Artigos de revistas: "Metallic effluents"

1

Israel, A. U., I. B. Obot, S. A. Umoren, V. Mkpenie e G. A. Ebong. "Effluents and Solid Waste Analysis in a Petrochemical Company- A Case Study of Eleme Petrochemical Company Ltd, Port Harcourt, Nigeria". E-Journal of Chemistry 5, n.º 1 (2008): 74–80. http://dx.doi.org/10.1155/2008/805957.

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Effluents and soil samples where sediments from the treated effluents are dumped were analyzed for physicochemical properties, metallic and non-metallic ions. These parameters were compared with established international standard (FEPA). Effluents were classified as process waste water (PWW), clarified water (CW), and final discharge (FD). The petrochemical effluents contained very high concentration of TDS (284.00±014 mg/L) and significant concentrations of TSS (78.89±0.01 mg/L), COD (30.10±0.02 mg/L), DO (13.20±0.01 mg/L), BOD (6.12±0.00 mg/L), PO43-(4.34±0.00 mg/L), SO42-(3.59±0.00 mg/L), Cl-(55.52±0.01 mg/L) and NO3-(8.40±0.01 mg/L). Low concentrations of iron, zinc, copper, cadmium, lead, nickel and cobalt was also observed. Some heavy metals were not detected at all in some of the effluent samples analyzed. Apart from temperature and total dissolved solid TDS, all the other parameters were below FEPA effluent limitations for guidelines for Petroleum Refinery, Fuel/Gasoline oil category in Nigeria.

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Ram, Chhotu, Bushra Zaman e Amit Dhir. "Study on corrosion investigations in industrial effluents: a review". Corrosion Reviews 37, n.º 2 (26 de março de 2019): 115–30. http://dx.doi.org/10.1515/corrrev-2017-0113.

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AbstractCorrosion affects the usefulness of metallic materials used in the construction of an effluent treatment plant (ETP). The present report investigates the corrosive and inhibitive properties of the chemicals present in the effluent of paper mill and distillery industries. Chemicals such as chloride, chlorophenols, phosphate, calcium, nitrite, and nitrate enhance corrosion, whereas the presence of sulfate, potassium, organic matter, and melanoidins (color) inhibits corrosion at an acidic pH level in distillery and paper mill effluents. A finding shows that pH level has an important role in increasing or decreasing the effect on corrosivity of effluents.

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Hernández Mata, Karla Miriam, Onofre Monge Amaya, María Teresa Certucha Barragán, Francisco Javier Almendariz Tapia e Evelia Acedo Félix. "Metallic Biosorption Using Yeasts in Continuous Systems". International Journal of Photoenergy 2013 (2013): 1–4. http://dx.doi.org/10.1155/2013/578729.

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Mining effluents were found to be the main source of pollution by heavy metals of the surface water in the San Pedro River in Sonora, Mexico. The overall objective of this study was to determine the biosorption of Zn, Cu, Mn, and Fe with yeasts isolated from San Pedro River in a continuous system. The tests conducted in two reactors packed with zeolite connected in series. The first reactor was inoculated mixing two yeasts species, and the effluent of the first reactor was fed to second reactor. Subsequently, the first reactor was fed with contaminated water of San Pedro River and effluent from this was the second reactor influent. After 40 days of the experiment a reduction of 81.5% zinc, 76.5% copper, manganese 95.5%, and 99.8% of iron was obtained. These results show that the selected yeasts are capable of biosorbing zinc, copper, manganese, and iron under these conditions.

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Gupta, G. S., e Y. C. Sharma. "Environmental Management of Textile and Metallic Industrial Effluents". Journal of Colloid and Interface Science 168, n.º 1 (novembro de 1994): 118–24. http://dx.doi.org/10.1006/jcis.1994.1400.

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Gupta, Ghan S., Arun K. Singh, Balbir S. Tyagi, Gur Prasad e Vishwa N. Singh. "Treatment of carpet and metallic effluents by China clay". Journal of Chemical Technology & Biotechnology 55, n.º 3 (24 de abril de 2007): 277–84. http://dx.doi.org/10.1002/jctb.280550313.

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de Jesus Carvalho de Souza, Vinícius, José Cláudio Caraschi, Wander Gustavo Botero, Luciana Camargo de Oliveira e Danielle Goveia. "Development of Cotton Linter Nanocellulose for Complexation of Ca, Fe, Mg and Mn in Effluent Organic Matter". Water 13, n.º 19 (6 de outubro de 2021): 2765. http://dx.doi.org/10.3390/w13192765.

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Effluent organic matter (EfOM) is present in different domestic and industrial effluents, and its capacity to hold metallic ions can interfere in the wastewater treatment process. Due to the low quality of water, new sustainable technologies for this purpose have become extremely important, with the development of renewable-source nanomaterials standing out in the literature. Nanocellulose (NC) deserves to be highlighted in this context due to its physicochemical characteristics and its natural and abundant origin. In this context, the interactions between NC extracted from cotton linter, organic matter fraction (humic substances) and metal ions have been evaluated. Free metal ions (Ca, Fe, Mg and Mn) were separated by ultrafiltration and quantified by atomic absorption spectrometry. The nanomaterial obtained showed potential for the treatment of effluents containing iron even in the presence of organic matter. The probable interaction of organic matter with NC prevents the efficient removal of calcium, magnesium and manganese. For these elements, it is desirable to increase the interaction between metal and NC by modifying the surface of the nanomaterial.

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Bykovsky, Nikolai A., Lyudmila N. Puchkova e Nadezhda N. Fanakova. "Regeneration of etching solution used in the production of printed circuit boards". E3S Web of Conferences 525 (2024): 02010. http://dx.doi.org/10.1051/e3sconf/202452502010.

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Some waste waters containing copper are formed during the production of printed circuit boards. When these effluents are discharged into the reservoir, they must be diluted 140,000 times, and the treatment of these copper-containing effluents causes the copper loosing. The paper presents the results obtained during the study of electrochemical processing of copper-containing effluents formed at the stage of PCBs etching. The spent solution processing was realized in a membrane electrolytic cell. An increase in current density results in an increase in process speed. Along with a decrease in copper concentration in the solution, the hydrochloric acid was concentrated. It is shown that it is possible to regenerate the etching solution and obtain a metallic copper.

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Ashok Kumar, B., S. Jothiramalingam, S. K. Thiyagarajan, T. Hidhayathullakhan e R. Nalini. "Phytoremediation of Heavy Metals from Paper Mill Effluent Soil Using Croton sparsiflorus". International Letters of Chemistry, Physics and Astronomy 36 (julho de 2014): 1–9. http://dx.doi.org/10.18052/www.scipress.com/ilcpa.36.1.

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Effluents from industries contain appreciable amount of metallic cations like zinc, copper, iron, manganese, lead and cadmium. Release of heavy metal without proper treatment poses a significant threat to public health because of its persistence biomagnifications and accumulation in food chain. To reduce metal pollution problems many processes have been developed for the treatment and disposal of metal containing wastes. Certain plants have the ability to accumulate heavy metals such as Pb, Cr, Cd and Zn. At present, phytoremediation of metals may be approaching commercialization. Hence, possibility can be explored to remove heavy metal load, present even in low concentration, in waste water of paper mill effluent soil by using Croton sparsiflorus.

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Ashok Kumar, B., S. Jothiramalingam, S. K. Thiyagarajan, T. Hidhayathullakhan e R. Nalini. "Phytoremediation of Heavy Metals from Paper Mill Effluent Soil Using Croton sparsiflorus". International Letters of Chemistry, Physics and Astronomy 36 (15 de julho de 2014): 1–9. http://dx.doi.org/10.56431/p-9s7q5s.

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Effluents from industries contain appreciable amount of metallic cations like zinc, copper, iron, manganese, lead and cadmium. Release of heavy metal without proper treatment poses a significant threat to public health because of its persistence biomagnifications and accumulation in food chain. To reduce metal pollution problems many processes have been developed for the treatment and disposal of metal containing wastes. Certain plants have the ability to accumulate heavy metals such as Pb, Cr, Cd and Zn. At present, phytoremediation of metals may be approaching commercialization. Hence, possibility can be explored to remove heavy metal load, present even in low concentration, in waste water of paper mill effluent soil by using Croton sparsiflorus.

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Dra, Abdelaiz, Abdelali El Gaidoumi, Karim Tanji, Aziz Chaouni Benabdallah, Abdeslem Taleb e Abdelhak Kherbeche. "Characterization and Quantification of Heavy Metals in Oued Sebou Sediments". Scientific World Journal 2019 (26 de junho de 2019): 1–9. http://dx.doi.org/10.1155/2019/7496576.

