Total Dissolved Solids Concentration Research Articles

Ecological water replenishment to the Yongding River, China: effects of different water sources on inorganic ions and organic matter characteristics.

Ecological water replenishment is considered to be an important project to adjust river ecosystems with water shortages and degradation, and its impact on the water quality of the target river section deserves attention. By investigating the characteristics of inorganic ions and organic components of the Beijing section of the Yongding River (YDR) from upstream to downstream, the sources of inorganic ions and dissolved organic matter (DOM) during an ecological water replenishment event were analysed and discussed. This study illustrated the hydrochemical response to different supplemental water sources in three sections of the YDR (mountain gorge section (MGS), urban plain section (UPS), and suburb plain section (SPS)). The results showed that the total dissolved solids (TDS) and ion concentrations were significantly different (p < 0.001) in the three river sections due to different supplemental water sources. The highest concentration of TDS was found in the UPS (870.92mg/L) replenished by reclaimed water, while the lowest concentration of TDS was found in the SPS (306.95mg/L) replenished by the water of the South-to-North Water Diversion Project (SNWD). Despite the differences in the water sources of replenishment, the optical parameters of DOM and fluorescent components showed similar protein-like dominated endogenous source characteristics in the three river sections of the YDR, which was due to the influence of reservoir water (MGS and SPS) and reclaimed water (UPS). Our study emphasizes the importance of understanding the impact of different water sources on the water replenishment process, which provides a scientific reference for the management of ecological water replenishment.

Evaluation of different atmospheric correction methods prior to the estimation of total dissolved solids concentrations from satellite imagery

Evaluation of different atmospheric correction methods prior to the estimation of total dissolved solids concentrations from satellite imagery

Effects of pasteurization on the physicochemical, sensory properties and microbiological quality of beetroot (Beta vulgaris L.) wine during storage

Introduction: In the beverage sector, pasteurization is combined with another means of preservation such as concentration, acidification to extend product shelf-life by inactivating all non-spore-forming pathogenic bacteria and the majority of vegetative spoilage microorganisms, as well as inhibiting or stopping microbial and enzyme activity. The main objective of this study was to focus on the effect of pasteurization and storage on the physical, antioxidant, and microbiological properties of red beetroot (beta vulgaris l.) wine. Method: After fermentation in 10 days, the red beetroot wine was either pasteurized at 700C in 10 minutes or unpasteurized before storing at 40C in different time (1 month, 2 months). Physicochemical properties and microbiological quality of beetroot wine were analyzed to study effect of pasteurization and storage on those properties of beetroot wine. Results: Physical properties like pH, total dissolved solids content were significantly affected by pasteurization (higher pH and higher TTS in pasteurized samples than in unpasteurized samples) but they were not affected by storage time in this project. After fermentation, the TPC of red beetroot wine was lost but it kept unchanged after pasteurization. Vitamin C of the wine sample was lost after pasteurization only when storage. Pasteurization and 2 month-storage caused significant reduction on antioxidant capacity of red beetroot wine. Sensory quality of beetroot wine was not affected by pasteurization but it was in the case of storage. Microorganism quality of wine was acceptable for consumption. Pasteurization process is effective in increasing shelf life of red beetroot wine but does not significantly affect its nutritional and sensory values.

Disease Risk Levels of Drinking Water Sources in Some Rural Communities in Kwara State, Nigeria

Human health, which can be affected by access to safe drinking water, or lack of it, is an area of common interest to the sustainable development goals (SDG, 6 target 1) and One health Initiative. Hence, this study examined the disease risk associated with drinking water sources in some rural agrarian communities in Kwara State, North-central Nigeria. Water from commonly used drinking water sources in the selected communities were tested for physicochemical properties (pH, Turbidity and Total dissolved solids content), and bacteriological quality. The health risks of the water sources were assessed in terms of presence and count of E. coli. Groundwater sources (wells and boreholes) were the predominant sources of drinking water in the communities. Only three (motorized boreholes) among the twenty-five water sources examined were free of coliforms. E. coli was found in thirteen water sources (a pond and twelves wells); with E. coli counts ranging from 2- 15 cfu/mL. The study revealed the need for urgent interventions to ensure the communities have access to safe water. The rural communities still depend heavily on groundwater as sources of drinking water, most of where portend had high level of disease risk.

