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.     

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.     

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.     

Assessing the potentials of Lemna minor in the treatment of domestic wastewater at pilot scale

Water crisis is one of the most serious problems faced by the world today. Phytoremediation is one of the serious efforts towards sustainability. Macrophyte-based wastewater treatment systems have several potential advantages compared with conventional treatment systems. Duckweeds (Lemna spp., Spirodela spp., Wolffia spp.) are small, green freshwater, free-floating aquatic plants. The primary objective of this work was to analyze the role of duckweeds in organic waste and nutrient removal from domestic wastewater being generated from hostels of Birla Institute of Technology, Mesra, Ranchi (India). Interesting results were obtained in which the BOD value reduced by 94.45% and the level of orthophosphate at the end of the work was found to be reduced by 79.39%. The duckweeds flourished well during the experimental period in the pH range of 7 to 8; it can be said that, other factors remaining favorable, the optimum pH for duckweed growth ranges from 7 to 8. Therefore, it can be concluded that this treatment can be successfully carried out on a large scale. Also, it is a low-cost solution to wastewater treatment problems and could satisfy the discharge standards.     

Adsorption of phosphate ions from water using a novel cellulose-based adsorbent

A novel cellulose-based adsorbent, iron(III)-coordinated amino-functionalised poly(glycidylmethacrylate)-grafted cellulose [Fe(III)–AM-PGMACell] was developed for the removal of phosphate from water and wastewater. The scanning electron micrograph showed that AM-PGMACell has a rougher surface than cellulose and the adsorption of Fe(III) on AM-PGMACell made the surface even rougher. Infrared spectroscopy revealed that amino groups on the surface of AM-PGMACell complexed with Fe(III) played an important role in the removal of phosphate from solutions. X-Ray diffraction patterns showed a decrease in crystallinity after graft copolymerisation onto cellulose. The effects of contact time, initial sorbate concentration, pH, agitation speed, dose of adsorbent and temperature on the removal process were investigated. Maximum removal of 99.1% was observed for an initial concentration of 25 mg·L ^?1 at pH 6.0 and an adsorbent dose of 2.0 g·L ^?1. A two-step pseudo-first-order kinetic model and Sips isotherm model represented the measured data very well. Complete removal of 11.6 mg·L ^?1 phosphate from fertiliser industry wastewater was achieved by 1.6 g·L ^?1 Fe(III)–AM-PGMACell. The adsorbent exhibited very high reusability for several cycles. Overall, the study demonstrated that Fe(III)–AM-PGMACell can be used as an efficient adsorbent for the removal and recovery of phosphate from water and wastewater.     

Alterations in plasma electrolyte levels of a freshwater fish Cyprinus carpio exposed to acidic pH

The impact of acidification (Low pH 5.0) on plasma electrolytes (Na⁺, K⁺, Cl^?, Ca²⁺, and Mg²⁺) in a freshwater fish Cyprinus carpio was studied for a 35 day (long term) exposure period, while control groups were maintained at neutral pH (7.3). During long-term (35 days) exposure periods, plasma K⁺ and Mg²⁺ levels were increased (77.8% and 16.0%) in the low pH (5.0) treated fish. On the other hand, plasma Na⁺, Cl^?, and Ca²⁺ levels were decreased (12.4%, 18.4% and 31.3%, respectively). The loss of plasma Na⁺, Cl^?, and Ca²⁺ indicates the displacement of Ca²⁺ from tight junctions. The increased plasma K⁺ ion might have resulted from acidosis, because intracellular K⁺ is released from muscle as H⁺ enters. The elevated level of plasma Mg²⁺ might be due to inhibition of active transport of magnesium across the kidneys resulting in the accumulation of this ion in the plasma. Ionic alteration takes place upon exposure to acidic pH and can be considered as a potential tool for detecting environmental stresses caused by acidification.     

Carbon nitride,metal nitrides,phosphides, chalcogenides,perovskites and carbides nanophotocatalysts for environmental applications

Environmental Chemistry Letters - Effective technologies and materials are needed for environmental detoxification and clean energy production. The actual photocatalytic technology is largely...     

Do developmental initiatives influence local attitudes toward conservation? A case study from the Kalakad–Mundanthurai Tiger Reserve,India

We evaluated the conservation attitudes of the local villagers living adjacent to the Kalakad-Mundanthurai Tiger Reserve in southern India 6 years after implementation of a World Bank funded eco-development project. We assessed attitudes towards three facets of conservation: the tiger, an emblematic species signifying India's commitment to wildlife conservation; the forest, a principle source of fuel-wood and other products; and the Forest Department, which manages the forest. More specifically we predicted that (i) attitudes would be an effective predictor of resource use interest in the forest and (ii) benefits obtained from the EDP would create more favorable attitudes towards conservation and the protected area employees. Twelve villages located within 3 km from the reserve boundary were chosen and 2-3% of the households interviewed with regard to their attitudes towards these three facets of conservation, their household resource use patterns, wealth, sex, age and length of residency. We found significant associations between wealth, sex, age and both tiger and forest conservation. Providing benefits has not changed the underlying attitudes of the communities. The poorer sections of society, whether receiving benefits or not, tended to support tiger conservation because conserving wildlife did not affect their livelihood in any way, whereas both the rich and poor had misgivings about forest conservation due to dependency on forest products. We conclude that the eco-development project has not effectively addressed the most important of the local concerns.     

Evaluation of Extracted Chitosan from Portunus Pelagicus for the Preparation of Chitosan Alginate Blend Scaffolds

In recent years there is a growing need in generating a biocompatible and cost effective porous scaffold for tissue engineering purposes. Therefore, this study focused on conversion of the shell waste of locally available crab variety P.pelagicus (Blue swimming crab) into the chitosan scaffold. As the poor mechanical strength of chitosan limits its usage in tissue engineering, it was blended with alginate. The scaffolds were prepared by the freeze gelation method which requires less time and minimum energy, with fewer residual solvent and easier to scale up. To the best of our knowledge there are no reports on scaffold preparation from the extracted chitosan, blended with alginate by freeze gelation method. The biological properties of chitosan-alginate scaffolds (Cts–Alg) were evaluated and compared with those of chitosan scaffolds. The prepared scaffolds were characterized by SEM, swelling property, in vitro enzymatic degradation, and hemo, biocompatibility properties. Chitosan-alginate scaffolds had an average pore size of 40 μm and tensile strength of 0.564 ± 0.0.018 % MPa. Its swelling ratio was 27.5 ± 0.28 %, with mass loss percentage of 10 ± 0.33 % after 4 weeks of degradation. It has exhibited good hemocompatible properties too. Mouse fibroblast 3T3 cells were able to adhere and proliferate well in the blended scaffold. All these results indicated that chitosan-alginate scaffold is a suitable alternative substitute for tissue engineering.