Articoli di riviste: "Chromium Environmental aspects"

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Puccini, Monica, e Domenico Castiello. "Use of Glucose to Improve the Environmental Aspects of Chrome Tanning Process". Advanced Materials Research 933 (maggio 2014): 144–50. http://dx.doi.org/10.4028/www.scientific.net/amr.933.144.

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A tanning process based on a preliminary stabilization with glucose, followed by a chromium tannage, has been optimized on semi-industrial scale. A higher chromium content in the tanned leather and a better exhaustion of the floats indicate that the presence of glucose in the hide improves the penetration and fixation of chromium. The stabilization with glucose allows the production of chromium-free waste shavings that may be reutilized through more sustainable routes. The crust leather obtained is characterized by mechanical and technical properties comparable to those of the traditionally chromium tanned crust leather. As far as roundness, fullness and hand, the glucose stabilized leather display better performances. The results obtained assess the glucose stabilized leather as a good candidate for producing high quality bovine upper leather through a more environmental sound chromium tannage, in terms of lower chromium consumption and discharge in the wastewaters and of better reutilization of chromium-free wastes.

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Gochfeld, M., e C. Witmer. "A research agenda for environmental health aspects of chromium." Environmental Health Perspectives 92 (maggio 1991): 141–44. http://dx.doi.org/10.1289/ehp.9192141.

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Lindström, David, Yolanda Hedberg e Inger Odnevall Wallinder. "Chromium(III) and Chromium(VI) Surface Treated Galvanized Steel for Outdoor Constructions: Environmental Aspects". Environmental Science & Technology 44, n. 11 (giugno 2010): 4322–27. http://dx.doi.org/10.1021/es1003022.

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Franchini, I., e A. Mutti. "Selected toxicological aspects of chromium(VI) compounds". Science of The Total Environment 71, n. 3 (giugno 1988): 379–87. http://dx.doi.org/10.1016/0048-9697(88)90210-0.

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MORIKAWA, Tsutomu, e Takuo NAKADE. "Environmental Aspects and Controlling Cr⁶⁺ Emissions of Chromium Electroplating". Journal of the Surface Finishing Society of Japan 68, n. 1 (2017): 14–20. http://dx.doi.org/10.4139/sfj.68.14.

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Biswal, Sudhansu Sekhar, Chittaranjan Panda, Priyanka Dash, Trilochan Jena, Smruti Ranjan Parida e Duryodhan Sahu. "Feasibility and Environmental Compatibility of Concrete using Chromium Bearing Wastewater". Asian Journal of Chemistry 34, n. 6 (2022): 1483–87. http://dx.doi.org/10.14233/ajchem.2022.23695.

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The effluents of chrome plating industry seepage contain toxic hexavalent chromium generally in the range of 100 to 300 mg/L. The said values of chromium are not advisable to dispose to surface water bodies or land and the treatment process of this wastewater is quite expensive. Herein, we found a course of action to reuse the wastewater in cement matrix in manufacturing concrete work. The M-30 grade concrete samples were casted with portland slag cement (PSC) at wastewater to binder ratio of 0.45. The technical compatibility of concrete specimen i.e. the chromium immobilization and other properties are well satisfied nevertheless a small decrease in hardened concrete values also observed. XRD study revealed that the hydration product Ca(OH)2 is replaced by more insoluble CaCrO4. Scanning electron microscopy study (SEM) with energy dispersive spectrum (EDS) study exhibited the immobilization of chromium and quantification of chromium content. The mortar samples from concrete after 56 days of air curing were subjected to toxicity characteristic leaching procedure (TCLP) test at pH 2.88. In addition, two days’ short tank leaching test was conducted with the concrete samples as a whole. The leachability of toxic Cr6+ found in the range 0.03-0.09 mg/L and the total chromium (TCr) values in the range 0.12 -0.17 mg/L, which are less than discharge standard as per EP Act (1986), India. All these leaching test results comply with the discharge norms to land and inland surface water, respectively. Thus, the concrete specimens using aforesaid wastewater satisfy the technical aspects and fulfil the environmental requirement.

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Kress, Nurit. "Chemical Aspects of Coal Fly Ash Disposal at Sea: Predicting and Monitoring Environmental Impact". Water Science and Technology 27, n. 7-8 (1 aprile 1993): 449–55. http://dx.doi.org/10.2166/wst.1993.0581.

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Monitoring studies at a deep sea fly ash dumping site found that the ash accumulates at the sea bed, causing a physical change in the sediments. Partial leaching of cadmium and chromium to seawater was detected in laboratory experiments, but no evidence of it was found in the sediments or benthic fauna sampled at the dumping site.

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Farooqi, Zahoor H., Muhammad Waseem Akram, Robina Begum, Weitai Wu e Ahmad Irfan. "Inorganic nanoparticles for reduction of hexavalent chromium: Physicochemical aspects". Journal of Hazardous Materials 402 (gennaio 2021): 123535. http://dx.doi.org/10.1016/j.jhazmat.2020.123535.

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Malovanyy, Myroslav, Oleg Blazhko, Halyna Sakalova e Tamara Vasylinych. "Ecological Aspects of Clay Sorption Materials Usage in Leather and Fur Production Technologies". Materials Science Forum 1038 (13 luglio 2021): 276–81. http://dx.doi.org/10.4028/www.scientific.net/msf.1038.276.

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The work is devoted to solving the current problem of increasing the level of environmental safety of treatment industrial wastewater of leather production from chromium ions (III) through the use of natural and modified bentonite. The studies of natural and modified bentonite use in the adsorption of Cr3 + ions were conducted. The influence of the process duration on the sorption efficiency of chromium ions was studied. Studies were conducted to use spent bentonite in tanning and filling processes. The efficiency of modification of montmorillonite has been proved and the expediency of using mineral dispersion for qualitative formation of the structure and properties of the leather during tanning has been established.

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Mytych, Piotr, Andrzej Karocki e Zofia Stasicka. "Mechanism of photochemical reduction of chromium(VI) by alcohols and its environmental aspects". Journal of Photochemistry and Photobiology A: Chemistry 160, n. 3 (agosto 2003): 163–70. http://dx.doi.org/10.1016/s1010-6030(03)00235-1.

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Korallus, U. "Chromium compounds: Occupational health, toxicological and biological monitoring aspects†". Toxicological & Environmental Chemistry 12, n. 1-2 (ottobre 1986): 47–59. http://dx.doi.org/10.1080/02772248609357149.

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Needleman, Carolyn. "Social aspects of high-risk notification among chromium-exposed workers". American Journal of Industrial Medicine 23, n. 1 (gennaio 1993): 113–23. http://dx.doi.org/10.1002/ajim.4700230117.

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Rajeshwar, Krishnan, C. R. Chenthamarakshan, Scott Goeringer e Miljana Djukic. "Titania-based heterogeneous photocatalysis. Materials, mechanistic issues, and implications for environmental remediation". Pure and Applied Chemistry 73, n. 12 (1 gennaio 2001): 1849–60. http://dx.doi.org/10.1351/pac200173121849.

