Evaluation of groundwater quality with emphasis on Arsenic and fluoride concentration in Guwahati: Economic hub of Northeast India

by A. K. Patel, R. Goswami and Manish Kuma

Arsenic mobilization in the flood plains: insights on co-contamination and risk characterization in Lakhimpur district of upper Brahmaputra flood plains, India

by Ritusmita Goswami, Nilotpal Das, Prosun Bhattacharya and Manish Kuma

Sustainable removal of pernicious arsenic and cadmium by a novel composite of MnO2 impregnated alginate beads: A cost-effective approach for wastewater treatment

There is a dire necessity of developing low cost waste water treatment systems, for the efficient removal of noxious heavy metals (and metalloids) such as Arsenic (As) and Cadmium (Cd). Magnetic biopolymer (CABs-MO) was synthesized by the entrapment of nanocrystalline MnO2 in the polymeric microcapsules of calcium alginate (CABs). Batch experiments were conducted under constant pH (6.5), temperature (25OC), different initial concentrations (30–300 mg L−1) and contact times (0–48 h) to study the adsorption isotherms and removal kinetics of pristine (CABs) and hybrid biopolymer (CABs-MO) for the removal of As and Cd. The pseudo-equilibrium process was mathematically well explained by the pseudo-second-order kinetic (R2 ≥ 0.99) and Langmuir isotherm model (R2 ≥ 0.99) with the highest monolayer sorption capacity of 63.6 mg g−1 for Cd on CABs-MO. The As removal rate was maximum up to 6.5 mg g−1 after 12 h of contact period in a single contaminant system than in the mixed contaminant (As + Cd) system (0.8 mg g−1), though the effect was non-significant for Cd (p < 0.05; t-test). The performance of the 10 mM HCl as a regenerating agent was superior (for As in comparison to Cd, p < 0.05; t-test) compared to distilled water (DW) through three to five regeneration cycles. Therefore, the obtained results clearly validate the feasibility of CABs-MO as a potential promising adsorbent for removing metal contaminants from the wastewater. Further research is required to study the decontamination of emerging contaminants with such novel composite beads characterized by varied physico-chemical properties.by Jaehong Shima, Manish Kumar, Santanu Mukherjee and Ritusmita Goswami

Uptake of Lead from Aqueous Solution using Eichhornia crassipes: Effect on Chlorophyll Content and Photosynthetic Rate

Abstract : Lead is the most significant toxin of the heavy metals posing serious effects on plants and animals. The remediation of this toxic pollutant using environment friendly materials is an urgent need. In the present study the effect of pH and concentrations on uptake capacity of lead by Eichhornia crassipes and their interplay have been studied. The rate of Pb uptake by Eichhornia crassipes is very rapid in the first 48 hrs for all the initial concentration and at various pH. The uptake efficiency of roots were more as compared to shoots. The accumulation of Pb in roots of Eichhornia crassipes was found to be very high at all pH and concentrations. The photosynthetic rate of Eichhornia crassipes sharply declined when grown in aquatic medium containing Pb. The chlorophyll content got reduced, with increasing concentration over the experimental duration, reflecting probable Pb toxicity. The results show that the plant Eichhornia crassipes does have the pH neutralizing capacity

Arsenic exposure and perception of health risk due to groundwater contamination in Majuli (river island), Assam, India

Island populations are rarely studied for risk of arsenic (As) poisoning. As poisoning, multimetal contamination and people�s perceptions of health risks were assessed on India�s Majuli Island, the largest inhabited river island in the world. This holistic approach illustrated the association of groundwater contamination status with consequent health risk by measuring levels of inorganic arsenic (iAs) in groundwater, borehole sediment and biological samples (hair, nails and urine). Piper and Gibbs�s plots discerned the underlying hydrogeochemical processes in the aquifer. Demographic data and qualitative factors were evaluated to assess the risks and uncertainties of exposure. The results exhibited significant enrichment of groundwater with As, Mn and Fe along with significant body burden. Maximum Hazard Index values indicated severe non-carcinogenic health impacts as well as a significantly elevated risk of cancer for both adults and children. Most (99%) of the locally affected population did not know about the adverse health impacts of metal contamination, and only 15% understood bodily ailments and health issues. Various aspects of the island environment were used to elucidate the status of contamination and future risk of disease. A projection showed adverse health outcomes rising significantly, especially among the young population of Majuli, due to overexposure to not only As but also Ba, Mn and Fe.by Ritusmita Goswami, Manish Kumar, Nivedita Biyani and Patrick J. She

Arsenic mobility and potential co-leaching of fluoride from the sediments of three tributaries of the upper Brahmaputra floodplain, Lakhimpur, Assam, India

A sequential extraction procedure (SEP), batch desorption experiments and the concept of partition coefficient were applied on seven sediment samples from the Subansiri-Dikrong-Ranganadi River System (SDRS), a subset of the upper Brahmaputra floodplain (BFP), to understand leaching of arsenic (As) and fluoride (F−). Sediment samples were collected during monsoon and post-monsoon seasons from each of three river banks to distinguish the effect of annual cyclic flooding events on As content and mobilization. SEP revealed that the readily leachable chemisorbed As phase and amorphous Fe (hydr)oxides were the principal contributors to mobilized As during the monsoon season. Constant flushing of the rivers removed most of the physisorbed and chemisorbed As during the monsoon. A submerged anoxic condition toward late monsoon resulted in Fe (hydr)oxides becoming the dominant source of removable As during the post-monsoon season. Iron in the sediments was positively correlated with F− during both monsoon and post-monsoon seasons. This suggests that Fe (hydr)oxides are a host for F− and a correlation between reductive hydrolysis and F−. Removal of Fe (hydr)oxides from the sediments significantly reduced As retention/leaching capacity. Arsenic desorption was especially high from raw sediments of the Ranganadi River owing to the fact that it had the highest amount of As associated with Fe (hydr)oxides, which falls sharply in the post-monsoon season due to a prolonged submerged state leading to reductive dissolution. However, as leached F− is being constantly flushed out by the SDRS, F− contamination may not pose a problem in the current or futuristic scenarios.by Arbind Kumar Patel, Nilotpal Das, Ritusmita Goswami and Manish Kuma

