- Ecotechnology, Ecological Engineering, Environmental Science, Ecotoxicology, Environmental Remediation, Toxic trace elements, and 8 moreBioremediation, Environmental microbiology, Aquatic Ecosystems, Aquatic biodiversity assessment, Wastewater Treatment, Ecosystem Health Assessment, Heavy metals, and Biomonitoringedit
- Inspired by Nature's time-testededit
Grass clippings have a good biomethane potential and, if acquired from roadside verges, nature management or natural grasslands do not compete for arable land, avoiding the food versus fuel debate. However, before the grass is processed... more
Grass clippings have a good biomethane potential and, if acquired from roadside verges, nature management or natural grasslands do not compete for arable land, avoiding the food versus fuel debate. However, before the grass is processed in a wet anaerobic digester, a pretreatment step is advisable to minimize the problems associated with its fibrous nature. In this study, the effects of a semi-industrial extrusion pretreatment on fresh and ensiled grass were investigated through an energetic and economic assessment. Extrusion improved the mixing properties of the grass feedstock and reduced the formation of a floating layer even at a solid concentration of 10% (w/v). This pretreatment also enhanced the biomethane potential of ensiled grass and fresh grass by, respectively, 18 and 11% on a fresh matter basis, while shredding reduced this value by 14% when compared to fresh grass. This was attributed to changes in the volatile solids (VS) content of the treated samples, as all conditions resulted in similar biomethane yields when calculated per ton of VS, ranging from 325.5 to 337.6 Nm3 CH4/ton VS. However, ensiling resulted in a longer lag phase during biogas production attributed to the leaching of readily available sugars from the ruptured plant cells; nevertheless, this is not expected to be significant in a buffered industrial system. The revenue resulting from the extrusion treatment, between €6 and €17 per tonne of FM, compensated the cost of this additional step, indicating that extrusion would be a techno-economically sound process for the anaerobic digestion of grass.
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Copper is one of the most important microelements required by all kind of life forms including human beings for their proper growth, development, and survival. Copper plays an important role in various body functions and regulation of... more
Copper is one of the most important microelements required by all kind of life forms including human beings for their proper growth, development, and survival. Copper plays an important role in various body functions and regulation of different pathways. Hence, it has been used since pre-Vedic time as potential medicine to cure a number of diseases. Although, copper has significant medicinal value, the maintenance of adequate copper levels in the body is of vital importance because the lack or excess amount of such essential trace elements are known to cause a variety of health problems. The failure in the regulation of copper metabolism is mainly responsible for deficiency and accumulation of copper in different parts of the body. Generally, deficiency of copper leads to several copper deficiency syndromes including Menkes' disease. Similarly, high level of copper due to accumulation results in many diseases like Wilson's diseases, Alzheimer's disease, etc. Considering the key role of copper in human health, the present chapter has been focused on such related aspects, which include uptake and metabolism of copper, and its dietary recommendations. In addition, various disorders caused due to deficiency and excess amount of copper are also discussed in detail.
Some of the authors of this publication are also working on these related projects: Na Ion Batteries,Glass Ceramic electrolytes View project Design of multisite coordinating ligands for the assembly of molecular magnets based on 3d/4f and... more
Some of the authors of this publication are also working on these related projects: Na Ion Batteries,Glass Ceramic electrolytes View project Design of multisite coordinating ligands for the assembly of molecular magnets based on 3d/4f and 4f metal cluster View project
Some of the authors of this publication are also working on these related projects: Thermoplastic extrusion of a binary mixture composed of cassava flour and Amazon river shrimp View project Assessment of ecosystem of the oxbow lake for... more
Some of the authors of this publication are also working on these related projects: Thermoplastic extrusion of a binary mixture composed of cassava flour and Amazon river shrimp View project Assessment of ecosystem of the oxbow lake for sustainable management with reference to Nadia district, West Bengal View project
Polyacrylamide gel electrophoresis (PAGE) is the most classical technique favored worldwide for resolution of macromolecules in many biochemistry laboratories due to its incessant advanced developments and wide modifications. These... more
Polyacrylamide gel electrophoresis (PAGE) is the most classical technique favored worldwide for resolution of macromolecules in many biochemistry laboratories due to its incessant advanced developments and wide modifications. These ever-growing advancements in the basic laboratory equipments lead to emergence of many expensive, complex, and tricky laboratory equipments. Practical courses of biochemistry at high school or undergraduate levels are often affected by these complications. Two dimensional gel electrophoresis technique (2D-PAGE) used for resolving thousands of proteins in a gel is a combination of isoelectric focusing (first dimension gel electrophoresis technique) and sodium-dodecylsulphate PAGE (second dimension gel electrophoresis technique or SDS-PAGE). Two different laboratory equipments are needed to carry out effective 2D-PAGE technique, which also invites extra burden to the school laboratory. Here, we describe a low cost, time saving and simple gel cassette for protein 2D-PAGE technique that uses easily fabricated components and routine off-theshelf materials. The performance of the apparatus was verified in a practical exercise by a group of high school students with positive outcomes. V
The user has requested enhancement of the downloaded file. Synthesis, characterization and antimicrobial activity of some nickel, cadmium and mercury complexes of 5-methyl pyrazole-3yl-N-(2 0methylthiophenyl) methyleneimine, (MP z OATA)... more