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Using hexavalent chromium [Cr(VI)] and methylene blue (MB) as model substrates, we discuss three aspects of TiO2-based heterogeneous photocatalysis. We show first that a given TiO2 sample may not be simultaneously optimal for photocatalytically driving the reduction of Cr(VI) and the oxidation of MB. We further show that a TiO2 sample that strongly adsorbs either of these substrates in the dark is not optimal as a photocatalyst. The other two aspects concern circumventing the rather poor surface catalytic properties and visible light photoresponse of TiO2, respectively. Strategies revolving around the visible light photoexcitation of the substrate itself and metal-modification of the TiO2 surface, are described as possible solutions.

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Bartlett, Lauren, P. Aarne Vesilind e P. Aarne Vesilind. "Expediency and human health: The regulation of environmental chromium". Science and Engineering Ethics 4, n. 2 (giugno 1998): 191–201. http://dx.doi.org/10.1007/s11948-998-0049-3.

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Gurumurthy Iyer, Vijayan. "Environmental health impact assessment of chrome composite leather-clad rollers used by Indian cotton roller ginning industries and design and development of Eco-friendly alternatives". International Journal of Emerging Trends in Health Sciences 4, n. 1 (30 aprile 2020): 36–67. http://dx.doi.org/10.18844/ijeths.v4i1.4496.

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This research article realises the hazards of chromium contamination and pollution caused by using chrome composite leather-clad (CCLC) rollers that are commonly used in the cotton roller ginning industries and attempts to eliminate the chromium contamination and pollution during the cotton ginning process. The chromium traces found contain hexavalent chromium being adsorbed from chromium-contaminated lint, yarn, fabrics, seeds, by-products and textile effluent. Chromium acts in three ways on humans, viz. (i) local action explained as dermatitis or absorption through skin, (ii) direct inhalation and (iii) ingestion or absorption into the stomach. Toxic effects are produced by prolonged contact with airborne or solid or liquid chromium compounds even in small quantities because of their properties, viz. carcinogenicity, mutagenicity and corrosiveness. Traces of Cr (VI) are found even in analar grade trivalent compounds, and complications do arise due to reduction in the nature of these traces that affect the organic tissues of the body. These regenerating effects occur rapidly and are dependent on the dose. This research article realises the hazards of chromium contamination and pollution caused by the use of dust-producing grinding of CCLC rollers that are commonly used in the cotton roller ginning industries and attempts to nullify this problem during cotton ginning. This research has been carried out with the following objectives: to identify and study the environmental health effects existing with the present CCLC rollers being used in the Indian cotton roller ginning industries; to conduct an environmental health impact assessment in Indian cotton roller ginning factories during the research years of 1998â€“2018; to design and develop an eco-friendly chrome-free roller and evaluate its performance with reference to environmental health effects and techno-commercial aspects in the ginning industries. With the authorâ€™s research background and practical experience in cotton ginning and textile industries, this study is attempted to eliminate the environmental health impacts to a great extent at the source itself, through a suitable design and development of an eco-friendly, pollution-free, chromeless roller for cotton roller gins. An eco-friendly roller ginning process has been designed and developed for replacing the conventional CCLC roller ginning process, to eliminate the chromium contamination and pollution from cotton roller ginning industries and to meet the requirements of World Health Organisation standards, while maintaining high-quality spun yarns and woven fabrics which meet the international standards. Keywords: Assessment, chromium, ginning, health, impact.

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Radjenovic, Ankica, e Gordana Medunic. "HEXAVALENT CHROMIUM ADSORPTION CAPABILITY ONTO CARBON BLACK: KINETIC AND THERMODYNAMIC ASPECTS". Environmental Engineering and Management Journal 17, n. 8 (2018): 1931–39. http://dx.doi.org/10.30638/eemj.2018.192.

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Aththanayake, A. M. K. C. B., I. V. N. Rathnayake e M. P. Deeyamulla. "Detoxification and Removal of Hexavalent Chromium in Aquatic Systems: Applications of Bioremediation". Nepal Journal of Biotechnology 10, n. 2 (31 dicembre 2022): 57–76. http://dx.doi.org/10.54796/njb.v10i2.243.

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Chromium is a transition metal with a wide range of applications in leather tanning, textile, electroplating, stainless steel production, inorganic chemical production and wood preservation industries due to yellow colouration, corrosion resistance, higher melting-point and crystalline structure with raging of oxidation states from 0 to +6. Trivalent and hexavalent chromium are the most abundant forms of chromium discharged into the aquatic environment by industries. It has been reported that hexavalent chromium is highly toxic than trivalent chromium due to the higher solubility, mobility and tendency to accumulate in higher trophic levels, which, therefore, become bioavailable and causes carcinogenic, mutagenic and teratogenic effects on most microorganisms and animals, growth inhibition, morphological and physiological changes and yield reductions in plants. Therefore, it is essential to detoxify the above hazardous pollutants up to permissible limits, which local and international authorities have legislated concerning its threat towards biotic components. Hexavalent chromium detoxification is possible to achieve using three methods i.e. physical, chemical and biological methods. These remediation processes can eliminate highly toxic hexavalent chromium or transform it into a less toxic form of trivalent chromium, completely or partially by adsorption and reduction. Biological remediation is considered a cost-effective and ecofriendly method compared to physical and chemical remediation. Further, many biological agents have been identified as agents that can tolerate the hexavalent chromium toxicity up to certain higher levels depending on the internal and external environmental factors, indicating different metal tolerance mechanisms that are assumed to be applied in metal remediation aspects. According to the testimonies of novel bioremediation studies, some hexavalent chromium tolerant organisms such as plants, bacteria, unicellular and multicellular fungi and algae are promising eco-friendly alternatives in detoxification and hexavalent chromium removal perspective. This article reviews the bioremediation approaches available for hexavalent chromium detoxification and removal and highlights the strengths and weaknesses of current bioremediation methods.

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Yavorovskiy, Oleksandr, Sergii Omelchuk, Lyudmyla Sokurenko, Tetyana Zinchenko, Nina Solokha, Vasyl Aleksiichuk e Roman Brukhno. "ENVIRONMENTAL AND OCCUPATIONAL HAZARDS OF METAL NANOCOMPOUNDS PRODUCTION AND APPLICATION: HYGIENIC, CLINICAL AND TOXICOLOGICAL ASPECTS". Wiadomości Lekarskie 72, n. 8 (2019): 1504–11. http://dx.doi.org/10.36740/wlek201908117.

