Alkalinity Research Articles

Statistical Appraisal of Major Ion Chemistry of Groundwater: A Case Study from a River-Bounded Rural Area

Abstract The present study deals with the application of statistical methods like correlation, factor, cluster and multiple regression analyses to interpret the controlling processes influencing the hydrogeochemisty of a river-dominated area. The groundwater is alkaline and hard but suitable for drinking. Most of the parameters show significant positive correlations with each other. The first three factors explain 83.884% of the variance and can be used to assess the dominant hydrochemical processes in operation. The first factor with strong loadings on total dissolved solids (TDS), total hardness (TH), Ca2+, Mg2+, Na+, HCO3- and F- is the salinity factor. It is geogenic in nature and constituent ions are derived from weathering of basement rocks. The second factor with strong loadings on K+, NO3,- SO42-and Cl- is anthropogenic as the first three ions are present in fertilizers used by people to increase crop production and the fourth is derived from domestic wastes. The third factor strongly loaded on pH and total alkalinity (TA) is the alkalinity factor. The cluster analysis replicates the results of the factor analysis. The multiple regression analysis suggests that Ca2+, Mg2+, HCO3- and SO42- contribute significantly to the bulk chemical composition of the groundwater. The chemical constituents of the groundwater may be attributed to the effects of weathering, mineral dissolution, drainage wastes, septic tank leakage, irrigation-return-flows, chemical fertilizers and/or increase or decrease of chemical variables due to dissolution, precipitation, ion exchange, etc. The study illustrates the usefulness of statistical methods as an effective tool for interpretation of the controlling processes of groundwater chemistry.

Assessment of hydrogeochemistry in groundwater using water quality index model and indices approaches

Groundwater resources around the world required periodic monitoring in order to ensure the safe and sustainable utilization for humans by keeping the good status of water quality. However, this could be a daunting task for developing countries due to the insufficient data in spatiotemporal resolution. Therefore, this research work aimed to assess groundwater quality in terms of drinking and irrigation purposes at the adjacent part of the Rooppur Nuclear Power Plant (RNPP) in Bangladesh. For the purposes of achieving the aim of this study, nine groundwater samples were collected seasonally (dry and wet season) and seventeen hydro-geochemical indicators were analyzed, including Temperature (Temp.), pH, electrical conductivity (EC), total dissolved solids (TDS), total alkalinity (TA), total hardness (TH), total organic carbon (TOC), bicarbonate (HCO3−), chloride (Cl−), phosphate (PO43−), sulfate (SO42−), nitrite (NO2−), nitrate (NO3−), sodium (Na+), potassium (K+), calcium (Ca2+) and magnesium (Mg2+). The present study utilized the Canadian Council of Ministers of the Environment water quality index (CCME-WQI) model to assess water quality for drinking purposes. In addition, nine indices including EC, TDS, TH, sodium adsorption ratio (SAR), percent sodium (Na%), permeability index (PI), Kelley's ratio (KR), magnesium hazard ratio (MHR), soluble sodium percentage (SSP), and Residual sodium carbonate (RSC) were used in this research for assessing the water quality for irrigation purposes. The computed mean CCME-WQI score found higher during the dry season (ranges 48 to 74) than the wet season (ranges 40 to 65). Moreover, CCME-WQI model ranked groundwater quality between the “poor” and “marginal” categories during the wet season implying unsuitable water for human consumption. Like CCME-WQI model, majority of the irrigation index also demonstrated suitable water for crop cultivation during dry season. The findings of this research indicate that it requires additional care to improve the monitoring programme for protecting groundwater quality in the RNPP area. Insightful information from this study might be useful as baseline for national strategic planners in order to protect groundwater resources during the any emergencies associated with RNPP.