The user has requested enhancement of the downloaded file. Synthesis, characterization and antimicrobial activity of some nickel, cadmium and mercury complexes of 5-methyl pyrazole-3yl-N-(2 0methylthiophenyl) methyleneimine, (MP z OATA) ligand
Some of the authors of this publication are also working on these related projects: Thermoplastic extrusion of a binary mixture composed of cassava flour and Amazon river shrimp View project Assessment of ecosystem of the oxbow lake for... more
Some of the authors of this publication are also working on these related projects: Thermoplastic extrusion of a binary mixture composed of cassava flour and Amazon river shrimp View project Assessment of ecosystem of the oxbow lake for sustainable management with reference to Nadia district, West Bengal View project
This study investigated the role of an allochthonous Gram-positive wastewater bacterium (Bacillus sp. KUJM2) selected through rigorous screening, for the removal of potentially toxic elements (PTEs; As, Cd, Cu, Ni) and promotion of plant... more
This study investigated the role of an allochthonous Gram-positive wastewater bacterium (Bacillus sp. KUJM2) selected through rigorous screening, for the removal of potentially toxic elements (PTEs; As, Cd, Cu, Ni) and promotion of plant growth under PTE-stress conditions. The dried biomass of the bacterial strain removed PTEs (5 mg L À1) from water by 90.17e94.75 and 60.4e81.41%, whereas live cells removed 87.15e91.69 and 57.5e78.8%, respectively, under single-PTE and co-contaminated conditions. When subjected to a single PTE, the bacterial production of indole-3-acetic acid (IAA) reached the maxima with Cu (67.66%) and Ni (64.33%), but Cd showed an inhibitory effect beyond 5 mg L À1 level. The multiple-PTE treatment induced IAA production only up to 5 mg L À1 beyond which inhibition ensued. Enhanced germination rate, germination index and seed production of lentil plant (Lens culinaris) under the
The ever growing advancements in the protein analysis of any cell or tissue using different variants of polyacrylamide gel electrophoresis and associated basic techniques offers its widespread application in almost all molecular biology... more
The ever growing advancements in the protein analysis of any cell or tissue using different variants of polyacrylamide gel electrophoresis and associated basic techniques offers its widespread application in almost all molecular biology laboratories. On the other hand, casting of several gels in parallel is a cumbersome task but is often an essential situation. A multi-gel casting apparatus for simultaneous casting of homogeneous concentration and gradient concentration sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) gel was described here. The efficiency of this newly modified apparatus was significantly improved by the flexibility of using the top pouring and bottom pouring mechanism at the same time along with the siphoning of used solution from polymerizing bottom gel surface which makes it suitable for all types of vertical polyacrylamide gels. This apparatus reliably produces different kinds of slab gels in multiple numbers with each gel having similar physical characteristics in its type and provides desired results comparable to the gels made by commercial sources.
The present study focuses on the isolation of three phosphate solubilizing bacteria (PSB), PSB1, PSB2 and PSB3 from the gut of earthworm Metaphire posthuma. The three stains were identified as Bacillus megaterium (MF 589715),... more
The present study focuses on the isolation of three phosphate solubilizing bacteria (PSB), PSB1, PSB2 and PSB3 from the gut of earthworm Metaphire posthuma. The three stains were identified as Bacillus megaterium (MF 589715), Staphylococcus haemolyticus (MF 589716) and Bacillus licheniformis (MF 589720) through 16 S rRNA gene sequencing and biochemical characterization. The strains showed resistance to the metals Cu and Zn at significant concentrations and could solubilize phosphate even in the presence of metals. Maximum phosphate was solubilized by strain PSB3 with a production of 222 ± 2.0 mg L −1 soluble phosphate followed by PSB1 (213.7 ± 1.3 mg L −1) and PSB2 (193.5 ± 1.5 mg L −1) at 96 h of incubation. The strains were able to produce indole acetic acid (IAA) in presence of L-tryptophan and possessed ammonium ion production potential in the order PSB3 > PSB1 > PSB2 (P < 0.05). The sterilized seeds of mung beans (Vigna radiata) displayed greater germination rate and higher growth under bacterium-enriched conditions. The effect on seed germination traits by the isolated strains followed the order of PSB3 > PSB1 > PSB2 (P < 0.05). Our results suggest that the three isolated PSB strains from earthworm gut possess intrinsic abilities of growth promotion, metal resistance and solubilization of phosphate which could be exploited for plant growth promotion and bioremediation even under metal-stress conditions.
Quantitative relationship of primary productivity and fish productivity and estimating aquatic health indices in tropical oxbow lake ecosystems remains to be addressed as predictors of fisheries yield in sustainable management. The... more
Quantitative relationship of primary productivity and fish productivity and estimating aquatic health indices in tropical oxbow lake ecosystems remains to be addressed as predictors of fisheries yield in sustainable management. The aquatic health indicators and aquatic health status assessed with biological properties of phytoplankton, zooplankton, macroinvertebrates, macrophytes and fish in a semi-closed tropical oxbow lake ecosystem in the eastern India were studied along with socioecological and socio-economical aspects. Five ecological classes namely phytoplankton, zooplankton, macroinvertebrate, macrophyte and fish have been championed as effective biological indicators supported by physicochemical attributes. The established aquatic health indices registered the health status as moderate to poor. Organic loading and consequent nutrient enrichment and water quality deterioration during monsoon led to more homogeneous benthic biotic assemblage. With observed diverse nature of each trophic level of the ecosystem, there occurred a downstream 'spillover' of diversity along the food chain. The 'structure affecting structure' argument goes in tune with the theory of consumers controlling species diversity. Total 38 fish productivity regression equation models explained clearly that fish abundance and productivity were declining due to high anthropogenic activities of jute retting and indiscriminate uses of fishing gears of various mesh sizes during monsoon and thereafter, which need to be regulated.
