Total Dissolved Solids Concentration Research Articles

Research of fresh/salt water in Upper-middle Pleistocene (qp\(_{2–3}\)) in Bac Lieu Province

This study identified the relationship between Total Dissolved Solids (TDS) and Electrical Conductivity (EC) with the TDS = 0.6628*EC = 0.1706 correlation, in which the correlation coefficient is r = 0.984 and the Standard Error (±%) is 2.78%. The TDS content is determined by small relative error and a high correlation coefficient of the conductivity, which applies to calculate the TDS content of other groundwater samples in Bac Lieu Province. Also, the temperature difference in the electrical conductivity measurement affects the TDS content; thus, the study has determined that the temperature compensated constant between the electrical conductivity on the field and those at 25oC is 0.002953. According to the data and the analysis of the TDS content, the fresh-salt water distribution map of the qp2–3 aquifers has been established, and its boundary has been more detailed and standardized than in the previous study. In particular, TDS values range from 0.437 g/L to 2.0 g/L. The areas that contain brackish and salt water are distributed discontinuously, forming the saline zones in Loc Ninh, Phuoc Long communes in Hong Dan district; Phuoc Long, Hung Phu communes in Phuoc Long district; Vinh Hau, Vinh Binh communes in Hoa Binh district, and Thuan Hoa commune in Bac Lieu city. The saltwater area of the qp2–3 aquifers is about 398 km2, accounting for 16% of the study’s total area. The results fresh-salt water distributed mapping provide the environmental management institution with a comprehensive view of the distribution of fresh-salt water to propose effective groundwater exploitation policies.

Mechanism controlling groundwater chemistry in the hyper-arid basin with intermittent river flow: insights from long-term observations (2001–2023) in the lower Heihe River, Northwest China

The geochemical processes of groundwater in arid regions are generally influenced by both natural hydrological processes and human activities. However, impacts of water-rock interactions on groundwater recharge via hydrological processes, controlled by both intermittent river water flow and groundwater withdrawals, is still poorly understood. In this study, 327 groundwater chemistry datasets collected from the upper, middle (including Gobi and riparian zones), and lower regions of the Ejina Delta in Northwest China from 2001 to 2023 were analyzed. Our results revealed that the total dissolved solids (TDS) concentration of groundwater in Ejina Delta ranged from approximately 881.5 ± 331.6 mg/L in the upper regions to 1,953.6 ± 1,208.5 mg/L in the lower regions, with an increasing trend observed. Ecological water conveyance (EWC), recharging aquifer through intermittent river water flow, resulted in a decrease in TDS concentrations from 2001 to 2023 mainly in the upper region. While irrigation notably affected groundwater chemistry in the lower region, resulting in a substantial increase in groundwater salinity. Groundwater chemistry in the Middle Gobi region remained relatively stable over the study period. Generally, the hydrochemical composition shifted from the Na-Mg-SO4-HCO3 and Na-Mg-Ca-SO4-HCO3 types in the upper region to Na-Mg-SO4-HCO3 and Na-Mg-SO4-Cl types in the lower region, with Na-SO4-Cl predominant in the Middle Gobi. These shifts were likely be attributed to the interplay of water-rock interactions, coupled with evaporation-crystallization processes. Inverse modeling using PHREEQC revealed that in the upper-middle region, primary water-rock interactions involved calcite dissolution and the precipitation of dolomite, gypsum, halite, and sylvite salts, as well as cation exchange reactions (2NaX+Ca2+→CaX2+2Na+). In contrast, the hydrogeological system in the middle-lower region exhibited an opposite pattern of water-rock interactions. Overall, ecological water conveyance partially facilitated water-rock interactions during lateral groundwater flow, while irrigation disrupted the natural hydrogeochemical equilibrium, involving halite dissolution and opposite cation exchange reactions compared to other regions.

