Bactericidal effects of adsorbent on Escherichia coli for use in disinfection of drinking water

A synergistic action of silver (Ag) and groundnut husk carbon was shown, which markedly enhanced inactivation of Escherichia coli. The purpose of this study was to assess the feasibility of using a silver-impregnated groundnut husk carbon adsorbent (AdSG) for drinking water disinfection and evaluate % disinfection of E. coli. The results showed that contact of bacterial cells with AdSG resulted in a transfer of Ag ion to the cell, as evidenced by bactericidal activity. It is also possible that Ag produced generation of reactive oxygen species in the cell that led to bactericidal activity of the adsorbent. Data indicated that AdSG was effective as a bactericidal agent and may prove to be economically beneficial in drinking water disinfection.     

Solid phase extraction of trace metals from environmental samples using Amberlite XAD-7 loaded with 2-hydroxy-propiophenone-4-phenyl-3-thiosemicarbazone and determination by inductively coupled plasma–atomic emission spectrometry

A method for the solid phase extraction of trace metals, namely Co, Cu, Pb, Ni and Zn, from environmental and biological samples using column Amberlite XAD-7 loaded with 2-hydroxy-propiophenone-4-phenyl-3-thiosemicarbazone (HPPPTSC) and determination by inductively coupled spectrometry (ICP–AES) has been developed. The reagent has the capacity to form chelate complexes with the metals because of three binding sites in the reagent molecule. The optimum experimental conditions for the quantitative sorption of five metals, pH, effect of flow rate, concentration of eluent, sorption capacity and the effect of diverse ions on the preconcentration of analytes have been investigated. The sorption capacity of the resin has 83, 127, 35, 88 and 85?µmol?g^?1 for Co²⁺, Cu²⁺, Pb²⁺, Ni²⁺ and Zn²⁺, respectively. The preconcentration factors for Co²⁺, Cu²⁺, Pb²⁺, Ni²⁺ and Zn²⁺ were 100, 110, 120, 140 and 150, respectively. The accuracy of the proposed procedure was evaluated by standard reference materials. The achieved results were in good agreement with certified values. The proposed method was applied for the determination of trace metals in river water and plant leaves.     

Metacommunity dynamics over 16 years in a pyrogenic shrubland

Metacommunity theory allows predictions about the dynamics of potentially interacting species' assemblages that are linked by dispersal, but strong empirical tests of the theory are rare. We analyzed the metacommunity dynamics of Florida rosemary scrub, a patchily distributed pyrogenic community, to test predictions about turnover rates, community nestedness, and responses to patch size, arrangement, and quality. We collected occurrence data for 45 plant species from 88 rosemary scrub patches in 1989 and 2005 and used growth form, mechanism of regeneration after fire, and degree of habitat specialization to categorize species by life history. We tested whether patch size, fire history, and structural connectivity (a measure of proximity and size of surrounding patches) could be used to predict apparent extinctions and colonizations. In addition, we tested the accuracy of incidence-function models built with the patch survey data from 1989. After fire local extinction rates were higher for herbs than woody plants, higher for species that regenerated only from seed than species able to resprout, and higher for generalist than specialist species. Fewer rosemary specialists and a higher proportion of habitat generalists were extirpated on recently burned patches than on patches not burned between 1989 and 2005. Nestedness was highest for specialists among all life-history groups. Estimated model parameters from 1989 predicted the observed (1989-2005) extinction rates and the number of patches with persistent populations of individual species. These results indicate that species with different life-history strategies within the same metacommunity can have substantially different responses to patch configuration and quality. Real metacommunities may not conform to certain assumptions of simple models, but incidence-function models that consider only patch size, configuration, and quality can have significant predictive accuracy.     

High consumption of pesticides in agricultural fields leads to prevalence of cancer cases in rural pockets of eastern India: A case study

This study was performed to evaluate the carcinogenic health risk of pesticides used in agricultural field in rural pockets of eastern India. The analysis of pesticide residue in rice grain sample was performed by Gas Chromatography Mass Spectrometry (GC-MS). It was observed that for pesticide DDT, the HR values was ranging between 0.5 to 3.2 and for lindane HR was 0.4 to 1.1, respectively. The DDT and Lindane exhibited HR values >1 in some sampling sites which revealed the carcinogenic effects and HR <1 in some sampling sites which revealed non carcinogenic effects of same pesticide. These results revealed a clear indication of potential carcinogenic health risk to human health through consumption of contaminated rice in some areas of Bargarh district. DDT has a long half-life, so it persists in the environment for a longer period of time and induces carcinogenic risk to human health predominantly than other pesticide lindane. A case study on cancer prevalence in Bargarh district was also carried out to support the findings of quantitative analysis. The primary data collected from the cancer affected area by personal questionnaires method to the person concern and the secondary data collected from the Bargarh District Head Quarters Hospital's register. The cancer death reported by the from the year 2015 to 2021 was 320, 380, 293, 323, 278, 409, 346 in the year of 2015, 2016, 2017, 2018, 2019, 2020, 2021 respectively, with the total number of 2349 cases. From the questionnaire data, it was observed that the occurrence of male and female cancer cases was 51.75% and 48.25%, respectively. Therefore, it was concluded that there was no significant difference in gender wise cancer prevalence. The most affected age group was 51–60, that is, 26.92% followed by 41–50, that is, 23.42%. Therefore, it was concluded that the middle-aged adults (40–60) were more vulnerable to the cancer than young adults (3–40) and old adults (60–100). The most prevalent cancer was breast (22.72%) followed by stomach (14.33%).     