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Introduction: Nanometals are the most common nanoobjects, used nearly in all industrial branches. Considerable advances in the nanotechnological production have led to progressive use of nanomaterials in industry, though occupational safety of the nanoindustry staff is insufficiently studied. The aim: Estimation of labor safety during production of metal nanoparticles for the purpose of defining necessary and efficient preventive measures. Materials and methods: The personnel of the hygienic departments of the O.Bogomolets National medical university have conducted numerous physiological, hygienic, biochemical, morphological and toxicological studies. The scientists have studied and revealed hazardous workplace factors of various metal nanoparticle production technologies, particularly those of metal nanoparticles: nanosilver, titanium nitride, chromium disilicide, lead sulphide, etc. Results and conclusions: The authors have developed method of the occupational exposure metal nanoparticles exposure air control, assessed and analyzed health of the personnel engaged in production of the nanometals. The paper contains data of the blood cells functional activity assessment, with the detected possible molecular nanoparticles toxicity mechanisms due to the altered gene expression. The authors have studied effect of nanoaerosols onto the laboratory rats respiratory organs, evaluated their blood biochemical characteristics, liver lipid content of fatty acids as well as defined morpho-functional hepatic transformations of the laboratory animals which underwent lead sulfide nanoparticles treatment.

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Ciavatta, Claudio, Chiara Manoli, Luciano Cavani, Clizia Franceschi e Paolo Sequi. "Chromium-Containing Organic Fertilizers from Tanned Hides and Skins: A Review on Chemical, Environmental, Agronomical and Legislative Aspects". Journal of Environmental Protection 03, n. 11 (2012): 1532–41. http://dx.doi.org/10.4236/jep.2012.311169.

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Basegio, T., C. Haas, A. Pokorny, A. M. Bernardes e C. P. Bergmann. "Production of materials with alumina and ashes from incineration of chromium tanned leather shavings: Environmental and technical aspects". Journal of Hazardous Materials 137, n. 2 (21 settembre 2006): 1156–64. http://dx.doi.org/10.1016/j.jhazmat.2006.03.059.

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Prado, Carolina, Mariana Rosa, Eduardo Pagano, Mirna Hilal e Fernando E. Prado. "Seasonal variability of physiological and biochemical aspects of chromium accumulation in outdoor-grown Salvinia minima". Chemosphere 81, n. 5 (ottobre 2010): 584–93. http://dx.doi.org/10.1016/j.chemosphere.2010.08.033.

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Shahtaheri, S. J., M. Khadem, F. Golbabaei e A. Rahimi-Froushani. "Solid Phase Extraction for Monitoring of Occupational Exposure to Cr (III)". Analytical Chemistry Insights 2 (gennaio 2007): 117739010700200. http://dx.doi.org/10.4137/117739010700200014.

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Chromium is an important constituent widely used in different industrial processes for production of various synthetic materials. For evaluation of workers' exposure to trace toxic metal of Cr (III), environmental and biological monitoring are essential processes, in which, preparation of samples is one of the most time-consuming and error-prone aspects prior to analysis. The use of solid-phase extraction (SPE) has grown and is a fertile technique of sample preparation as it provides better results than those produced by liquid-liquid extraction (LLE). SPE using mini columns filled with XAD-4 resin was optimized regarding to sample pH, ligand concentration, loading flow rate, elution solvent, sample volume, elution volume, amount of resins, and sample matrix interferences. Chromium was retained on solid sorbent and was eluted with 2 M HNO3 followed by simple determination of analytes by using flame atomic absorption spectrometery. Obtained recoveries of metal ion were more than 92%. The optimized procedure was also validated with three different pools of spiked urine samples and showed a good reproducibility over six consecutive days as well as six within-day experiments. Through this study, suitable results were obtained for relative standard deviation, therefore, it is concluded that, this optimized method can be considered to be successful in simplifying sample preparation for trace residue analysis of Cr in different matrices for evaluation of occupational and environmental exposures. To evaluate occupational exposure to chromium, 16 urine samples were taken, prepared, and analyzed based on optimized procedure.

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Iov, Tatiana, Mihnea Costescu, Madalina Diac, Daniel Tabian, Sofia Mihaela David, Anton Knieling e Simona Irina Damian. "Dangerous Chemical Agents: General and Odonto-Stomatological Aspects with Importance in Forensic Toxicology". Revista de Chimie 70, n. 5 (15 giugno 2019): 1829–34. http://dx.doi.org/10.37358/rc.19.5.7225.

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In the heavy and light industry, the food and pharmaceutical industry, there are chemicals that contain metals with high toxic potential. Toxicity of metals is due to the harmful effect in certain forms and doses. Some metals become toxic when they form soluble compounds or in a certain chemical structure at certain doses (eg lead, mercury and candium). Not only heavy metals are toxic metals, there are also light metals that can become toxic, some of which are essential elements (iron, selenium, copper, chromium, zinc) and metals used therapeutically in medicine (aluminum, bismuth, gold, gallium, lithium and silver) may have negative effects when administered in large quantities or the elimination from the human body is deficient. Metal poisoning occurs through nutrition, medication, environmental factors. Most professional pollutants with intraoral manifestations appear in the heavy industry. The oral cavity is an entry gate for various toxic pathogens, so intoxications can be detected early due to the manifestations inside the mouth.

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Li, Junguo, Bao Liu, Yanan Zeng e Ziming Wang. "Mineralogical determination and geo-chemical modeling of chromium release from AOD slag: Distribution and leachability aspects". Chemosphere 167 (gennaio 2017): 360–66. http://dx.doi.org/10.1016/j.chemosphere.2016.10.020.

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Cherchintsev, V. D., Ye V. Nefedova e A. S. Kozlov. "Environmental aspects of implementation of resource-saving dolomite-free technologies of sodium monochromatee production at Novotroitsk Plant of Chromium Compounds". Vestnik of Nosov Magnitogorsk State Technical University 14, n. 1 (2016): 124–29. http://dx.doi.org/10.18503/1995-2732-2016-14-1-124-129.

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Fytianos, Konstantinos. "Speciation Analysis of Heavy Metals in Natural Waters: A Review". Journal of AOAC INTERNATIONAL 84, n. 6 (1 novembre 2001): 1763–69. http://dx.doi.org/10.1093/jaoac/84.6.1763.

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Abstract Metal speciation in natural waters is of increasing interest and importance because toxicity, bioavailability, environmental mobility, biogeochemical behavior, and potential risk in general are strongly dependent on the chemical species of metals. This paper provides an overview of the need for speciation of heavy metals in natural waters, the chemical and toxicological aspects of speciation, and the analytical procedures for separation and the different techniques for final determination that are used today. The trends and developments of speciation are also discussed. Finally, the case of chromium (Cr) was selected for a detailed presentation because the speciation of this metal has attracted a great deal of interest in view of the toxic properties of Cr(VI).

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Miškufová, Andrea, Alexandra Medvecová, Anna Kochmanová, Dušan Olčák e Viktor Hronský. "Problems with Solidification of Fly Ashes from the Municipal Solid Waste Incineration". Applied Mechanics and Materials 832 (aprile 2016): 31–38. http://dx.doi.org/10.4028/www.scientific.net/amm.832.31.

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One of the negative aspects of MSW (municipal solid waste) incineration is production of hazardous fly ashes. MSW fly ash usually contains heavy metals like for example chromium, lead, cadmium and organic substances (dioxins, furans), soluble compounds (salts) and other harmful substances. According to environmental legislative and with respect to the environment fly ash as a hazardous waste should be stabilized before landfilling. This work deals with certain problems occurring at solidification process of MSW fly ash by cementation. This work also describes efficiency of stabilization by two different binders (slag cement and waste containing alumina and silica). Leachability tests by TCLP (toxicity characteristic leaching procedure) and compressive strength of original and solidified samples by use of uniaxial pressing were studied in order to find suitable parameters for effective stabilization.