Economic assessment of a multistage surface-heated vacuum membrane distillation process for the treatment of hypersaline produced water

The treatment and disposal of hypersaline produced water remains a challenge, particularly for oil and gas producers in the Permian basin where production wells generate significant amounts of wastewater, and the traditional method of injecting wastewater into disposal wells is coming under increasing scrutiny. Here we investigate the viability of using solar energy to power a multi-stage, surface heated, vacuum membrane distillation (SHVMD) with energy recovery to treat hypersaline produced wastewater from Midland, Texas. Membrane distillation is a process that can desalinate waters with high total dissolved solids concentration, and when incorporated into a system with surface heating and energy recovery can achieve high water recovery rates. Model results show that a 6-stage SHVMD system with a 54.4 % water recovery rate and a gained output ratio (GOR) of 3.28 has the potential to be economically viable when used to treat hypersaline produced water in the Permian basin. Assuming energy costs of $0.03/kWhthermal and $0.12kWhelectric, we estimate a project net present value (NPV) of $225,525 and an internal rate of return (IRR) of 13.5 % when an air cooled condensor is used to cool the distillate and a NPV of $570,791 and IRR of 24.52 % when a liquid coooling source is available. SynopsisThis work presents a comprehensive economic assessment of utilizing a surface-heated membrane distillation system with heat recovery to treat hypersaline produced well water.

Assessment of surface and groundwater quality in Tikamgarh city, Madhya Pradesh, India

Surface water and groundwater are primary resources for communities living in arid and semi-arid regions. The expansion of industrial and agricultural practices has raised pressure on natural resources. Water quality assessment provides valuable information about potential of resources for intended uses. The correlation study was carried out on the physicochemical parameters of surface water and groundwater in the Tikamgarh city. The physicochemical parameters, such as pH, total dissolved solids (TDS), total hardness (TH), calcium (Ca2+), magnesium (Mg2+), total alkalinity (TA), sulphate (SO42-), fluoride (F-), iron (Fe), nitrate (NO3-), chloride (Cl-) and turbidity were analysed to determine correlation between parameters. The grab sampling technique was adopted to collect water samples from selected dug wells and reservoirs. The results of physicochemical parameters were fitted in the correlation coefficient equation to predict probable values of different parameters for selected locations. Results of the correlation study showed that calcium and TH are strongly correlated, followed by TH with chloride. However, Ca2+, TH, Cl-, TA, TDS, SO42-, and iron show a high correlation. The findings show that water quality can be managed by controlling TH and TDS concentrations through conventional and non-conventional treatment methods.

Analisis Kimia Kopi Cherry Arabika (Coffea arabica) dengan Kajian Kadar Alkohol, Kadar Kafein, Total Padatan Terlarut dan Total Asam Pada Limbah Hasil Fermentasi Anaerobik

This study aimed to determine the quantitative measurements of alcohol concentration, caffeine content, total dissolved solids, and total acid. This study used an experimental design with a non-factorial, Completely Randomized Design (CRD) that included three treatment levels, each replicated three times. The study consists of the following treatment levels: H5 represents the fermentation of cherry Arabica coffee for five days, H10 for ten days, and H15 for 15 days. The collected data underwent analysis of variance (ANOVA) using SPSS version 22. The Duncan's New Multiple Range Test (DNMRT) was used at a 5% significance level to determine the differences in the effects of each therapy. The study showed that the length of anaerobic fermentation of Arabica coffee cherries significantly affected the concentrations of alcohol, caffeine, total dissolved solids, and total acid (p<0.05). With longer fermentation, alcohol concentration, caffeine content, and total acid levels increase while the total dissolved solids content decreases. The most effective treatment in this study was noted on the 5th day of fermentation, showing an average alcohol content of 11.93%, caffeine content of 3.36%, total dissolved solids of 4.83oBrix, and total acid of 1.62%.

Chemistry, Growth, and Fate of the Unique, Short‐Lived (2019–2020) Water Lake at the Summit of Kīlauea Volcano, Hawaii