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The discharge of large quantities of industrial and domestic effluents into the estuaries, with or without treatment, has led to an increase in the amount of micropollutants present in the sediments. In this study, we have assessed the quality of sediments of Sebou river studying the physicochemical parameters, percentage of organic matter, mineralogy, and trace levels of metal elements trapped in the sample sediments of Sebou river. The sediments samples were collected from the upstream of Fez river, confluence between the Fez river and the Sebou river, Ain Nokbi river, and edge of Sebou river, where wastewaters from the city of Fez are discharged. The sediments samples were characterized by scanning electron microscopy, X-ray diffraction, and Fourier Transform Infrared Spectroscopy, while trace levels of metallic elements, Calcium, Zinc, Copper, Cadmium, Iron, and Nickel, were determined by the ICP-AES analysis. The obtained results show that there is a significant change in the values of the studied metals which is probably due to industrial effluents. Indeed, the metal content in the sediments reaches particularly high values exceeding the limit recommended by WHO. These results suggested that the pollution by metallic industrial effluents discharged without treatments poses potential threat to the receiving rivers and may represent a danger for humans which are exposed to pollutants due to the numerous uses of such river waters.

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Fiset, Jean F., Rajeshwar D. Tyagi e Jean-François Blais. "Cocoa Shells as Adsorbent for Metal Recovery from Acid Effluent". Water Quality Research Journal 37, n.º 2 (1 de maio de 2002): 379–88. http://dx.doi.org/10.2166/wqrj.2002.024.

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Abstract Cocoa shells are commonly used in the horticulture field. This inexpensive substrate was studied for metal removal from acidic effluents. Batch adsorption tests in shake flasks revealed that cocoa shells were particularly efficient for lead removal. More than 90% of lead could be removed from a mono-metallic solution containing 51.8 mg Pb/L (250 µM Pb) using 20 g/L of cocoa shells. Langmuir isotherm indicated that cocoa shells have a maximum lead uptake of 7.56 mg/g (36.5 µmol/g) at pH = 2.0. Adsorption tests were also successfully completed with three types of heavily contaminated acid effluents: a multi-element synthetic solution and effluents produced during sewage sludge and soil decontamination. These tests have shown that the presence of other metals and organic matter only slightly decreases the lead removal by cocoa shells. After adsorption, metals could be eluted using a diluted acid solution (0.5 N) and the cocoa shells could be reused for many adsorption/desorption cycles.

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Dzaparov, Viacheslav, Aleksandr Sakhnov, Igor Zdorovets e Semen Shokhov. "Industrial effluents of mining enterprises of the North Caucasus and water resources". Izvestiya vysshikh uchebnykh zavedenii. Gornyi zhurnal, n.º 1 (20 de fevereiro de 2023): 101–9. http://dx.doi.org/10.21440/0536-1028-2023-1-101-109.

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Subject of research. The article is devoted to the problem of preserving the quality of the global water resources under the threat of its deterioration caused by industrial effluents polluting the hydrosphere. Research objective is to establish the patterns of changes in water resources state and carry out the ecological detailing of the mechanism for managing water quality and protecting water resources. Methods of research include the generalization and systematization of reported data and literature on the aquatic environment condition in the metallic ore mining regions and methods of mine effluents treatment, laboratory experiments on electrochemical treatment of mineralized effluents to restore their quality, recommendations for improving the management of the aquatic environment state. Research results and scope. A distinctive feature of the problem for regions with mountainous terrain is indicated. The surroundings of mining enterprises were ranked according to metal pollution. The research results on the effluents state at non-ferrous metallurgy facilities are presented. The results of research by the precipitation curve method are summarized. The laboratory experiment results are shown on electrochemical treatment of mineralized effluents and their quality restoration. The direction is indicated of improving the economic efficiency of effluents treatment by increasing by-products output. A technology with the generation of self-neutralizing agents is recommended. It has been established that in the case of heavy metal pollution, the extent of the pollution bubble is determined by the processes of chemicals mixing and dilution. Conclusions. The management of water resources quality and industrial effluents pollution prevention should begin with the establishment of patterns of change in their state as well as with the control mechanism detailing in mountainous terrain.

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S., Thevasundari, Thilagavathi C., Hemalatha M., Abirami P. e Rajeswari B. "Microbial Application in Heavy Metal Removal from Pharmacological Industrial Effluent". Environment and Ecology 42, n.º 2A (maio de 2024): 553–57. http://dx.doi.org/10.60151/envec/ymuj2409.

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In industrial effluents, significant amounts of metallic cations such as zinc, copper, iron, manganese, lead, nickel, and cadmium are present. Long-term irrigation with these effluents increases the amount of organic carbon and heavy metals in the soil, increasing the likelihood that they will enter the food chain and, eventually, result in significant bioaccumulation. Many techniques for the treatment and disposal of metal-containing wastes, such as ion exchange, reverse osmosis, in flotation, and evaporation, have been developed in order to reduce metal pollution issues. The main disadvantages of conventional treatments are low efficiency at low concentrations of heavy metals, expensive handling, and safe disposal of toxic sludge. In light of this, an effort has been made to investigate how tannery affects the growth of green gram.

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Teixeira, Raimundo Nonato Pereira, Vicente Oliveira Sousa Neto, Juliene Tomé Oliveira, Lucas Fontenele Amorim, Eliezer Fares Abdala Neto, Diego de Quadros Melo, Henrique Douglas Melo Coutinho, Bonglee Kim, Jorge Marcell Coelho Menezes e Ronaldo Ferreira do Nascimento. "Removal of Toxic Metal Ions from Aqueous Solutions in Integrated Clay Adsorption and Electroflotation". Adsorption Science & Technology 2022 (20 de julho de 2022): 1–16. http://dx.doi.org/10.1155/2022/3669652.

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Most galvanic process industries treat their effluents by chemical precipitation methods. Such a method produces an amount of galvanic sludge that is often disposed of inappropriately to the environment, causing major environmental damage. These rejects present high concentrations of toxic metallic ions, such as copper (Cu(II)), lead (Pb(II)), nickel (Ni(II)), and cadmium (Cd(II)). Several alternatives have been proposed to contribute in a cheaper and efficient way to treat these effluents. This study aimed to describe the results obtained in the removal of the concentrations of Cu(II), Ni(II), Cd(II), and Pb(II) ions, present in an aqueous solution, by the use of a hybrid system combining the adsorption and electroflotation processes simultaneously. The adsorbent materials used were two Brazilian soil clays classified as sodium clay (SC) and ferric clay (FC). For the electroflotation process, aluminum, iron, and stainless-steel electrodes were used. The obtained data showed good efficiency in the removal of the four metallic ion concentrations. The best results presented a reduction in the concentration of Cu(II), Ni(II), Cd(II), and Pb(II) ions of 50.11%, 36.71%, 21.59%, and 23.43%, respectively, when it was used the hybrid system formed by the ferrous clay as adsorbent and the aluminum electrode for the electroflotation process.

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Ojstršek, Alenka, Primož Vouk e Darinka Fakin. "Adsorption of Pollutants from Colored Wastewaters after Natural Wool Dyeing". Materials 15, n.º 4 (16 de fevereiro de 2022): 1488. http://dx.doi.org/10.3390/ma15041488.

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The presented study assesses the efficiency of selected adsorbents, zeolite 4A in two particle sizes and pelletized activated carbon (AC), for the potential removal of color, chemical oxygen demand (COD), total organic carbon (TOC) and metals from wastewaters after natural wool dyeing. Firstly, the natural coloring compounds were extracted from dried common walnut (Juglans regia) leaves and used further for exhaustion dyeing of wool fibers, together with three different metallic salts in two concentrations (meta-mordanting). Effluents with higher mordant concentration were additionally treated according to a shake-flask adsorption experiment. The obtained results revealed efficient removal of exceeded metallic ions by zeolite (up to 94.7%), on account of their superior ion exchange capability as compared to AC. The zeolites also reduced turbidity and electrical conductivity significantly. On the other hand, AC was more efficient for the reduction in organic pollution, COD up to 96% and TOC up to 95%, due to its higher specific surface area and total pore volume, and, thus, higher potential for adsorption of different compounds in comparison to 4A. All three proposed adsorbents lowered wastewaters’ coloration remarkably, up to 78% (AC) and up to 71% (4A), depending on the type of effluent/mordant and inspected wavelength; although, the spectral absorbance coefficient (SAC) values remained highly above the limit values for discharge of wastewaters into watercourses.

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Alhammadi, Eeman, Normala Halimoon, Zufarzaana Zulkeflee e Wan Lutfi Wan Johari. "Study of Some Physiological Activities for Multimetal Tolerant Bacteria Under Metallic Stress". International Journal of Membrane Science and Technology 10, n.º 2 (31 de julho de 2023): 3976–93. http://dx.doi.org/10.15379/ijmst.v10i2.3296.