Analysis of Well Water Quality Index as Panacea for Sustainable Healthy Living in Zing Local Government Area of Taraba State, Nigeria

This investigation was carried out to analyze the hand-dug well water quality index as a panacea for sustainable healthy living in Zing Local Government Area of Taraba state, Nigeria. Ten (10) different hand-dug well water samples were studied for a period of six months (October- March). Various physicochemical parameters such as PH, EC, Turbidity, Total hardness, total dissolves solids, chlorides, sulphates, calcium, magnesium, total alkalinity, fluorides and phosphates were assessed using standard methods and instruments recommended by WHO. The arithmetic index method was adopted to calculate the Water Quality Index (WQI). The investigations revealed that Zing A1, Zing A2, Yakoko, Monkin A and Monkin B, Lamma, Bitako and Bubong hand-dug well water were not suitable for domestic uses, while Zing B and Dinding showed a very poor water quality for domestic uses and human consumptions. It was therefore recommended that alternative portable sources of drinking water for these communities be provided to avert contracting waterborne diseases and that regular monitoring be encouraged by authority concerns.

Characteristics of fish community structure and environmental driving factors in Taihu Lake during the first year of fishing ban.

Taihu Lake has officially implemented the full fishing ban policy since October 1, 2020. We investigated fish community of Taihu Lake in the four seasons of 2020. A total of 42 fish species were collected, belonging to 6 orders, 7 families, and 33 genera. The first five dominant species ranked by the index of relative importance were Coilia nasus, Toxabramis swinhonis, Hypophthalmichthys molitrix, Hypophthalmichthys nobilis, and Salangichthys tangkahkeii. The number of C. nasus accounted for 85.1% of the total number of catches. According to the distributional characteristics of cyanobacterial blooms and aquatic plants, Taihu Lake could be divided into the northern, central, and eastern regions. There was no significant difference in catch per unit effort (CPUE) among different lake regions, but Shannon diversity index and Pielou evenness index in the eastern region was greater than in the other two regions. The CPUE, Shannon diversity index, and Pielou evenness index were significantly different among the four seasons, with the lowest CPUE in autumn and higher diversity in autumn and winter than in spring and summer. Electrical conductivity, water depth, chloride, and transparency were the main environmental factors driving the seasonal variations of fish community in Taihu Lake, while electrical conductivity, dissolved oxygen, total alkalinity, and transparency were key variables driving the spatial patterns. The results could be used as the baseline data for fish community studies in Taihu Lake after the fishing ban.

Studies on Limnological Parameters and their Impact on the Distribution and Diversity of Zooplankton in Anchar Lake, Kashmir

The transfer of energy from producers to consumers, such as fish, fish larvae, and invertebrates, is facilitated by zooplankton. Consequently, zooplankton play a crucial part in the productivity and functioning of aquatic ecosystems, and they are also involved in the application of several emerging environmental management concepts, such as Environmental Impact Assessment (EIA), bioindication of pollution, and biomonitoring. To analyse the present condition of the Anchar Lake, this research was conducted to investigate the zooplankton association, their abundance, richness, diversity (Cladocera and Rotifera), and their seasonal fluctuations in connection to limnological factors. Four sampling sites were used to examine thirteen physicochemical parameters along with the abundance of zooplankton from January 2019 to December 2020. During the present investigation, significant variation (p < 0.05) was observed in transparency (trans), dissolved oxygen (DO), pH, electrical conductivity (EC), total alkalinity (TA), nitrate-nitrogen (NO3-N), total hardness (TH), and total phosphorus (TP) between the different sites of Anchar Lake, whereas non-significant variation was observed in air temperature (AT), water temperature (WT), free carbon dioxide (FCO2), chloride (Cl-), and nitrite-nitrogen (NO2-N). The results further revealed a total of 44 zooplankton species, belonging to two: Rotifera (27 species) and Cladocera (17 species). The zooplankton diversity was found to vary on spatiotemporal scales showing maximum values for the Shannon diversity index in the case of Cladocera during spring (2.63±0.25) and for Rotifera during summer (2.53±0.25) whereas, minimum diversity values were recorded during winter for both Cladocera and Rotifera (1.54±0.44 & 1.47±0.54 respectively). On the spatial scale, site-A2 showed maximum diversity of Cladocera (2.3±0.21), while site-A4 showed maximum diversity of Rotifera (1.99±0.03). The influence of physicochemical parameters on zooplankton distribution and diversity provides a detailed picture of the impact of pollution load in Anchar Lake.