AbstractLess than a year after the 2018 Kīlauea caldera collapse and eruption, water appeared in newly deepened Halemaʻumaʻu crater. The lake—unprecedented in the written record—grew to a depth of ∼50 m before lava from the December 2020 eruption boiled it away. Surface water heightened concerns of potential phreatic or phreatomagmatic explosions but also offered a new means of possibly identifying eruption precursors. The U.S. Geological Survey Hawaiian Volcano Observatory (HVO) monitored the lake via direct visual observation, webcams, thermal imaging, colorimetry, and laser rangefinders. HVO also employed uncrewed aircraft systems to sample the water and measure near‐lake gas composition. The lake's δD and δ18O indicate a groundwater source with substantial evaporation. The initial sample had a salinity (total dissolved solids concentration) of 71,000 mg/L and was rich in sulfate (∼53,000 mg/L), iron (∼500 mg/L), and magnesium (∼10,000 mg/L). Subsequent samples were slightly more dilute. The water's pH (∼4), δ34S (+4.3‰), and surface temperatures (up to 85°C) suggest, rather than significant scrubbing of magmatic volatiles, leaching of basalt and reactions with sulfate minerals resulted in high concentrations of sulfate and other solutes. Thermodynamic modeling and precipitate mineralogy indicate that water composition was controlled by iron oxidation and sulfate dissolution. Although the lake exhibited no detectable precursors before the next eruption, and phreatic or phreatomagmatic explosions did not materialize, our multi‐parameter approach to monitoring yielded an enhanced understanding of the hydrologic, geologic, and magmatic conditions that led to the formation of the unique and short‐lived lake.

Annual Temporal Changes in Concentration of Total Dissolved Solid (TDS), Nitrate and Sulphate in Koyna River water, Maharashtra, India

The objective of the study is to recognize temporal changes that affect the Koyna River's water quality parameters throughout time. 52 samples of water in total were collected at weekly intervals from March 2018 to March 2019 at the Koyna River in the vicinity of Karad, Maharashtra, India, to determine the concentrations of TDS, sulphate (SO4--), and nitrate (NO3-). The average annual concentration of NO3-, SO4--, and TDS is considerably lower than the values prescribed by WHO and BIS for irrigation and drinking. Timely variations in the parameters have been recorded. Increasing patterns were observed throughout the monsoon season (June to September 2018), followed by a deceased pattern (October to December 2018), and then a remarkably high level of certain variables in January 2019. The outcomes showed that water entering the river from upstream sources, runoff from agriculture, and household and industrial sewage discharges in tributaries and the mainstream are responsible for variations in concentration that occur gradually, suddenly, and in various manners

Study of the dyeing industry pollution after mandatory installation of ETP in Madhabdi municipality, Bangladesh

ABSTRACT Madhabdi municipality of the Narsingdi district of Bangladesh, the “Manchester of the East,” is famous for its cloth market and fabric dyeing industries. The untreated effluent discharge has been mixed with the water and soil, degrading the environmental standards of this area for years. Installing an effluent treatment plant (ETP) in all textile industries in Bangladesh is mandatory. This study evaluates the soil condition, surface water quality, and heavy metal contamination in cultivated vegetables after the compulsory installation of ETP. Soil and water samples from eight locations and cultivated vegetable samples from three locations are collected and analyzed for this study. The pH, EC (electric conductivity), TDS (total dissolved solids), DO (dissolved oxygen), and heavy metal concentrations are observed. The water quality index, contamination index, metal evaluation index, pollution load index, and metal pollution index are calculated from the collected samples. The study found that the physico-chemical properties of water pH (9.19), EC (2232.38 µScm-1), and DO (0.79 mgL-1) violate the national standards. The mean TDS is below the maximum permissible level. The heavy metal concentrations of Cr and Pb in water are 1.03 and 0.13 mgL-1, crossing the permissible limit, respectively, but Mn, having 0.89 mgL-1, is within the limit. The water quality is unsuitable for domestic and agricultural use, contamination is “medium,” and metal evaluation is “medium.” The soil is alkaline, having a pH of 8.58. The soil’s Cr, Pb and Mn concentrations are 68.21 µgg-1, 52.73 µgg-1and 805.16 µgg-1, respectively. The soil contamination level is low to moderate. Cultivated leafy vegetables have a concentration of Cr, Pb and Mn; 2.61 µgg-1, 0.30 µgg-1and 288.67 µgg-1, respectively, where Cr has crossed, Pb is within, and Mn is lower than the permissible limit. Produced vegetables have high (12.10–33.09) MPI (metal pollution index) and are at a high-risk level for consumption as food.