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Electroplating effluents contain heavy metals besides nitrate, which can be harmful to aquatic and terrestrial life if released into the environment. Bioremediation is an imperative task to remove these contaminants from aquatic surfaces. Bacterial species that are tolerant to multiple metals were isolated from electroplating effluents and studied for their ability to withstand high metal concentrations and perform physiological activities. These activities included the production of carotenoid pigments and the reduction of nitrate during exponential and stationary growth phases after exposure to high concentrations of single and quaternary metals. The influence of heavy metals on these activities and bacterial behavior was evaluated. The results showed that the production of carotenoid pigments increased over time, with the highest quantities produced at 48 hours with Zn, Cu, and quaternary. Pigments produced vary with the different types of metals and their concentrations. The ratio of pigment extract to unladen metal cells was higher compared to laden metals cells. The isolates were also capable of reducing nitrate and producing nitrite, but high metal concentrations hindered the conversion of nitrite to nitrogen gas and accumulated great amounts of nitrite between the end of the exponential phase and the start of the stationary phase. The production of carotenoids allowed the bacteria to tolerate high metal concentrations and continue reducing nitrate. This study suggests that pigmented bacteria and aerobic denitrifiers have the potential for bioremediation and nitrate reduction, which can help clean and recover contaminated environments.

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Hemdan, Bahaa, Vijay Kumar Garlapati, Swati Sharma, Sudipa Bhadra, Shivani Maddirala, Varsha K.M., Vineela Motru, Pranab Goswami, Surajbhan Sevda e Tejraj M. Aminabhavi. "Bioelectrochemical systems-based metal recovery: Resource, conservation and recycling of metallic industrial effluents". Environmental Research 204 (março de 2022): 112346. http://dx.doi.org/10.1016/j.envres.2021.112346.

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Gounou, C., G. Varrault, K. Amedzro, J. Gasperi, R. Moilleron, S. Garnaud e G. Chebbo. "Research of trace metals as markers of entry pathways in combined sewers". Water Science and Technology 63, n.º 4 (1 de fevereiro de 2011): 633–40. http://dx.doi.org/10.2166/wst.2011.219.

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Combined sewers receive high toxic trace metal loads emitted by various sources, such as traffic, industry, urban heating and building materials. During heavy rain events, Combined Sewer Overflows (CSO) can occur and, if so, are discharged directly into the aquatic system and therefore could have an acute impact on receiving waters. In this study, the concentrations of 18 metals have been measured in 89 samples drawn from the three pollutant Entry Pathways in Combined Sewers (EPCS): i) roof runoff, ii) street runoff, and iii) industrial and domestic effluents and also drawn from sewer deposits (SD). The aim of this research is to identify metallic markers for each EPCS; the data matrix was submitted to principal component analysis in order to determine metallic markers for the three EPCS and SD. This study highlights the fact that metallic content variability across samples from different EPCS and SD exceeds the spatio-temporal variability of samples from the same EPCS. In the catchment studied here, the most valuable EPCS and SD markers are lead, sodium, boron, antimony and zinc; these markers could be used in future studies to identify the contributions of each EPCS to CSO metallic loads.

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Rajendran, Suriyaprabha, Shivraj Gangadhar Wanale, Amel Gacem, Virendra Kumar Yadav, Inas A. Ahmed, Jari S. Algethami, Shakti Devi Kakodiya et al. "Nanostructured Iron Oxides: Structural, Optical, Magnetic, and Adsorption Characteristics for Cleaning Industrial Effluents". Crystals 13, n.º 3 (9 de março de 2023): 472. http://dx.doi.org/10.3390/cryst13030472.

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Globally, efforts are being made to upgrade and improvise the current wastewater treatment technologies. Industrial wastewater is being generated exponentially, owing to the expansion in chemical industries and civilizations necessitating remediation to prevent further environmental damage and lower associated human risks. In this work, iron oxide nanoparticles (IONPs) have been developed and employed as an efficient nanocatalyst for heavy metal adsorption via the chemical route. The shape, absorbance optical, crystal phase, and magnetization of as-prepared magnetic nanostructures were characterized using XRD (X-ray diffraction), UV-Vis (ultraviolet-visible), HRTEM (High-resolution transmission electron microscopy), FTIR (Fourier transfer infrared spectroscopy), and VSM. Further, the adsorption ability of iron oxide to remove the bulk metallic elements considering cadmium (Cd), lead (Pb), zinc (Zn), chromium (Cr), copper (Cu), and nickel (Ni), present in industrial effluents, were studied. The Maghemite Fe2O3 crystal phase having an R-3c group is observed in the XRD results. An identical shape of spherical nanostructures is determined using TEM including ≈21 nm for pure Fe2O3. A removal % was studied by using ICP-OES, and showed a Cr (61.2%), Cd (98%), Cu (66%), Ni (64%), Zn (97%), and Pb (98%) removal ability. The application of such monitored nanomaterials to effluent cleaning and sewage discharge emitted via labs and petrochemical industries could be expanded.

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González Lara, Juan, Francisco Cardona, Antonio Vallmajor e Montserrat Cadevall. "Oxidation of Thiosulfate with Oxygen Using Copper (II) as a Catalyst". Metals 9, n.º 4 (28 de março de 2019): 387. http://dx.doi.org/10.3390/met9040387.

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Thiosulfate effluents are generated in the photography and radiography industrial sectors, and in a plant in which thiosulfates are used to recover the gold and silver contained in ores. Similar effluents also containing thiosulfate are those generated from the petrochemical, pharmaceutical and pigment sectors. In the future, the amounts of these effluents may increase, particularly if the cyanides used in the extraction of gold and silver from ores are substituted by thiosulfates, or if the same happens to electronic scrap or in metallic coating processes. This paper reports a study of the oxidation of thiosulfate, with oxygen using copper (II) as a catalyst, at a pH between 4 and 5. The basic idea is to avoid the formation of tetrathionate and polythionate, transforming the thiosulfate into sulfate. The nature of the reaction and a kinetic study of thiosulfate transformation, by reaction with oxygen and Cu2+ at a ppm level, are determined and reported. The best conditions were obtained at 60 °C, pH 5, with an initial concentration of copper of 53 ppm and an oxygen pressure of 1 atm. Under these conditions, the thiosulfate concentration was reduced from 1 g·L−1 to less than 20 ppm in less than three hours.

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Madani, Fatima-Zahra El, Nisrine Idrissi, Nouha El Allaoui, Mohamed Ben Abbou, Zakia Rais e Mustapha Taleb. "Treatment of Endocrine Pollutants Upstream of the Wadis Tghat and Zhoun of the City of Fez by Coagulation-Flocculation (Morocco)". International Journal of Membrane Science and Technology 10, n.º 2 (27 de agosto de 2023): 4187–97. http://dx.doi.org/10.15379/ijmst.v10i2.3342.

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In recent years, the quality of the surface water of the city of Fez has deteriorated due to the development of various anthropic activities, ill-considered modernization, unregulated discharge of wastewater and solid waste. This is a worrying threat to human health and the environment. Previous studies on these wadis have shown that Tghat and Zhoun wadis are the most polluted [1]; [2]; [3]. Adequate treatment of effluents upstream is therefore of crucial importance. The objective of this study is to contribute to the treatment of endocrine pollutants discharged upstream of these two wadis after their characterization and monitoring of their pollutant load for six months (El Madani et al., 2019). The most polluted wadis of the city of Fez [2] by coagulation-flocculation.The results showed that these effluents have a medium faecal load and are loaded by organic pollution at the limit of biodegradability rich in nitrogen and phosphorus matter and a high metallic load with endocrine disrupting effect, mainly Cr, As, Pb and Cd.The treatment of these pollutants by coagulation-flocculation with aluminum sulphate of the effluents studied under optimal conditions of pH, a dose of coagulant and flocculant and coagulation and flocculation agitation speeds, allowed the reduction of almost all the organic matter and 90 to 96% of the metal load.

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Gatcha-Bandjun, Nadège, Chicgoua Noubactep e Benoît Benguellah Loura. "Mitigation of contamination in effluents by metallic iron: The role of iron corrosion products". Environmental Technology & Innovation 8 (novembro de 2017): 71–83. http://dx.doi.org/10.1016/j.eti.2017.05.002.

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Okoro, Hussein K., Muyiwa M. Orosun, Faith A. Oriade, Tawakalit M. Momoh-Salami, Clement O. Ogunkunle, Adewale G. Adeniyi, Caliphs Zvinowanda e Jane C. Ngila. "Potentially Toxic Elements in Pharmaceutical Industrial Effluents: A Review on Risk Assessment, Treatment, and Management for Human Health". Sustainability 15, n.º 8 (21 de abril de 2023): 6974. http://dx.doi.org/10.3390/su15086974.

