Recovering metallic fractions from waste electrical and electronic equipment by a novel vibration system

The need to recover and recycle valuable resources from Waste Electrical and Electronic Equipment (WEEE) is of growing importance as increasing amounts are generated due to shorter product life cycles, market expansions, new product developments and, higher consumption and production rates. The European Commission (EC) directive, 2002/96/EC, on WEEE became law in UK in January 2007 setting targets to recover up to 80% of all WEEE generated.Printed Wire Board (PWB) and/or Printed Circuit Board (PCB) is an important component of WEEE with an ever increasing tonnage being generated. However, the lack of an accurate estimate for PCB production, future supply and uncertain demands of its recycled materials in international markets has provided the motivation to explore different approaches to recycle PCBs.The work contained in this paper focuses on a novel, dry separation methodology in which vertical vibration is used to separate the metallic and non-metallic fractions of PCBs. When PCBs were comminuted to less than 1 mm in size, metallic grades as high as 95% (measured by heavy liquid analysis) could be achieved in the recovered products.     

Synthesizing habitat connectivity analyses of a globally important human-dominated tiger-conservation landscape

As ecological data and associated analyses become more widely available, synthesizing results for effective communication with stakeholders is essential. In the case of wildlife corridors, managers in human-dominated landscapes need to identify both the locations of corridors and multiple stakeholders for effective oversight. We synthesized five independent studies of tiger (Panthera tigris) connectivity in central India, a global priority landscape for tiger conservation, to quantify agreement on landscape permeability for tiger movement and potential movement pathways. We used the latter analysis to identify connectivity areas on which studies agreed and stakeholders associated with these areas to determine relevant participants in corridor management. Three or more of the five studies’ resistance layers agreed in 63% of the study area. Areas in which all studies agree on resistance were of primarily low (66%, e.g., forest) and high (24%, e.g., urban) resistance. Agreement was lower in intermediate resistance areas (e.g., agriculture). Despite these differences, the studies largely agreed on areas with high levels of potential movement: >40% of high average (top 20%) current-flow pixels were also in the top 20% of current-flow agreement pixels (measured by low variation), indicating consensus connectivity areas (CCAs) as conservation priorities. Roughly 70% of the CCAs fell within village administrative boundaries, and 100% overlapped forest department management boundaries, suggesting that people live and use forests within these priority areas. Over 16% of total CCAs’ area was within 1 km of linear infrastructure (437 road, 170 railway, 179 transmission line, and 339 canal crossings; 105 mines within 1 km of CCAs). In 2019, 78% of forest land diversions for infrastructure and mining in Madhya Pradesh (which comprises most of the study region) took place in districts with CCAs. Acute competition for land in this landscape with globally important wildlife corridors calls for an effective comanagement strategy involving local communities, forest departments, and infrastructure planners.     

Association of textile industry effluent with mutagenicity and its toxic health implications upon acute and sub-chronic exposure

Complex industrial discharges pose certain risks to the ecosystem. This study was aimed at identifying acute and sub-chronic toxicological effects of the textile industry wastewater. The textile wastewater was evaluated for the metals and organic pollutants by atomic absorption spectrophotometer and GC-MS respectively. In vitro genotoxicity and mutagenicity were assessed by Comet assay in peripheral lymphocytes isolated from Ovis aries and Ames test in Salmonella typhimurium strains TA-100 and 102 respectively. Physiological and behavioral changes along with systemic toxicity were determined in Rattus norvegicus albinus following acute and sub-chronic exposure. High amount of heavy metals such as Cr, Pb, Hg, As, and Cd were detected in textile wastewater. Organic pollutants such as 25-deacetoxy cucurbitacin-b, E-14-Hexadecenal, 11-Tricosene, and phthalates were also found. In vitro genotoxicity assessment in lymphocytes showed statistically significant DNA damaging potential of textile wastewater. Textile wastewater also showed significantly higher (p? 0.05) mutagenic potential in Salmonella TA-100 and TA-102 strains than sodium azide and 2-amino anthracycline. Acute exposure of textile wastewater to Rattus norvegicus was associated with several physiological changes and behavioral symptoms. Sub-chronic exposure of textile wastewater in Rattus norvegicus instigated the degeneration and necrosis of epithelial cells in renal tubules, hydropic degeneration and necrosis of hepatocytes, peri-bronchiolar infiltration and emphysema of the alveoli, and the degradation of myocardial cells. This study concludes that the textile wastewater may cause genotoxicity and mutagenicity, result in physiological and behavioral changes upon acute exposure, and inflict various pathological lesions upon sub-chronic exposure.     

Investigating degradation metabolites and underlying pathway of azo dye “Reactive Black 5” in bioaugmented floating treatment wetlands

Environmental Science and Pollution Research - The direct discharge of azo dyes and/or their metabolites into the environment may exert toxic, mutagenic, and carcinogenic effects on exposed fauna...     