Arsenic (As) is a toxic metalloid associated with various negative human health impacts including cancer, skin lesions, cardiovascular diseases, and diabetes. Arsenic contamination of groundwater and soil is a major human health issue,... more
Arsenic (As) is a toxic metalloid associated with various negative human health impacts including cancer, skin lesions, cardiovascular diseases, and diabetes. Arsenic contamination of groundwater and soil is a major human health issue, particularly in South and Southeast Asia. Use of As-contaminated groundwater from shallow tube wells for irrigation of paddy rice, the staple food for people in this region, is one of the causes of As-related health impacts. The anaerobic growing conditions of flooded rice paddies and the unique physiology of the rice plants lead to increased As levels in rice. The World Health Organization (WHO) has set advisory levels of As in polished (i.e., white) rice grain at 0.2 mg/kg, but the EU and USA are yet to set legal standards for As in rice and rice-based products. Strategies for lowering As accumulation in rice revolve around two approaches-agronomic and biotechnological. Agronomic approaches, such as mineral supplementation of soil using iron, phosphorus, sulfur, silicon, water management, soil aeration practices, and the use of biological agents, are designed to lower As solubility, and uptake by rice. Rotation of the rice crop with As accumulating plants could also result in lowering soil As. Biotechnological approaches involve producing transgenic rice varieties by altering the expression of genes involved in As uptake, translocation, and sequestration in the plant. These approaches, combined with proper diet management and creating public awareness on potential health risks resulting from chronic exposure to As in rice, could play a key role in risk reduction. Keywords Arsenic. Rice. Uptake. Food chain. Human health. Agronomic practices This article is part of the Topical Collection on Human Health Effects of Environmental Pollution
Some of the authors of this publication are also working on these related projects: Thermoplastic extrusion of a binary mixture composed of cassava flour and Amazon river shrimp View project Assessment of impact of climate change on... more
Some of the authors of this publication are also working on these related projects: Thermoplastic extrusion of a binary mixture composed of cassava flour and Amazon river shrimp View project Assessment of impact of climate change on inland aquaculture in selected districts of West Bengal View project
Hooghly-Matla estuarine system along with the Sundarbans mangroves forms one of the most diverse and vulnerable ecosystems in the world. We have investigated the distribution of Co, Cr, Cu, Fe and Zn along with sediment properties at six... more
Hooghly-Matla estuarine system along with the Sundarbans mangroves forms one of the most diverse and vulnerable ecosystems in the world. We have investigated the distribution of Co, Cr, Cu, Fe and Zn along with sediment properties at six locations [Shamshernagar (S1), Kumirmari (S2 and S3), Petuaghat (S4), Tapoban (S5) and Chemaguri (S6)] in the Hooghly estuary and reclaimed islands of the Sundarbans for assessing the degree of contamination and potential ecological risks. Enrichment factor values (0.9-21.6) show enrichment of Co, Cu and Zn in the intertidal sediments considering all sampling locations and depth profiles. Geo-accumulation index values irrespective of sampling locations and depth revealed that Co and Cu are under class II and class III level indicating a moderate contamination of sediments. The pollution load index was higher than unity (1.6-2.1), and Co and Cu were the major contributors to the sediment pollution followed by Zn, Cr and Fe with the minimum values at S1 and the maximum
Universities can play a pivotal role in upholding sustainability practices through diverse drivers and catalysts. A suite of eco-friendly management strategies and practices for energy, water, wastes, natural environment including... more
Universities can play a pivotal role in upholding sustainability practices through diverse drivers and catalysts. A suite of eco-friendly management strategies and practices for energy, water, wastes, natural environment including biodiversity, built environment and education can shrink institutional ecological footprint and usher in a paradigm shift in the mindset.By gauging sustainability drives one can evaluate university's commitment towards sustainability, and university can maneuver organizational changes.The article presents a spectrum of green practices as benchmark for measuring potential, performance and progress of universities towards sustainable development goals.
Self-assemblies of N 2 O 4 donor Schiff base ligands, that is, N,N'-Bis(3-ethoxysalicylidenimino) 1, 3-diaminopropane (H 2 L OEt) with cadmium acetate salts in presence of auxiliary co-ligands thiocyanato/azido/chloride allow the... more
Self-assemblies of N 2 O 4 donor Schiff base ligands, that is, N,N'-Bis(3-ethoxysalicylidenimino) 1, 3-diaminopropane (H 2 L OEt) with cadmium acetate salts in presence of auxiliary co-ligands thiocyanato/azido/chloride allow the formation of three anion control complexes, specifically, [Cd 2 L OEt (m 1,3-SCN)(h 1-SCN)] n (1), {Cd 4 (L OEt) 2 (m 1,1-N 3) 3 (h 1-N 3)] 2 (2) and [Cd 2 (L OEt)(Cl) 2 .CH 3 OH].CH 3 OH] (3). Crystal structures of complexes 1-3 were determined by single-crystal X-ray diffraction studies. The single-crystal X-ray diffraction analysis confirmed that complex 1 is an one-dimensional polymeric chain in which Cd(II) ions are bridged by one thiocyanate group bonding in an end-to-end fashion. Complex 2 is a centrosymmetric octanuclear complex with double endon azide (m 1,1-N 3 À) as linker. On the other hand, 3 is a dinuclear complex with terminally bound Cl À ions. Analysis of the structure revealed that all the complexes possess a 4membered Cd 2 (m 2-O) 2 core fastened by the combined coordination action of a doubly deprotonated ligand. Complexes 1-3 have been successfully characterized by elemental analyses, IR and UV-Vis spectroscopy. The luminescent properties of complexes 1-3 have been studied in DMSO solution. The antibacterial and antibiofilm potential for complexes 1-3 were investigated against Gram-positive and Gram-negative bacterial strains. Intermolecular interactions with respect to percentages of hydrogen bonding of cadmium complexes were quantified by Hirshfeld surface.
h i g h l i g h t s High exposure through ingestion suggests higher risk due to biomagnification. PAH sources were both from pyrolytic and petrogenic origins together. PAH carcinogenic potential were lower than other Indian and Asian... more
h i g h l i g h t s High exposure through ingestion suggests higher risk due to biomagnification. PAH sources were both from pyrolytic and petrogenic origins together. PAH carcinogenic potential were lower than other Indian and Asian river estuaries. p,pʹ-DDE and o,pʹ-DDT exceeded the average global concentration. a-HCH/g-HCH indicated sources from lindane and HCH technical mixtures.
