Relevant bibliographies by topics / Dissolved heavy metal ion

Academic literature on the topic 'Dissolved heavy metal ion'

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Published: 14 March 2023

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Journal articles on the topic "Dissolved heavy metal ion"

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Theodoridou, E., A. D. Jannakoudakis, P. D. Jannakoudakis, and S. Antoniadou. "Electrochemically oxidized carbon fibres as an adsorbent for the attachment of dissolved substances. Adsorption of nitro compounds and ion-exchange of heavy metals." Canadian Journal of Chemistry 69, no. 12 (December 1, 1991): 1881–85. http://dx.doi.org/10.1139/v91-272.

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The adsorption of several aromatic nitro compounds and the ion-exchange of heavy metal ions on electro-oxidized carbon fibres have been investigated using cyclic voltammetric and polarographic techniques. Electro-oxidation is performed by potentiostatic double pulse application. This procedure results in the generation of many functional —OH and —COOH groups with adsorptive and ion-exchanging properties.Multimolecular layers of adsorbed substances may be formed through a procedure of successive adsorption of the nitro-compound and electro-reduction to the corresponding amine, resulting in the attachment of considerable amounts of the nitro-compound to the carbon fibres.The ion-exchange capacity is estimated to be ca. 1 mequiv. g−1 and with slight deviations it follows the rank Ag, Cu, Cd, Pb, Hg. After the electro-reduction of the exchanged metal ions, the ion-exchange process can be repeated several times. This procedure is of importance for the removal of significant amounts of heavy and toxic metals from industrial waste waters. Key words: electro-oxidized carbon fibres, adsorption of aromatic nitro compounds, cation-exchange of heavy metals.
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Bartzis, Vasileios, Georgios Ninos, and Ioannis E. Sarris. "Water Purification from Heavy Metals Due to Electric Field Ion Drift." Water 14, no. 15 (July 31, 2022): 2372. http://dx.doi.org/10.3390/w14152372.

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A water purification method using a static electric field that may drift the dissolved ions of heavy metals is proposed here. The electric field force drifts the positively charged metal ions of continuously flowing contaminated water to one sidewall, where the negative electrode is placed, leaving most of the area of the duct purified. The steady-state ion distributions, as well as the time evolution in the linear regime, are studied analytically and ion concentration distributions for various electric field magnitudes and widths of the duct are reported. The method performs well with a duct width less than 10−3 m and an electrode potential of 0.26 V or more. Moreover, a significant reduction of more than 90% in heavy metals concentration is accomplished in less than a second at a low cost.
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Liu, Xing Yu, Ming Jiang Zhang, Yi Bin Li, Zi Ning Wang, and Jian Kang Wen. "In Situ Bioremediation of Tailings by Sulfate Reducing Bacteria and Iron Reducing Bacteria: Lab- and Field-Scale Remediation of Sulfidic Mine Tailings." Solid State Phenomena 262 (August 2017): 651–55. http://dx.doi.org/10.4028/www.scientific.net/ssp.262.651.

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To research the remediation efficiency of sulfate reducing bacteria and iron reducing bacteria on heavy metals, the remediation experiments of laboratory-scale and field-scale were conducted respectively with chalcopyrite tailings and 3 hectares lead-zinc sulfides mine tailings. The ion concentration of exudate was determined using inductively coupled plasma atomic emission spectroscopy, and key bacterial strains were investigated by real-time PCR. The laboratory-scale experiment of chalcopyrite tailings indicated pH of exudate rose to neutral, penetration time of exudate significantly increased, redox potential and dissolved iron notably decreased, and black metal sulfides were formed during remediation by sulfate reducing bacteria and iron reducing bacteria. The field-scale lead-zinc sulfides mine tailings remediation results indicated that the concentration of dissolved heavy metals in exudate decreased, and the growth of both moss and plants were promoted.
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Ma, Jingxi, Shuqing Wu, N. V. Ravi Shekhar, Supriya Biswas, and Anoop Kumar Sahu. "Determination of Physicochemical Parameters and Levels of Heavy Metals in Food Waste Water with Environmental Effects." Bioinorganic Chemistry and Applications 2020 (August 20, 2020): 1–9. http://dx.doi.org/10.1155/2020/8886093.