COMPARATIVE UNDERSTANDING OF ARSENIC ENRICHMENT AND MOBILIZATION IN THE AQUIFERS OF THE RIVER GANGES AND BRAHMAPUTRA: A PROVENANCE, PREVALENCE AND HEALTH PERSPECTIVE

by Manish Kumar, Arbind Kumar Patel, Aparna Das, Nilotpal Das and Ritusmita Goswam

Removal of p-cresol and tylosin from water using a novel composite of alginate, recycled MnO2 and activated carbon

For sustainable production, there is an urgent need to minimize the adverse environmental impacts of swine farming, which is a major contributor of the pollutants p-cresol and tylosin. Novel reactive composite alginate beads (CAB-MOACs) were fabricated by combining alginate with activated carbon (AC) and MnO2 recovered from spent battery waste and used for efficient removal of p-cresol and tylosin from water. Batch experiments were carried out under varying pH (3–11), temperature (15–50 °C), and agitation speed (50–200 rpm) to understand their effects on removal efficiency. The CAB-MOACs had better removal efficiency for p-cresol and tylosin than alginate beads alone or beads containing only AC or MnO2. Adsorption to CAB-MOACs followed pseudo-second-order kinetics (R2≥0.98) and Langmuir isotherm models (R2≥0.95). CAB-MOACs showed higher removal efficiency (∼99.9% after 10 h) compared to beads containing only immobilized MnO2 (60–70%) or AC (94–96%). Regeneration and reuse performance of the CAB-MOACs was excellent through five cycles, although slightly better for p-cresol than tylosin. With low-cost manufacturing and beneficial utilization of hazardous waste such as spent batteries, the newly developed composite beads show potential as an effective adsorbent for treating wastewater effluent containing emerging contaminants like p-cresol and tylosin. Future studies may focus on product refinement and large-scale testing on actual wastewaters.by Jaehong Shim, Manish Kumar, Ritusmita Goswami,Payal Mazumder, Byung-Taek Oh and Patrick J. She

Efficacy and field applicability of Burmese grape leaf extract (BGLE) for cadmium removal: an implication of metal removal from natural water

Burmese Grape Leaf Extract (BGLE), a low cost adsorbent was studied for cadmium (Cd(II)) removal from metal solutions and natural water samples. Batch adsorption studies were carried out to examine the influence of contact time and initial metal concentration after characterization under scanning electron microscopy (SEM). Cd(II)adsorptiononto BGLE was best explained by pseudo-second order kinetics (R2 = 0.99) and best fitted with Langmuir isotherm model (R2 = 0.76). Beside the selective adsorption activity of BGLE towards Cd(II), only 0.1g of BGLE have shown effective adsorption of these ions with a maximum adsorption capacity (qm) of 44.72mgg-1. This study was a unique combination of laboratory experiments and field implication. Study indicates that same efficacy cannot be obtained in natural water samples as obtained in the case of laboratory due to the interference of major ions in water.by Rinkumoni Borah, Deepa Kumari, Anindita Gogoi, Sunayana Biswas, Ritusmita Goswami, Jaehong Shim, Naznin Ara Begum and Manish Kuma

Response of wastewater-based epidemiology predictor for the second wave of COVID-19 in Ahmedabad, India: A long-term data Perspective

In this work, we present an eight-month longitudinal study of wastewater-based epidemiology (WBE) in Ahmedabad, India, where wastewater surveillance was introduced in September 2020 after the successful containment of the first wave of COVID-19 to predict the resurge of the infection during the second wave of the pandemic. The study aims to elucidate the weekly resolution of the SARS-CoV-2 RNA data for eight months in wastewater samples to predict the COVID-19 situation and identify hotspots in Ahmedabad. A total of 287 samples were analyzed for SARS-CoV-2 RNA using RT-PCR, and Spearman\u27s rank correlation was applied to depict the early warning potential of WBE. During September 2020 to April 2021, the increasing number of positive wastewater influent samples correlated with the growing number of confirmed clinical cases. It also showed clear evidence of early detection of the second wave of COVID-19 in Ahmedabad (March 2021). 258 out of a total 287 samples were detected positive with at least two out of three SARS-CoV-2 genes (N, ORF- 1 ab, and S). Monthly variation represented a significant decline in all three gene copies in October compared to September 2020, followed by an abrupt increase in November 2020. A similar increment in the gene copies was observed in March and April 2021, which would be an indicator of the second wave of COVID-19. A lead time of 1–2 weeks was observed in the change of gene concentrations compared with clinically confirmed cases. Measured wastewater ORF- 1 ab gene copies ranged from 6.1 x 102 (October 2020) to 1.4 x 104 (November 2020) copies/mL, and wastewater gene levels typically lead to confirmed cases by one to two weeks. The study highlights the value of WBE as a monitoring tool to predict waves within a pandemic, identify local disease hotspots within a city, and guide rapid management interventions