Geochemical Characteristics of Water, Sediments and Suspended Solids in Sibuti River Estuary and Its Potential Effect on the Miri-Sibuti Coral Reefs

The hydrological regime of the Sibuti River is mainly controlled by rainfall associated with Pacific Decadal Oscillation (PDO) and discharging into SW part of Miri coast, East Malaysia. The current study reveals that natural weathering of siliciclastic sediments coupled with deforestation and agricultural and wastewater effluents are the major sources for the geochemistry of river basin. The estuarine contaminants runoffs have minor to major influence on Miri Sibuti Coral Reefs depending on the seasonal variation

Salinity-Induced Changes in Heavy Metal Behavior and Mobility in Semi-Arid Coastal Aquifers: A Comprehensive Review

Semi-arid coastal aquifers face critical challenges characterized by lower rainfall, higher evaporation rates, and looming risk of over-exploitation. These conditions, coupled with climate change, are conducive to seawater intrusion and promote mechanisms associated with it. The understanding of metal behavior in such environments is limited, and hence, an attempt is made through this review to bridge the knowledge gap. A study on the behavior of trace metals within a specific context of semi-arid coastal aquifers was carried out, and 11 aquifers from 6 different countries were included. The review observed that trace metals within semi-arid coastal aquifers exhibit distinctive behaviors influenced by their surrounding environment. The prevalence of evaporation and continuous seawater intrusion played a pivotal role in shaping trace metal dynamics by curtailing groundwater flux. The findings suggest that the formation of stable Cl and organic ligands under increased alkaline conditions (pH > 8) has higher control over Zn, Pb, and Cd toxicity in a highly ionic reactive condition. In addition, dominant control of Fe/Mn-hydroxide association with Pb and high organic affinity of Zn played a pivotal role in controlling its bioavailability in aquifers such as WFB, Saudi Arabia NW-C and India. On the contrary, under prevailing acidic conditions (pH 4-ligands become more dominant, controlling the bioavailability/desorption of Cu irrespective of its origin. The behavior of Ni is found to be controlled by stable organic ligands increasing salinity. An increase in salinity in the considered aquifers shows an increase in bioavailability of Ni, except UmC, South Africa, where organic ligands act as a sink for the metal, even at low pH conditions (pH 8), and chloride complexes govern the distribution of trace metals further enhanced by prolonged water residence time. Nonetheless, specific conditions, such as a reducing and acidic environment, could potentially elevate the solubility of highly toxic Cr (VI) released from anthropogenic sources

Hydrogeochemical Studies in and Around Kaveripakkam Block, Vellore District, Tamil Nadu

The region like Vellore has a higher density of population to be supported with water. Nearly greater than 50% of the day to day need of people in this Arakonam Taluk including domestic, industrial, agricultural and partly drinking purpose is made by the groundwater resources only. A study on hydrogeochemistry is done to understand the utilization of groundwater for various purposes. A total of 12 groundwater samples were from various parts of Kaveripakkam Block were collected and Physico-chemical parameters [pH, Electrical Conductivity (EC) and Total Dissolved Solid (TDS)], ions (Na, K, Cl, HCO3,Ca, Mg, SO4, PO4, H4SiO4) were analyzed to understand the suitability of groundwater for consumption, cultivation and household purpose and also to identify the hydrogeochemical processes.The Piper trilinear diagram and USSL diagram were also plotted which indicates CaHCO3 facies and shows high salinity hazard. Quality of groundwater has been measured to ensure its suitability for consumption and irrigation, based on WHO standards, US Salinity Laboratory (USSL), Sodium Absorption Ratio (SAR), Residual Sodium Carbonate (RSC), and Na%. The study implies that most of the groundwater samples are suitable for irrigation and drinking purposes. The study also identified that hydrogeochemistry of the region is mainly influenced by weathering processes

An insight on the speciation and genetical imprint of bicarbonate ion in the groundwater along K/T boundary, South India

Groundwater stored in sand, clay, and underground rocks that act as huge aquifers of water have been vastly explored by human civilization for drinking and irrigation purposes. This underlying sand, clay, and rocks greatly influence the chemistry of groundwater by fluctuation in various concentrations of ions. The geochemistry of Ariyalur region was studied by taking 142 samples in both Pre monsoon (PRM) and Post monsoon (POM) seasons. Analysis for crucial cations and anions like K+, Na+, F-, Cl-, HCO3-, Mg2+, Ca2+, SO42-, PO43-, NO3-, and H4SiO4and the physico-chemical variables like pH, total dissolved solid (TDS), and electrical conductivity (EC) were carried out to understand the suitability of groundwater. From all these information, Piper-plot has been used to analyze the water type in both the seasons. The study revealed that in both the seasons, HCO3-covers the major factors followed by H2CO3which are responsible for the change of chemistry of groundwater and proved its importance in the study area. Hence to determine the relationship of HCO3-with other ions, various charts were used. To obtain the origin of this HCO3-and reactions related to it, correlation of different species like HCO3, CaHCO3, MgHCO3, NaHCO3, CaCO3, MgCO3, NaCO3, and H2CO3were analyzed along with major physico-chemical variables like pH and logpCO2. The factor analysis for these species revealed the processes and reactions taking place in the study area. The contour diagrams for all the species in both the season has revealed the origin of HCO3-and dissolution by comparing lithology and geology of the study area