Contaminant removal from water involves various technologies among which adsorption is considered to be simple, effective, economical, and sustainable. In recent years, nanocomposites prepared by combining clay minerals and polymers have... more
Contaminant removal from water involves various technologies among which adsorption is considered to be simple, effective, economical, and sustainable. In recent years, nanocomposites prepared by combining clay minerals and polymers have emerged as a novel technology for cleaning contaminated water. Here, we provide an overview of various types of clay-polymer nanocomposites focusing on their synthesis processes, characteristics, and possible applications in water treatment. By evaluating various mechanisms and factors involved in the decontamination processes, we demonstrate that the nanocomposites can overcome the limitations of individual polymer and clay components such as poor specificity, pH dependence, particle size sensitivity, and low water wettability. We also discuss different regeneration and wastewater treatment options (e.g., membrane, coagulant, and barrier/columns) using clay-polymer nanocomposites. Finally, we provide an economic analysis of the use of these adsorbents and suggest future research directions.
Water chest nut Trapa is a minor fruit crop and potential carbon sequester of atmospheric carbon. Mass production of water chest nut using a vast number of unused small water bodies and derelict waters is a win-win-win-win strategy toward... more
Water chest nut Trapa is a minor fruit crop and potential carbon sequester of atmospheric carbon. Mass production of water chest nut using a vast number of unused small water bodies and derelict waters is a win-win-win-win strategy toward mitigation of global warming, nutritional security, empowerment and resource utilization. Growth performance of Trapa was conducted in small culture units using different CNP ratios (25:02:01; 101:08:01; 290:01:01) at a fixed dose (0.2 kg/tank) of mixed manure with different doses (100, 200, 400, 600 g) of optimal CNP ratio (101:08:01) during the life cycle of Trapa. The total number of fruits and the wet weight of Trapa in different dose treatments ranged from 56 to 192 and from 258 to 379 g/tank. Yield of Trapa remained maximum when CNP ratio was 101:8:1 at 200 g/tank and the dosage was 200 g/tank with the optimal CNP ratio (134 g) and then declined with further rise in fertilizer dose. The proximate analysis of Trapa revealed the highest phosphorus content in all the tissues (fruit, leaf, and root) of Trapa grown in the CNP ratio of 101:08:01. Of the total amount of carbon in Trapa, contribution was maximum by the fruit (38-41%), followed by leaf (27-35%) and root (23-32%) in different ratio treatment. The C content of harvested Trapa grown in different CNP ratios (Table 4) was higher in fruit (38-41%) followed by leaf (27-35%) and root (23-32%) among tissues. The amount of C observed in control (32%) increased by 6% in 25:02:01 (34%) which was higher than remaining two treatments (31%). Dry weight or total carbon content of water chestnut tended to rise with increasing levels of phosphate of water from the dosage of 100 to 200 g with optimal CNP ratio and declined thereafter. A direct relationship between the dry weight or carbon content of Trapa and the total carbon content or phosphate to total carbon ratio of water was established. However, the carbon content remained between 27-32% in all the three tissues of Trapa culture when cultured in different dose treatments. It is reasonable to conclude that water chestnut may be promoted for mass cultivation using the recommended culture protocol that would help trapping atmospheric carbon, provide nutritional security and employment generation and resource utilization.
Crop losses mainly occur due to biotic factors, which include soil-borne phytopathogens, insect pests, parasites, and predators. The major loss of food in the food industry is due to its spoilage by various microorganisms. With... more
Crop losses mainly occur due to biotic factors, which include soil-borne phytopathogens, insect pests, parasites, and predators. The major loss of food in the food industry is due to its spoilage by various microorganisms. With advancement in nanotechnology, the use of nanoparticles in food and agriculture crop yield can be improved. In this context, copper nanoparticles (CuNPs) have attracted a great deal of attention from all over the world due to their broad-spectrum antimicrobial activity. Copper is one of the key micronutrients, which plays an important role in growth and development of plants. CuNP-based fertilizer and herbicide can be used in agriculture. The small size of CuNPs facilitates their easy absorption by the plants. CuNPs can be promisingly used in the food packaging to avoid the growth of food spoilage microorganisms. The use of CuNP-based agar packaging materials has substantial potential to increase the shelflife of food. The present review focuses on the application of Cu and CuNPs in food and agriculture. Moreover, antimicrobial and pesticidal properties of CuNPs are also discussed.
This work aimed at elucidating the role of bacteria present in the gut of the earthworm Metaphire posthuma in plant growth promotion and toxic trace elements (TTEs) bioremediation. We isolated and identified three bacterial strains... more
This work aimed at elucidating the role of bacteria present in the gut of the earthworm Metaphire posthuma in plant growth promotion and toxic trace elements (TTEs) bioremediation. We isolated and identified three bacterial strains Bacillus safensis (MF 589718), Bacillus flexus (MF 589717) and Staphylococcus haemolyticus (MF 589719) among which the Bacillus strains appeared to be significantly more potent than the Staphylococcus strain (P < 0.05) in promoting plant growth and removing TTE (Cr(VI), Cu(II) and Zn(II)) from aqueous media. These strains exhibited several plant growth promoting traits (e.g., indole acetic acid (IAA), gibberellic acid (GA) and ammonium ion production, 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase activity, and phosphate solubilizing potential). In a pot trial, the gut isolates improved Vigna radiata seed germination, and enhanced the leaf area (30-79%), total chlorophyll content (26-67%) and overall root-shoot biomass (32-83%) as compared to the control. Bacillus safensis and Bacillus flexus were equipotent in removing Cr(VI) (40.5 and 40.3%) from aqueous media; the former triumphed for Zn(II) removal (52.8%), while the latter performed better for Cu(II) removal (43.5%). The gut isolates successfully solubilized phosphate even in TTE-contaminated conditions. The results demonstrate that the earthworm's enteric bacteria possess inherent plant growth promoting, TTE resistance and phosphate solubilization (even under TTE stress) properties which can be further explored for their application in sustainable crop production and environmental management.