Geochemistry of lanthanides in thermal waters of Issyk-Kul Lake Basin

The distribution and abundance of lanthanides in thermal waters of the northern Tien Shan (Issyk-Kul lake basin) were studied. Waters are represented by three types: Na-Cl-SO4-HCO3, Na-Ca-Cl-SO4 and Na-Ca-Cl, demonstrates alkaline pH (7.3–9.7) and Eh from -260 to +98 mV. Discharge temperature varies from 15 to 50oC, and total dissolved solids from 0.2 to 13.0 g/l. It is established that lanthanides (or rare earth elements, REE) concentrations vary from 0.07 to 0.81 ppb, the maximal concentrations relate to a Na-Ca-Cl water type, which demonstrates the influence of reverse ion exchange. The total concentration of rare earth elements roughly increases as pH decreases, implying that the absolute abundance of REE is totally controlled by pH conditions. The ΣREE concentrations in groundwater exhibit a high positive correlation (R=0.8) with the total dissolved solids contents indicating that ΣREE are well related to the salinity of the thermal water samples. The major ions HCO3, SO4, Ca, K, and Mg have minor associations with REE. The geochemical and geological data suggest that the principal REE source of the thermal waters is bedrock mineralogy and lithology. The distribution and abundance of REE in thermal waters of Issyk-Kul basin were studied for the first time.

A Simplified Approach for Estimating Ionic Concentrations from Specific Conductance Data in the San Francisco Estuary

This work presents a simplified approach for estimating ionic concentrations from specific electrical conductance (EC) data in the San Francisco Estuary. Monitoring the EC of water through electrodes is simple and inexpensive. As a result, a wealth of high-resolution time-series data is available to indirectly estimate salinity concentrations and, by extension, seawater intrusion throughout the study domain. However, scientists and managers are also interested in quantifying ionic (e.g., bromide, chloride) and total dissolved solids (TDS) concentrations to meet water-quality regulations, protect beneficial uses, support environmental analyses, and track source-water dominance. These constituent concentrations, reported with lower spatial and temporal resolution than EC, are typically measured in the laboratory from discrete (grab) water samples. We divided the study domain into four unique regions to estimate concentrations of major ions and TDS as mathematical functions of measured or model-simulated EC. Salinity relationships in three of the four regions—regions that represent Sacramento-San Joaquin Delta (Delta) inflow and seawater-dominated boundaries—reflect ionic make-ups that are either independent of or weakly dependent on season and hydrologic condition, and are highly correlated with EC. The fourth region—represented by the interior Delta—exhibits salinity characteristics associated with complex-boundary source-water mixing that varies by season and hydrologic condition. We introduce a novel method to estimate ionic and dissolved solids concentrations within this fourth region, given month, water year type, and (optionally) X2 isohaline position, which allows for more accurate EC-based estimates than previously available. The resulting approach, while not a substitute for hydrodynamic modeling, can provide useful information under constrained schedules and budgets.

Groundwater Geochemical Investigation and Quality Assessment for Drinking and Irrigation Uses in Sohagpur Coalfield, Madhya Pradesh, India

The present investigation aims to assess the processes controlling the composition of groundwater in the Sohagpur coalfield and its quality concerning drinking and irrigation purposes using hydrogeochemical and statistical approaches, water quality indices, and a geographic information system (GIS). Twenty-seven groundwater samples collected from different sites were analysed for electrical conductivity (EC), pH, turbidity, major anions and cations, total dissolved solids (TDS), and total hardness (TH). The study results show that the pH of samples varied from 5.97 to 8.26, suggesting the acidic to slightly alkaline nature of the water samples. The TDS ranged from 265 to 1450 mg/L with 78% of the samples being in the freshwater category. The Ca2+-Mg2+-SO4 2− and Ca2+-Mg2+-HCO3 − are dominant hydrogeochemical facies in the Sohagpur coalfield. The hydrogeochemical and statistical methods show that the groundwater chemistry of the Sohagpur coalfield is primarily controlled by the dissolution and weathering of minerals and secondarily due to the influence of anthropogenic activities (i.e., agricultural practices, sewage, and animal waste discharge). In the majority of the groundwater samples, concentrations of TH, TDS, turbidity, and SO4 2− exceeded the Bureau of Indian Standards (BIS) drinking acceptable limits and suggested that water is unsuitable for direct consumption. Moreover, the estimated water quality index (WQI) indicated that 52% of the samples (especially from the Dhanpuri and Amlai areas) belong to poor to unfit water categories. High values of EC in 56% of the samples and magnesium hazard (MH) at two sites restrict the irrigation suitability at these locations.

