Hydrogeochemical investigations to assess groundwater and saline water interaction in coastal aquifers of the southeast coast,Tamil Nadu,India

Environmental Science and Pollution Research - Groundwater and saline water interaction is the most common processes in the coastal aquifers that alters the quality of aquifer waters. The...     

Groundwater pollution index (GPI) and GIS-based appraisal of groundwater quality for drinking and irrigation in coastal aquifers of Tiruchendur,South India

Environmental Science and Pollution Research - We assessed groundwater pollution index (GPI) and groundwater quality of coastal aquifers from Tiruchendur in South India for drinking and irrigation...     

Identification of groundwater microbial communities and their connection to the hydrochemical environment in southern Laizhou Bay,China

Environmental Science and Pollution Research - The microbial community plays an important role in the biogeochemical cycle in coastal groundwater ecosystems. However, the composition and...     

Polychlorinated naphthalenes (PCNs) in riverine and marine sediments of the Laizhou Bay area, North China

PCN congeners were analyzed in marine and riverine sediments of the Laizhou Bay area, North China. Concentrations of PCNs ranged from 0.12 to 5.1 ng g⁻¹ dry weight (dw) with a mean value of 1.1 ng g⁻¹ dw. The levels of PCNs varied largely, with industrial group approximately ten folds higher than those of the rural in riverine sediment. A strong impact by direct discharge from local factories was suggested. Similar compositional profiles were found within groups. High resemblance of compositional profiles between industrial samples and Halowax 1014 was observed. It was indicated that PCNs in riverine sediments were mainly from release of industrial usage, with additional contributions from industrial thermal process at certain sites. In marine sediments, it was suggested that PCNs along the coast of Laizhou Bay were mainly controlled by riverine input. While in the central bay, PCN distributions were possibly impacted by combined multiple factors.     

Hydrogeochemical assessment of carcinogenic and non-carcinogenic health risks of potentially toxic elements in aquifers of the Hindukush ranges,Pakistan: insights from groundwater pollution indexing,GIS-based,and multivariate statistical approaches

Environmental Science and Pollution Research - Globally, potentially toxic elements (PTEs) and bacterial contamination pose health hazards, persistency, and genotoxicity in the groundwater aquifer....     

Hydrogeochemical characteristics of groundwater uses for agricultural and drinking and groundwater quality of pollution index in the western part of Telangana,South India

Environmental Science and Pollution Research - A total of fifty groundwater samples were collected in the western part of Nizamabad district, Telangana State, India. The results obtained were...     

Hydrogeochemical evaluation,suitability, and health risk assessment of groundwater in the watershed of Godavari basin,Maharashtra, Central India

Environmental Science and Pollution Research - In this investigation, the geochemical progression of a total of 31 groundwater samples of pre-monsoon season was assessed with categorization based...     

Hydrochemical characteristics and quality assessment of shallow groundwater in Yangtze River Delta of eastern China

Environmental Science and Pollution Research - Water resource is in high demand within the Yangtze River Delta, given its developed economy. Long-term exploitation of this resource has posed risks...     

Levels and distribution of polybrominated diphenyl ethers in plant, shellfish and sediment samples from Laizhou Bay in China

Polybrominated diphenyl ethers (PBDEs) are potentially harmful and persistent environmental pollutants. PBDEs concentrations are reported in plant, shellfish and sediment samples collected from Chinese Laizhou Bay. The summation operator(11)PBDE concentrations in plant and shellfish samples from Laizhou Bay were in the range of 70-5900ngg(-1) and 230-720ngg(-1) lipid, respectively. The summation operator(11)PBDEs concentrations in river sediment intervals samples ranged from 1.3 to 1800ng g(-1) dry weight. Pearson correlation analyses were performed on concentrations of PBDEs congeners of different sediment sample intervals. There were significant positive correlations for BDE 28 and BDE 100 (r=0.945, p<0.01), BDE 47 and BDE 99 (r=0.879, p<0.01), BDE 153 and BDE 154 (r=0.934, p<0.01), nona-BDEs and BDE 209 (r>0.934, p<0.01). BDE 209 was the predominant congener in all analyzed samples, consistent with the fact that deca-BDE technical mixtures are the dominant PBDEs product in Laizhou Bay. Data showed that PBDEs should be considered as an increasing pollution problem in the Laizhou Bay region.     