Monitoring of River Estuary Turbidity using Satellite Image Analysis and Its Correlation to Rainfall (A Case Study of the Krueng River in Aceh, Indonesia)

Activities along the Krueng Aceh river such as port activities, fisheries, ship breeding, tourist attractions, market activities and settlements cause a lot of domestic waste in the environment around the river and affect river clarity and increase the concentration of turbidity. High turbidity in rivers can affect the entry of light into the waters because light has an important role in the photosynthesis process. The method of monitoring water quality can be done by remote sensing because it has several advantages such as being able to carry out measurements on a larger scale for a long time, relatively quickly, and reducing the amount of costs incurred. Monitoring the Krueng Aceh River is carried out using remote sensing technology using Sentinel-2 imagery. This study aims to obtain the value of the distribution of turbidity by analyzing satellite imagery and its correlation with rainfall, and to determine the value of the distribution of turbidity, Total Suspended Solid (TSS), Total Dissolved Solid (TDS), and Power of Hydrogen (pH) in the Krueng Aceh River. The results showed that sentinel-2 image analysis got the lowest turbidity on September 6, 2021, which was -0.992424, and the highest on October 5, 2019 which was 0.248641. The distribution of water quality is known to have the highest turbidity concentration obtained at sampling location point 1, which was 107.9 NTU. The highest concentration of TSS was found at sampling locations 1, 4, and 7, which was 400 mg/l. The highest TDS concentration was found at point location 1, which was 1,413 mg/l. The pH concentration at the Krueng Aceh River sampling location has met the quality standards set in PP No. 82 of 2021

River–Lake System Connectivity Effectively Reduced the Salinity of Lake Water in Bosten Lake, Northwest China

High salinity in water constitutes a serious problem for the aquatic environment management of Bosten Lake. Weak water exchange and water movement are the essential factors for the high total dissolved solids (TDS) content of lake water. To improve the water quality of Bosten Lake, a river–lake system connectivity project (water diversion) was introduced starting at the end of 2018, which diverted fresh water from the Kaidu River and the Huangshuigou River to Bosten Lake. In this study, the effect and its mechanism of water diversion on the TDS content of Bosten Lake were evaluated using continuous-field monitoring data. The results showed that the water diversion effectively reduced the TDS content of the lake water and changed Bosten Lake from a brackish lake back to a freshwater lake. Water diversion also improved the spatial distribution of TDS content. One year, two years, and three years after the implementation of the water diversion project, the TDS content of northern, southern, and eastern lake water significantly decreased by more than 20%, 25%, and 30%, respectively. Our study demonstrated that water diversion significantly increased the annual endogenous TDS pollutant amount discharged from the lake and reduced and homogenized the TDS content of the whole lake. TDS content reduction of the lake was realized by water diversion accelerating water movement and water exchange in the lake, especially for the northern, southern, and eastern waters. Therefore, water diversion could be used as an effective measure for water quality improvement in semi-closed inland lakes in arid areas.

Evaluation of water quality and its non-cancer risk in the rural environment of Bundelkhand region: geochemical and statistical approaches

ABSTRACT The Bundelkhand region of Central India has been facing increasing severity of droughts, water-level depletion and deterioration in water quality. In this perspective, an attempt has been made for a qualitative evaluation of surface and groundwater resources belonging to the rural environment of this region to understand the contaminant’s source and probable human health risk due to the intake of the available water. The water samples collected from this region were analysed for pH, electrical conductivity (EC), total dissolved solids (TDS), turbidity, total hardness (TH), major anions (F−, Cl−, HCO3 −, SO4 2−, NO3 −) and major cations (Ca2+, Mg2+, Na+, K+). The observations revealed a near-neutral to slightly alkaline nature of the studied water samples. The computed water quality index implies that around 82% water samples are of good to excellent category for drinking uses. Turbidity, TDS, TH and NO3 − were identified as the major parameters which violate the limits of drinking water. Geochemical investigations in association with multivariate statistical analysis identify carbonate weathering in coordination with the ion-exchange process as the major hydrogeochemical mechanism controlling the solute chemistry and concentrations of TH, TDS, HCO3 −, F−, Ca2+, Mg2+ and Na+. On the contrary NO3 −, Cl−, SO4 2− and K+ were strongly associated with anthropogenic activities. Water at most of the locations expresses positive saturation indices with respect to calcite and dolomite minerals, inferring the precipitation of these mineral phases. Sodium adsorption ratio (SAR) and percent sodium (%Na) values show a low alkali hazard and water can be used safely for irrigation purposes. However, high salinity in 39% of the water samples makes it unfit for application in agricultural fields. The non-carcinogenic hazard indices (HI) calculated by adding hazard quotient values of NO3 − and F− for child, adult male and female population show that more than 64% of the water samples are deemed to be unfit for human consumption.

