Characterizing In Situ Methane‐Enhanced Biostimulation Potential for 1,4‐Dioxane Biodegradation in Groundwater

This study characterizes the 1,4‐dioxane biodegradation potential for an in situ methane‐enhanced biostimulation field pilot study conducted at Air Force Plant 44, located south of the Tucson International Airport in Arizona. In this study, the use of methane as the primary substrate in aerobic cometabolic biodegradation of 1,4‐dioxane is evaluated using environmental molecular diagnostic tools. The findings are compared to an adjacent pilot study, wherein methane was generated via enhanced reductive dechlorination and where methane monooxygenase and methane‐oxidizing bacteria were also found to be abundant. This article also presents the use of ¹³C and ²H isotopic ratio enrichment, a more recent tool, to support the understanding of 1,4‐dioxane biodegradation in situ. This study is the first of its kind, although alkane gas‐enhanced biodegradation of 1,4‐dioxane has been evaluated extensively in microcosm studies and propane‐enhanced biodegradation of 1,4‐dioxane has been previously studied in the field. ©2016 Wiley Periodicals, Inc.     

The identification of phytoextraction potential of Melilotus officinalis and Amaranthus retroflexus growing on copper- and molybdenum-polluted soils

Environmental Geochemistry and Health - The contamination of soils by heavy metals from the mining industry nowadays is one of the greatest threats to environment and human health. The cleaning of...     

Commitment,procedural fairness,and organizational citizenship behavior: a multifoci analysis

Research on commitment, procedural fairness, and organizational citizenship behavior (OCB) suggests that employees maintain distinct beliefs about, and direct behaviors towards, multiple targets in the workplace (e.g., the organization as a whole, their supervisor, and fellow workgroup members). The present studies were designed to test for “target similarity effects,” in which the relationships between commitment, procedural fairness, and OCB were expected to be stronger when they referred to the same target than when they referred to different targets. As predicted, we found that: (1) the positive relationship between commitment and OCB, and (2) the mediating effect of commitment on the positive relationship between procedural fairness and OCB, was particularly likely to emerge when the constructs were in reference to the same target. Support for these target similarity effects was found among layoff survivors (Study 1) and student project teams (Study 2). Theoretical and practical implications are discussed, as are limitations of the studies and suggestions for future research. Copyright © 2008 John Wiley & Sons, Ltd.     

Determination of Cd,Cr, Cu,Pb and Zn from various water samples with use of FAAS techniques after the solid phase extraction on rice bran

A facile and novel method has been developed for the determination of cadmium, chromium, copper, lead, and zinc from various water samples using FAAS. In the present investigation, a syringe was loaded with sorbent (rice bran) for the separation and enrichment of cadmium, chromium, copper, lead, and zinc, prior to their analysis by flame atomic absorption spectrometry which was described to substitute the batch and column techniques. The syringe was loaded with 2.0 g of sorbent in order to retain the analyte elements. Six milliliter of sample solution (pH 8.0 ± 0.2) was drawn into the syringe in 15 s and discharged over a period of 15 s. Then, 2.0 M HCl eluent was drawn into the syringe and ejected back to desorb the analyte elements. At the optimum conditions, the percentage recoveries of Cd, Cr, Cu, Pb, and Zn was in the range of 95.5–99.4% with SD of 0.10%. The elements could be concentrated by drawing and discharging several portions of sample successively. The detailed study of various interferences made the confirmation of the method highly selective. The risk of contamination is less than that with the column technique. The method was successfully applied for the determination of Cd, Cr, Cu, Pb, and Zn in spiked and natural water samples. The results obtained are in good agreement with the reported methods at the 95% confidence level.     

SITING OF A WATER POLLUTION CONTROL FACILITY AT JAMESTOWN,RHODE ISLAND1

ABSTRACT: The town of Jamestown, Rhode Island, located on Conanicut Island in Narragansett Bay, is constructing a secondary treatment plant in order to comply with NPDES regulations. Twelve candidate sites for the plant and marine outfall were initially proposed, and ability to meet State water quality standards at these sites was evaluated using an EPA buoyant plume model. A final outfall site, Taylor Point, was selected by the Town from among the sites considered acceptable. Taylor Point was then subjected to field hydrographic studies including drogue tracking, current recordings, and tracer dye surveys. Results of the measurement program served as input to a two-dimensional effluent dispersion model which predicted excess BOD, coliform, and suspended solids resulting from effluent discharge off Taylor Point. The model predictions demonstrated that State water quality standards can be maintained outside the initial discharge plume.     