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Bioinorganic chemistry is found as a sizzling field in today’s era. It deals with chemistry amongst the heavy metals with natural resources, i.e., air, soil, water, plant byproducts (foods), and environmental essences. The aim of this research is to determine the concentration of heavy metals present in the food waste water sample and to study the environmental effects of metal ion concentration. To conduct the research work, the physicochemical parameters and levels of five heavy metals of food waste water samples were collected from five sampling points of renowned hotels, restaurants, canteens, and confectionaries of a state of India and assessed using the standard analytical procedure. Sampling was carried out from January 2017 up to December 2017. The physicochemical parameters were determined such as pH, temperature, turbidity, conductivity, total dissolved solids, total suspended solids, total alkalinity, biological oxygen demand, chemical oxygen demand, dissolved oxygen, total organic carbon, sulphate, nitrate, and phosphate. The heavy metal concentration was determined by using the UV-spectrophotometer, and the results were compared with the standards prescribed by the WHO, BIS, ICMR, and municipal authorities. The results obtained in the physicochemical analysis revealed that a few parameters were found beyond limits, and the metal ion concentration (iron and zinc) results were found above the permissible limits set by the CPCB (Central Pollution Control Board), ICMR, BIS, and World Health Organization (WHO), most especially, effluent from point P1. It was concluded that all the effluents required further treatment before releasing them into the water body or land to prevent pollution. The obtained results reveal that waste water used for irrigation and farming of nearby areas and water drained from restaurant kitchens were considerably polluted and not suitable for aquatic organisms, irrigation, and agricultural purposes.
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Danila, Vaidotas, and Saulius Vasarevičius. "Theoretical Modelling of Immobilization of Cadmium and Nickel in Soil Using Iron Nanoparticles." Mokslas - Lietuvos ateitis 9, no. 4 (September 11, 2017): 381–86. http://dx.doi.org/10.3846/mla.2017.1067.

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Immobilization using zero valent using iron nanoparticles is a soil remediation technology that reduces concentrations of dissolved contaminants in soil solution. Immobilization of heavy metals in soil can be achieved through heavy metals adsorption and surface complexation reactions. These processes result in adsorption of heavy metals from solution phase and thus reducing their mobility in soil. Theoretical modelling of heavy metals, namely, cadmium and nickel, adsorption using zero valent iron nanoparticles was conducted using Visual MINTEQ. Adsorption of cadmium and nickel from soil solutions were modelled separately and when these metals were dissolved together. Results have showed that iron nanoparticles can be successfully applied as an effective adsorbent for cadmium and nickel removal from soil solution by producing insoluble compounds. After conducting the modelling of dependences of Cd+2 and Ni+2 ions adsorption on soil solution pH using iron nanoparticles, it was found that increasing pH of solution results in the increase of these ions adsorption. Adsorption of cadmium reached approximately 100% when pH ≥ 8.0, and adsorption of nickel reached approximately 100% when pH ≥ 7.0. During the modelling, it was found that adsorption of heavy metals Cd and Ni mostly occur, when one heavy metal ion is chemically adsorbed on two sorption sites. During the adsorption modelling, when Cd+2 and Ni+2 ions were dissolved together in acidic phase, it was found that adsorption is slightly lower than modelling adsorption of these metals separately. It was influenced by the competition of Cd+2 and Ni+2 ions for sorption sites on the surface of iron nanoparticles.
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Flores-Rodríguez, J., A. L. Bussy, and D. R. Thévenot. "Toxic Metals in Urban Runoff: Physico-Chemical Mobility Assessment Using Speciation Schemes." Water Science and Technology 29, no. 1-2 (January 1, 1994): 83–93. http://dx.doi.org/10.2166/wst.1994.0654.

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Physico-chemical characterization of lead, zinc and cadmium has been carried out on eight samples from both separate and combined sewers. Dissolved and paniculate total metal levels have been determined. A speciation scheme has been used to further divide these phases in two dissolved fractions, bioavailable and stable, and five paniculate fractions, ion-exchangeable, acid-soluble, reducible, oxidizable and residual. Total dissolved lead concentrations were found to be largely below European Community (EC) directives for drinking water production. Lead was represented by stable forms while zinc and cadmium were mainly bioavailable. Paniculate concentrations were higher than natural levels found in the Seine-Normandie basin. Zinc was characteristic for municipal effluents, and lead and cadmium were more concentrated in separate sewers. Correlations have been observed between paniculate heavy metals and volatile matter on the ring highway, or with iron at the Savigny site. The paniculate metal speciation scheme has demonstrated the important dependence of heavy metal distribution on the sampling site, as well as the potentially more mobile nature of zinc and cadmium, compared to that of lead. The structural modifications undergone by solids during their transport along the sewer networks had a significant impact on paniculate metal mobility. This has been clearly noted for lead, whose mobility decreased from upstream to downstream in the studied system.
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Percival, H. J. "Soil and soil solution chemistry of a New Zealand pasture soil amended with heavy metal-containing sewage sludge." Soil Research 41, no. 1 (2003): 1. http://dx.doi.org/10.1071/sr01061.