Investigation of extraction phenomena in continuous circulation coffee brewing and comparison with other brewing methods

AbstractThis study investigated a continuous circulation cold brewing (CCCB) process using a modified single‐serve brewer that allowed recirculation of the brew within the single‐use capsules. The changes of total dissolved solids (TDS), titratable acidity (TA), caffeine and 5‐caffeoylquinic (5‐CQA) concentrations over time during the CCCB process were evaluated using two masses of coffee grounds (10 and 12.5 g). To elucidate the extraction process, Weibull distribution, pseudo‐first order, and pseudo‐second order models were fitted to the extraction kinetics data. The physicochemical quality of the brews produced from the CCCB process were also compared to brews produced though traditional cold brew steeping (separated by gravity and forced filtration) and single‐serve hot brewing processes. Significantly lower (p < 0.05) TDS, TA, and 5‐CQA concentrations than traditional cold brew methods were observed. This observation was due to flow channeling/detachment phenomena in the coffee bed which resulted in localized flow and reduction of coffee‐water contact area. In comparison, the 30 min full immersion processes resulted in approximately 70% of the TDS, TA, and caffeine levels during the first 30 min of brewing, suggesting that cold brewing processes may not have to be >8 h in length if these are the targeted brew quality indices.Practical applicationsThis study examined the kinetics and physicochemical quality of continuous circulation cold brewing of coffee and compared it to traditional full immersion cold brewing methods. The findings in this study indicated that: (1) The brew recirculation method explored was not on par with traditional full immersion cold brewing methods in terms of extraction yield due to flow channeling issues present in single‐use capsules; (2) The extraction time of traditional cold brewing processes can potentially be shortened on the basis of TDS, TA and caffeine content; (3) The choice of filtration mechanism is significant when considering the extraction yield of a brewing process.

Effect of Carboxyl Methyl Cellulose Addition and Heating Time on The Production of Keribang Barbant Jam (Dioscorea alata L.)

Keribang tubers are a prospective local food and can be used as food for claims and food diversification. Anthocyanins from keribang tubers can be processed into food products, one of them is made into jam. Jam is a food product with a gel consistency, therefore a thickening agent such as Carboxyl Methyl Cellulose (CMC) is needed. The purpose of this study was to determine the effect of adding CMC and heating time as well as the best combination to the physicochemical characteristics of keribang tuber jam. This research design used a Randomized Block Design (RAK) with two treatment factors, consisting of 3 treatments of CMC (0.5%; 0.75%; and 1%) and 2 treatments of heating time (15 minutes and 20 minutes), with 4 replications. Parameters observed were water content, total polyphenols, total dissolved solids, antioxidant activity, smearing power, and organoleptic tests. The best treatment was tested using the effectiveness index test. The results showed that CMC concentration treatment and heating time did not significantly affect the water content, total dissolved solids content, antioxidant activity, and spread ability, but significant on the total polyphenol content value in keribang tubers jam. The organoleptic test showed that the panelists preferred the keribang tubers jam with a CMC concentration of 0.5% and a heating time of 15 minutes in terms of color and texture. Based on the effectiveness index test, the best treatment for keribang tubers jam was 1% CMC concentration and 20 minutes of heating time

Effect of edible film gelatin nano-biocomposite packaging and storage temperature on the store quality of strawberry (Fragaria x ananassa var.duchesne)

An edible film is a type of bioplastic packaging that can be used to package strawberries. Therefore, this study aimed to determine the packaging effect using nanobiocomposite edible film based on gelatin/nanocrystalline cellulose with the addition of antioxidants nanopropolis and storage temperature on the quality and shelf life of strawberries. The strawberries fruit were packed with edible film nanobiocomposite and stored at 5 °C, 10 °C, and 30 °C. The parameters analyzed were water content, Vitamin C, hardness, total dissolved solids, pH, and shelf life. The results showed that the water content ranged from 23.95 to 65.89%w/b at the end of the storage period and was stable at 5 °C and 10 °C. The decrease in water content occurs very quickly at a storage temperature of 30 °C and control. Furthermore, hardness at the end of storage ranged between 0.265 – 0.431 kg/cm² and the fastest decrease in hardness occurred at storage at a temperature of 30 °C. All treatments experienced a decrease in Vitamin C content during storage. The total dissolved solids content at the end of storage was 5.92–12%Brix, with a shelf life ranging from 3 to 21 days of storage, as determined by all treatment parameters. Bionanocomposite edible gelatin film packaging with added nanopropolis can increase shelf life to 21 days of storage. These results showed that bionanocomposite edible film gelatin packaging can increase the shelf life of strawberries.