Assessment of Ground Water Quality of Lucknow City under GIS Framework Using Water Quality Index (WQI)

Continuous groundwater quality monitoring is crucial for ensuring safe drinking and irrigation by mitigating risks from geochemical contaminants through appropriate treatment methods. Therefore, the primary objective of this study was to assess the suitability of groundwater collected from Lucknow, India, for both drinking and irrigation. Forty samples were collected from different sites within the study area to evaluate groundwater quality. Various parameters such as pH, turbidity, total dissolved solids (TDS), chlorides (Cl−), total alkalinity, total hardness, sulphate (SO42−), nitrate (NO3−), fluorides (F−), iron (Fe), arsenic (As), magnesium (Mg2+), and calcium (Ca2+) were analyzed. The weighted arithmetic water quality index (WAWQI), a vital rating system representing overall water quality, was employed to classify the water into different categories, such as very good, good, moderate, poor, and unfit for drinking. This classification is invaluable for public awareness and decision-making to make informed decisions regarding effective management, treatment, and sustainable societal development on a broader scale. A correlation matrix was generated and analyzed to observe correlations between the various parameters. Additionally, spatial distribution maps for the analyzed parameters and WQI were prepared using the inverse distance weighted (IDW) method. The study found that WQI values in the area ranged from 2.64 to 168.68, indicating good water quality in most places except for the Kukrail region, where the water quality is unfit for drinking purposes. The water quality map shows that 86% of the area falls under the very good category, 14.63% under good to moderate quality, and 0.37% is categorized as unfit for drinking. Consequently, the findings suggest that the groundwater in the studied area is safe and suitable for drinking and irrigation purposes.

Effect of Gum Arabic on the Clarity of Artificially Turbid Water and Ground Water Systems

The high cost of using synthetic polymers such as polyacrylamides in the water purification process, and their monomers toxicity produced from the polymer synthesis encouraged many researchers to find a good replacement to clarify turbid water. This work was carried out to determine the effectiveness of Gum Arabic (GA) as a natural coagulant aid in the treatment of artificially turbid water (water saturated with silica (SiO2), the main component of rocks) and ground drinking water systems, which is rich in rocks. The experimental results showed that the highest efficiency for GA as a water clearer was increased by increasing its content to 5 wt %. This was confirmed by a reduction in the turbidity from 1269 NTU to 56 NTU. Interaction kinetic fits specified that the two-phase decay model was found to be the proper fit (R2 ~ 1) for the kinetic data at 0.001, 0.01, 0.1 wt% of added GA. This proposes that at a low content of GA molecules, some SiO2 particles remain suspended in bulk solution, while only one phase decay fitted the data well when 1 and 5 wt% of GA were added, which means a complete GA-SiO2 interaction. Furthermore, the turbidity decay dependence on the GA content was noted as a minimum interaction lifetime (τ = 9 min) has been observed at 5 wt%. The physicochemical analyses have revealed that GA is effective in reducing turbidity, total dissolved solids, total alkalinity and total hardness of water and has the ability for water purification by owning unwanted minerals and hardness removal characteristics. This eco-friendly and economical natural polymer could be a promising material to use in groundwater treatment.

Preparation and quality control of in‐house reference materials for marine dissolved inorganic carbon and total alkalinity measurements

AbstractAccurate measurements of seawater carbonate chemistry are crucial for marine carbon cycle research. Certified reference materials (CRMs) are typically analyzed alongside samples to correct measurements for calibration drift. However, the COVID‐19 pandemic led to a limited access to CRMs. In response to this shortage, we prepared and monitored in‐house reference materials (IHRMs) for total alkalinity (TA) and dissolved inorganic carbon (DIC), over 12 and 15 months, respectively. Overall, TA was stable, but a slight increase in DIC of about 2 μmol kg−1 occurred over 15 months. The increase could potentially be attributed to bacterial growth, despite mercuric chloride fixation and repeated UV exposure. It is noted that this small increase was most likely within our instrument and measurements uncertainties. Our repeated measurements also identified a few bottles that had TA or DIC concentrations 4–5 μmol kg−1 higher than the rest, indicating issues during cleaning, fixation, or storage of individual bottles. This study emphasizes the importance of careful and continuous monitoring if self‐prepared IHRMs are used. Given that the amount of work required is very high, IHRM preparation is only recommended when CRMs are not available.