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Potentially toxic elements (PTEs) are metallic chemicals with densities that are higher than that of water. Water pollution by PTEs due to the discharge of untreated pharmaceutical industrial effluents is a risk to human health and ecological integrity. The present review paper provides an overview of the threats to human health due to water contamination by PTEs such as lead, cobalt, cadmium, nickel, and arsenic originating from pharmaceutical industrial wastewater. This review reveals the associated advantages and shortcomings of the outmoded and the modern methods and the challenges involved in addressing the shortcomings. Additionally, due to the increasing amount of uncontrollable pharmaceutical effluents entering the ecosystem, this paper reviewed the management approach supported by the World Health Organization and the Environmental Protection Agency. Studies revealed that PTEs find their way into human bodies through different pathways, which include drinking water, edibles, and dermal vulnerability at intervals. This paper focuses on how pharmaceutical effluents can be handled and how regulations and strategies can be reinforced step by step. To preserve public health and the environment, a comprehensive study on the environmental evaluation of carcinogenic substances, particularly toxic elements and metalloids, should be supported and advocated. To protect living organisms and the welfare of consumers, efforts should be made to reduce the presence of potentially hazardous elements on land and water.

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Phiri, Jesse T., Hun Pak, Junhyung We e Sanghwa Oh. "Evaluation of Pb, Mg, Al, Zn, and Cu as Electrode Materials in the Electrocoagulation of Microalgae". Processes 9, n.º 10 (2 de outubro de 2021): 1769. http://dx.doi.org/10.3390/pr9101769.

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Apart from the conventionally used iron (Fe) and aluminum (Al) electrodes in microalgae harvesting, experiments were designed to examine the viability of lead (Pb), magnesium (Mg), zinc (Zn), and copper (Cu) as electrode materials in the harvesting of microalgae. The effect of voltage on the flocculation efficiency (FE) of the electrode materials was examined and compared. By dividing the optimal FE values by their corresponding periods, a simple yet practical approach was used to rank the electrode materials. From highest to lowest flocculation efficiency, the results were as follows: Cu, Zn, Mg, Al, and Pb at 10 V; Mg, Zn, Cu, Al, and Pb at 20 V; and Mg, Zn, Al, Cu, and Pb at 30 V. Important factors such as temperature, periodic FE, consumption of electrode material, pH, and metallic concentrations in the effluent were evaluated. The temperature increase proposed to have been affected by electric resistance drop and anodic corrosion, between 1.7 °C and 3.3 °C, 5 °C and 8.9 °C, and 10.5 °C and 18.4 °C was recorded at 10 V, 20 V, and 30 V respectively. Except for the supernatants of the experiments from Al electrodes, which remained relatively unaffected by voltage and time, the pH of all the other supernatants increased with time and voltage. The effluents recorded metallic concentrations between 0.513 mg/L and 43.8 mg/L for Pb, 7.02 mg/L and 20.5 mg/L for Mg, 1.34 mg/L and 9.09 mg/L for Al, 0.079 mg/L and 0.089 mg/L for Zn, and 0.252 mg/L and 0.434 mg/L for Cu electrodes.

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Gavriloaiei, T., Raluca Mocanu, Maria Calistru e R. Olariu. "COMPARATIVE STUDY OF BIOSORPTION OF METALLIC CATIONS BY DIFFERENT BACTERIA". SOUTHERN BRAZILIAN JOURNAL OF CHEMISTRY 6, n.º 6 (20 de junho de 1998): 33–44. http://dx.doi.org/10.48141/sbjchem.v6.n6.1998.35_1998.pdf.

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Certain species of microorganisms have been found to accumulate surprisingly large quantities of important metals, involved in the toxicity provoked by human activities (Cd, Pb, Hg) and metals of economic values (Ag, Au). Microbiological methods are applied to large-scale recovery or removal of metallic ions from aqueous solutions. These applications involved the removal of heavy metals from sewage sludge, industrial effluents, and mine or wastewaters. This process has been developed using immobilized extracellular or cellular ligands or more simple chemical models based upon them. The uptake of metal ions on the cell surface and their translocations into the cell are well-known natural processes. These adsorption processes could be expressed using Langmuir isotherms. Fe2+ and Mn2+ appeared to .be the most effective cations for adsorption by Bacillus subtilis, Pseudomonas aeruginosa, even by Saccharomyces cerevisiae, while the Zn2+ cation, in spite of a great value of maximum adsorption, has a toxic action on microorganisms and the 'detoxification" mechanism depends on genetic control.

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Zeng, Lingyu, Yecan Peng, Guirong Ye, Xiaona Shang, Shuangfei Wang e Jinghong Zhou. "Adsorption of organic matter from papermaking wastewater by CoFe2O4-coated sand in batch and fixed-bed systems". BioResources 16, n.º 3 (2 de julho de 2021): 5806–20. http://dx.doi.org/10.15376/biores.16.3.5806-5820.

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The secondary treated effluents of pulp and paper mills contain high chemical oxygen demand (COD) that is associated with organic matter. Therefore, this study explores the adsorption of substances contributing to COD using CoFe2O4 and quartz sand-coated CoFe2O4 in batch and fixed-bed column experiments. X-ray diffraction, scanning electron microscopy, Brunauer–Emmett–Teller analysis, and X-ray photoelectron spectroscopy were used to characterize the adsorbents. The quartz sand-loaded CoFe2O4 exhibited a larger pore volume and average pore size. Batch experiments revealed that adsorption on CoFe2O4 closely fit the pseudo-second-order model. To explore the effects of bed depth, feed flow rate, and initial solution pH on the breakthrough characteristics of CoFe2O4-coated sand, fixed-bed column experiments were conducted, and the breakthrough curves were drawn from the ratio of influent COD concentration to effluent COD concentration. The breakthrough time decreased with an increase in the feed flow rate and initial pH but increased with the bed depth. According to the X-ray photoelectron spectroscopy analysis, CoFe2O4-coated sand showed excellent stability due to negligible leaching of metallic elements. These findings have important implications for the advanced treatment of industrial wastewater.

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L.F., Boko, Musibono D.E., Matand T., P. Ngelikoto P. e Iketsh L.B. "EVALUATION DE LA CONTAMINATION EN ELEMENTS -TRACES METALLIQUES (MN, CO, CU, PB, HG, NI, ZN)DES EAUX ET SEDIMENTS DE LA RIVIERE YOLO (KINSHASA, RDC)". International Journal of Advanced Research 10, n.º 7 (31 de julho de 2022): 894–903. http://dx.doi.org/10.21474/ijar01/15110.

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This study aimed to determine the level of selected contaminants (Mn, Co, Cu, Pb, Hg, Ni and Zn) in the water and sediments of the Yolo River which receives effluent from the Limete Industrial District of the Limete area. (Kinshasa, DR Congo). Indeed, in the absence of treatment plants, all urban effluents from neighbourhoods drained by the river and those from industries installed in the neighbourhood are discharged into the collector and the Yolo River, one of the tributaries of the Congo River.The study made it possible to highlight the presence of seven (7) metallic trace elements (Cu, Pb, Fe, Cd, Zn and Hg) in the waters and sediments of the collector of the industrial district and the Yolo River in the city. of Kinshasa, considered problematic, given their toxic nature for living organisms, even at low concentrations of the elements.To do this, collected water samples of the composite type were obtained by mixing three spot samples taken at five stations using a bottle with the neck down at 30 cm depth. In contrast, the sediment samples were hand-collected from 0.5m depth and the resulting composite sediment core was packaged in a clean, labeled 500ml plastic box.All the water and sediment samples were stored in situ at 4Ã‚Â°C in the cooler before being sent to the Center for Geological and Mining Research (CRGM) laboratory in Kinshasa for analysis.The physic-chemical parameters (pH, temperature, SS, BOD5) and metallic elements (Mn, Co, Cu, Pb, Hg, Ni and Zn)) were determined in the waters and sediments of the Yolo River. The results showed that the chemical properties were superior to those of the WHO guide standards.

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Nogueira, Márcio da Costa, Edson Rodrigo Fernandes dos Santos, Kaushik Pal e Fernando Gomes de Souza Júnior. "Removal of chromium VI and others metals from wastewater treatment by modification of macrophytes and magnetite: A review". Revista Brasileira de Gestão Ambiental e Sustentabilidade 7, n.º 17 (2020): 1439–53. http://dx.doi.org/10.21438/rbgas(2020)071725.