A comparison of sediment quality guidelines for toxicity assessment in the Sunderban wetlands (Bay of Bengal, India)

The aim of this paper was to obtain the first screening ecotoxicological risk evaluation in the Sunderban wetlands, the largest prograding delta in the estuarine phase of the River Ganges. The characterization of exposure was conducted by means of an extensive survey of several persistent organic pollutants (PAHs, PCBs, DDTs, PBDEs, HCHs, HCB) measured in seven core sediments from the Sunderban wetlands, obtaining a dataset with more than 2200 analyses. The pollutant effects were assessed by the use of three different sediment quality guidelines (SQGs) previously developed in the literature to evaluate toxicity induced in sediment-dwelling organisms. The three different approaches chosen for risk assessment of the Sunderban were the consensus SQGs obtained by TEC (threshold effect concentration), PEC (probable effect concentration) and EEC (extreme effect concentration), the threshold/probable effect level (TEL/PEL) approach and, finally, the ERL-ERM guidelines, including the m-ERM-Q (mean ERM quotient). The evaluation of the toxicity induced by a mixture of the target pollutants indicated the importance of gamma-HCH contamination in the Sunderban sediments despite the very low concentrations measured in core sediments. A different sensitivity for toxicity assessment due to quality guidelines was obtained, as the consensus SQGs based on TEC were less conservative and protective than the TEL and ERL approaches, while the use of m-ERM-Q seems to be the most powerful tool to predict the toxicity related to a contaminant mixture.     

Using multi-integrated biomarker indexes approach to assess marine quality and health status of marine organism: a case study of Ruditapes philippinarum in Laizhou Bay,China

With the progress of technology and the deepening of understanding of biological monitoring, much more attention has been paid to the multiple evaluation of marine pollution monitoring. In view of this, our study aimed at establishing a multi-integrated biomarker indexes approach to evaluate marine condition systematically and comprehensively. In the current study, sampling was conducted in Laizhou Bay, China (S1, S2, and S3) in May, August, and October of 2015. And then, multi-integrated biomarker indexes approach was applied to assess marine PAHs pollution, select appropriate biomarkers, and evaluate marine environmental quality and health status of the clams of Ruditapes philippinarum. As the results showed, S2 was the most PAHs-polluted site while S1 was the least polluted site, and the levels of tPAHs in seawater and sediments ranged from 69.78 to 315.30 ng/L and 163.19 to 565.17 ng/g d.w., respectively. And all three sampling sites had different sources of PAHs. IBR represented DNA damage (F value), the expression of SOD, EROD activity, GST activity, and LPO could be served as biomarkers to monitor the PAHs pollution in Laizhou Bay. And MPI suggested the quality of all three sites: S1 was generally favorable, S2 was moderately polluted, and S3 was lightly polluted. BRI values showed that the order of health status of R. philippinarum was S1?>?S3?>?S2.

     

Multivariate statistical evaluation of trace elements in groundwater in a coastal area in Shenzhen, China

Multivariate statistical techniques are efficient ways to display complex relationships among many objects. An attempt was made to study the data of trace elements in groundwater using multivariate statistical techniques such as principal component analysis (PCA), Q-mode factor analysis and cluster analysis. The original matrix consisted of 17 trace elements estimated from 55 groundwater samples colleted in 27 wells located in a coastal area in Shenzhen, China. PCA results show that trace elements of V, Cr, As, Mo, W, and U with greatest positive loadings typically occur as soluble oxyanions in oxidizing waters, while Mn and Co with greatest negative loadings are generally more soluble within oxygen depleted groundwater. Cluster analyses demonstrate that most groundwater samples collected from the same well in the study area during summer and winter still fall into the same group. This study also demonstrates the usefulness of multivariate statistical analysis in hydrochemical studies.     