Hospital wastewater treatment coupling electrochemical coagulation and activated sludge process

Abstract Dual treatment of raw hospital wastewater (RHWW) is investigated by coupling electrochemical coagulation (ECC) with the activated sludge process (ASP) to achieve the goal of partial mineralization and reclaim quality water. The quality parameters of focus were chemical oxygen demand (COD), color, mixed liquor suspended solids (MLSS), total dissolved solids (TDS), chloride, total alkalinity, and fecal coliform. The initial ECC process with short hydraulic retention time (HRT) could remove 75–82% of the insoluble constituents in <60 min, while the HRT for ASP was >7–8 h. The combined ECC + ASP hybrid treatment process showed effective removal of COD, color, TDS, and fecal coliform by 98.5, 99.6, 83.1, and 97.9%, respectively, from its initial values of 4,000, 2,200, 77, and 2,400 MPN/100 mL, respectively. By coupling ECC and ASP, both the insoluble and soluble pollutants/contaminants in the RHWW were removed effectively. The ECC–ASP dual treatment offers a small energy and spatial footprint for mineralizing RHWW.

Effects of organic amendments on soil bacterial community structure and yield in a saline‐sodic soil cropped with rice

AbstractOrganic improvement measures play a crucial role in the reclamation of saline‐sodic soil. However, there is still a limited understanding regarding the relationships between soil microbes and soil properties and crop yield in response to the application of these organic materials to saline‐sodic soils. In a field trial, the following treatments were carried out: no modifier input (CK) and compound lignite organic modifier 30 t/ha (LOM) with 2 years of rice cultivation, no modifier input (RF) with 5 years of rice cultivation, and the full amount of straw was returned to the field with rice‐duck farming (SW). Compared with RF and CK, the SOM content in the 0–20 cm soil layer of SW and LOM was significantly increased by 4.600 and 5.020 g kg−1, respectively, while the total alkalinity and pH were significantly decreased. In the 20–40 cm soil layer, the LOM treatment resulted in decreased pH and total alkalinity compared with other treatments. Overall, changes in soil microbial structure changes were significantly associated with SOM and pH levels. In the 0–20 cm soil layer, the LOM treatment significantly increased the relative abundance of Proteobacteria, while SW treatment significantly increased the relative abundance of Bacteroidetes and Firmicutes compared with CK. Moreover，the relative abundances of Longobacteriaceae of Bacteroidetes, Hydrogenaceae, and Xanthomonas of Proteobacteria were positively correlated with crop yield. The yields of SW and LOM were 6985.587 and 7879.910 kg ha−1, respectively. These results demonstrate that implementing comprehensive organic improvement measures can enhance the properties of saline‐sodic soil and increase crop yield, with lignite composite organic amendments may be more suitable for sustainable agricultural development.

Alkalinity generation from carbonate weathering in a silicate-dominated headwater catchment at Iskorasfjellet, northern Norway

Abstract. The weathering rate of carbonate minerals is several orders of magnitude higher than for silicate minerals. Therefore, small amounts of carbonate minerals have the potential to control the dissolved weathering loads in silicate-dominated catchments. Both weathering processes produce alkalinity under the consumption of CO2. Given that only alkalinity generation from silicate weathering is thought to be a long-term sink for CO2, a misattributed weathering source could lead to incorrect conclusions about long- and short-term CO2 fixation. In this study, we aimed to identify the weathering sources responsible for alkalinity generation and CO2 fixation across watershed scales in a degrading permafrost landscape in northern Norway, 68.7–70.5∘ N, and on a temporal scale, in a subarctic headwater catchment on the mountainside of Iskorasfjellet, characterized by sporadic permafrost and underlain mainly by silicates as the alkalinity-bearing lithology. By analyzing total alkalinity (AT) and dissolved inorganic carbon (DIC) concentrations, as well as the stable isotope signature of the latter (δ13C-DIC), in conjunction with dissolved cation and anion loads, we found that AT was almost entirely derived from weathering of the sparse carbonate minerals. We propose that in the headwater catchment the riparian zone is a hotspot area of AT generation and release due to its enhanced hydrological connectivity and that the weathering load contribution from the uphill catchment is limited by insufficient contact time of weathering agents and weatherable materials. By using stable water isotopes, it was possible to explain temporal variations in AT concentrations following a precipitation event due to surface runoff. In addition to carbonic acid, sulfuric acid, probably originating from oxidation of pyrite or reduced sulfur in wetlands or from acid deposition, is shown to be a potential corrosive reactant. An increased proportion of sulfuric acid as a potential weathering agent may have resulted in a decrease in AT. Therefore, carbonate weathering in the studied area should be considered not only as a short-term CO2 sink but also as a potential CO2 source. Finally, we found that AT increased with decreasing permafrost probability, and attributed this relation to an increased water storage capacity associated with increasing contact of weathering agent and rock surfaces and enhanced microbial activity. As both soil respiration and permafrost thaw are expected to increase with climate change, increasing the availability of weathering agents in the form of CO2 and water storage capacity, respectively, we suggest that future weathering rates and alkalinity generation will increase concomitantly in the study area.