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One of the problems that affect the environment is the chemical pollution of the nature of the water, mainly by the presence of toxic metals, among them the chromium, copper, nickel, zinc, among others. Numerous studies report the application of biosorption with the use of Eichhornia crassipes for the treatment of effluents from diverse origins, with very satisfactory results. However, several factors influence biosorption, such as pH, temperature, and contact time, and, therefore, cannot be neglected. Submerged macrophytes have important prospective to bioconcentrate heavy metals due to their larger surface area compared to non-submerged plants. On the other hand, the magnetite nanoparticles also present good results for the treatment of aqueous solutions contaminated by chromium and by other metal ions. The adsorption capacity of the Fe3O4 nanoparticles is high for various metal cations. Besides, these nanoparticles, which constitute polymer nanocomposites, are of particular interest because they combine excellent magnetic properties, greater stability of magnetic nanoparticles, and have higher biocompatibility, allowing more excellent suitability with biological materials involved in the removal of metallic cations. Therefore, the treatments described in this study are of great relevance as excellent alternatives in the treatment of several types of effluents.

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von Canstein, H., Y. Li, K. N. Timmis, W. D. Deckwer e I. Wagner-Döbler. "Removal of Mercury from Chloralkali Electrolysis Wastewater by a Mercury-Resistant Pseudomonas putidaStrain". Applied and Environmental Microbiology 65, n.º 12 (1 de dezembro de 1999): 5279–84. http://dx.doi.org/10.1128/aem.65.12.5279-5284.1999.

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ABSTRACT A mercury-resistant bacterial strain which is able to reduce ionic mercury to metallic mercury was used to remediate in laboratory columns mercury-containing wastewater produced during electrolytic production of chlorine. Factory effluents from several chloralkali plants in Europe were analyzed, and these effluents contained total mercury concentrations between 1.6 and 7.6 mg/liter and high chloride concentrations (up to 25 g/liter) and had pH values which were either acidic (pH 2.4) or alkaline (pH 13.0). A mercury-resistant bacterial strain, Pseudomonas putida Spi3, was isolated from polluted river sediments. Biofilms of P. putida Spi3 were grown on porous carrier material in laboratory column bioreactors. The bioreactors were continuously fed with sterile synthetic model wastewater or nonsterile, neutralized, aerated chloralkali wastewater. We found that sodium chloride concentrations up to 24 g/liter did not inhibit microbial mercury retention and that mercury concentrations up to 7 mg/liter could be treated with the bacterial biofilm with no loss of activity. When wastewater samples from three different chloralkali plants in Europe were used, levels of mercury retention efficiency between 90 and 98% were obtained. Thus, microbial mercury removal is a potential biological treatment for chloralkali electrolysis wastewater.

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ARSAND, Daniel Ricardo, Andréa Moura BERNARDES e Jane Zoppas FERREIRA. "STUDY OF COMPETITIVENESS BETWEEN METAL IONS IN SOLUTION IN THE TREATMENT OF SYNTHETIC EFFLUENTS OF PHOSPHATIZATION LINES CONTAINING IRON, NICKEL AND ZINC IONS BY ELECTRODIALYSIS". Periódico Tchê Química 05, n.º 10 (20 de agosto de 2008): 26–36. http://dx.doi.org/10.52571/ptq.v5.n10.2008.agosto/4_pgs_26_36.pdf.

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Using the electrodialysis in treatment of rinsewater, two other solutions are obtained: one concentrated, which can be returned to the galvanic bath; and the other diluted, which has perfect conditions to be reused in a closed circuit as rinsewater. The aim of this work was to evaluate the competitiveness between metallic ions (iron, niquel and zinc) during the electrodialysis technique as a method for treatment of wastewater produced by the phosphatization process. Experiments were conduced with different rinsewater composition and Nafion® 450 and Selemion® AMP membranes. The results obtained show correlation between percentual extractions, current efficiency and the presence of metallic ions in solution.

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Sosa Lissarrague, Matías H., Sameer Alshehri, Abdullah Alsalhi, Verónica L. Lassalle e Ignacio López Corral. "Heavy Metal Removal from Aqueous Effluents by TiO2 and ZnO Nanomaterials". Adsorption Science & Technology 2023 (24 de janeiro de 2023): 1–15. http://dx.doi.org/10.1155/2023/2728305.

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The presence of heavy metals in wastewater, such as Ni, Pb, Cd, V, Cr, and Cu, is a serious environmental problem. This kind of inorganic pollutant is not biodegradable for several years, and its harmful effect is cumulative. Recently, semiconductor nanomaterials based on metal oxides have gained interest due to their efficiency in the removal of heavy metals from contaminated water, by inducing photocatalytic ion reduction when they absorb light of the appropriate wavelength. The most commonly applied semiconductor oxides for these purposes are titanium oxide (TiO2), zinc oxide (ZnO), and binary nanomaterials composed of both types of oxides. The main purpose of this work is to critically analyse the existent literature concerning this topic focusing specially in the most important factors affecting the adsorption or photocatalytic capacities of this type of nanomaterials. In particular, photocatalytic activity is altered by various factors, such as proportion of polymorphs, synthesis method, surface area, concentration of defects and particle size, among others. After a survey of the actual literature, it was found that, although these metal oxides have low absorption capacity for visible light, it is possible to obtain an acceptable heavy metal reduction performance by sensitization with dyes, doping with metallic or nonmetallic atoms, introduction of defects, or the coupling of two or more semiconductors.

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Waiman, Carolina V., Ignacio E. dell’Erba, Carlos A. Chesta e María Lorena Gómez. "Hybrid Films Based on a Bridged Silsesquioxane Doped with Goethite and Montmorillonite Nanoparticles as Sorbents of Wastewater Contaminants". Journal of Nanomaterials 2016 (2016): 1–9. http://dx.doi.org/10.1155/2016/6286247.

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The synthesis and characterization of silsesquioxane (SSO) films with pendant dodecyl groups and doped with goethite (Gt) or montmorillonite (MMT) nanoparticles were carried out and the new materials tested as sorbents of diverse contaminants. The synthetic method used yielded SSO films with the inorganic substrates homogeneously distributed within the polymeric matrices. The new materials were characterized by SEM, FTIR, XRD, and DSC and tested to evaluate their capability for adsorbing metallic cations, organic dyes, and phosphate, frequent contaminants of industrial effluents. All films were found suitable for removing metallic cations. Results also showed that the SSO films undoped and doped with Gt are primarily apt for anionic compounds removal. Although the SSO films doped with MMT are capable of removing cationic contaminants from aqueous samples, the stiffness of the SSO matrix hinders MMT properties as an adsorbent. The possibility of dispersing nanoparticulate systems in the stable and chemically inert SSO matrices simplifies their application for contaminant removal, particularly because it makes the separation process of the absorbed pollutant from the treated medium easier.

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Vetturayasudharsanan, R., S. Kavitha, Uzwal mandal, S. Bhavadharini, A. Dharani e G. Balaji. "Employment of cisco metal slag in fly ash bricks for a progressive sustainable solution for reusing waste from manufacture of creation materials". IOP Conference Series: Earth and Environmental Science 1125, n.º 1 (1 de dezembro de 2022): 012024. http://dx.doi.org/10.1088/1755-1315/1125/1/012024.

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Abstract The metal-production industry creates a wide exhibit of strong waste, fluid effluents, and vaporous squanders. The stable wastes include slag, powdery materials, sludge, and scrap. So feasibility have a look at of metal slag recycling in fly ash bricks applied laboratory assessments and commercial trials on three exceptional styles of wastes and clay bodies. Crucial necessities consist of slag grinding at 90micron in size, in addition to magnetic separation. In an effort to replace everyday conventional bricks with Cisco metallic ash CSA) and Fly Ash (FA), lime is used as a binder cloth and whereas gypsum as a stabilizer. A huge variety of houses became examined, which includes unit weight and workability of fresh concrete, compressive strength, dihydrogen monoxide (water absorption), efflorescence of hardened concrete. In keeping with Indian codal provision three types were taken in account (Type1, Type2, Type3) with alternative of composition like [Type I - Fly ash: lime: M-sand: gypsum, Type II-Fly ash: cisco steel: M-sand: gypsum, Type III- - Fly ash: cisco steel: lime: M-sand: gypsum] to test the energy properties. While doing the test with metallic ash composition, it effects in higher electricity in lieu of metallic performs a tension position at some stage in loading. Although this addition of metal slag consequences in the discount of shrinkage which ends up in financial and better nice bricks.

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Achille, Aurélie, Fabrice Mauvy, Sebastien Fourcade, Dominique Michau, Marjorie Cavarroc e Angéline Poulon-Quintin. "Electrochemical Behavior of Tantalum Nitride Protective Layers for PEMFC Application". Energies 17, n.º 20 (14 de outubro de 2024): 5099. http://dx.doi.org/10.3390/en17205099.