Soil fertility and its productivity are the two pillars for maintaining agricultural output and it is a measure of soil performance. Growing concerns about climate change have recently focused on the fate of high-performance soils. Soil... more
Soil fertility and its productivity are the two pillars for maintaining agricultural output and it is a measure of soil performance. Growing concerns about climate change have recently focused on the fate of high-performance soils. Soil biological health is an important aspect of agricultural productivity and a global Author deceased in January 2019. Professor Lily Pereg was expert in soil microbial ecology with long-standing experience. We have lost a very active scientist in this field. All co-authors extend the deepest condolence to family, friends and colleagues of Prof Pereg.
The present study shows the potential of an extracellular polymeric substance (EPS) produced by Bacillus licheniformis strain KX657843 isolated from earthworm (Metaphire posthuma) gut in the sorption of Cu(II) and Zn(II) and in... more
The present study shows the potential of an extracellular polymeric substance (EPS) produced by Bacillus licheniformis strain KX657843 isolated from earthworm (Metaphire posthuma) gut in the sorption of Cu(II) and Zn(II) and in flocculation. After harvesting bacterial cells from sucrose supplemented denitrifying culture medium, the EPS was extracted following ethanolic extraction method. The Fourier Transform Infrared Spectroscopy (FTIR) and 1 H and 13 C Nuclear Magnetic Resonance (NMR) of EPS revealed its functional groups, electronegative constituents, unsaturated carbon, and carbonyl groups. The negatively charged functional groups of carbohydrates and protein moiety of the EPS endowed it with heavy metal binding capacity through electrostatic interactions. The highest flocculation activity (83%) of EPS was observed at 4 mg L −1 and pH 11. The metal sorption by EPS increased with increasing pH. At pH 8, the EPS was able to remove 86 and 81% Cu(II) and Zn(II), respectively, from a 25 mg L −1 metal solution. 94.8% of both the metals at 25 mg L −1 metal solutions were removed by EPS at EPS concentration of 100 mg L −1. From Langmuir isotherm model, the maximum sorption capacities of EPS were calculated to be 58.82 mg g −1 for Cu(II) and 52.45 mg g −1 for Zn(II). The bacterial EPS showed encouraging flocculating and metal sorption properties. The potential to remove Cu(II) and Zn(II) implies that the EPS obtained from the earthworm gut bacteria can be used as an effective agent for environmental remediation of heavy metals and in bioflocculation.
The aim was to isolate, characterize, and explore potentials of gut bacteria from the earthworm (Metaphire posthuma) and imply these bacteria for remediation of Cu(II) and Zn(II). An extracellular polymeric substance (EPS) producing gut... more
The aim was to isolate, characterize, and explore potentials of gut bacteria from the earthworm (Metaphire posthuma) and imply these bacteria for remediation of Cu(II) and Zn(II). An extracellular polymeric substance (EPS) producing gut bacteria (Bacillus licheniformis strain KX657843) was isolated and identified based on 16S rRNA sequencing and phylogenetic analysis. The strain showed maximum tolerance of 8 and 6 mM for Cu(II) and Zn(II) respectively. It removed 34.5% of Cu(II) and 54.4% of Zn(II) at 25 mg L-1 after 72 and 96 h incubation respectively. The bacteria possessed a great potential to produce indole acetic acid (38.49 lg mL-1) at 5 mg mL-1 L-tryptophan following 12 days incubation. The sterilized seeds of mung beans (Vigna radiata) displayed greater germination and growth under bacterium enriched condition. We observed that the bacterial strain phosphate solubilization ability
Background: Despite the available clinico-epidemiological evidence of heavy metal-associated respiratory health hazards among metal arc-welders, experimental confirmation of such an association is lacking. Methods: In this study, we... more
Background: Despite the available clinico-epidemiological evidence of heavy metal-associated respiratory health hazards among metal arc-welders, experimental confirmation of such an association is lacking. Methods: In this study, we recruited 15 metal arc-welders and 10 referent workers without direct exposure. We assessed respiratory health through a questionnaire and spirometry; estimated manganese, nickel and cadmium levels in blood, urine and induced sputum; performed differential counts of sputum leucocytes and measured plasma malondialdehyde (MDA). We used atomic force and scanning electron microscopy to assess the physical property of the alveolar macrophages (AMs) obtained from induced sputum and analysed cell surface deposition of heavy metals using energy dispersion X-ray analysis (EDX). Sputum cellular DNA damage was assessed by DNA-laddering assay. Results: There was a higher body burden of manganese and nickel in the metal arc-welders than the referents. Among major spirometric indices, only the forced mid-expiratory flow rates (FEF 25-75) were reduced in the welders compared with the referents (63.4 + 14.7 vs. 89.2 + 26.7, p < 0.01); this reduction was associated with both heavy metal levels (: À41.8, 95% CI: À78.5% to À5.1%) and plasma MDA (À0.37; À0.68 to À0.06). In metal arc-welders, significant physical and morphological changes were observed in AMs through microscopic evaluation while EDX analyses demonstrated higher deposition of heavy metals on the AM cell surface than the referents. We also observed a higher degree of DNA damage in the sputum cells of the exposed workers than the referents. Conclusion: Heavy metal exposure-induced adverse respiratory effects among metal arc-welders are mediated through haematological and cytological interactions.
This study investigated the preparation of magnetic biochar from N 2-and CO 2-assisted pyrolysis of spent coffee ground (SCG) for use as an adsorption medium for As(V), and the effects of FeCl 3 pretreatment of SCG on the material... more
This study investigated the preparation of magnetic biochar from N 2-and CO 2-assisted pyrolysis of spent coffee ground (SCG) for use as an adsorption medium for As(V), and the effects of FeCl 3 pretreatment of SCG on the material properties and adsorption capability of the produced biochar. Pyrolysis of FeCl 3pretreated SCG in CO 2 atmosphere produced highly porous biochar with its surface area~70 times greater than that produced in N 2 condition. However, despite the small surface area, biochar produced in N 2 showed greater As(V) adsorption capability. X-ray diffraction and X-ray photoelectron spectrometer analyses identified Fe 3 C and Fe 3 O 4 as dominant mineral phases in N 2 and CO 2 conditions, with the former being much more adsorptive toward As(V). The overall results suggest functional biochar can be facilely fabricated by necessary pretreatment to expand the applicability of biochar for specific purposes.