Ecological study of some physical, chemical and bacteriological characteristics of Tigris River water in Wasit province, Iraq

This study was performed in the Tigris River water as it passed through Wasit province at the rate of five stations extending along the river, (Al-Sowarah, Al-Nu'maniyah, Al-Kut before Al-Kut Dam, after leaving Al-Kut city and Sheikh Saad), to evaluate the environmental quality of Tigris River water. Samples were collecting monthly, two samples were taken each month, and for a period of one complete year starting from the January 2016 - December 2016. The study included measuring some of the Physical, Chemical and Bacteriological Factors. The results of this study showed significant monthly changes in the values of all studied factors. The parameters values of current study showed that the water temperature values ranged from 9-29 °C and the values of turbidity ranged between 8-55 NTU, electrical conductivity ranged between 749-1352 μs/cm with Salinity 0.479-0.865 ppt, total dissolved solid 499 – 960 mg/l, total suspended solid values ranging from 12-190 mg/l. It was found that the water of the Tigris River is slightly alkalinity, with pH ranged between 7-8.1. The monthly concentrations of dissolved oxygen (DO) ranged from 6.2 - 12 mg / l, BOD ranged between 0.8 - 6.4 mg / l, total alkalinity ranged between 120-230 mg CaCO3/l, total hardness ranged between 284-520 mg/L, while the concentrations of calcium and magnesium were 71-189, 36-97.4 mg/l respectively, chlorides values varied from 90-151 mg/l, the sulphate values ranged between 185- 410 mg/l. Nitrate values varied from 0.6 -6.7 mg/l and the phosphate values ranged between 0.08-1 mg/l. Tigris River can be considered adequate for civilian uses according to WHO and Iraqi Quality Assurance System after adequate treatment in filtration and sterilization stations.

Modelling of Amino Acid Fermentations and Stabilization of Anaerobic Digestates by Extracting Ammonium Bicarbonate

With the current increase in demand for animal and agricultural products, management of agrowaste has become critical to avoid greenhouse gas emissions. The present article investigates the applicability of ammonium bicarbonate synthesis via flash distillation to valorize and stabilize several types of anaerobic digestates which are produced from individual fermentations of amino acids. The content of CO2 in the digestate was found to be responsible for the OH alkalinity (0.4 equivalents of acid/kg digestate), while the partial and total alkalinities (0.8 eq/kg digestate) were essentially derived from the content of NH3. The most suitable conditions for the flash distillation were 95 °C and 1 bar with the condensation occurring at 25 °C. However, in order to attain the precipitation of NH4HCO3 in the distillate, it was necessary to consider digestates with a moisture content of 50 wt.%, since saturation levels of inorganic nitrogen and inorganic carbon were not attained otherwise. Even under these conditions, few amino acids (i.e., arginine, glycine, and histidine) were able to provide an anaerobic digestate upon fermentation that would be suitable for NH4HCO3 stabilization. The process of stabilization with a capacity of a t of digestate per h was improved by adding hydrochloric acid or sodium hydroxide at a rate of 44 kg/h, leading to production of 34 kg NH4HCO3/h. Given the role of the volatile elements of the biogas as endogenous stripping agents, it is recommended to use a fresh and saturated digestate as feed for the flash distillation.