Temporal variability of groundwater chemistry in shallow and deep aquifers of Araihazar, Bangladesh

Samples were collected every 2-4 weeks from a set of 37 monitoring wells over a period of 2-3 years in Araihazar, Bangladesh, to evaluate the temporal variability of groundwater composition for As and other constituents. The monitoring wells are grouped in 6 nests and span the 5-91 m depth range. Concentrations of As, Ca, Fe, K, Mg, Mn, Na, P, and S were measured by high-resolution ICPMS with a precision of 5% or better; concentrations of Cl were measured by ion chromatography. In shallow wells <30 m deep, As and P concentrations generally varied by <30%, whereas concentrations of the major ions (Na, K, Mg, Ca and Cl) and the redox-sensitive elements (Fe, Mn, and S) varied over time by up to +/-90%. In wells tapping the deeper aquifers >30 m often below clay layers concentrations of groundwater As were much lower and varied by <10%. The concentrations of major cations also varied by <10% in these deep aquifers. In contrast, the concentration of redox-sensitive constituents Fe, S, and Mn in deep aquifers varied by up to 97% over time. Thus, strong decoupling between variations in As and Fe concentrations is evident in groundwaters from shallow and deep aquifers. Comparison of the time series data with groundwater ages determined by (3)H/(3)He and (14)C dating shows that large seasonal or inter-annual variations in major cation and chloride concentrations are restricted to shallow aquifers and groundwater recharged <5 years ago. There is no corresponding change in As concentrations despite having significant variations of redox sensitive constituents in these very young waters. This is attributed to chemical buffering due to rapid equilibrium between solute and solid As. At two sites where the As content of groundwater in existing shallow wells averages 102 microg/L (range: <5 to 648 microg/L; n=118) and 272 microg/L (range: 10 to 485 microg/L; n=65), respectively, a systematic long-term decline in As concentrations lends support to the notion that flushing may slowly deplete an aquifer of As. Shallow aquifer water with >5 years (3)H/(3)He age show a constant As:P molar ratio of 9.6 over time, suggesting common mechanisms of mobilization.     

Use of the landfill water pollution index (LWPI) for groundwater quality assessment near the landfill sites

The purpose of the paper is to assess the groundwater quality near the landfill sites using landfill water pollution index (LWPI). In order to investigate the scale of groundwater contamination, three landfills (E, H and S) in different stages of their operation were taken into analysis. Samples of groundwater in the vicinity of studied landfills were collected four times each year in the period from 2004 to 2014. A total of over 300 groundwater samples were analysed for pH, EC, PAH, TOC, Cr, Hg, Zn, Pb, Cd, Cu, as required by the UE legal acts for landfill monitoring system. The calculated values of the LWPI allowed the quantification of the overall water quality near the landfill sites. The obtained results indicated that the most negative impact on groundwater quality is observed near the old Landfill H. Improper location of piezometer at the Landfill S favoured infiltration of run-off from road pavement into the soil-water environment. Deep deposition of the groundwater level at Landfill S area reduced the landfill impact on the water quality. Conducted analyses revealed that the LWPI can be used for evaluation of water pollution near a landfill, for assessment of the variability of water pollution with time and for comparison of water quality from different piezometers, landfills or time periods. The applied WQI (Water Quality Index) can also be an important information tool for landfill policy makers and the public about the groundwater pollution threat from landfill.     

Impact of human activities on coastal groundwater pollution in the Yang-Dai River plain,northern China

Environmental Science and Pollution Research - Overexploitation of groundwater has resulted in seawater intrusion in many semiarid and arid coastal areas. This study illustrates the origin of...     

Distributions,origins, and health-risk assessment of nitrate in groundwater in typical alluvial-pluvial fans,North China Plain

Environmental Science and Pollution Research - High concentration of nitrate (NO3?) in groundwater is a major concern because of its complex origin and harmful effects on human health. This...     

