Hydro-chemical assessment of groundwater pollutant and corresponding health risk in the Ganges delta, Indo-Bangladesh region

Abstract In this study, the hydrochemical characteristics of groundwater were assessed based on 64 shallow groundwater samples collected in the Guanzhong Basin, China, and the health risk of nitrate (NO3 -) in drinking water was assessed. In addition, the spatial distributions of major water quality indicators were investigated, while bivariate plots, saturation index, and stable isotopes were used to reveal the processes controlling groundwater hydrogeochemistry. The results showed that groundwater in the study area was mostly fresh water. However, the maximum and average NO3 – concentrations were 397.0 and 92.9 mg/L, respectively, indicating serious groundwater NO3 – pollution. The percolation of contaminated river water exhibited considerable impacts on groundwater quality. Carbonate dissolution was the major process controlling the hydrochemical characteristics of groundwater, while human activities were responsible for the high concentrations of groundwater pollutants, especially NO3 –. Evaporation fraction of groundwater in the study area revealed by stable hydrogen and oxygen isotopes ranged from 4 to 13% and 4 to 11%, respectively. High non-carcinogenic health risks of NO3 – to adults and children were observed in about 46.88 and 75% of the collected groundwater samples, respectively. The risk value ranges were 0-6.00 and 0-14.06, with average values of 1.36 and 3.19, for adults and children, respectively.

Major ion hydrogeochemistry and health risk of groundwater nitrate in selected rural areas of the Guanzhong Basin, China

Water pollution indexing and health risk assessment due to PTE ingestion and dermal absorption for nine human populations in Southeast Nigeria

Regeneration efficiency was enhanced by adding auxin and cytokinin at different concentrations to the media. It was found that the two highest frequencies–90 and 85%–of callus induction occured when the buds were cultured in an MS medium supplemented with 2 mgL α-naphthalene acetic acid (NAA) plus 1 mgL N-benzylaminopurine (BAP) (CIM2) and in the same medium supplemented with 2 mgL NAA plus 1 mgL kinetin (CIM5), respectively. When cultured further in a plant regeneration medium supplemented with 1 mgL NAA and 2 mgL BAP (PRM1), these calli regenerated with high efficiencies, 80% for calli grown in CIM2 and 85% for calli grown in CIM5. The low BAP concentration in CIM1 (2 mgL NAA and 0.5 mgL BAP) resulted in a low regeneration efficiency and fewer shoots per callus even though the PRM3 regeneration medium had a high concentration of cytokinins (2 mgL BAP and 2 mgL kinetin) . However, the calli cultured in CIM2 without kinetin but with a suitable level of BAP still regenerated with high efficiencies in PRM2 and PRM3 that contained 1 and 2 mgL kinetin, respectively. Similarly, when calli cultured in CIM5 without BAP but with kinetin were regenerated in PRM1 with BAP alone, they also regenerated with a high regeneration efficiency. These results showed that culturing a specific tissue in a medium with suitable concentrations of NAA and BAP or kinetin resulted in a large number of multiple shoots, and BAP and kinetin worked synergistically to produce a high plant regeneration efficiency.

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Synergistic effects of BAP and kinetin media additives on regeneration of vetiver grass (Vetiveria zizanioides L. Nash)

Groundwater Quality Assessment Using EWQI With Updated Water Quality Classification Criteria: A Case Study in and Around Zhouzhi County, Guanzhong Basin (China)

The present study aims to assess the causes of pollution in groundwater before and after the monsoon in relation to water types, chemical elements, and their statistical variation in a rural region of Wanaparthy district, Telangana, India. Groundwater samples collected in both seasons were analyzed. Results indicated that pH, TDS, Ca2+, Mg2+, K+, Cl-, SO42−, and NO3− values were higher after the monsoon. The Overall Water Quality Index indicated that moderate (53.86%) and very low (20.18%) groundwater quality zones increased spatially during post-monsoon compared to pre-monsoon (35.22% and 4.77%, respctively). Piper's diagram showed that the transition from freshwater to mixed water type (70%) predominates in post-monsoon. Gibbs diagrams indicated 93.33% and 80% of groundwater samples had lithological influence before and after the monsoon, respectively. Genetic water quality classification revealed that 53% and 87% of groundwater samples showed Cl−−HCO3− type before and after the monsoon, respectively. The ionic ratios indicated the dominance of mineral weathering and dissolution, ion exchange, and evaporation in pre-monsoon, but they also indicated that anthropogenic pollution activities prevailed in post-monsoon, as confirmed by the high correlations between Cl-, SO42−, and NO3− ions and supported by land use practice. Principal component (PC) analysis captured three and four PCs with 80.795% and 78.532% of the total variance and eigenvalue greater than one (1.020–5.748) before and after the monsoon, respectively, which also supported human induced contamination in post-monsoon groundwater. PC scores (>1) identified index-wells for regularly monitoring groundwater quality and also assessed pollution causes for proper management planning to reduce cost and protect the aquifer system. 

Monitoring the causes of pollution using groundwater quality and chemistry before and after the monsoon

Pteris spp., a member of Pteridaceae family, was investigated for its efficacy in remediation of cadmium through foliar absorption. Fern species were selected for phytoremediation particularly for their limited role in food chain of herbivores and humans. The fern fronds of uniform size and mass were cultured in Knop’s medium containing different concentrations of cadmium salt (50, 100, 150, and 200 mM) under controlled conditions. Parameters such as biomass, hydration, chlorophyll content, protein content, and proline content were monitored at regular intervals of 24 h for a period of 1 week. The samples were tested for cadmium accumulation at the end of 1 week using atomic absorption spectroscopy. Results have shown that the total ­protein content has increased significantly up to 72 h. Increased proline ­concentration was observed at 150 mM of Cd salt treatment up to 48 h ­irrespective of the position of the frond. Maximum foliar absorption of 70 mg kg−1 dry weight was found just after 24 h of Cd salt treatment in the tip region of the frond. Our studies indicate that local Pteris sp. is a potential candidate plant for phytoremediation.

B. C. Sunitha

Papers

Monitoring the causes of pollution using groundwater quality and chemistry before and after the monsoon

Phytoremediation of Cadmium Using Pteris sp.

Geochemistry of granites in and around Chityala, Cuddapah Basin