Simultaneous removal of sulfide and bicarbonate from synthetic wastewater using an algae-assisted microbial fuel cell

ABSTRACT The anaerobic digestion (AD) process is one of the most practiced technologies for the remediation of organic waste and maximization of energy recovery in terms of biogas or biomethane. The presence of other gaseous components in biogas, e.g. CO2 and H2S, often makes its direct application in engines and electricity production unsuitable. This work aimed to develop and utilize an algae-assisted microbial fuel cell (AMFC) for the purification of biogas by removing both CO2 and H2S and simultaneous bioelectricity generation. In addition to biogas clean-up, elemental sulfur recovery and CO2 utilization for algae cultivation add value to the proposed AMFC process. Experiments were performed with both sulfide and bicarbonate in their dissolved form, in the respective anodic and cathodic chambers of the AMFC. The sulfide concentration was varied from 100 to 800 mg/l and the AMFC exhibited a sulfide removal efficiency exceeding 97% at all concentrations tested. The process efficiency dropped, however, at sulfide concentrations above 300 mg/l in terms of both sulfide removal and power output. The AMFC performed best at 400 mg/l sulfide by exhibiting a power density of 24.99 mW/m3 and sulfide removal efficiency of 98.87%. The system exhibited columbic efficiency (CE %) in the range of 7.85–80%. The total alkalinity representing CO2, carbonate and bicarbonate levels in the algae-based system was reduced by 49.54%. The electrical energy recovered from the AMFC was 0.1 kWh/m3 and the total energy recovery, which is the sum of the electrical and algal lipid energy, amounted to 7.25 kWh/m3.

Effect of Abattoir Waste on Surface Water Quality Parameters of Iwofe River, Port-Harcourt, Rivers State, Nigeria

Indiscriminate discharge of abattoir wastewater has been a major cause of concern globally due to its negative effect on the environment. This study analyzed the effect of abattoir waste on surface water quality parameters the of Iwofe River, Port-Harcourt, and the River’s state using standard methods. The water samples were collected at three different points (upstream, midstream, and downstream) and the results were analyzed using Oneway ANOVA at p = 0.05. From the results; temperature, pH, salinity, conductivity, oxidation-reduction potential, and turbidity were in the range of 28.50 – 29.70 oC, 7.19 – 7, 3.00 – 6.35 PSU, 5059 – 11208 µS/cm, 91.70 – 164.80 mV, and 59.60 – 78.10 NTU respectively. Although the temperature was slightly above WHO standards, pH, Electrical conductivity, and Turbidity were all within WHO acceptable limits. TDS, TSS, DO, BOD5, and COD were in the range of 2542 - 5604 mg/L, 2.90 – 7.75 mg/L, 5.90 – 12.90 mg/L, 0.42 – 3.08 mg/L, and 5.90 – 18.50 mg/L respectively. DO and TS were above WHO permissible limit while BOD5, COD, TSS, COD, and ORQ were within WHO permissible limit in all samples. Total alkalinity, hardness, Cl-, CO32-, and NO3- were 25 – 113 mg/L, 990.00 – 1256.00 mg/L, 3669.08 – 7887.63 mg/L, 12.50 to 66.00 mg/L, 0.85 – 1.08 mg/L. SO42-, PO42-, oil and grease, and total coliform were in the range of 133.56 – 283.17 mg/L, 90.00 – 100.00 mg/L, 0.10 – 0.15 mg/L, 1.34 × 104 to 2.98 × 105 cfu/mL. Total Alkalinity was within limit only in upstream, while hardness, Cl-, NO3, SO42-, and total coliform were all above WHO permissible limit in drinking water. Heavy/trace metals results ranged as follow; As (<0.001 – 0.009 mg/L), Pb (<0.001 – 0.002 mg/L), Zn (<0.001), Fe (0.019 – 0.285 mg/L), K (8.245 – 8.540 mg/L), Mn (<0.001 – 0.005 mg/L), Mg (3.345 – 4.076 mg/L), Ca (2.452 – 4.085 mg/L), Ni (0.002 – 0.010 mg/L), Cu (<0.001 – 0.006 mg/L), Cr (0.001 – 0.003 mg/L), Cd (0.006 – 0.013 mg/L). As, Pb, Zn, K, Mn, and Ca were not above WHO permissible limit, but were present in significant amount indicating that the river was gradually being polluted with metals. Most of the water quality parameters did not meet WHO permissible limits for drinking water. Also, the study indicates that the meat processing industry can potentially reduce water portability, thereby adversely affecting the range of its uses. Hence the activities of the abattoir should be monitored closely by relevant agencies in order to prevent full-blown environmental problems and health hazards in the near future.