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Tarraste, Marek, Jakob Kübarsepp, Kristjan Juhani, Märt Kolnes, Mart Viljus e Arvo Mere. "Sintering of High Mn Cemented Carbides in Mn-Rich Environment". Defect and Diffusion Forum 405 (novembre 2020): 402–7. http://dx.doi.org/10.4028/www.scientific.net/ddf.405.402.

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The economic, environmental and healthcare aspects are pushing cemented carbide industry to reduce or even avoid the usage of conventional binder metals – nickel and cobalt. Commonly, austenitic Fe-Ni alloys have been preferred choice for substituting Co. Similar to Ni, manganese acts as austenite stabilizer and studies have shown that Fe-Mn alloys offer alternative binder metal to Co and Ni in cemented tungsten carbides. In addition, Fe-Mn as a binder potentially offers improved wear resistance due to the well-known wear properties of Fe-Mn-C steels. Addition of chromium to the binder composition increases corrosion performance of composite. Cemented carbides bonded with austenitic FeCrNi binder have demonstrated promising performance. In present work the possibility of achieving austenitic binder phase through substitution of nickel by manganese as an austenite stabilizer is investigated. Structure formation, phase composition and mechanical performance of WC-FeMn and WC-FeCrMn cemented carbides are discussed.

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Ni, Xiaomin, e Yingjia Shen. "Transgenerational Effects of Hexavalent Chromium on Marine Medaka (Oryzias melastigma) Reveal Complex Transgenerational Adaptation in Offspring". Biomolecules 11, n. 2 (22 gennaio 2021): 138. http://dx.doi.org/10.3390/biom11020138.

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Hexavalent chromium [Cr(VI)] pollution is one of most serious heavy metal pollutants in the coastal area and posed serious threats to marine organisms and human beings. Many studies have been conducted on its toxicological effects on living organisms from morphological to physiological aspects. However, there are few studies about the transgenerational toxicological of Cr(VI). In this study, we exposed adult marine medaka fishes with Cr(VI) and their offspring with Cr(VI) to examine transgenerational effects of Cr(VI). We found that there were mechanisms such as changing reproduction modes in males to compensate for impacts on the reproduction. There were differences and similarities between the parental effect and the environmental effect, with the former one causing more serious adverse effects on the offspring of Cr(VI)-exposed fish. It was noteworthy that there was an interaction between the parental and offspring treatment which leads to the attenuation of the parental effects on offspring when the offspring also underwent the same treatment. In addition, physiological adaptation has also been observed in fish to improve their fitness. Overall, effects of Cr(VI) on fish and their offspring were studied to pave a way to study the of mechanisms of adaptation.

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Shayakhmetov, Salim F., N. M. Meshchakova, L. G. Lisetskaya, A. V. Merinov, O. M. Zhurba, A. N. Alekseyenko e V. S. Rukavishnikov. "HYGIENIC ASPECTS OF WORKING CONDITIONS IN THE MODERN PRODUCTION OF ALUMINUM". Hygiene and sanitation 97, n. 10 (15 ottobre 2018): 899–904. http://dx.doi.org/10.18821/0016-9900-2018-97-10-899-904.

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Introduction. The production of primary aluminum is one of the leading and belonging to the category of an increased health hazard for workers in the economy, which requires close attention to working conditions while modernizing production technology. Material and methods. The research methodology included a comprehensive study of working conditions and assessment of priority occupational risk factors, an in-depth study of the morphology, dispersed and component composition of dust and gas components air-suspended at different technologies of electrolysis of aluminum. Results. The leading production factors of occupational risk, degrees are fluorine-containing compounds, dust and gas-aerosol mixtures in the form of separate and assembled into agglomerates micro- and nanostructured particles of complex chemical composition (fluorine, carbon, aluminum, sodium, oxygen, silicon, iron, sulfur, chromium, nickel, etc.), unfavorable microclimate, electromagnetic field, noise, vibration, physical loads, which are related to the 3rd (harmful) class of 1 to 3 degree. Discussion. Modernization of aluminum production with the introduction of technology of pre-baked anodes allows significantly improve working conditions, reduce the admission of harmful chemical substances into the air of the working area, with the exception of hydrofluoride, the concentration of which exceeds extremely permissible levels in 1.5-3.1 times. Noteworthy is the fact of the detection of aerosols of disintegration and condensation, including particles of nanoscale range, impurities of heavy metals in the air. The consequences of the effect of such complex combination mixtures, their combined effects with other factors on the body, can have pronounced negative effects, which is important with adequate exposure analysis and personalized assessment of the health risks of workers engaged in the production of aluminum. Conclusion. Working conditions at workplaces with the technology of self-baking anodes are characterized by moderate or severe professional risk, with the technology of pre-baked anodes - mild or moderate risk, which makes the urgent problem of further improvement of aluminum production technologies, detailed analysis of personal exposures of harmful substances for a correct assessment of the health risk of workers, is relevant.

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Lanovenko, O. "Autistic spectrum disorders: genetic and epigenetic aspects (review of modern foreign publications)". Visnyk of Lviv University. Biological series, n. 85 (25 febbraio 2021): 3–17. http://dx.doi.org/10.30970/vlubs.2021.85.01.

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Autism spectrum disorders (ASD) are diseases of a complex interaction of heredity and the environment with an estimate of heritability from 40 to 80 %, the etiology of which is multigenic and heterogeneous (people with similar pathogenetic variants have completely different phenotypes). Genetic and epigenetic factors play a key role in the onset of pathology; among them, the most important are gene copy number variations (CNV), single nucleotide polymorphisms (SNP), epigenetic modulators. Different variations in gene copy numbers have been identified in people with autism, which explains the heterogeneous genetic architecture of the disorder. Short single nucleotide polymorphisms have been identified in the genes of neuronal receptors and proteins of cell detoxification, the metabolism of neurotransmitters and metabolites, in particular, the metabolic chains of methylation and transulfuration. Despite the identification of about 800 risk genes for ASD, none of them is the cause of more than 1 % of all cases of pathology. Among the recently identified 215 candidate genes, 19.5 % are epigenetic regulators. During the formation of autism spectrum disorders, nuclear and cytoplasmic mechanisms regulating gene activity undergo epigenetic transformation: chromatin remodeling, transcription, DNA methylation in the promoter region, alternative mRNA splicing, translation regulation, post-transcriptional regulation using microRNA, protein ubiquitination, protein degradation. Mutant proteins encoded by candidate ASD genes interfere with normal cell proliferation, correct synaptic architecture, and correct synaptic function. Most often, people with autism have inherited changes with incomplete penetrance, variable severity, or both. The most studied environmental risk factors that potentially contribute to the onset of ASD in offspring are: the age of the spouses (especially the father), perinatal risk factors, impaired metabolism of vitamins (in particular, vitamin D) and trace elements (zinc, chromium, magnesium), obesity, and Diabetes mellitus in the mother ... In the urine of children with autism, the content of dopamine is significantly increased, and the normal microflora in the intestine is disrupted as a result of replacing beneficial probiotics with clostridium bacteria. Given the complexity of the etiology of autism and the growing prevalence of new confirmed cases of ASD around the world, there is an urgent need to find effective diagnostic methods and identify the main risk factors for pathology.