Hydrogeochemical comparison and effects of overlapping redox zones on groundwater arsenic near the Western (Bhagirathi sub-basin, India) and Eastern (Meghna sub-basin, Bangladesh) margins of the Bengal Basin

Although arsenic (As) contamination of groundwater in the Bengal Basin has received wide attention over the past decade, comparative studies of hydrogeochemistry in geologically different sub-basins within the basin have been lacking. Groundwater samples were collected from sub-basins in the western margin (River Bhagirathi sub-basin, Nadia, India; 90 samples) and eastern margin (River Meghna sub-basin; Brahmanbaria, Bangladesh; 35 samples) of the Bengal Basin. Groundwater in the western site (Nadia) has mostly Ca-HCO(3) water while that in the eastern site (Brahmanbaria) is much more variable consisting of at least six different facies. The two sites show differences in major and minor solute trends indicating varying pathways of hydrogeochemical evolution However, both sites have similar reducing, postoxic environments (p(e): +5 to -2) with high concentrations of dissolved organic carbon, indicating dominantly metal-reducing processes and similarity in As mobilization mechanism. The trends of various redox-sensitive solutes (e.g. As, CH(4), Fe, Mn, NO(3)(-), NH(4)(+), SO(4)(2-)) indicate overlapping redox zones, leading to partial redox equilibrium conditions where As, once liberated from source minerals, would tend to remain in solution because of the complex interplay among the electron acceptors.     

Metal concentrations and mobility in marine sediment and groundwater in coastal reclamation areas: a case study in Shenzhen, China

The concentrations of metals in the buried marine sediment and groundwater were differently affected by land reclamation. Nine metals (V, Cr, Mn, Co, Ni, Cu, Zn, Cd and Pb) in sediment and coastal groundwater from reclamation areas in Shenzhen were examined. The gradually decreased concentrations (V, Cr, Mn, Ni, Cu, Zn) in sediment and relatively higher concentrations (V, Cr, Mn, Co, Ni, Cu and Cd) in groundwater within reclamation areas were observed. The increase of V, Cr, Mn, Ni, Cu and Cd concentrations in groundwater within reclamation areas subsequently after land reclamation should be resulted from the mobilization of these metals accumulated in the sediment. These metals appear to be easily mobilized from solid phase to solution phase after reclamation. The physico-chemical changes such as reduction in pH and salinity in water environment induced by land reclamation appear to be responsible for metal mobility in the sediment-groundwater system.     

Assessment of organic contamination along the coast of Laizhou Bay,China: chemical analysis and integrated biomarker responses in the clam Ruditapes philippinarum

An investigative biomonitoring study was conducted along the coastal area of Laizhou Bay (China) to evaluate the impact of organic pollution on the clam Ruditapes philippinarum using bioaccumulation and multi-biomarker measurements. In addition, the polychlorinated biphenyls (PCBs), total petroleum hydrocarbons (TPHs) and nonylphenol (NP) content in surface sediment at the study sites were also analyzed. Concentrations of PCBs, TPHs and NP in the sediments of the study area were 1.90 ± 0.10 μg kg^?1, 39.55 ± 2.42 mg kg^?1, 9.23 ± 0.41 μg kg^?1 dry weight, respectively, while the organic contaminants in the soft tissues of R. philippinarum were 14.81 ± 0.96 μg kg^?1 for PCBs, 165.87 ± 5.03 mg kg^?1 for TPHs and 86.16 ± 5.29 μg kg^?1 for NP. Linear regression analysis on the levels of organic pollutants accumulated in R. philippinarum and in sediments showed no significant correlation. Multi-biomarkers including superoxide dismutase, catalase, glutathione peroxidase, glutathione S-transferase, total glutathione and lipid peroxidation were assayed in gills and digestive glands of R. philippinarum. Finally, the biomarkers in gills were selected to calculate the Integrated Biomarker Response (IBR) index and to evaluate the impact of the three organic contaminants on R. philippinarum collected from different sites. According to IBR results, the western coast and eastern coast exhibited higher environmental stress than the sampling sites along the southern coast of Laizhou Bay. Significant correlation was found between the level of organic contaminants in the sediments and IBR whereas no dependence was found between pollutants’ concentrations in sediments and separate biomarker responses. The results showed that PCBs and NP were the main organic pollutants among the three studied which have caused pollution pressure on R. philippinarum in Laizhou Bay coastal area.