Temporal variability in seawater Sr/Ca ratios within a coral atoll as an indicator of marine calcifier community diversity

Coral reefs are marine environments where calcium carbonate production and dissolution along with photosynthesis and respiration can have a large impact on the daily biogeochemical cycles of seawater dissolved inorganic carbon (DIC), total alkalinity (TA), oxygen (O2), and major nutrients. Using seawater samples from Tetiaroa Atoll, French Polynesia, we apply isotope dilution thermal ionization mass spectrometry (ID-TIMS) to show that these daily cycles of variability extend to the dissolved seawater Sr/Ca ratio (Sr/Casw). Hourly measurements over a 27+ hour period indicate that Sr/Casw covaries with DIC and TA and exhibits up to a 2% relative difference compared to the regional Pacific Ocean source water Sr/Casw value of 8.53 mmol/mol. We hypothesize that the primary mechanism of hourly variability in Sr/Casw is carbonate precipitation/dissolution by corals and other marine calcifiers on the Tetiaroa reef, while sedimentary redox processes may significantly contribute to an apparent decoupling between net calcification rates estimated from TA compared to dissolved calcium [Ca]sw concentrations. Using a simple Rayleigh distillation model and a two-member mixing equation, we estimate the net partition coefficient of Sr (KD-Sr) for each hourly sample as a mixture of coral (aragonite; KD-Sr ∼ 1.06) and crustose coralline algae (high Mg-calcite; KD-Sr ∼ 0.39) contributions to the measured variability of [Ca]sw and Sr/Casw. As the high Mg-calcites of crustose coralline algae are (1) integral components to the structure and stability of the reef framework and (2) more soluble than aragonite under more acidic conditions, we propose that continued analyses of Sr/Casw within coral reef environments could be a useful tool for monitoring the ecological distribution and contributions of marine calcifiers on reefs as ocean warming and acidification intensify in response to anthropogenic climate change. Additionally, seasonal, interannual, and/or centennial-scale offsets between the Sr/Casw of open ocean source seawater and ambient reef seawater may have significant implications for interpreting past changes in sea surface temperatures derived from the coral Sr/Ca paleothermometer.

Assessment of Thiruvarur region groundwater samples using Physicochemical parameters

Groundwater is one of the most important sources of water for drinking and irrigation purpose in the world. So water quality analysis is important one. Hence we choose to determine physicochemical parameter of Thiruvarur region groundwater. In this study, 10 groundwater samples were collected and analyzed various physicochemical parameters such as Ca2+, Mg2+, Fe3+, pH, TDS, etc., and compare with BIS limit value for determine the drinking water quality. From the research Results the groundwater sample numbers S3, S5, S6, S7 and S8 was slightly alkaline in nature, because these region groundwater has slightly excess of TDS and Total Alkalinity (TA) compare than BIS limit. However, all the water samples has low hardness, SO4-, NO3-, etc., Hence, we are concluded the collected groundwater samples is suitable for drinking and irrigation purpose.

Physico-chemical Parameters and Freshwater Fish Diversity of Sip River Madhya Pradesh, India