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V., Anantha Rama, Prakash P. e Kiran Kumar B.V. "Impact of Hazardous Industrial Waste on Health and Environment". Mapana - Journal of Sciences 5, n. 1 (25 luglio 2006): 38–46. http://dx.doi.org/10.12723/mjs.8.5.

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From the days of primitive society, human and animals have used the resource of the earth to support life and to dispose waste. Rapid population growth and uncontrolled industrial development are seriously degrading the urban and semi-urban environment in many of the developing countries placing enormous strain on natural resources and undermining efficient and sustainable development. Industrial operations lead to considerable generation of hazardous waste and in rapidly industrializing countries such as India the contribution to hazardous waste from industries are largest. Hazardous waste genarations from industries is also critical due to their large geophysical spread in the country, leading to regionwide impacts. Due to liberalization policy the pace of industrialization has been accelerated, which has resulted in increasing amount of hazardous waste every year. This long with a growing amount of municipal solid waste due to rapid urbanization and inadequate policy and technological measures continues to remain a daunting issue of environmental concern to India. In this scenario the present paper discusses various aspects of hazardous industrial waste like its origin, distribution and environmental and health hazards. Hazardous waste from industrial sectors contains heavy metals, pesticides, radioactive materials and other chemicals, which are toxic, flammable, reactive, corrosive, or have explosive properties. Normally Arsenic, Cadmium, Chromium, Copper, Lead, Zinc, Boron etc are found in pulverized fly ash. Cement industries emit huge quality of fluoride into the environment. Large quantity of mercury emitted from caustic soda industries using mercury electrodes, from chemical industries, paper and pulp industries etc. Tin mines emit tin in the vicinity of the mines. The metals such as Cadmium, Lead, Chromium, Arsenic etc, if present in the body, are hazardous to the health. Presence of fluoride within the range of 0.5 to 1.5 ppm is very essential in water for health, if present in excess leads to Florosis. Fouride may cause harm not only through water but also through air by way of respiration and soil. In river estuaries, the concentration of metal traces will reach to a high degrees of contamination because of stagnant water, when industrial effluents are fed into rivers and streams. This paper throws light upon many more such factors and also suggest measures to control and manage hazardous waste.

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Nirmala, A. "On the Phytotoxicity of Waste-Water from Textile Industry on Selected Crop Seed Germination and its Treatment Using Bacteria with Zinc Oxide Nanoparticles". Bioscience Biotechnology Research Communications 14, n. 4 (25 dicembre 2021): 1564–70. http://dx.doi.org/10.21786/bbrc/14.4.30.

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Industrialization plays a major role for the economic development of any nation. In spite of various positive aspects of industrialization, the foremost negative aspect is pollution by discharge of more waste water in to the environment. So, the aim of the present work is to analyse the phytotoxic effect of textile industry waste water on seed germination and treating the waste water using Bacterial Species and Zinc Oxide Nanoparticle. Physico-chemical parameters of dying industry waste water such as color, temperature, pH, conductivity, turbidity, total dissolved solid, total hardness, COD, BOD, oil and greases, chloride, sodium, potassium, chromium, copper, total alkalinity and zinc were analysed as per standard methods. To confirm the harmfulness, an investigation was made to study the degree of toxicity of dyeing industry effluent on seed germination and growth of Sorghum bicolor (white sorghum) Vigna unguiculata (cow pea) were selected for this study and it was placed in soil containing pots and watering with untreated industry waste water and treated waste water. The waste water was treated by two methods, one by bacterial degradation, using Pseudomonas fluroscence and the secondly, by chemical oxidation, using zinc oxide nanoparticles. After treatment their efficiency was tested with above two plants. All the above said parameter were found to be high in untreated waste water. There was a gradual decrease in the percentage of seed germination and seedling growth due to higher concentration of effluent, when compared with control. In this comparative study, methyl orange degradation by the chemical oxidation using zinc oxide nanoparticle was more effective and faster than the biological oxidation of bacterial species.

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Zakaria, E. S. "Kinetic aspects of the ion-exchange reactions of Cs+, Na+, Sr2+and Eu2+ ions on the H+ form of chromium hexacyanoferrate(II)". Journal of Radioanalytical and Nuclear Chemistry 264, n. 3 (maggio 2005): 629–35. http://dx.doi.org/10.1007/s10967-005-0763-0.

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35

Izydorczyk, Grzegorz, Katarzyna Mikula, Dawid Skrzypczak, Krzystof Trzaska, Konstantinos Moustakas, Anna Witek-Krowiak e Katarzyna Chojnacka. "Agricultural and non-agricultural directions of bio-based sewage sludge valorization by chemical conditioning". Environmental Science and Pollution Research 28, n. 35 (19 luglio 2021): 47725–40. http://dx.doi.org/10.1007/s11356-021-15293-4.

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AbstractThis literature review outlines the most important—agricultural and non-agricultural—types of sewage sludge management. The potential of waste sludge protein hydrolysates obtained by chemical sludge conditioning was reported. The discussed areas include acidic and alkaline hydrolysis, lime conditioning, polyelectrolyte dewatering and other supporting techniques such as ultrasounds, microwave or thermal methods. The legislative aspects related to the indication of the development method and admission to various applications based on specified criteria were discussed. Particular attention was devoted to the legally regulated content of toxic elements: cadmium, lead, nickel, mercury, chromium and microelements that may be toxic: copper and zinc. Various methods of extracting valuable proteins from sewage sludge have been proposed: chemical, physical and enzymatic. While developing the process concept, you need to consider extraction efficiency (time, temperature, humidity, pH), drainage efficiency of post-extraction residues and directions of their management. The final process optimization is crucial. Despite the development of assumptions for various technologies, excess sewage sludge remains a big problem for sewage treatment plants. The high costs of enzymatic hydrolysis, thermal hydrolysis and ultrasonic methods and the need for a neutralizing agent in acid solubilization limit the rapid implementation of these processes in industrial practice. Graphical abstract

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Journal, Baghdad Science. "Oilfield Produced Water Management: Treatment, Reuse and Disposal". Baghdad Science Journal 9, n. 1 (4 marzo 2012): 124–32. http://dx.doi.org/10.21123/bsj.9.1.124-132.