Heavy metal(loid)s and organic contaminants are two major groups of pollutants in soils. The fate and exposure of such pollutants in soil depends on their chemical properties, speciation, and soil properties. Soil properties and processes... more
Heavy metal(loid)s and organic contaminants are two major groups of pollutants in soils. The fate and exposure of such pollutants in soil depends on their chemical properties, speciation, and soil properties. Soil properties and processes that control the toxicological aspects of pollutants include temperature, moisture, organic matter, mineral fractions, and microbial activities. These processes are vulnerable to climate change associated with global warming, including increased incidences of extreme rainfall, extended dry periods, soil erosion, and a rise in sea level. Here we explain evidence that relates to the effects of climate change-driven soil processes on the mobility, transport, and storage of pollutants in soil. The review found that changes in climate could increase human exposure to soil contaminants mainly due to processes involving soil organic carbon (SOC), surface runoff, redox state, and microbial community. However, uncertainties remain in relation to the extent of contaminant toxicity to human health, which is linked to global change drivers.
Traditional medicine is the earliest healthcare system of humanity, which relies on the revered traditional legacy of healing powers hidden in the natural objects like medicinal plants, animals, etc. It encompasses the Indian Ayurveda,... more
Traditional medicine is the earliest healthcare system of humanity, which relies on the revered traditional legacy of healing powers hidden in the natural objects like medicinal plants, animals, etc. It encompasses the Indian Ayurveda, traditional Chinese medicine, Arabic Unani medicine, and other forms of indigenous medicine. The Ayurveda is the most commonly practised system of traditional medicine in the Indian subcontinent and has been carving niche in the Western countries. It is based on the Vedic hypothesis that there are some common cardinal premises underlying the harmony and homeostasis maintained in the microcosm (individual body) and macrocosm (nature/universe). Both man and the universe are composed of the same basic elements, and disease manifests when the balance is destabilized. Some heavy metal(oid)s are added intentionally in Ayurvedic products as it is thought that the equilibrium of lead, copper, gold, iron, mercury, silver, tin, zinc thallium, and arsenic is essential for normal functioning of the human body. Similarly, traditional Chinese medicine believes that the human body has an organic unity based on the opposing and complementary relationships of yin and yang. Such medicine also contains heavy metals which come from contaminated soil source or are deliberately added as ingredients for specific curative cause. Traditional medicine focuses on causes, not the symptoms, heal the "whole", not the "part" by only correcting the symptoms, like the modern medicine. These low-cost medicines are thought of treating diseases and disorders without posing any risk of side effects. But it is wrong in reality, raising human health concerns and
The geochemical fractionation and potential mobilization of cadmium, chromium, copper, nickel and lead were studied in surficial sediments (top 0-10 cm; < 63 μm grain-size) of the Hooghly (Ganges) River Estuary, eastern part of India,... more
The geochemical fractionation and potential mobilization of cadmium, chromium, copper, nickel and lead were studied in surficial sediments (top 0-10 cm; < 63 μm grain-size) of the Hooghly (Ganges) River Estuary, eastern part of India, using a sequential extraction procedure. The risk assessment was evaluated at three specific levels; i.e., enrichment level (enrichment factor, geo-accumulation index), the availability level (elements bound to different fractions, risk assessment code, Individual and Global contamination factors) and biological toxicity level (Potential ecological risk index; sediment quality guidelines). Different geochemical phases indicated heterogeneities in TE distribution patterns as follows: (i) Cd was dominant in the exchangeable phase and significant proportion of Pb was bounded to the reducible fractions; (ii) the potential mobile fraction (ΣF1 − F3) in the sediments was higher for Cd and Pb (> 46%), reflecting their adverse impact on benthic organisms as they are weakly bound to the sediment and can migrate to water; (iii) a minor fraction of Cu (< 10%) was found in the oxidizable fraction suggesting less environmental risk to the aquatic biota and (iv) the dominance of the Ni, Cr and Cu in the residual fraction supports the assumption of their geogenic origin. Both Cd and Cu posed medium to high ecological risk values based on risk assessment code (RAC). Global Contamination Factor (GCF) values allowed to identify the "pollution hotspots" in the study area.
Water quality measurements can indicate carbon status or algal biomass. Microalgae have an excellent ability to utilize all forms of dissolved inorganic carbon at different pH conditions. Water quality signature (WQS) using three... more
Water quality measurements can indicate carbon status or algal biomass. Microalgae have an excellent ability to utilize all forms of dissolved inorganic carbon at different pH conditions. Water quality signature (WQS) using three different expressions with (i) pH; (ii) total alkalinity, hardness and total dissolved solids; and (iii) nitrate and conductivity of water was assessed in 32 wetlands distributed across 5 districts of West Bengal, India. Two zones were clearly discernible: coldwater (15-23 C) high-altitude lakes in Darjeeling, and tropical (31-32 C) low-altitude wetlands. Multivariate analysis of the Akaike information criterion (ACI) model revealed location-specific variability of agroclimatic and biogeochemical interactions. Dissolved inorganic carbon and inorganic nitrogen appeared to be important in regulating the phytocarbon content of microalgae. The wetlands located in the Gangetic alluvial tropical or semi-coastal areas (Hooghly, 24-Parganas, Nadia, Midnapore) were alkaline (pH ¼ 7.52-7.97) where half-bound carbon dioxide comprised the major component (18-26%) of total inorganic carbon, with moderate to eutrophic (PO 4-P À 0.16-0.23 mg/l) states which have a negative feedback to global warming. The heterogeneity of measured water quality signature consolidated the sanative nature of wetlands for their complex functional attributes with agroclimatic, biogeochemical and soil-water-biological interactions.