Total Dissolved Solids (TDS) Less than 1000 ppm in Drinking Water Did Not Impact Nursery Pig Performance.

High concentrations of total dissolved solids (TDS) in water have been reported to increase the incidence of diarrhea and reduce nursery pig growth performance. The objective of this study was to investigate the effects of drinking water with high concentrations of TDS from sulfate salts on nursery pigs. Weaned pigs sorted to equalize gender were placed in 44 pens with 26 pigs per pen. One of four water treatments was randomly assigned to each pen: (1) combination of CaSO4, MgSO4, and NaSO4; (2) CaSO4; (3) MgSO4; (4) NaSO4. Access to water and feed (nursery diets fed in four phases) was unrestricted throughout. The weights of pens were measured, feed remaining on weigh days was calculated, and pen water meters were read on d 0, 7, 21, 35, and 42. Water treatment did not affect (p > 0.07) average daily gain, average daily feed intake, or gut integrity of pigs. Water disappearance tended to be greater (p = 0.10) in pens receiving the CaSO4 water compared to the combination treatment from d 21 to 35. The TDS concentrations from sulfate salts used in this experiment did not impact the growth performance or feed or water disappearance of newly weaned nursery pigs.

Characteristics of Dissolved Organic Matter and Its Relationship with Water Quality along the Downstream of the Kaidu River in China

The variability in the quality of water that runs along the course of a river, flowing out of a mountain pass, through an agricultural oasis and into a lake, has been a key topic of research in recent years. In this study, the characteristics of dissolved organic matter (DOM) along the river flow, and its relationship with water quality, were analyzed using the Canadian water quality index (CWQI), parallel factor (PARAFAC) and self-organizing map (SOM). The study results include: (1) The conclusion of field sampling along the lower reaches of the Kaidu River and laboratory measurements of water quality parameters, using CWQI to determine the water quality index of the lower Kaidu River, ranging between 59.58 and 93.47. The water quality of the lower reaches of the Kaidu River generally ranges between moderate and good, and can meet the water use requirements of Class II water function standards. (2) The DOM composition of the river predominantly contained three fluorescence components, while the three fluorescence indices of the water body varied less in different river sections. Based on the SOM training model, the fluorescence intensity of the C1 component was larger among the three fluorescence components, followed by the C2 component, and the smallest fluorescence intensity of the C3, which was dominated by humic-like substances, with a high authigenic origin and humification degree. (3) The fluorescence index and fluorescence components were correlated with water quality parameters, and it was found that C1, C2 and C3 were negative and correlated significantly with SO42- and Total-dissolved solids (TDS) concentrations; FI, HIX and BIX showed strong positive correlations with SAL and Cu and negative correlations with dissolved oxygen (DO). This study provides a scientific basis for surface water quality monitoring and water quality pollution management in the Kaidu River.