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Produced water is accompanied with the production of oil and gas especially at the fields producing by water drive or water injection. The quantity of these waters is expected to be more complicated problem with an increasing in water cut which is expected to be 3-8 barrels water/produced barrel oil.Produced water may contain many constituents based on what is present in the subsurface at a particular location. Produced water contains dissolved solids and hydrocarbons (dissolved and suspended) and oxygen depletion. The most common dissolved solid is salt with concentrations range between a few parts per thousand to hundreds parts per thousand. In addition to salt, many produced waters also contain high levels of heavy metals like zinc, barium, chromium, lead, nickel, uranium, vanadium and low levels of naturally occurring radioactive materials (NORM).This study will highlight the main aspects of the different international experiences with the produced water treatment for subsequent reuse or disposal. These different treatment methods vary considerably in effectiveness, cost and their environmental impacts. Samples of produced water from Al-Mishrif formation in ten wells belongs to five fields southern Iraq were taken and analyzed chemically to define the basic features of these waters and to have guide lines for the best strategy that required handling the increased water cut in these fields.

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Zhang, Li, Zheng Yang, Min Peng e Xiaomeng Cheng. "Contamination Levels and the Ecological and Human Health Risks of Potentially Toxic Elements (PTEs) in Soil of Baoshan Area, Southwest China". Applied Sciences 12, n. 3 (7 febbraio 2022): 1693. http://dx.doi.org/10.3390/app12031693.

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The primary goals of this study were to reveal the environmental status of potentially toxic elements (PTEs) and their ecological risks, as well as their associated health risks in the Baoshan area, southwest China, which has been surveyed with the scale of 1:250,000 geochemical mapping. Based on a comparison of the PTE concentrations with the soil environmental quality of China and the enrichment factor (EF), geo-accumulation index (Igeo), contamination factor (Cf), and potential ecological risk indexes (Eri and PERI), as well as the potential non-carcinogenic hazard indices (HI and CHI) and carcinogenic risks indices (TCR and CTCR), the following conclusions were drawn: The PTE concentrations in the surface soil samples that were collected from the investigated area (1.65% sites) exceeded the risk intervention values (RIV) for soil contamination of agricultural land of China. Cadmium (Cd) and mercury (Hg) posed higher ecological risks than other PTEs (arsenic (As), chromium (Cr), lead (Pb), copper (Cu), nickel (Ni), and zinc (Zn)), which was highlighted by their toxic response factor. Arsenic was the main PTE with a non-carcinogenic risk (19.57% sites for children and 0.25% sites for adults) and the only PTE that carries a carcinogenic risk (2.67% sites for Children and 0.76% sites for adults) to humans in the research area. Children are more vulnerable to health risks when compared to adults because of their behavioral and physiological traits. Geological genesis was responsible for the high concentrations, ecological risk, and health risk distribution patterns of the examined PTEs. Even though the present research highlights several important aspects related to PTE pollution in the research area, further investigations are needed, especially in mining areas.

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Zaitseva, N. V., Irina V. May, S. V. Klein, S. S. Khankharev e A. A. Boloshinova. "SCIENTIFIC AND METHODOLOGICAL ASPECTS AND PRACTICAL EXPERIENCE FOR THE FORMATION OF THE EVIDENTIAL BASE OF HAZARD TO HEALTH IN THE POPULATION IN THE ZONE OF INFLUENCE OF WASTE FROM THE PAST ECONOMIC ACTIVITY". Hygiene and sanitation 96, n. 11 (27 marzo 2019): 1038–44. http://dx.doi.org/10.18821/0016-9900-2017-96-11-1038-1044.

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There are described an algorithm and methods for collecting the evidential base for causing hazard to the health of the population of Zakamensk (the Republic of Buryatia) in the zone of influence of the waste of the past activities of the Dzhidinsky tungsten-molybdenum combine. The source of danger is lying sands, containing a complex of toxic heavy metals - lead, cadmium, manganese, nickel, chromium, etc. The algorithm for the formation of the evidential base included: a general analysis of the sanitary and hygienic situation; assessment in the dynamics of the quality of atmospheric air, drinking water, soil, food; assessment of the risk to the health of the population; epidemiological studies; in-depth clinical surveys of a representative group of city residents (280 people). In the blood of the examinees, heavy metals were identified as biological markers of the exposure. There was evaluated a complex of the response (effect) adequate to effects of laboratory markers. By methods of mathematical statistics there was established the presence of reliable relationships in the system “source of hazard - the quality of the environment - exposure to risk factors - health status.” The hazard to the health of a citizen, due to the negative impact of the factor, was considered to be proven if it was possible to build a continuous step-by-step logical chain of relationships between the source of the harmful effect, the quality of the habitat and the establishment of the fact of the disease. The quality of the habitat of the population of Zakamensk was shown to give rise in unacceptable risks to the health of residents. The main influencing factor is the pollution of atmospheric air, local food products and drinking water from public and private wells. Risks are realized in terms of a level of the primary morbidity rate of the population of the respiratory diseases, endocrine system, digestive organs that is relatively high compared to the matched area. The relationship between health hazard and environmental factors has been fully proved in 14% of the surveyed persons. At the same time, the territory was shown not be characterized as a zone of “ecological disaster” or “an emergency environmental situation”.

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Dehghan, Saeed, Koroush Shahriar, Parviz Maarefvand e Kamran Goshtasbi. "The Effect of Chromite Slag as a Binder Agent on Stress-Strain Behaviour of Cemented Tailing Backfill in Compression, a Case Study: Faryab Chromite Mine / Wpływ dodatku żużla zawierającego spoiwo w postaci chromitu na wytrzymałość na ściskanie materiału podsadzkowego zawierającego odpady pogórnicze z dodatkiem cementu. studium przypadku: kopalnia chromitu (żelaziaka chromowego) w faryab". Archives of Mining Sciences 58, n. 1 (1 marzo 2013): 189–98. http://dx.doi.org/10.2478/amsc-2013-0013.

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Due to improving the environmental aspect and reduce the backfilling cost, the Faryab mine carry out researches into the replacement of cement by chromite slag. The test samples consisted of tailing from the washing plant of Faryab mine and different binders such as Portland cement, Pozzolanic cement and different combinations of Portland cement with chromite slag. The chromite slag produced by Ferrochromite refinery plant of this mine. The purpose of this paper is to analyze the findings from extensive laboratory test programs carried out to determine the effects of chromite slag on mechanical properties of cemented tailing backfills (CTB). The results show that chromite slag improves the mechanical properties of CTB samples. Also, the results indicate that chromite slag can be used as a replaceable material with cement and reduced 2-3% consumption of cement in 1 m3 of backfill mixes. In addition, improving the environmental conditions can be achieved by reducing the cement content and moving tailing and chromite slag to underground stopes.

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Matusiak, Jolanta, Joanna Wyciślik e Andrzej Wyciślik. "Environmental Criteria for Shielding Gas Selection during Arc Welding of Stainless Steels". Solid State Phenomena 246 (febbraio 2016): 275–78. http://dx.doi.org/10.4028/www.scientific.net/ssp.246.275.

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Gas-shielded arc welding of stainless steels belongs to processes which are characterized by the highest concentration of chromium (VI) and nickel in welding fume. These substances are carcinogenic to humans. Material and technological conditions of gas-shielded arc welding of stainless steels influence fume emission rates and chemical composition of welding fume. This fact creates the possibility of process optimization in aspect of emission rates and chemical composition of welding fume including carcinogenic compounds. This paper presents the correlation between shielding gas compositions and fume emission rates and carcinogenic substances contents during gas-shielded arc welding of stainless steels using MIG/MAG, Cold Arc and CMT methods.