Distribution of heavy metals in polluted creek sediment

Sediments affect the water quality substantially. The metal concentrations in sediments often reflect the degree of pollution of the aquatic environment. The sediments of Thane Creek near Bombay were analyzed for nine metals Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn on twenty stations. The average metal concentrations in the sediments were 2.29, 37.25, 39.89, 103.38, 69825.0, 860.15, 105.08, 54.08, and 169.60 g g^-1 dwt respectively. The metal concentrations at certain stations were relatively higher than those of uncontaminated sediments, possibly due to industrial activity in the former area.     

Cell cycle stage specific application of municipal landfill leachates to assess the genotoxicity in root meristem cells of barley (Hordeum vulgare)

Municipal solid wastes (MSW) are unavoidable sources of environmental pollution. Improper disposal of municipal waste results in the leaching of toxic metals and organic chemicals, which can contaminate the surface and ground water leading to serious health hazard. In this study, the toxic effects of the leachate prepared from municipal solid waste samples were examined in root meristem cells of barley (Hordeum vulgare L.) at various stages of cell cycle, i.e., G₁, S, and G₂. Seeds of barley were exposed to 2.5, 5, and 10 % of leachates in soil and aqueous media in 48 h at different cell cycle stages. The physicochemical data of the present study revealed that municipal solid waste leachate contains high amount of heavy metals, which significantly affected growth and physiological activities of barley. Significant inhibition in hypocotyl length, germination, and mitotic index were observed at all concentration of leachate treatment. Induction of chromosomal aberrations (CA’s) and micronuclei (MN) formation were also observed with different concentrations of leachate treatment at 7, 17, and 27 h of presoaking durations, which falls in G₁, S, and G₂ phase of the cell cycle, respectively. Also, exposure of leachate at S phase of the cell cycle had significant effects in barley through chromosomal aberration and micronuclei formation.     

Energy management in hybrid electric vehicles using optimized radial basis function neural network

This paper deals with energy management in hybrid electric vehicles. Use of radial basis function neural network (RBFNN) for the problem of energy management gains importance in the present decade. Use of genetic algorithm (GA) and particle swarm optimization (PSO) as optimization algorithms for parameter estimation is also well known. However, none of the researchers in the area tried to use GA and PSO as training algorithms for the problem. Hence in this paper, we propose two novel methods, based on RBFNN. The difference between RBFNN-based approaches in the literature and those used in this paper is the use of GA and PSO (i.e. optimising algorithms) as training algorithm to train RBFNNs. Interestingly, it is seen that the proposed approaches of this paper outperform RBFNN-based approaches in the literature with traditional training.     

An overview of policies for managing polybrominated diphenyl ethers (PBDEs) in the Great Lakes basin

The Great Lakes are an important environmental and economic resource for Canada and the United States. The ecological integrity of the Great Lakes, however, is becoming increasingly threatened by a number of persistent, bio-accumulative and harmful chemicals that enter the Great Lakes ecosystem through fluvial and atmospheric deposition. Polybrominated diphenyl ethers (PBDEs), a class of brominated flame retardant, are among such chemicals, whose concentration in the Great Lakes has greatly increased in recent years. Despite growing concern over the possible health and environmental effects of these compounds, only four of the eight Great Lakes states have enacted regulations to ban/restrict the use of PBDE while the two Canadian Great Lakes provinces are yet to endorse any regulation. Of the three main commercial PBDE mixtures (pentaBDE, octaBDE and decaBDE), penta- and octaBDE are no longer manufactured or imported into the United States and Canada. DecaBDE, however, still finds use in a variety of products. In the present paper, the authors review the current regulations and policies for managing PBDEs in the Great Lakes jurisdictions and briefly review commercially available non-bromine chemical alternatives to PBDE. As these alternatives are comparatively more expensive than PBDE, future adoption of more eco-friendly flame retardants by the polymer industry will likely depend on stricter legislation regulating the use of PBDE and/or an increased public demand for PBDE-free products.     

The future of global warming: will it be emissions control or environmental damages?

This paper explores the role of risk perceptions in influencing public policy related to global warming. It solves for the optimal paths for emissions, abatement and investment in pollution-eliminating research by incorporating perceived risks into public decision making. It also compares the impact of differential risk perceptions on international collaboration on carbon abatement. Key findings are that the perception of risks related to environmental damages and technological breakthroughs plays an important role in determining the level of mitigation efforts. A high level of perceived risk of environmental damages discourages investment in pollution-eliminating research as there are few benefits from eliminating pollution after damages are realized. Other options that allow for sequestering carbon from the atmosphere may still remain viable. Another key finding is that when it comes to effort sharing between nations, differential mitigation efforts are primarily caused due to the differences in abatement technology, benefits from emissions and research capabilities. However, such differences could be accentuated or mitigated depending upon the differences in risk perception of developed and developing countries.