Chemical quality assessment of major brands of bottled mineral water available in the Ethiopian market

Assessing bottled mineral water with drinking water guidelines set by the World Health Organization (WHO) and the Ethiopian Standard Agency (ESA) are highly relevant for practitioners, bottling companies, managers, regulators, and policymakers regarding water supply particularly bottled water. The present study was carried out to report the physicochemical quality of six branded bottled mineral water widely available in the Ethiopian market and compare them with drinking water standards. The investigated physicochemical parameters were pH, electrical conductivity (EC), total dissolved solids (TDS), chloride ion (CL - ), nitrate ion (NO3 - ), potassium (K+ ), sodium (Na+ ), zinc (Zn+ ), iron (Fe3+), calcium (Ca2+) and magnesium ion (Mg2+) using standard analytical techniques. Flame Atomic Absorption Spectroscopy (FAAS) was used to determine the number of metal elements. The Ultra Violet-Visible Spectrophotometer (UV-VIS) analysis was used to determine the amount of NO- in the bottled mineral water. The TDS and CL-values were determined by using gravimetric and volumetric methods. The study results revealed that the values of the quality parameter concentrations measured experimentally were slightly varied from the labeled values on the bottle. However, all brands were within EAS and WHO limit values for drinking water. The calculated correlation coefficient between the bottled water and the soil sample, between some dissolved solids and the TDS concentration in bottled mineral water, and between TDS and the pH concentration in bottled mineral waters was 0.99, 0.77 and 0.94, respectively. The study also verified that all the studied bottled water brands are safe for human consumption.

A Novel Approach to Developing Thresholds for Total Dissolved Solids Using Standardized and Experimental Toxicity Test Methods.

The increasing salinization of freshwater streams from anthropogenic land uses and activities is a growing global environmental problem. Increases in individual ions (such as sodium or chloride) and combined measures such as total dissolved solids (TDS) threaten drinking water supplies, agricultural and economic interests, and the ecological health of freshwater streams. Because the toxicity of high ionic strength waters depends on the specific ion composition, few water quality standards exist to protect freshwater streams from salinization. In the present study, we used a novel approach to develop site-specific and ecologically relevant TDS thresholds for the protection of aquatic life. The first step of the approach was to characterize the ion composition of the waterbody or region of interest and prepare artificial samples to match that composition. Using a combination of standardized toxicity test species and more ecologically relevant field-collected species, toxicity tests were then conducted on these artificial samples prepared at a range of TDS concentrations. The advantage of this approach is that water quality criteria can be developed for easy-to-measure generalized parameters such as TDS while ensuring that the criteria are protective of instream aquatic life and account for the complex interactions of the various ions contributing to salinization. We tested this approach in Sand Branch, Loudoun County, Virginia, USA, where salinization from hard rock mining and urban runoff has impaired aquatic life. Acute and chronic TDS thresholds of 938 and 463 mg/L, respectively, were developed in this stream and used for total maximum daily load development in the watershed. The approach provides a potential model for establishing protective thresholds for other waterbodies impacted by salinization. Environ Toxicol Chem 2022;41:2782-2796. © 2022 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Novel electro-oxidation unit for electro-disinfection of E. coli and some waterborne pathogens during wastewater treatment: batch and continuous experiments

The prime objective of the current investigation is to evaluate a promising alternative method for disinfection wastewater using a novel electro-oxidation unit. The study focused on determining the best-operating conditions from a techno-economic point of view to be applied to continuous flow simulating actual disinfection modules. The treatment unit consisted of a Plexiglas container with a 3 L volume containing nine cylindrical shape electrodes (6 graphite as anode and 3 stainless steel as a cathode) connected to a variable DC power supply. Determination of the best operating parameters was investigated in batch mode on synthetic wastewater by studying the effect of contact time, current density (CD), total dissolved solids concentration (TDS), and bacterial density. Moreover, the continuous mode experiment was considered on real wastewater from an agricultural drain and the secondary wastewater treatment plant effluent before chlorination. The batch mode results revealed that the best applicable operational conditions that achieved the complete removal of E. coli were at a contact time of less than 5 min, TDS of 2000 mg/L, and CD of 4 mA/cm2. Application of these conditions on the continuous mode experiment indicated the complete removal of all bacterial indicators after 5 min in the drainage wastewater and after 3 min in the secondary treated wastewater. Physico-chemical characterization also suggested that no chlorine by-products displaying the hydroxide ion formed due to water electrolysis is the main reason for prohibiting the growth of pathogenic microbes. The electrical consumption was calculated in the continuous mode and found to be 0.5 kWh/m3 with an operational cost of about 0.06 $/m3, including the cost of adding chemicals to increase the TDS. The results proved that this novel electro-oxidation unit is a robust and affordable disinfection method for complete bacterial removal from wastewater and is more environmentally benign than other conventional disinfection methods.