Multifunctional photocatalytic membrane distillation for treatment of hypersaline produced water using hydrophobically modified tubular ceramic membranes

Produced water (PW) is the subsurface water brought to the surface during oil and gas production. PW is primarily disposed of by deep well injection, but it can be treated for beneficial use applications. However, efficient technologies for treating hypersaline PW with complex water chemistry are limited. This study developed an innovative, multifunctional photocatalytic membrane distillation (PMD) technology using hydrophobically modified tubular ceramic membranes coated with TiO2 nanoparticles as photocatalysts for treating unconventional PW. The effects of membrane modifications were characterized in terms of membrane morphology, pore size, chemical functionality, zeta potential, hydrophobicity, liquid entry pressure, water production, permeate water quality, and membrane fouling and scaling propensity. The desalination performance of the PMD technology was demonstrated using unconventional PW with total dissolved solids concentrations of 135,000 mg/L and 175,000 mg/L, and NH3-N concentrations of 1551 mg/L and 613 mg/L, respectively. The novel PMD concept provides a promising technology for hypersaline PW treatment, and TiO2 coating significantly reduced membrane fouling and scaling, improved distillate quality, and maintained stable permeate flux. The photocatalyst activation by ultraviolet-light emitting diodes (UV-LED) light further increased the permeate flux and enhanced the total organic carbon removal from 82.0% (without UV-LED) to 89.7% (with UV-LED). UV-LED irradiation did not affect ammonia and metals removal in PMD, reaching 99.4% and > 99.99% removal, respectively.

Machine learning algorithm and neural network architecture for optimization of pharmaceutical and drug manufacturing industrial effluent treatment using activated carbon derived from breadfruit (Treculia africana)

In a recent development, attention has shifted to the application of artificial intelligence for the optimization of wastewater treatment processes. This research compared the performances of the machine learning (ML) model: random forest, decision tree, support vector machine, artificial neural network, convolutional neural network, long-short term memory, and multiple linear regressors for optimization in effluent treatment. The training, testing, and validation datasets were obtained via the design of an experiment conducted on the removal of total dissolved solids (TDS) from pharmaceutical effluent. The breadfruit-activated carbon (BFAC) adsorbent was characterized using scanning electron microscopy and X-ray diffraction techniques. The predictive capacity of an ML algorithm, and neural network architecture implemented to optimize the treatment process using statistical metrics. The results showed that MSE ≤ 1.68, MAE ≤ 0.95, and predicted-R2 ≥ 0.9035 were recorded across all ML. The ML output with minimum error functions that satisfied the criterion for clean discharge was adopted. The predicted optimum conditions correspond to BFAC dosage, contact time, particle size, and pH of 2.5 mg/L, 10 min, 0.60 mm, and 6, respectively. The optimum transcends to a reduction in TDS concentration from 450 mg/L to a residual ≤ 40 mg/L and corresponds to 90% removal efficiency, indicating ± 1.01 standard deviation from the actual observation practicable. The findings established the ML model outperformed the neural network architecture and affirmed validation for the optimization of the adsorption treatment in the pharmaceutical effluent domain. Results demonstrated the reliability of the selected ML algorithm and the feasibility of BFAC for use in broad-scale effluent treatment.

Chemical Characteristics-Based Evolution of Groundwater in Tailan River Basin, Xinjiang, China