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Proton Exchange Membrane Fuel Cells (PEMFCs) are promising technology to convert chemical energy from dihydrogen in electrical energy. HT-PEMFCs are working at high temperatures (above 120 °C) and with doped orthophosphoric acid H3PO4 PBI membranes. In such devices, bipolar metallic plates are used to provide reactive gas inside the fuel cell and collect the electrical current. The metallic elements used as bipolar plates, end plates, and interconnectors in acid electrolyte and gaseous fuel cells are severely damaged by a combination of oxidation (due in particular to the use of oxygen, whether pure or contained in the air) and corrosion (due in particular to acid effluents from the electrolyte). This degradation rapidly leads to the loss of the electrical conductivity of the metallic elements and today requires the use of very specific alloys, possibly coated with pure gold. The solution investigated in the present study is the use of a protective coating based on single-phase nitrides obtained by reactive magnetron sputtering or reactive HiPIMS (High-Power Impulse Magnetron Sputtering). The influence of the microstructure on the physical–chemical properties was studied. The electrochemical properties were quantified following two approaches. First, the corrosion current of the developed coatings was measured at room temperature and at higher temperatures using the Linear Sweep Voltammetry (LSV) technique. Then, Electrochemical Impedance Spectroscopy (EIS) measurements were performed to better identify and evaluate their corrosion-resistance performances.

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Bringas, Eugenio, M. Fresnedo San Roman, A. Miren Urtiaga e Inmaculada Ortiz. "Membrane contactors (NDSX and EPT): an innovative alternative for the treatment of effluents containing metallic pollutants". International Journal of Environment and Waste Management 9, n.º 3/4 (2012): 201. http://dx.doi.org/10.1504/ijewm.2012.046387.

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Peralta-Zamora, P., S. Gomes de Moraes, J. Reyes e N. Dur�n. "Heterogeneous photocatalysis treatment of Kraft and textile effluents using metallic and polymeric semiconductors (ZnO and polyaniline)". Polymer Bulletin 37, n.º 4 (outubro de 1996): 531–37. http://dx.doi.org/10.1007/bf00556816.

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Jadaa, Waleed. "Wastewater Treatment Utilizing Industrial Waste Fly Ash as a Low-Cost Adsorbent for Heavy Metal Removal: Literature Review". Clean Technologies 6, n.º 1 (28 de fevereiro de 2024): 221–79. http://dx.doi.org/10.3390/cleantechnol6010013.

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Wastewater discharges from industrial processes typically include elevated concentrations of contaminants, which largely consist of potentially harmful chemicals such as heavy metals. These contaminants are characterized by their slow rate of decomposition. Hence, the removal of these metallic ions from effluents poses a challenge. Among different treatments, the adsorption approach has considerable potential due to its ability to effectively eliminate both soluble and insoluble pollutants from effluent, even at lower levels of concentration. Of various wastes, fly ash (FA) material has been the subject of attention because it is abundant, has favorable qualities, and contains a high percentage of minerals. This review investigates multiple facets, with a specific focus on the application of FA, an industrial byproduct, as an adsorbent in removing heavy metals. A comprehensive examination was conducted on a range of concerns pertaining to the pollution caused by metallic ions, including the underlying causes, levels of contamination, health implications of heavy metals, and removal methods. Multiple factors were found to affect the adsorption process. Of all the factors, the pH value considerably influences the elimination of heavy metals. An acidic pH range of 2.5–4.5 was found to be optimal for achieving the highest possible elimination of As(V), Cu(II), Hg(II), and Cr(VI). The latter elimination rate reached 89% at the optimal pH level. Most heavy metals’ adsorption isotherms conformed to the Langmuir or Freundlich models, while the pseudo-second-order kinetics provided a satisfactory match for their removal. Using a raw FA, adsorption capacities were achieved in the removal of metallic ions, Ni(II), Pb(II), and Cr(VI), that ranged from 14.0 to 23.9 mg g−1. Meanwhile, the FA-zeolite showed a remarkable capacity to adsorb ions Mn(II), Ni(II), Cd(II), Cu(II), and Pb(II), with values ranging from about 31 to 66 mg g−1. The cost analysis showed that the treatment of FA is economically advantageous and may result in significant cost reductions in comparison to commercial adsorbents. In summary, FA is an inexpensive waste material with potential for water treatment applications and several other purposes due to its excellent chemical and mineralogical composition.

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Bykovsky, N. A., L. N. Puchkova e N. N. Fanakova. "REGENERATION OF ETCH SOLUTION USED IN PRINTED CIRCUIT BOARDS PRODUCTION". Problems of Gathering Treatment and Transportation of Oil and Oil Products, n.º 6 (21 de dezembro de 2023): 137–45. http://dx.doi.org/10.17122/ntj-oil-2023-6-137-145.

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In printed circuit boards production, wastewater containing copper is generated. When these effluents are discharged into a reservoir, they must be diluted by a factor of 140000, and at the same time copper is lost during these copper-containing wastewaters treatment. The paper presents the results obtained in the study of electrochemical processing of copper-containing wastes formed at the stage of etching of printed circuit boards. The waste solution is processed in a membrane electrolyzer. Increasing the current density leads to an increase in the process rate Along with a decrease in the copper concentration in the solution, the hydrochloric acid concentration occurs. It is shown that in this case it is possible to regenerate the etch solution and obtain metallic copper.

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Ossepe, Yapi Jean Louis Fernandez, Anauma Casimir Koko, Nazo Edith Kpata-Konan e N’zué Benjamin Yao. "Valeur qualitative du digestat issu d’un digesteur continu des effluents de manioc". International Journal of Biological and Chemical Sciences 18, n.º 4 (3 de dezembro de 2024): 1395–405. https://doi.org/10.4314/ijbcs.v18i4.15.

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La méthanisation des effluents issus de la fabrique d’attiéké produit en plus du biogaz, du digestat qui pourrait être utilisé en agriculture. Cette étude avait pour objectif de déterminer la qualité fertilisante de ce digestat en vue de son utilisation dans la culture du manioc. Ainsi, des digestats issus de trois productions ont été caractérisés selon des méthodes conventionnelles. Les données recueillies ont été soumises à des traitements statistiques. Les résultats ont révélé que les digestats avaient un pH moyen de 8,42 ± 0,18, une DCO de 207,68 ± 60,64 mg O2/L, une DBO de 58,83 ± 29,02 mg O2/L et un COT de 35,81±22,25 mg/L. Ils renfermaient également des matières fertilisantes dont l’azote (1,5 ± 0,07 g/L), le phosphore (0,738 ± 0,415 g/L) et le potassium (1,65 ± 0,60 g/L). Des éléments traces métalliques ont été quantifiés avec des valeurs moyennes conformes à la réglementation. Par ailleurs, les analyses microbiologiques ont montré la présence de coliformes totaux, Staphylococcus aureus, Bacillus cereus d’une part et l’absence des E. coli, Salmonella sp, Clostridium perfringens et des ASR d’autre part. Dans l’ensemble, les résultats de l’étude ont montré que les digestats caractérisés présentaient des potentialités pour un épandage dans les cultures. Qualitative value of digestate from a continuous cassava effluent digester Methanization of effluent from attiéké factory produces, in addition to biogas, digestate that could be used in agriculture. The aim of this study was to determine the fertilizing quality of this digestate, with a view to its use in cassava cultivation. Digestates from three productions were characterized using conventional methods. The data collected was subjected to statistical analyses. The results showed that the digestates had an average pH of 8.42 ± 0.18, a COD of 207.68 ± 60.64 mg O2/L, a BOD of 58.83 ± 29.02 mg O2/L and a TOC of 35.81 ± 22.25 mg/L. They also contained fertilizing elements including nitrogen (1.5 ± 0.07 g/L), phosphorus (0.738 ± 0.415 g/L) and potassium (1.65 ± 0.60 g/L). Trace metallic elements were quantified with average values in accordance with regulations. Microbiological analyses showed the presence of total coliforms, Staphylococcus aureus and Bacillus cereus on the one hand, and the absence of E. coli, Salmonella sp, Clostridium perfringens and RSA on the other. Overall, the results of the study showed that the digestates characterized had the potential to be spread on crops.

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Dra, Rafik El Arslene, Nadia Ramdani, Malika Medjahdi, Sidi Mohamed Mami e Zakaria Khettab. "Potential contamination of groundwater quality in west Algeria by non-biodegradable effluents from public discharges". STUDIES IN ENGINEERING AND EXACT SCIENCES 5, n.º 2 (29 de julho de 2024): e6188. http://dx.doi.org/10.54021/seesv5n2-057.