Seasonal Variability of Phytoplanktons in the Non-Point Source Polluted River Nggada, Maiduguri – Borno State, Nigeria

Borno State is the epicenter of Boko Haram crisis which displaced millions of individuals. Maiduguri metropolis which became the principal refuge centre, has witnessed a rapid demographic change, land use and economic activities resulting into intense irrigational practice along the bank of river Nggada. This may result into changes in the physico – chemical parameters of the aquatic ecosystem and the dynamism may disrupt phytoplantonic community. The study was aimed at assessing the seasonal variability of phytoplanktons in non-point source polluted river Nggada of Maiduguri. Water samples for physico -chemical analysis were collected bi-weekly for a period of 11 months at three sampling stations. Physico-chemical parameters, including Dissolve Oxygen (DO), Dissolved Nitrate concentration, Dissolved Phosphorus Concentration, Total Dissolved Solids (TDS), Total Suspended Solids (TSS), Surface Water Temperature (SWT) and potential Hydrogen (pH) were determined using standard procedures. Results indicated that all physico – chemical parameters except temperature, DO and pH of the river during both irrigational and non-irrigational regimes were slightly above the National Environmental Standards and Regulations Enforcement Agency’s (NESREA) permissible limits. A total of 7 classes (Cyanophyceae Chlorophyceae, Cryptophyceace, Euglenophyceae, Bacillariophyceae, Crysophyceace and Rhodophyceae) and 16 genera of phytoplanktons were identified. The results further revealed that the irrigation activities (dry season) have impacted on the physico – chemical parameters (pH, DO, TDS, nitrate and phosphate concentrations) of the study area. Remarkably, the changes in the physico – chemical parameters during the irrigational regime (dry season) have not impacted on the abundance and distribution of phytoplanktons. Hence, the non-point pollutants influenced the physico – chemical parameters of the river butalgal abundance and distribution were not influenced by the changes in the physico – chemical parameters of the river. The study thus, recommends the continuous monitoring and systematic effort to conserve the bio-resources and water quality of the river

Laboratory Comparative Study of Anionic and Cationic High-Viscosity Friction Reducers in Moderate to Extremely High Total Dissolved Solids Environments

Summary High-viscosity friction reducers (HVFRs) have been recently gaining more attention and increasing in use, not only as friction-reducing agents but also as proppant carriers. Reusing produced water has also been driven by both environmental and economic benefits. Currently, most friction reducers on the market are anionic friction reducers, which are fully compatible with most produced water with low to medium level of total dissolved solids (TDS) but show a significant drop at high TDS conditions in terms of their friction reduction performance in most cases. On the contrary, cationic friction reducers are believed to have better TDS tolerance and friction reduction performance under high TDS conditions. However, concerns remain about performance of using anionic and cationic HVFRs with produced water to transport proppant. The ultimate objective of this experimental study is to comparably analyze the proppant transport capabilities of anionic and cationic HVFRs in high TDS and reservoir temperature environments. An anionic HVFR and a cationic HVFR, both at 4 gallons per thousand gallons (GPT), were selected and analyzed. The rheology measurements of these anionic and cationic HVFRs were conducted in deionized (DI) water and high TDS water conditions. Static and dynamic proppant settling tests were conducted at various TDS conditions at reservoir temperature. Wall retardation and particle hindering on the performance of both anionic and cationic HVFRs were also observed and investigated using the particle image velocimetry (PIV) method. The results showed that the anionic HVFR had higher viscosity than the cationic HVFR due to larger molecular weight and had much higher elasticity. Increase in TDS concentration would decrease the viscous and elastic profiles of both anionic and cationic HVFRs. In particular, the elastic profile became negligible for both HVFRs. Besides, the “critical salinity” phenomenon was observed. Above this salinity, the viscosity of HVFRs was no longer affected by increasing TDS level. The “critical salinity” for both of the 4-GPT anionic and cationic HVFRs was in the range of 30 000 to 200 000 mg/L. Moreover, the cationic HVFR had lower “critical salinity” than the anionic HVFR. Finally, the correlation between rheology and proppant transport capabilities of HVFRs is discussed in this paper, and a simplified decision-making process of selecting fracturing fluids is proposed.