Effect of stocking density and food quality on the growth and fecundity of an epigeic earthworm (<Emphasis Type="Italic">Eisenia fetida</Emphasis>) during vermicomposting

Physico-chemical characteristics of the feed and optimum worm density are important parameters for the efficient working of a vermicomposting system. Overcrowding of worms can affect the efficiency of a vermicomposting system even if all other parameters have been optimized. This article reports the effect of stocking density and feed quality on the growth and fecundity of Eisenia fetida under laboratory conditions. The feed mixtures contained cow dung and textile mill wastewater sludge in different ratios. Three feed mixtures and five stocking rates (1, 2, 4, 8, and 12) were tested for 12 weeks. The results showed that E. fetida growth rate was faster at higher stocking densities; however, biomass gain per worm was faster at lower stocking densities. Sexual maturity was attained earlier at higher stocking densities. Growth rate was highest in 100% cow dung at all the stocking densities when compared to textile mill wastewater sludge containing feed mixtures. A worm population of 27–53 worms per kg of feed was found to be the most favorable stocking density.     

Livestock excreta management through vermicomposting using an epigeic earthworm Eisenia foetida

In India, millions of tones of livestock excreta are produced. Our study explores the potential of an epigeic earthworm Eisenia foetida to compost different livestock excreta (cow, buffalo, horse, donkey, sheep, goat and camel) into value added product (vermicompost) at the laboratory scale. Vermicomposting resulted in lowering of pH, electrical conductivity, potassium and C:N ratio and increase in nitrogen and phosphorus contents. Total K was lower in the final cast than in the initial feed. C:N ratios of the vermicomposts ranged from 16.2 ± 2.17 to 75.4 ± 6.84. Microbial activity measured as dehydrogenase activity in buffalo, donkey and camel wastes increased with time up to day 90. But in sheep and goat wastes, maximum dehydrogenase activity was recorded on day 60 and decreased thereafter. The cocoons and hatchlings production by Eisenia foetida in different excreta were also investigated. The greatest number and biomass of hatchlings was recorded in horse excreta followed by cow, goat and sheep excreta. Thus, cow, horse, sheep and goat excreta show potential as good substrates in vermicomposting using Eisenia foetida, although further research is required to explore the feasibility of use of buffalo, donkey and camel excreta in combination with cow/sheep/goat excreta.     

Mapping epistemic cultures and learning potential of participants in citizen science projects

The ever‐widening scope and range of global change and interconnected systemic risks arising from people–environment relationships (social‐ecological risks) appears to be increasing concern among, and involvement of, citizens in an increasingly diversified number of citizen science projects responding to these risks. We examined the relationship between epistemic cultures in citizen science projects and learning potential related to matters of concern. We then developed a typology of purposes and a citizen science epistemic‐cultures heuristic and mapped 56 projects in southern Africa using this framework. The purpose typology represents the range of knowledge‐production purposes, ranging from laboratory science to social learning, whereas the epistemic‐cultures typology is a relational representation of scientist and citizen participation and their approach to knowledge production. Results showed an iterative relationship between matters of fact and matters of concern across the projects; the nexus of citizens’ engagement in knowledge‐production activities varied. The knowledge‐production purposes informed and shaped the epistemic cultures of all the sampled citizen science projects, which in turn influenced the potential for learning within each project. Through a historical review of 3 phases in a long‐term river health‐monitoring project, we found that it is possible to evolve the learning curve of citizen science projects. This evolution involved the development of scientific water monitoring tools, the parallel development of pedagogic practices supporting monitoring activities, and situated engagement around matters of concern within social activism leading to learning‐led change. We conclude that such evolutionary processes serve to increase potential for learning and are necessary if citizen science is to contribute to wider restructuring of the epistemic culture of science under conditions of expanding social‐ecological risk.     

Current understanding of the influence of environmental factors on SARS-CoV-2 transmission,persistence, and infectivity

Environmental Science and Pollution Research - Coronavirus disease 2019 (COVID-19) has emerged as a significant public health emergency in recent times. It is a respiratory illness caused by the...     

Indicator-Based Approach for Assessing the Vulnerability of Freshwater Resources in the Bagmati River Basin,Nepal

To assess the vulnerability of water resources in the Bagmati River Basin in Nepal, this paper adopts an indicator-based approach wherein vulnerability is expressed as a function of water stress and adaptive capacity. Water stress encompasses indicators of water resources variation, scarcity, and exploitation and water pollution, whereas adaptive capacity covers indicators of natural, physical, human resource, and economic capacities. Based on the evaluation of eleven indicators, which were aggregated into eight vulnerability parameters, an increasingly stressful situation and lack of adaptive capacity became evident. Considerable spatial variation in indicator values suggests differential policy options. While the northern parts need attention to reduce pollution loading and conserve vegetation cover, the southern parts need improvements in physical capacity, i.e. water infrastructures. The comprehensive and easily interpretable findings of the study are expected to help decision makers reach sound solutions to reduce freshwater resources vulnerability in the Bagmati River Basin, Nepal. With its inherent flexibility, the approach has demonstrated its potential for application in different times and areas for monitoring and comparison purposes.