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Ghosh, Sreejita, Amrita Jasu e Rina Rani Ray. "Hexavalent chromium bioremediation with insight into molecular aspect: an overview". Bioremediation Journal 25, n. 3 (17 febbraio 2021): 225–51. http://dx.doi.org/10.1080/10889868.2021.1884529.

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Iyer, Vijayan Gurumurthy. "Social impact assessment process for an efficient socio-economic transformation towards poverty alleviation and sustainable development". New Trends and Issues Proceedings on Advances in Pure and Applied Sciences, n. 7 (30 novembre 2016): 150–69. http://dx.doi.org/10.18844/gjpaas.v0i7.3175.

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Abstract Sustainable social entrepreneurship (SSE) is a kind of entrepreneurship that meets the needs of the present without compromising the ability, efficiency and values of future generations to meet their own needs. SSE leads to sustainable development. Social entrepreneurs were developed through well-conceived and well directed training programmes around thrust areas, thus advancing the frontiers of theories and practice SSE. The concept of SSE challenges that fosters long-term protection of the society, environment and its habitants as the technological or engineering developments are guided by efficiency, productivity, profitability, health and environmental impacts, resource and energy conservation, waste management, and social impacts such as public convenience, unemployment and crime. The specific objectives of this research were: (i) To formulate and appraise forty-three number of detailed project reports (DPRs) of Diploma in Entrepreneurship and Business Management (DEBM ) course extension learners in eleven batches attached with the DEBM Counsellor and Co- ordinator of Entrepreneurship Development Institute of India -Ahmedabad (EDI),India as well author of this research during the research year (RY) 2007-2014 , (ii) To conduct social impact assessment and environmental health impact assessment (EHIA) for projects , (iii) To design and develop a comprehensive and green economic system modelling and (iv) To promote sustainable socio- economic policies of SIA process for an efficient socio- economic transformation development based on social entrepreneurial research conducted in South India . The design of the study is cross sectional. SIA is defined as the systematic identification and evaluation of the potential social impacts of proposed projects, plans, programs, policies or legislative actions relative to the socio- economic components of the society and total environment. Social factor has been considered in project planning and decision-making process in order to arrive at action which should be socio-economically compatible. Environmental health impact assessment process has been conducted in order to mitigate the environmental health impacts. Socio-economic environment is a man-made environment related to a set of considerations such as demographical study including population trends and population distribution , population interaction and interrelation to the social problem and solution, economic indicators of human welfare services, educational systems, transportation systems, environmental protective infrastructural facilities such as water supply system, waste water treatment system, solid and hazardous waste management, resource conservation and recovery process, environmental public health services and medical facilities. Social impact assessment process should be enacted as social policy act in order to encourage the considerations of human society in project planning and decision making process . Extension learners were equipped with the knowledge, skills and motivation to set up their sustainable social enterprises and function dynamically and manage successfully. DPRs proposed by learners have been investigated as per guidelines provided by EDI. Entrepreneurial business planning assessment regimes (EBPARs) have been accomplished for their credibility and communicability. DEBM projects were screened for the seven fatal flaws viz., (i) Scientific feasibility, (ii) technical feasibility, (iii) economic feasibility, (iv) marketing feasibility, (v) environmental feasibility, (vi) social feasibility and (vii) fundamental legality. Social entrepreneur of an entrepreneurial team should need skills in ethics, accounting, law, finance, team creation and marketing aspects in order to avoid failures in the process. The result analysis of forty- three learners has been discussed. Based on comprehensive socio-economic analysis, a green socio-economic system model has been presented. A famous project case of a DPR-I has been presented on unsafe chromium pollution and contamination of about 18 000 to 30 000 mg/kg from Indian cotton roller ginneries and development of green design roller gin rollers for cotton gins duly investigated in a ginning factory. Such low-carbon and energy-efficient agricultural technologies of agricultural hi-tech industries have made important contributions to mitigating the impacts of economic growth on global warming. Hitherto state-of-the- art literatures, market effects have been considered. It is reported that non-market impacts such as social and environmental impact assessment should be considered for proposed projects, plans, programs, policies and legislative action. It is concluded that this action-based and extension learning field study on SSE shall promote sustainable socio-economic policies for sustainable development and poverty alleviation. Keywords: action, efficient, entrepreneurship, environmental impact assessment process, project, social impact assessment (SIA) process, transformation.

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Bhattacharya, Amrik, Anshu Gupta, Amarjeet Kaur e Darshan Malik. "Alleviation of hexavalent chromium by using microorganisms: insight into the strategies and complications". Water Science and Technology 79, n. 3 (1 febbraio 2019): 411–24. http://dx.doi.org/10.2166/wst.2019.060.

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AbstractExcessive industrialization and anthropogenic activities have resulted in widespread prevalence of heavy metals including hexavalent chromium in the environment. In addition to toxic properties, Cr(VI) possesses high stability and mobility, which in total makes it included in the list of priority heavy metals; thus it needs to be managed urgently. Among different methods available for remediation of Cr(VI), bioremediation is considered as one of the sustainable methods which could effectively be utilized for controlling Cr(VI) pollution. In this aspect, the treatment of Cr(VI)-containing wastewater originating from industries is noteworthy. The present review thus is an attempt to present a systematic overview dealing with studies on remediation of hexavalent chromium by using microorganisms and their application in treatment of Cr(VI)–containing industrial wastewaters. Various factors affecting the Cr(VI) removal and methods to enhance the bio-treatment are highlighted, which might act as a basis for researchers developing Cr(VI) bioremediation techniques.

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Kim, Gyung Guk, Joung Ah Kang, Seon Jin Kim, Sun Jae Kim e Seung Han Shin. "Improved Adhesion to ABS Plastics by a Photocatalytic Reaction". Materials Science Forum 544-545 (maggio 2007): 75–78. http://dx.doi.org/10.4028/www.scientific.net/msf.544-545.75.

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The pretreatment of ABS (acrylonitrile-butadiene-styrene) plastics prior to metallization has been generally performed with strong acids, such as sulfuric, chromic, or potassium-permanganate acid. However, conventional wet-chemical pretreatment presents inherent environmental and safety problems to consider. In particular, the presence of Cr+6 imposes a serious environmental threat. Therefore, in this study, aspects of pretreatment, using the photocatalytic reaction in TiO2 sol, were investigated as a replacement for wet-chemical pretreatment. Surface characterization, before and after the pretreatment, was examined by X-ray photoelectron spectroscopy and scanning electron microscopy. A copper film was deposited by electroless plating, and the adhesion strength between the deposited film and ABS plastics was evaluated by the cross-cut tape test (ISO 2409). When ABS plastics were pre-treated in TiO2 sol, the adhesion strength was improved to levels obtained using a strong acid solution.

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Das, B. K., P. K. Das e P. Dash. "Evaluation of Phenotypic Responses of Selected Rice (Oryza sativa L.) Cultivars to Hexavalent Chromium Stress in Soil". Nature Environment and Pollution Technology 21, n. 3 (1 settembre 2022): 1341–47. http://dx.doi.org/10.46488/nept.2022.v21i03.041.