Coupled modeling and process optimization in a genetic-algorithm paradigm for reverse osmosis dialysate production plant

The integrity of dialysis procedure is dependent on multivariate factors of which the production of ultrapure dialysate is considered a vital criterion in the spate of the growing rate of renal-related hospitalization. Hence the need to maintain equilibrium between process conditions and configuration of operational factors is attributed to ensuring dialysate purity under a reverse osmosis technique is an identified focus for research. This study is designed to model and optimize osmotic pressure, specific energy, and permeate water quality in a reverse osmosis (RO) plant intended to improve dialysate quality by utilizing established computational resources. The simulation of feed pressure, feed temperature, concentrate recycle and membrane type, on recovery percentage, permeate total dissolved solids concentration (TDS), cost of operation, and energy consumption, is implemented using Water Application Value Engine (WAVE) Software. The optimization efficiencies are analyzed via an artificial neural network (ANN) type generic algorithm (GA) scheme in the water purification model on the architecture of Neural Power Software. The ANN model R2 for the three outputs, permeate recovery, permeate total dissolved solids concentration (TDS) and specific energy, is 1, 0.99997 and 0.99999 respectively, while RMSE for ANN is estimated as 0.0213, 0.0248, and 0.0085 respectively. The optimum design shows a net energy saving of 2.4% can be achieved, accompanied by a 24% reduction in operating cost, a 14% reduction in permeate TDS, and a 20% increase in permeate recovery. The study achieves energy minimization, cost-effectiveness, and process integrity under a modified process design for RO-mediated ultrapure dialysate production suitable for highly sensitive applications such as clinical hemodialysis systems.

Linking remote sensing analysis and reservoir operation optimization for improving water quality management of reservoirs

The present study proposes and evaluates an integrated framework in which water quality distribution model of the lake and reservoir operation optimization are linked for improving the environmental management of the reservoir. Coupled remote sensing data processing- machine learning model was utilized to simulate water quality distribution in the reservoir in which one machine-learning model was used for converting the spectral images to the total dissolved solids (TDS) distribution in the reservoir. Then, another machine-learning model was developed based on the generated data by the first model for predicting water quality distribution map for unseens reservoir inflow/outflow scenarios. This machine-learning model was applied in the structure of reservoir operation optimization. Particle swarm optimization was utilized in the optimization process. Based on the results in the case study, the proposed method is able to minimize environmental impacts in the reservoir while the benefits from the reservoir such as water supply are maximized. However, its performance is not perfect that seems logical. In fact, the proposed model is able to balance the environmental requirements and losses of the reservoir. According to the generated water quality distribution map in a critical month of the simulated period, TDS concentration alters in range of 258 mg/L to 1091 mg/L in the lake that demonstrates using water quality distribution model in the optimal reservoir operation is necessary. The proposed method highlights the importance of using the remote sensing-based models in the structure of water resources optimization systems.

Heavy metal pollution in leachates and its impacts on the quality of groundwater resources around Iringa municipal solid waste dumpsite.

Heavy metal pollution in groundwater due to leachates leaking from the Iringa municipal dumpsite was investigated. The pollution was studied by analyzing pH, electrical conductivity (EC), total dissolved solids (TDS), and heavy metals (Fe, Pb, Cr, Cd, Cu, Ni, Mn, and Zn) in leachates collected within the dumpsite and groundwater samples from residential wells close to the dumpsite. The pH of the leachate samples varied from 7.40 to 9.10, implying alkaline behavior and the methanogenic phase of solid waste deposits. The levels of EC, TDS, and heavy metals (Fe, Pb, Cr, Cu, Ni, Mn, and Zn) in leachates were above the national and/or international standards. On other hand, groundwater samples presented pH values ranging from 7.15 to 7.60 which were within the World Health Organization acceptable limit. The concentrations of EC, TDS, Fe, Pb, Ni, Mn, and Zn in most groundwater samples exceeded the national and/or international permissible limits for drinking water. In addition, the water quality indices (WQI) of groundwater samples ranged between 8.30 and 17.90, which implied the excellent quality of groundwater sources. However, the presence of high levels of heavy metals above the permissible limits in both leachate and groundwater samples signified potential risks to the environment and public health. Therefore, the present study calls for proper management of municipal solid waste to reduce the potential risks of further contamination on the groundwater resources and environment around the Iringa municipal dumpsite.