The increasing demand for sustainable, robust and cost-efficient wastewater treatment techniques strengthen the implementation of constructed wetlands (CWs) in the agricultural sector. In countries like Belgium (Flanders), the compliance... more
The increasing demand for sustainable, robust and cost-efficient wastewater treatment techniques strengthen the implementation of constructed wetlands (CWs) in the agricultural sector. In countries like Belgium (Flanders), the compliance of strict water quality standards and surface area requirements have hindered considerably their application. New wetland designs such as aerated CWs, could help to overcome these challenges. This study evaluated the capacity of artificially aerated mesocosm systems to decrease chemical oxygen demand (COD) concentrations below the 125 mgO 2 /L limit imposed on installations treating animal manure. The treatment of this high-strength wastewater has been slightly studied via aerated CWs. A three-stage experiment investigated the effect of constant, intermittent and non-aeration regimes on: ammonium volatilisation, the evolution of organic and nitrogen compounds concentrations, and denitrification. The results were assessed through a mixed modelling procedure using SAS 9.4 software. A COD removal between 65% and 58% in constantly and intermittent aerated systems, versus 27% COD removal in the non-aerated system indicated the effectiveness of aeration. However, a dissimilarity was encountered in the removal of nitrogen compounds, resulting in an 82% decrease of nitrate concentrations in the non-aerated system, versus 0.5% and 11% in the aerated ones. Based on the results, this experimental setup adjusted to field operational conditions can prove that aerated CWs can treat the liquid fraction of piggery manure.
Purpose This study was conducted to evaluate the synergistic effects of organic amendments and soil water status on trace metal release from serpentine soil. Materials and methods Two organic amendments, dendro-biochar (BC) and municipal... more
Purpose This study was conducted to evaluate the synergistic effects of organic amendments and soil water status on trace metal release from serpentine soil. Materials and methods Two organic amendments, dendro-biochar (BC) and municipal solid waste compost (CM), were added to serpentine soil at four different ratios, specifically 2.5:0.0, 2.5:1.0, 2.5:2.5, and 2.5:5.0% (w/w). Along with the control (with no organic amendments), each soil treatment was incubated separately under saturated point (SP) and field capacity (FC) water content for 10 days. Subsamples were obtained from each treatment to analyze the bioavailable trace metal concentration and related edaphic parameters, namely total organic carbon (TOC), nitrate (NO 3 −), phosphate (PO 4 3−
Two new dicyanamide-interlaced tetranuclear Zn(II)-Schiff-base complexes [Zn 2 (L OMe)(µdca-κN 1 κN 5)(µ-dca-κN 1)] 2 (1) and [Zn 2 (L OEt)(µdca-κN 1 κN 5)(µ-dca-κN 1)] 2 (2) were synthesized by using salicylaldimino type Schiff bases (H... more
Two new dicyanamide-interlaced tetranuclear Zn(II)-Schiff-base complexes [Zn 2 (L OMe)(µdca-κN 1 κN 5)(µ-dca-κN 1)] 2 (1) and [Zn 2 (L OEt)(µdca-κN 1 κN 5)(µ-dca-κN 1)] 2 (2) were synthesized by using salicylaldimino type Schiff bases (H 2 L OMe) and (H 2 L OEt) respectively. Schiff base ligands and the complexes were characterized by elemental analyses, powder X-ray diffraction, FT-IR, FT-Raman, 1 H NMR, 13 C NMR, UV-Vis, TGA and fluorescence spectroscopy. Dicyanamide modulated complexes were structurally characterized by single crystal X-ray diffraction studies. X-ray crystal structure divulges that the two complexes are isostructural. In both the complexes, the Zn1 metal centers fulfill 5-coordinated distorted square pyramidal geometry having ZnN 3 O 2 chromospheres where Schiff bases are mainly trapped in their complete deprotonated dianionic forms[L] 2− , whereas Zn2 metal center attained distorted octahedral geometry. In both complexes two asymmetric units are connected by double μ 1,5dicyanamide ion thus forming Zn 4-nuclear metal complex. B3LYP/def2-TZVP level of theory (DFT) successfully applied in both complexes. The complexes (1-2) exhibit intraligand (π → π *) fluorescence in DMSO solvent with lifetimes in the range 0.66-0.82 ns. In vitro antibacterial, membrane damage assay and anti-biofilm properties of both complexes are evaluated against some important Gram-positive and Gram-negative bacterial strains. Finally, the UV-Vis experimental spectral findings are well rationalized with the electronic distribution of HOMO-LUMO through TD-DFT level of calculations.