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The aim of this work is to study the environmental impact of the municipal landfill in the town of Sidi Bel Abbes (western Algeria), in particular on the water table, which circulates at a shallow depth (Max. 20 m) under permeable soil. The huge quantities of putrescible waste discharged into this landfill generate highly polluting leachate water, rich in organic matter (COD up to 1300 mg/L, 209 mg/L in BOD5), salts and micro-organisms. A physico-chemical study of well water in the region reveals a significant deterioration in the quality of the underlying groundwater. In fact, electrical conductivities (on average 5.75 mS/cm) are common in wells, especially those located close to the landfill site. This indicates heavy contamination of the water in these wells by leachate. As for the organic and metallic load, abnormally high levels (82 mg/l in COD, 40 mg/l in BOD₅, 0.74 mg/L in Cr, 0.45 mg/L in Cd, 0.24 mg/L in Cu, 0.85 mg/L in Ni) were observed, mainly in the wells located near and downstream of the landfill, in the direction of groundwater flow.

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Pathak, Chakresh, A. K. Chopra, Sachin Srivastava e Deepika Thakur. "Translocation and enrichment of heavy metals in Brassica juncea grown in Paper mill effluent irrigated soil". Journal of Applied and Natural Science 5, n.º 2 (1 de dezembro de 2013): 510–15. http://dx.doi.org/10.31018/jans.v5i2.361.

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The present study observed the accumulation of heavy metals in Brassica juncea irrigated with paper mill effluent (PME) and control Bore well water (BWW). The soil was treated to five rates of effluents viz. 10, 25, 50, 75 and 100 ml/Kg soil. It was revealed 100% PME irrigation of soil increased Pb (+46.44%), Cr (+83.21%), Ni (+38.43%) and Cd (+78.92%). The enrichment factor (Ef) for Cr and Cd showed moderate enrichment with 10% to 75% PME irrigated soil, except Cr (5.96) which showed significant enrichment with 100% PME irrigated soil. Ef value for Pb and Ni showed deficiency to mineral enrichment with different concentrations of PME irrigated soil. The maximum accumulation of Pb (42.66±2.05 mg/kg), Cr (39.80±5.95 mg/kg), Ni (88.64±11.29 mg/kg) and Cd (5.85±0.29 mg/kg) were recorded in leaves of B. juncea, while that of Pb (43.85±3.46 mg/kg), Cr (48.59±3.81 mg/kg), Cd (6.74±1.22 mg/kg) with 100% and Ni (74.93±2.54 mg/kg) were recorded with 75% PME after 60 days in roots of the B. juncea. Ef value was found maximum for Cr (5.08) in leaves and for Pb (6.64) in roots, while the Translocation factor (Tf) was found maximum for Pb (2.45) in root of the crop irrigated with PME. The use of PME with proper dilution and with the metallic concentrations in permissible limit can be used as biofertigant for irrigation of B. juncea.

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ENNOURI, Rym, Sami MILI e Hechmi MISSAOUI. "Environmental Effects of A Marine Fish Farm of Sea Bass and Sea Bream in The Eastern Mediterranean Sea on Water Column and Sediment". Maritime Technology and Research 3, n.º 2 (4 de dezembro de 2020): Manuscript. http://dx.doi.org/10.33175/mtr.2021.240838.

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Concentration of selected Metallic Element Contaminants (MECs) (Cd, Pb, Hg,Cu, Fe, Zn, Mn, Mg, Ca, Na and K), Total Organic Carbon (TOC) and Total Nitrogen (TN) in the superficial layer of sediments from four fish farms in the Eastern Mediterranean Sea were studied in order to evaluate the environmental effects of marine aquaculture and to establish correlations between aquaculture and accumulation of selected Metallic Elements Contaminants (MECs)(Cd, Pb, Hg, Cu, Fe, Zn, Mg, Mn, K, Na and Ca). The levels of nutrients (Nitrate (NO3, Nitrite (NO2), Ammonium (NH4), Phosphate (PO4), Silicate (Si), Total Nitrogen (TN) and Total Phosphorus (TP) in the water column was evaluated. The concentrations of Cd, Pb and Cu were determined by atomic absorption spectrophotometry with graphite furnace and Zeeman correction (Varian 220 Z). The Metallic Element Fe, Zn, Mg, Mn, K, Na and Ca were measured by the flame atomic absorption spectrophotometry (Varian AA 10). Hg was analyzed by Direct Analyzer of Mercury. Nutrients analyses were carried out by Autoanalyzer using the standard colorimetric methods according to Strickland and Parsons. The results suggested that MECs enrichment in the sediments may be attributed to the fish farm effluents, although metal concentrations are not likely to cause harmful effects in the marine ecosystem. Continuous monitoring and further studies of the area are recommended to determine long-term effects. The nutrient levels in the water column can be due to sources arising from various anthropogenic activities within the study area. Moreover, the spatial variability was due to increasing nutrient concentrations at the localities close to nonpoint sources.

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Jadaa, Waleed, e Hamad K. Mohammed. "Toxic Heavy Metals Elimination from Contaminated Effluents Utilizing Various Adsorbents: Critical Mini-Review". Journal of Biomedical Research & Environmental Sciences 4, n.º 2 (fevereiro de 2023): 281–96. http://dx.doi.org/10.37871/jbres1673.

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The release of massive pollutants amounts continuously because of urbanization and industrialization has caused a big ecological problem worldwide. Due to their activities, effluents of many industries: mining operations, paper/pulp, and batteries, release different heavy metals, including Copper (Cu), Lead (Pb), and Nickel (Ni), into the environment. Heavy metals are of big concern due to their high toxicity, big bioaccumulation susceptibility, and serious threat to humans and ecosystems. Compared to organic pollutants, which are highly influenced by biological and chemical degradation, heavy metals have no degradation into end products using these methods. Therefore, the removal of such metals is considered a big challenge in water purification. For metals removal, different techniques have been applied, such as precipitation, ultrafiltration, and coagulation. However, those applications have many drawbacks: low-efficiency, high consumption of reagents, and generation of toxic sludge. In contrast, adsorption considers an effective method for metal removal, owing to the method’s simplicity, economic and versatility, making it the most convenient way for toxic metals removal. Many conventional adsorbents, such as activated carbon and alumina, have been effectively employed. Nevertheless, the biggest disadvantages of using such adsorbents appear to be their price due to high activation costs and limited reusability. Biosorption has lately emerged as a method with several advantages, including minimal cost, ease of use, and great efficacy, even for trace amounts of metallic ions. This paper aims to review the relevant literature regarding the adsorption method for heavy metals removal from wastewater. Different treatments of heavy metals from wastewater and their related features are highlighted. The metals’ toxicity and hazards to health and the environment are also discussed. The application of various materials as bioadsorbents is explored, such as natural adsorbents and industrial and agricultural wastes.

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L.F., Boko, Musibono D.E, Matand A., Ngelikoto P. e Iketsh L.B. "CONTRIBUTION A LETUDE DE LA CONTAMINATION AUX ELEMENTS TRACES METALLIQUES (MN, CO, CU, PB, HG, NI, ZN) DOREOCHROMIS NILOTICUS ET CLARIAS GARIEPINUS DE LA RIVIERE YOLO (KINSHASA, RDC)". International Journal of Advanced Research 10, n.º 7 (31 de julho de 2022): 871–84. http://dx.doi.org/10.21474/ijar01/15108.

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This 3-year study, was conducted from July to September during the following years 2019, 2020 and 2021. It aimed to determine the concentration of heavy metals (Mn, Co, Cu, Pb, Hg, Ni, Zn) in two fish species, namely Oreochromis niloticus(herbivore) and Clarias gariepinus (omnivore) from the Yolo River in Kinshasa (DRC), which receives , in addition to the urban effluents along its watercourse, all the effluents of the industrial Limete district discharged without any pre-treatment into the drains and main collector of the district which leads to the river, in order to assess the risks related by the chronic consumption of these fish species by the population of the city of Kinshasa.The study revealed the presence of seven (7) metallic trace elements (Cu, Pb, Fe, Cd, Zn and Hg) in two species of fish studied according to the level of the food chain: Oreochromis niloticus having a primary diet (herbivore) and Clarias gariepinus having a tertiary diet (omnivore).The results thus found reveal on the one hand that the Oreochromis niloticus (herbivorous) were less contaminated than the Clarias gariepinus (omnivorous) and on the other hand, the heads are more contaminated than the flesh. However, not knowing the age of these species, we used the size to distinguish the young from the adults and the results obtained indicate how much the adult fish accumulate more heavy metals compared to the juveniles.Consequently, the regular consumption of fish from the Yolo River exposes the population of the city of Kinshasa to metabolic disturbances (mutagenic, teratogenic effects) and fatal diseases such as cancer.

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Kabengele, Carlos N., Giresse N. Kasiama, Etienne M. Ngoyi, Clement L. Inkoto, Juvenal M. Bete, Philippe B. Babady, Damien S. T. Tshibangu et al. "Biogenic synthesis, characterization and effects of Mn-CuO composite nanocatalysts on Methylene blue photodegradation and Human erythrocytes". AIMS Materials Science 10, n.º 2 (2023): 356–69. http://dx.doi.org/10.3934/matersci.2023019.