Optimization of the biological salt removal process from artificial industrial wastewater with high TDS by Spirulina microalga using the response surface method.

This study aimed to examine the direct applicability of Spirulina maxima as a new conceptual method for removing total dissolved solids (TDS) from artificial industrial wastewater (AIW). In this study, live microalgal cells were used in a photobioreactor for TDS removal. The effects of TDS levels, pH, light intensity, and light retention time on microalgal growth and TDS removal were investigated, and optimal conditions were determined using the response surface method and Box-Behnken Design (RSM-BBD). The calculated values of coefficient of determination (R2), adjusted R2, and predicted R2 were 0.9754, 0.9508, and 0.636, respectively, which are close to the R2 values and validated the proposed statistical model. A second-order model could optimally determine the interactions between the studied variables according to the one-way analysis of variance (ANOVA). The results showed that increasing TDS levels reduced microalgal growth and TDS removal efficiency in AIW. S. maxima reduced TDS by 76% and 47% at TDS concentrations of 2,000-4,000 mg/L, respectively, when used in AIW. Maximum biomass efficiency (1.8 g/L) was obtained at a TDS concentration of 2,000 mg/L with other parameters optimized.

Source water vulnerability to elevated total dissolved solids within a mixed-use Appalachian River basin

The upper Monongahela River basin in West Virginia represents a watershed wherein historic land use activities, including coal mining, conventional oil and gas development, and residential and urban development have contributed to elevated total dissolved solids (TDS) concentrations within surface and source waters with widespread exceedance of the 500 mg/L secondary drinking water standard for TDS. Our research was designed to characterize spatial variability in and sources of elevated and assess vulnerability of surface and source waters to additional TDS sources and loading. We compiled 3439 unique water quality sampling records throughout the study area over a ten-year period and applied boosted regression tree (BRT) analysis to model log[x]-transformed TDS as a function of landscape attributes across the 885 sampled NHD catchments. We predicted (i.e., elevated TDS and reduced dilution capacity) and observed (i.e., increased variability in TDS and temporary exceedances of 500 mg/L) elevated vulnerability of source waters, with vulnerability being largely driven by a few dominant contributors of TDS throughout the stream network. Notably, seven 12-digit hydrologic unit code (HUC) inflows to the Monongahela River and its vulnerable tributaries were predicted to require a combined 6,664,879 m3 of water (i.e., chemical footprint) to dilute TDS concentrations below 500 mg/L from July through September. Our results provide insights into how the mixed land uses containing extractive industries can impact water quality and demonstrates the importance of both spatial and temporal processes in controlling vulnerability of source waters to water pollution.

Geochemical analysis and quality assessment of geothermal water in Gujarat, India

Geothermal water can have a wide range of direct applications, including drinking, domestic use, irrigation and industrial use. This study analyses geothermal water from Dholera, Diu, Gandhar, Kutch, Porbandar, Tulsishyam, and Unai regions located in Gujarat, India, to determine the hydrochemistry for establishing the water's suitability for drinking and irrigation purposes. From each region, three different water samples were collected. For drinking purpose, total eleven water quality parameters such as pH, electrical conductivity, total dissolved solids, calcium, magnesium, sodium, potassium, chloride, sulphate, carbonate and bicarbonate were evaluated. Piper and Durov plots were used to understand the ionic composition and evolution of water. Whereas for irrigation, the parameters such as total dissolved solids, sodium absorption ration, electrical conductivity, and potential salinity were used for water quality check. Wilcox Plot was plotted to understand the sodium and salinity hazard of water. Water quality index and irrigation water quality index were used to assess the water quality for making the analytical procedure easy. The findings indicate that the water samples from the Dholera and Diu areas had extremely high values for both the water quality index and total dissolved solids content. Water in these places may be appropriate for making salt. All the other samples show adequacy for utilization in irrigation purpose.