Game theory and hybrid genetic algorithm for energy management and real-time pricing in smart grid: the Tunisian case

ABSTRACT

Microgrids are the key for integrating renewable energy from different sources into smart grid, that is why power grid evolves into a combination of interconnected microgrids. In fact, future power grids are undergoing this groundbreaking change that will help meet the increasing demand of electric power and reduce carbon emission. In this sense we study in this paper, based on measured data, a real case of energy management in the area of Beja located in Tunisia. Indeed, we propose a model for the power exchange which proves the potential of applying game theory in the development of both real-time pricing and energy management mechanism for an open electricity market. We also introduce a hybrid genetic algorithm to compute the Nash Equilibrium. Results show that the proposed smart energy management can decrease the real cost of power up to 20%, to divide the energy transmission losses by a factor of two and to reduce the carbon emission in the area of Beja.     

Investigation on thermal degradation kinetics and mechanisms of chicken manure,lignite, and their blends by TGA

Environmental Science and Pollution Research - In this study, thermogravimetric analysis (TGA) was performed under the air environment for four different heating rates (10, 20, 30, and 40 °C...     

Effects of sewage sludge fertilizer on heavy metal accumulation and consequent responses of sunflower (<Emphasis Type="Italic">Helianthus annuus</Emphasis>)

Use of sewage sludge, a biological residue produced from sewage treatment processes in agriculture, is an alternative disposal technique of waste. To study the usefulness of sewage sludge amendment for Helianthus annuus, a pot experiment was conducted by mixing sewage sludge at 2.5, 5, and 7.5 % (w/w) amendment ratios to the agricultural soil. Soil pH decreased whereas electrical conductivity, organic matter, total N, available P, and exchangeable Na, K, and Ca increased in soil amended with sewage sludge in comparison to unamended soil. Sewage sludge amendment led to significant increase in Pb, Ni, Cu, Cr, and Zn concentrations of soil. The increased concentration of heavy metals in soil due to sewage sludge amendment led to increases in shoot and root concentrations of Cr, Cu, Ni, and Zn in plant as compared to those grown on unamended soil. Accumulation was more in roots than shoots for most of the heavy metals. Moreover, high metal removal for the harvestable parts of the crops was recorded. Sewage sludge amendment increased root and shoot length, leaves number, biomass, and antioxidant activities of sunflower. Significant increases in the activities of antioxidant enzymes and in the glutathione, proline, and soluble sugar content in response to amendment with sewage sludge may be defense mechanisms induced in response to heavy metal stress.

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Graphical abstract Origin, fate and behavior of sewage sludge fertilizer

     

A comparison of two procedures to estimate three basic monitoring landscape metrics for monitoring

An interesting alternative to wall-to-wall mapping approaches for the estimation of landscape metrics is to use sampling. Sample-based approaches are cost-efficient, and measurement errors can be reduced considerably. The previous efforts of sample-based estimation of landscape metrics have mainly been focused on data collection methods, but in this study, we consider two estimation procedures. First, landscape metrics of interest are calculated separately for each sampled image and then the image values are averaged to obtain an estimate of the entire landscape (separated procedure, SP). Second, metric components are calculated in all sampled images and then the aggregated values are inserted into the landscape metric formulas (aggregated procedure, AP). The national land cover map (NLCM) of Sweden, reflecting the status of land cover in the year 2000, was used to provide population information to investigate the statistical performance of the estimation procedures. For this purpose, sampling simulation with a large number of replications was used. For all three landscape metrics, the second procedure (AP) produced a lower relative RMSE and bias than the first one (SP). A smaller sample unit size (50 ha) produced larger bias than a larger one (100 ha), whereas a smaller sample unit size produced a lower variance than a larger sample unit. The efficiency of a metric estimator is highly related to the degree of landscape fragmentation and the selected procedure. Incorporating information from all of the sampled images into a single one (aggregated procedure, AP) is one way to improve the statistical performance of estimators.     

Impact of mechanical deweeding on the phytophilous macroinvertebrate community of an eutrophic lake

The aim of the study was to estimate the impact of mechanical deweeding on the community structure of phytophilous macroinvertebrates. The eutrophic lake selected for the study was Dal Lake in the Kashmir Himalayas. The dissolved nutrient concentration was found to be highest in August and September, i.e., nitrates-nitrogen (513 μg l^?l) and total phosphorus (685 μg l^?l). During the period of investigation, a total of 22 macroinvertebrate taxa were recorded which belonged to phylum Arthropoda, Mollusca, and Annelida. The samples were collected with the help of a composite Gerking frame box and grappler. Mechanical deweeding had a profound impact on the population density of phylum Mollusca and Arthropoda followed by Annelida. However, family Tubificidae was not influenced by deweeding, as the harvester only trimmed the vegetation, and these organisms were recorded in the sediment of the lake. On average, the reference site had higher density of macroinvertebrates as compared to deweeded areas. The abundance of macroinvertebrates decreased from 200 ind. (individuals)?m^?2 in the reference site to 51 ind.?m^?2 in the deweeded site as a result of weed removal. Species richness and composition of major macroinvertebrates in harvested and unharvested areas of the lake were also dissimilar as portrayed by biotic indices vis-à-vis Shannon diversity index, evenness index, and Simpson index.