Groundwater plays an important role in ecological environment protection in arid and semi-arid areas. Therefore, understanding the characteristics of hydrochemical evolution is of great significance for the sustainable use of groundwater in the area of the Tailan River Basin. The Tailan River Basin is located in an arid, ecologically sensitive area in western China. In this study, we collected 42 groups of representative water samples from the Tailan River Basin and analyzed the chemical distribution in the groundwater using mathematical statistics, Piper and Gibbs diagrams, ion ratio analysis, and hydrogeochemical simulation methods. We also discussed the water–rock interactions in the groundwater hydrochemical evolutionary process. The results were as follows: (1) The chemical types of groundwater changed from HCO3·SO4-Ca·Na to SO4·Cl-Na·Ca, Cl·SO4-Na, and Cl-Na, and the total dissolved solids content increased from less than 1 g/L to more than 40 g/L from the gravel plain to the fine soil plain. (2) The Gibbs diagram, the ion ratio analysis, and the saturation index showed that the groundwater chemical characteristics in the study area were mainly controlled by water–rock interactions, as well as evaporation and concentration. Along the runoff of groundwater, halite and gypsum were dissolved. Nevertheless, dolomite and calcite precipitated. The relationship between the chlor-alkali index and [(Na+ + K+)-Cl−] and [(Ca2+ + Mg2+)-(HCO3− + SO42−)] indicated that cation exchange also affects the chemical composition of groundwater in the area. (3) Through reverse hydrogeochemical simulation, the main water–rock effect of the groundwater runoff process revealed by qualitative analysis was quantitatively verified.

FROM ABUNDANCE TO ADVERSITY: UNDERSTANDING THE CHANGING DYNAMICS OF LAKE ALAU'S WATER QUALITY

Lake Alau, a critical water resource in the region, was subject to an extensive water quality assessment with the aim of assessing the impact of human activities on the physico-chemical parameters of Lake Alau, with a specific focus on water quality potentials of the Lake. The study spanned over a year, capturing variations in several physicochemical parameters using standard laboratory techniques. The data were computed and analysed using ANOVA. The findings reveal that the lake generally maintains water quality within permissible limits for aquatic ecosystems. The physical parameters of the lake, including Temperature, Total Solids (TS), Total Dissolved Solids (TDS), and Total Suspended Solids (TSS), were within the range of a productive lake, but higher concentrations of TDS (365.68g/L) and TSS (171.95g/L) might have altered the ecological balance of the lake. The chemical parameters, including pH, biochemical oxygen demand (BOD), Chemical Oxygen Demand (COD), Nitrite, Nitrate, and Phosphate, were within the permissible limit for a productive lake, supporting the biological parameters of the lake However, phosphate concentrations exceed 0.1mg/l which is the limit for drinking water. The observed variations underscore the lake's vulnerability to human activities and seasonal changes. Despite some concerns, Lake Alau remains suitable for aquatic life, with certain water quality management practices recommended to maintain its intergrity.

Physicochemical and Sensory Properties of Tongka Langit Banana (Musa troglodytarum) Jam with Different Pectin Concentrations

<p><em>The substantial beta carotene content and health benefits of tongka langit bananas make them a popular constituent in processed food products, such as jam, which helps extend shelf life and diversifies processed tongka langit bananas. This study aimed to determine the optimal pectin concentration for the production of tongka langit banana </em><em>jam</em><em> </em><em>by analyzing its physicochemical and sensorial properties. Without the addition of pectin, tongka langit banana jam ha</em><em>d</em><em> the finest physicochemical and sensorial properties. The tongka langit banana jam had a moisture content of 52.90%, a vitamin C content of 46.05 mg/100g, a fiber content of 0.30%, a total sugar content of 35.10%, a total acid content of 3.55%, and a total dissolved solids content of 32.15°brix. It had the highest percentage of preference in almost all sensory categories, including taste, color, texture, and overall likeability, and had the characteristic, taste of tongka langit banana, faintly flavored with tongka langit banana, a yellow </em><em>color</em><em>, a soft texture, and a spreadability that </em><em>was</em><em> relatively simple.</em><em></em></p>

Enhancing Water Quality Assessment in Indonesia Through Digital Image Processing and Machine Learning

Indonesia's diverse climate types, influenced by its unique geographical features, pose significant environmental challenges, including water quality issues related to turbidity and Total Dissolved Solids (TDS). Many Indonesians lack awareness of water quality, particularly turbidity, which can harbor harmful microorganisms. To address these challenges, this study employs digital image processing and machine learning, specifically Support Vector Machine (SVM) algorithms, for water quality assessment. A dataset of 80 water images, categorized into seven turbidity classes, is used to train and test the model. Results show a clear correlation between turbidity levels and TDS concentrations and pH values. The system accurately assesses water suitability for different sources, offering a user-friendly and cost-effective solution for water quality monitoring in dynamic environmental conditions. However, limitations include the dataset size and the narrow focus on turbidity. Future research could expand to encompass a broader range of water quality factors. This approach holds promise for enhancing water quality management in Indonesia and similar regions.