This study was carried out to analyze the variation in water quality and to investigate the current status of the fish fauna of the Sip river. Water samples and fish specimens were collected on monthly basis from six stations in the months of August 2017- July 2018. All the water quality attributes were found in the acceptable range that supports fish species, except stations IV and V, where pollution load was gradually increases. Seasonal changes in the physico-chemical parameters such as water temperature, pH, DO, free CO2 and total alkalinity revealed the effect on fish species diversity as well as health status of the river. The checklist of fish species recovered during the study was a total of 19 fish species belonging to 9 families, 13 genera and 4 orders. The family Cyprinidae dominant with 11 species, followed by Ambassidae 2 species, while as Bagridae, Channidae, Gobidae, Heteropneustidae, Nandidae and Siluridae each recorded 1 species, respectively. A total of 341 individuals of different fish species were caught from the different stations by using various fishing gears like cast net, gill net, hook and rod methods. Among all the stations studied, the maximum values of abundance 112 and 105 individuals was recorded from V and II stations, followed by I and VI stations having 57 and 51 individuals, while as minimum abundance 7 and 9 individuals was recorded from III and IV stations, respectively. Maximum values of Shannon-Weiner index (2.454) and Simpson’s index (0.906) were recorded from station-V (Pandagaon), while as minimum values of these indices (0.529 and 0.345) were recorded from stations-IV (Syampura). However, maximum values of Margalef’s index (2.793) and Pielou’s index (0.9898) were found from station-II (Ambhakadim) and station-III (Jiryna). The results of the study showed that the Sip river harbors rich ichthyofaunal diversity, but due to some anthropogenic pressure and illegal fishing practices adversely affected the fish diversity. The present study provide base line data initiative to update the current status of fish diversity and water quality parameters and will be useful to enhance the management and conservation strategies, for the fish species of Sip river. Therefore, important steps should be taken into consideration to increase the long-term sustainability of water health and fish activities in the river system

Organic Alkalinity as an Important Constituent of Total Alkalinity and the Buffering System in River‐To‐Coast Transition Zones

AbstractOrganic acid‐base species in the dissolved organic carbon pool have been shown to make an important contribution (i.e., organic alkalinity; OrgAlk) to the total alkalinity (TA) in many coastal systems. This study documents an intensive investigation of OrgAlk characteristics in the river‐to‐coast transition zones of six southeast Chinese rivers. OrgAlk, mainly originating from river input, accounted for an important proportion of TA (0.3%–12%) in six estuaries. Carboxylic acid groups were commonly present in all estuaries. Notable differences in the TA values (1–18 μmol kg−1) determined by several established TA measurement approaches were identified in estuaries where organic acids with pKa <5.2 were abundant. The most widely used open‐cell titration method, in comparison with closed‐cell titration and single‐step titration, is the best approach to incorporate OrgAlk in titrated TA when the pKa values of organic acids were >5 in the study estuaries. Across our study sites, OrgAlk might modify H+ concentrations by 3%–69% (i.e., pH by 0.01–0.78) and aragonite saturation states by 1%–72%, indicating that OrgAlk can play a significant role in the coastal carbonate buffering system. It is essential to improve current TA measurement approaches to more accurately represent OrgAlk in the coastal system and assess impacts of OrgAlk on coastal carbonate chemistry.

Assessing of drinking water quality in Al-karak province in central Jordan; based on water saturation indices

Jordan is renowned for having limited water resources. The demand for water will increasing rapidly as the country's population grows and the number of refugees increases. In order to maintain the highest water quality for consumers, the Ministry of Water and Irrigation and other governmental agencies are striving to manage Jordan's water resources through continuous monitoring. The main objective was to evaluate the drinking water quality at storage mixing tanks at Al-Karak province, besides, assessing its suitability for safe consumption. The investigation scheme was to monitor Al-Karak's drinking water system for three successive months. The fourteen principal storage tanks for the water distribution system in the area of investigation were sampled. The pH, electrical conductivity (EC), major cations, major anions, total dissolved solids (TDS), total hardness (TH), turbidity, total alkalinity (TA), and heavy metals were measured. The scaling and originality of the dissolved salt elements in the collected water samples and geochemical processes were examined using Piper and Durov diagrams. The indices used in all samples over the period of investigation, are Langelier Saturation Index (LSI), Ryznar Stability Index (RSI), Aggressive Index (AI), Puckorius Scaling Index (PSI), and Water Quality Index (WQI). The results showed that scale development is high in all storage tanks, as the water is calcium carbonate supersaturated, evident from LSI values that ranges 0.5–2. According to the range of RSI values (5.91–6.6), all water tanks are resistant to corrosion. Throughout the period of study (October–December), the estimated WQIs of all samples upon average were found to be less than 50, indicating excellent water quality. Finally, the collected water samples are analyzed and found to be within the acceptable levels of Jordan's drinking water standards.