Utilization of nanotechnology and nanomaterials is an integral part of modern life. The increased use of nanomaterials in various consumer products, industries, medical instruments, and information technology and energy sectors has... more
Utilization of nanotechnology and nanomaterials is an integral part of modern life. The increased use of nanomaterials in various consumer products, industries, medical instruments, and information technology and energy sectors has created research interest because of their potential toxicity for the environment. Nanomaterials can also be added directly and indirectly to the soil and water treatment plants to reduce pollutant concentrations. Nanoparticles may enter the aquatic system through runoff and industrial effluent discharge, therefore, potentially contaminate both the aquatic and terrestrial systems. Researchers have used laboratory experiments to understand the effect of nanomaterials and their transformation in water and soil environment. The transformation of nanoparticles in the environment involves various physical and chemical processes, and their degradation/transformation products may introduce further toxicity. Various microparticles or host materials can be used to support or coat nanoparticles in order to reduce their toxicity. Microparticles including clay minerals, polymer, carbon-based materials (biochar) are popular to support nanoparticles due to their large surface area and improved functional char
When on March 24, 2020 the Government of India ordered a complete lockdown of the country as a response to the COVID-19 pandemic, it had serious unwanted implications for farmers and the supply chains for agricultural produce. This was... more
When on March 24, 2020 the Government of India ordered a complete lockdown of the country as a response to the COVID-19 pandemic, it had serious unwanted implications for farmers and the supply chains for agricultural produce. This was magnified by the fact that, as typically in developing countries, India's economy is strongly based on farming, industrialization of its agricultural systems being only modest. This paper reports on the various consequences of the COVID-19 lockdown for farming systems in India, including the economy, taking into account the associated emergency responses of state and national governments. Combining quantitative and qualitative sources of information with a focus on the Indian state of Uttar Pradesh, including expert elicitation and a survey of farmers, the paper identifies and analyzes the different factors that contributed to the severe disruption of farming systems and the agricultural sector as a whole following the lockdown. Among other issues, our study finds that the lack of migrant labor in some regions and a surplus of workers in others greatly affected the April harvest, leading to a decline in agricultural wages in some communities and an increase in others, as well as to critical losses of produce. Moreover, the partial closure of rural markets and procurement options, combined with the insufficient supply of products, led to shortages of food supplies and dramatically increased prices, which particularly affected urban dwellers and the poor. We argue that the lessons learned from the COVID-19 crisis could fuel the development of new sustainable agro-policies and decision-making in response not only to future pandemics but also to the sustainable development of agricultural systems in India and in developing countries in general.
Nanotechnology has evolved as an outstanding versatile technology expected to become ubiquitous and to revolutionize the functionality of products in various sectors. The hallmarks of nanomaterials are higher surface area to volume ratio... more
Nanotechnology has evolved as an outstanding versatile technology expected to become ubiquitous and to revolutionize the functionality of products in various sectors. The hallmarks of nanomaterials are higher surface area to volume ratio and greater interfacial nature that pave way to their unique fascinating features and functionalities. The environmental fate and behaviour of nanoparticles entail bioavailability, uptake, internalization, and toxicity, which are conditioned by and interactions of the chemistry of both the nanomaterial and the ambient aquatic environment, and the biology of the organisms. Oxidative stress is a predictive paradigm for ambient nanomaterials' toxicity. Nanoparticles can cross trophic boundaries via bioconcentration and biomagnifications through food chain. Majority of the nanotoxicological studies undertaken so far are descriptive or "proof-of-principle" experiments, which have tried to document toxic effects on individual organisms, bearing hardly any concrete ecological implications. To bridge the knowledge gap an urgent
Nanomaterials have been benefiting human by their wide applications in different fields. Till date, many types of natural and engineered nanomaterials have been reported. Each of them has specific characteristics, which are helpful in... more
Nanomaterials have been benefiting human by their wide applications in different fields. Till date, many types of natural and engineered nanomaterials have been reported. Each of them has specific characteristics, which are helpful in deciding their use for particular application. Although they are beneficial to the human beings, there is probability of their harmful effects on the ecosystem. After the desired use of the nanomaterials, they are routinely disposed of into the environment either intentionally or unintentionally. This scenario can create the harmful environment for the whole ecosystem. The ecotoxicity of nanomaterials is an imperative point to be considered for the safety of flora and fauna. Hence, with argument on their characteristics and applications, their safety for human and environment should also be considered. Therefore, the present chapter introduces the nanomaterials, encompasses the discussion on major types of nanomaterials, which are being available naturally and others that are synthesized artificially. The parameters which make M. Rai
Salinity and acidity have affected several hundred million hectares of land throughout the globe which poses a major threat to global food security and biodiversity. Application of organic amendments for salt-affected soils has been... more
Salinity and acidity have affected several hundred million hectares of land throughout the globe which poses a major threat to global food security and biodiversity. Application of organic amendments for salt-affected soils has been identified as one of the most effective ways to mitigate salinity-induced problems and considered as a green technique offering twin benefits of waste load reduction and land reclamation. However, studies on reclaiming acidic-salt affected soils are limited. Therefore, this study aimed to determine the reclamation potential of biochars and organic amendments involving Gliricidia sepium biochar produced at 300 °C, 500 °C, and 700 °C, green waste compost, and municipal sewage sludge at three different amendment ratios, 1.0%, 2.5% and 5.0%. The incubation experiment was conducted for a 4-month period with different amendment ratios applied to the coastal acidic-salt affected soil. Subsamples were extracted from incubation pots after 1 and 4 months and analyzed for soil chemical parameters (pH, EC, NO 3 − , PO 4 3− , total organic carbon, cation exchange capacity, sodium adsorption ratio, exchangeable sodium percentage) and microbial enzyme activity (catalase activity, and acid-and alkaline phosphatase activity). All organic amendments demonstrated enhancement of the soil properties in a significant manner. However, increasing incubation time and amendment ratio increase the changes of soil parameters by a great percentage. Therefore, the maximum amendment ratio of 5.0% and 4 months of incubation period rendered a significant improvement in the reclamation of acidic-salt affected soil. However, the biochar produced at 500 °C contributed the maximum towards the improved physicochemical and biochemical profile of acidic-salt affected soil, making it the most promising organic amendment for the reclamation of acidic-salt affected soil. The overall reclamation efficiency of organic amendments registered the following order of variation: 700 BC < Sludge < 300 BC < Compost < 500 BC.
Mangroves have wide applications in traditional medicines due to their several therapeutic properties. Potentially toxic elements (PTEs), in mangrove habitats, need serious concern because of their toxicity, bioaccumulation capacity and... more
Mangroves have wide applications in traditional medicines due to their several therapeutic properties. Potentially toxic elements (PTEs), in mangrove habitats, need serious concern because of their toxicity, bioaccumulation capacity and ecotoxicological risks. In the current study, we aimed to examine sediment quality and bioaccumulation of PTEs in a mangrove-dominated habitat of Sundarban, India, and their relation with antimicrobial property of ten mangrove species of the region. Antimicrobial