundwater and by groundwater mixing in its flow path. Water types are Ca-HCO3, Mg-HCO3 and Mg-Cl while hydrogeochemical facies are Ca-Mg-HCO3 and Ca-Mg-Cl-SO4. Most water samples are fresh, potable and soft all seasons. The hydrogeological conceptual model is that of a three-layered single phreatic fractured-rock-aquifer while other researchers postulated a two-aquifer, phreatic and semi-confined, two-layered model.

Analysis of soil effects as leachate filter: A case study of TPA Mandung Tabanan

The accumulation in large volume of solid waste in the area of TPA Mandung is creating a new serious problem since the leachate is extremely increasing. The spill drastically contaminates the groundwater and the surrounding environment because the wastewater treatment plant isn’t working on full capacity. Based on those facts, it is necessary to start researching on how the leachate influences the soil characteristics, and how to get the soil to provide a proper filtration. The samples of soil and the leachate from TPA Mandung have, at first, been collected; soil properties have been physically and mechanically tested, while the leachate characteristics have been determined from the parameters of the contained substances. The leachate filtration was performed simultaneously with a hydraulic conductivity test simply varying its height from 7 cm, 9 cm, and 11 cm. The water drained from the hydraulic conductivity test has been reexamined to determine the changes in the leachate parameters after passing through the soil. The K value (hydraulic conductivity coefficient) in the soil hydraulic conductivity test sampled with height 11 cm, 9 cm, 7 cm, were respectively 0.000050 cm/sec, 0.000062 cm/sec, and 0.000065 cm/sec. The results showed a decrease in the coefficient of hydraulic conductivity along with the addition of leachate and the variation in sample height. The leachate in TPA Mandung before and after filtration had COD, BOD5, TSS, TDS and oil levels that exceeded the permitted threshold according to Regulation of Minister of Environment No. 5 of2014 concerning Wastewater Quality Standard.

Extent of Groundwater Contamination Due to Leachate Migration Adjacent to Unlined Landfill Site of Delhi

The leachate and groundwater samples were collected from the 2 km radius of Ghazipur landfill site. The high levels of EC, TDS, Chloride, Nitrate, Sodium, Potassium, BOD, and COD were observed in the leachate and groundwater samples. In leachate, metal concentrations were found in the order as – Fe > Zn > Cu > Pb > Ni > Cr > Cd. In groundwater, Zn, Ni, and Cu ranged as 0–0.386 mg/l, 0–0.013 mg/l, and 0–0.027 mg/l, respectively whereas Cd, Cr, and Pb were found in trace amount. The study clearly indicates that the percolation of leachate from the landfill site results in the contamination of groundwater of the surrounding area.

Forward osmosis remediation of high salinity Permian Basin produced water from unconventional oil and gas development

Unconventional oil and gas operations are on the rise, and they are an integral component to meeting the nation's energy needs. Produced water is the primary by-product of oil and gas operations, and it has proven challenging to treat to date. The aim of this study was to evaluate the feasibility of using forward osmosis with thin-film composite hollow fiber membranes as a remediation option for produced water with high total dissolved solids levels from the Permian Basin. Trials consisted of a series of 5 experiments in order to evaluate the performance of the membrane. Three PW samples, each from different locations, were used to conduct the series of experiments and compare the performance of the membranes on samples with TDS levels ranging from 16,000 to 210,000 mg/L. It was concluded that forward osmosis can be used to extract water from high salinity oil field brines and PW. Flux decreased over the course of the trials due to a combination of membrane fouling, concentration polarization, and temperature fluctuations. The flux of the PW was similar to the flux measured for the PW mimic with small difference due to the influence of activity on the osmotic pressure. The flux was also influenced by temperature and the linear velocity of the feed solution and draw solution.

Influence of coastal groundwater salinization on the distribution and risks of heavy metals

Coastal groundwater quality significantly affects the regional sustainable development, due to the water resource shortage in coastal zone. Current studies on coastal groundwater have mainly focused on saline water intrusion and over-extraction. Information on the heavy metal pollution of coastal groundwater with salinization trend is limited. This study investigated heavy metals in groundwater from a typical coastal region with intensive anthropogenic activities and saline water intrusion. The southwestern coastal plains of the study area showed significant groundwater salinization trend. Heavy metals in the coastal groundwater mainly originated from anthropogenic activities and groundwater salinization according to principal component analysis. Relative high concentrations of As, Co, Cr, Cu, Fe, Mn, and Ni occurred in the southwestern coast of the study area with high TDS level, indicating that the concentrations of these heavy metals in shallow aquifer of the study area might be influenced by the groundwater salinization. Average concentrations of heavy metals in groundwater of the study area ranged from 0.03 (Cd) to 686.92 (Fe) μg/L. Fe was the dominant heavy metal in groundwater with the maximal concentration of 2333.76 μg/L and exceeding-standard rate reaching 98.23%. Approximately 13.27% of sampling sites showed moderate or higher heavy metal pollution of groundwater based on heavy metal pollution index. Heavy metals in groundwater exerted low ecological risks. Elements Fe, Ni, and As were the main contributors for ecological risks. Cancer risks of heavy metals for both adults and children were high at all sampling sites. Non-cancer risks for adults and children were unacceptable at 4.42% and 17.70% of sampling sites, respectively. The salinization of the coastal groundwater could also lead to the increase in the ecological and health risks of heavy metals in coastal groundwater. These findings provide initial and important information on heavy metals pollution in coastal aquifer with saline water intrusion.