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<abstract> Each year more than 150, 000 tons of dyes are released in effluents by industries. These chemicals entities non-biodegradable and toxic can be removed from effluent by metallic nanomaterials. The aqueous extract of <italic>Manotes expansa</italic> leaves is used as reducing and stabilizing agent in the biogenic synthesis of Mn-CuO nanocomposites. The nanoparticles obtained were characterized using UV-visible spectroscopy, X-ray Diffraction (XRD), X-ray Fluorescence, Dynamic Light Scattering (DSL), and Scanning Electron Microscopy (SEM). The hemotoxicity of biosynthesized nanomaterials was assessed by evaluating their hemolytic activity using erythrocytes as a model system. The photocatalytic activity of Mn-CuO was carried out by photocatalytic degradation of Methylene Blue dye as a model. The results obtained by UV-vis spectroscopy showed a Plasmonic Surface Resonance band at 408 nm. XRD and X-ray fluorescence made it possible to identify the presence of particles of formula Mn0.53Cu0.21O having crystallized in a Hexagonal system (a = 3.1080 Å and c = 5.2020 Å). Spherical morphology and average height 49.34 ± 6.71 nm were determined by SEM and DSL, respectively. The hemolytic activity of biosynthesized nanomaterials revealed that they are not hemotoxic in vitro (% hemolysis 3.2%) and 98.3% of Methylene Blue dye was removed after 120 min under irradiation with solar light in the presence of Mn-CuO nanocomposites. </abstract>

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Crooker, A. R., E. W. Devlin, D. E. Johnson e N. K. Mottet. "Comparative ultrastructural pathology of methyl mercury-induced lesions in a teleostean and a mammalian cell line". Proceedings, annual meeting, Electron Microscopy Society of America 44 (agosto de 1986): 362–63. http://dx.doi.org/10.1017/s0424820100143432.

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Toxic organic mercury compounds, especially methyl mercury (MeHg), have been responsible for severe environmental contamination. Industrial effluents of inorganic or metallic mercury are methylated by aquatic organisms leading to transfer and bioconcentration of MeHg up the food chain to fish and man. In vivo mammalian and teleostean (bony fish) models have provided useful data on mercury toxicity; cultures of animal cells have been used to investigate the toxic actions of heavy metals such as mercury. The present study was designed to determine if RTG-2 cells, a fibroblast-like line derived from rainbow trout (Salmo gairdneri) gonads, would provide a highly controlled system in which to study the mercury-cell interaction. A mammalian cell line derived from Chinese hamster ovary (CHO)2 and known to be sensitive to MeHg3 was chosen as a positive control. The specific objective was to determine the effect of MeHg on RTG-2 and CHO cell viability and ultrastructure.

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Chu, Duc Chinh, Mouhamadou Amar, Mahfoud Benzerzour, Joelle Kleib e Nor-Edine Abriak. "Flash-Calcined Sediments for Zinc Adsorption". Sustainability 15, n.º 13 (28 de junho de 2023): 10230. http://dx.doi.org/10.3390/su151310230.

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Heavy metal contamination of the environment could pose health risks to humans. Until recently, several geochemical routes were considered to address the issue of metallic leachates from sources such as e-waste deposal sites or mining areas. Following the adsorption pathway, this study focused on investigating the ability of calcination products as a low-cost option for the remediation of zinc contaminated effluents. Sediments dredged in northern France were calcined by flash calcination method, before testing the calcination products (FCS750 hereafter) as adsorbent for zinc removal. The calcination process performed at 750 °C resulted in a denser material with a higher specific surface area and lower organic matter content, suited for aqueous remediation. Kinetic and equilibrium assessment underlined a rapid adsorption better described with the Pseudo Second Order model than the Pseudo First Order or Bangham equations. Adsorption models (Langmuir, Freundlich and Temkin) implemented to describe the interaction under two pH conditions (pH = 2; pH = 7) resulted in a maximum adsorption capacity (qmax) of 89.61 mg g−1 under the most favourable configuration. The pH conditions had poor influence on the adsorbing capacity value, which suggested a good buffering property of the calcined sediment and a potential applicability on effluents with different chemistries. A qmax comparison based on 42 studies indicated that FCS750 was more beneficial than most raw organic adsorbents but remained less effective than grafted and composite materials. Nevertheless, the low number of steps necessary for FCS750 processing, the easy access of its precursor (harboring wastes) and its low energy cost suggested good economic competitiveness and pleaded in favor of field experimentations.

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de Almeida Neto, Ambrósio Florêncio, Melissa Gurgel Adeodato Vieira e Meuris Gurgel Carlos da Silva. "Modification of Sodium Bentonitic Clay Used in Zinc Ion Adsorption". Materials Science Forum 798-799 (junho de 2014): 520–25. http://dx.doi.org/10.4028/www.scientific.net/msf.798-799.520.

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In this study, it was evaluated the potential use of commercial sodium bentonitic clay, called Fluidgel, chemically and thermally treated, as an adsorbent in the removal of zinc ions from aqueous effluents. The chemical treatment was carried out with 10 g of clay dispersed in 100 mL of acetic acid 4 %. The heat treatment was obtained by calcination at 750 °C for 24 hours in muffle. The adsorption experiments were performed in thermostatic bath system and fixed bed, both based on preliminary study of metallic cationic speciation. The kinetics of zinc ions adsorption by acid-treated clay was rapid, requiring a minimum time of 60 min to reach equilibrium. The adsorbed amount and percentage of total zinc removal, at equilibrium time, was 0.06 mmol/g and 45 %, respectively, using the acid-treated clay. There was no removal of zinc by Fluidgel calcined clay in bath system, but in fixed bed it was obtained the total amount of zinc removal of 0.11 mmol/g and 41 % of percentage of removal.

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Hajji, Yassine, Denis Entemeyer, Jérôme Serri, Mustapha Yahiaoui, Abdel Tazibt e Thierry Grosdidier. "High Pressure Cryogenic Nitrogen Jet for Clean Coating Removal: Experimental Study of Polyamide Ablation". Materials Science Forum 941 (dezembro de 2018): 1651–55. http://dx.doi.org/10.4028/www.scientific.net/msf.941.1651.

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The potential of a recently developed technique that uses a clean supercritical High Pressure Cryogenic Nitrogen Jet (HPCryoN2Jet) for surface ablation and cleaning is depicted. In contrast to existent coating-removal techniques (chemical stripping, hydro-blast, water jet cleaning...), as nitrogen is naturally recycled in the air, this process has a high potential for surface treatment without any chemical and physical effluents or sewage disposal. The treatment consists in impacting the surface with a high pressure (up to 3500 bar) cryogenic nitrogen jet (down to-160°C). The pressurized cryogenic nitrogen exits from a nozzle - having generally a 0.2 to 0.5 mm diameter outlet - to form the high velocity (supersonic) nitrogen jet. In this contribution, the ability of the process to remove polymeric (PA) coatings is evaluated on different types of metallic substrates (Cu, Al, E24, 316L stainless steel). The mechanisms of chip formation have been visualized using a high speed camera. Coating failure is shown experimentally to occur downstream of the jet and the influence of the substrate thermal properties on the stripping efficiency of the PA coating is highlighted.

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Oláh, Viktor, Muhammad Irfan, Zsuzsanna Barnáné Szabó, Zsófi Sajtos, Ágota Zsófia Ragyák, Boglárka Döncző, Marcel A. K. Jansen, Sándor Szabó e Ilona Mészáros. "Species- and Metal-Specific Responses of the Ionome of Three Duckweed Species under Chromate and Nickel Treatments". Plants 12, n.º 1 (1 de janeiro de 2023): 180. http://dx.doi.org/10.3390/plants12010180.

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In this study, growth and ionomic responses of three duckweed species were analyzed, namely Lemna minor, Landoltia punctata, and Spirodela polyrhiza, were exposed for short-term periods to hexavalent chromium or nickel under laboratory conditions. It was found that different duckweed species had distinct ionomic patterns that can change considerably due to metal treatments. The results also show that, because of the stress-induced increase in leaf mass-to-area ratio, the studied species showed different order of metal uptake efficiency if plant area was used as unit of reference instead of the traditional dry weight-based approach. Furthermore, this study revealed that μXRF is applicable in mapping elemental distributions in duckweed fronds. By using this method, we found that within-frond and within-colony compartmentation of metallic ions were strongly metal- and in part species-specific. Analysis of duckweed ionomics is a valuable approach in exploring factors that affect bioaccumulation of trace pollutants by these plants. Apart from remediating industrial effluents, this aspect will gain relevance in food and feed safety when duckweed biomass is produced for nutritional purposes.

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