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The current work is designed to search for suitable rice (Oryza sativa L.) cultivars capable of growing on Cr(VI), hexavalent chromium contaminated soils. The study of tolerance and phenotypical changes of three selected rice cultivars like Bina Dhan 11, Kalachampa, and Pratikshya, at the seedling stages, was done under soil Cr(VI) concentrations up to 300 mg.kg-1 of soil. The 7-day seedlings of these rice cultivars growing on Cr(VI) treated soils were found to exhibit a significant reduction in shoot and root growth at p ≤ 0.05. The experimental results support that 7-day seedlings of Bina Dhan 11 were found to be the best among the three cultivars under soil Cr(VI) stress conditions. The present work may help in selecting suitable rice cultivar for paddy cultivation on Cr(VI) contaminated crop lands present in mining and industrial belts. Further work on this aspect may be useful in increasing rice productivity, catering to the increase in demand for food.

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Gómez-Aguilar, Dora Luz, Javier Andrés Esteban-Muñoz, Juan Pablo Rodríguez-Miranda, Deisy Baracaldo-Guzmán e Octavio José Salcedo-Parra. "Desorption of Coffee Pulp Used as an Adsorbent Material for Cr(III and VI) Ions in Synthetic Wastewater: A Preliminary Study". Molecules 27, n. 7 (27 marzo 2022): 2170. http://dx.doi.org/10.3390/molecules27072170.

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Some of the diverse agro-industrial waste generated in primary or secondary stages have proved to be promising biomaterials for treating aqueous effluents contaminated, in this case, with heavy metals. Therefore, it is necessary to know their optimal operating conditions and the regeneration or reusability of the solid by-product, an aspect related to desorption. Considering the above, this article presents the findings of a preliminary study related to the desorption process of coffee pulp without physicochemical modification (Castilla variety), an agricultural waste used as a sorbent of Cr(III and VI) ions in synthetic wastewater. The desorption efficiency of four eluting agents at defined concentrations (0.10M)—HC1, HNO3, H2SO4, and EDTA—was evaluated in a time interval of 1 to 9 days. Likewise, the proposals for the sorption and/or desorption mechanisms proposed and reported in the literature with respect to the use of biosorbents derived from the coffee crop are presented. With respect to the results, the coffee pulp used in previous studies of the adsorption of chromium species mentioned (optimal conditions in synthetic water of particle size 180 μm, dose 20 g·L−1, agitation 100 RPM, room temperature, time of 90 to 105 min) showed efficiencies in the removal of Cr(III) and Cr(VI) of 93.26% and 74.80%, respectively. Regarding the extracting substances used, H2SO4 0.10 M was the one that presented the highest desorption percentage in both chromic species, with a desorption of 45.75% Cr(VI) and 66.84% Cr(III) in periods of 5 and 9 days, respectively, with agitation of 100 RPM and room temperature. Finally, the dissemination of preliminary results on the desorption of coffee pulp contaminated with chromic species without physicochemical modification is novel in this study, as similar work with this specific material has not yet been reported in the literature. On the other hand, the limitations of the study and future research are related to the evaluation at different concentrations and of other extractor solutions that allow improving the efficiency of desorption of these chemical species in a shorter time from the coffee pulp (with and without modification) as well as the reuse cycles. As a result, the desorption of coffee pulp used as an adsorbent material in real water could help researchers identify the possible interfering factors that affect the process (foreign anions and cations, organic matter, environmental conditions, among others).

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Senthurchelvan, R., Y. Wang, S. Basak e K. Rajeshwar. "Reduction of Hexavalent Chromium in Aqueous Solutions by Polypyrrole: II. Thermodynamic, Kinetic, and Mechanistic Aspects". Journal of The Electrochemical Society 143, n. 1 (1 gennaio 1996): 44–51. http://dx.doi.org/10.1149/1.1836385.

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Yamina, Benmalek, Benayad Tahar e Fardeau Marie Laure. "Isolation and screening of heavy metal resistant bacteria from wastewater: a study of heavy metal co-resistance and antibiotics resistance". Water Science and Technology 66, n. 10 (1 novembre 2012): 2041–48. http://dx.doi.org/10.2166/wst.2012.355.

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The uncontrolled discharges of wastes containing a large quantity of heavy metal create huge economical and healthcare burdens particularly for people living near that area. However, the bioremediation of metal pollutants from wastewater using metal-resistant bacteria is a very important aspect of environmental biotechnology. In this study, 13 heavy metal resistant bacteria were isolated from the wastewater of wadi El Harrach in the east of Algiers and characterized. These include zinc-, lead-, chromium- and cadmium-resistant bacteria. The metal-resistant isolates characterized include both Gram-negative (77%) and Gram-positive (23%) bacteria. The Minimum Inhibitory Concentration (MIC) of wastewater isolates against the four heavy metals was determined in solid media and ranged from 100 to 1,500 μg/ml. All the isolates showed co-resistance to other heavy metals and antibiotic resistance of which 15% were resistant to one antibiotic and 85% were multi- and bi-antibiotics resistant. The zinc-resistant species Micrococcus luteus was the much more heavy metal resistant. The results of toxicity tests on Vibrio fischeri showed that the DI50 (5 min) as low as 0.1 carried away luminescence inhibition greater than 50%.

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Xia, Lin, Ejii Akiyama, Gerald Frankel e Richard McCreery. "Storage and Release of Soluble Hexavalent Chromium from Chromate Conversion Coatings Equilibrium Aspects of Cr[sup VI] Concentration". Journal of The Electrochemical Society 147, n. 7 (2000): 2556. http://dx.doi.org/10.1149/1.1393568.

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Diotti, Alessandra, Giovanni Plizzari e Sabrina Sorlini. "Leaching Behaviour of Construction and Demolition Wastes and Recycled Aggregates: Statistical Analysis Applied to the Release of Contaminants". Applied Sciences 11, n. 14 (6 luglio 2021): 6265. http://dx.doi.org/10.3390/app11146265.

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Construction and demolition wastes represent a primary source of new alternative materials which, if properly recovered, can be used to replace virgin raw materials partially or totally. The distrust of end-users in the use of recycled aggregates is mainly due to the environmental performance of these materials. In particular, the release of pollutants into the surrounding environment appears to be the aspect of greatest concern. This is because these materials are characterized by a strong heterogeneity which can sometimes lead to contaminant releases above the legal limits for recovery. In this context, an analysis of the leaching behaviour of both CDWs and RAs was conducted by applying a statistical analysis methodology. Subsequently, to evaluate the influence of the particle size and the volumetric reduction of the material on the release of contaminants, several experimental leaching tests were carried out according to the UNI EN 12457-2 and UNI EN 12457-4 standards. The results obtained show that chromium, mercury, and COD are the most critical parameters for both CDWs and RAs. Moreover, the material particle size generally affects the release of contaminants (i.e., finer particles showed higher releases), while the crushing process does not always involve higher releases than the sieving process.

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