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The disposal of wastewater treatment sewage sludge onto agricultural land in New Zealand has led to the development of guidelines for the upper limit concentrations for total heavy metals in the underlying soil. However, those soil biological and biochemical processes now known to be most sensitive to environmental change are being used internationally to set new soil limits. The soil solution chemistry of a pasture soil amended with heavy metals has been used to assess the bioavailability of several important heavy metals. Field trial plots were treated with both spiked (Cu, Ni, or Zn) and unspiked sewage sludge to raise total soil metal concentrations, both above and below the current New Zealand guideline values. Soils were sampled pre-amendment in 1997 and post-amendment in 1998, 1999, and 2000. Soil solutions were extracted by centrifugation and analysed for pH, for concentrations of heavy metals, major cations and anions, and dissolved organic carbon. Heavy metal speciation was calculated with the GEOCHEM-PC model.Soil solution concentrations of Cu, Ni, and Zn increased with increasing levels of metal in the spiked sludge, reflecting increases in total soil metal concentrations. Cu concentrations changed little with time, but those of Ni and Zn tended to decrease. Cu was much more adsorbed by the soil than was Ni or Zn. The free metal ions, Cu2+, Ni2+, and Zn2+ (representing the most 'bioavailable' fraction), were the dominant metal species in the soil solutions. Variations in free metal ion percentages with metal-spiking level depended on the balance between organic and sulfate complexation for Cu, but on sulfate complexation alone for Ni and Zn. Cu and Ni free metal-ion activities in soil solution were relatively low even at the highest metal loadings in the soil, but may be high enough to cause toxicity problems. Zn activities were very much higher, and at the regulatory limit for zinc likely to affect sensitive biological and biochemical properties of the soil.
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Alam, Masood, Sumbul Rais, and Mohd Aslam. "Hydro-chemical Survey of Groundwater of Delhi, India." E-Journal of Chemistry 6, no. 2 (2009): 429–36. http://dx.doi.org/10.1155/2009/908647.

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The physicochemical parameters and trace metal contents of water samples from Delhi were assessed. A total of 20 water samples were collected from boring, tube well and hand pump and analyzed for the various physicochemical parameters like pH, conductivity, total dissolved solid, total alkalinity, Ca2+and Mg2+hardness, chloride ion, dissolved oxygen, biochemical oxygen demand, sulphate and heavy metal contents like Cu, Cr, Cd, Co, Zn and Ni. The results were compared with BIS standards for drinking water. The quality of water samples under study were within the maximum permissible limits. Therefore, the groundwater samples are fit for human consumption without prior treatment.
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Amala, O., Lakshmi K. Vara, Anima Sunil Dadhich, and M. Ramesh. "Water Quality Index and Heavy Metal Pollution Index of Groundwater Quality: A case Study in Visakhapatnam District, AP." Research Journal of Chemistry and Environment 26, no. 8 (July 25, 2022): 61–76. http://dx.doi.org/10.25303/2608rjce061076.

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The main objective of the present study was to assess the groundwater quality of selected Mandals in Visakhapatnam district Andhra Pradesh. Fifty samples were collected from hand pumps of various Mandals. Water Quality Index (WQI) and Heavy Metal Pollution Index (HPI) along with Metal Quality Index (MQI) were determined. Physicochemical parameters such as pH, Electrical Conductivity (EC), Total Hardness (TH) and Total Dissolved Solids (TDS) were measured by various standard techniques. Calcium (Ca+2), Magnesium (Mg+2), Chloride (Cl-), Nitrate (NO3 -) and Sulfate (SO4 -2) were analyzed by 930 Compact Ion Chromatograph Flex. Heavy metals such as Lead (Pb), Zinc (Zn), Chromium (Cr), Aluminum (Al), Copper (Cu), Nickel (Ni), Manganese (Mn) and Cadmium (Cd) were analyzed by using 4200 Microwave Plasma – Atomic Emission Spectrometer (MP-AES). Iron (Fe) was analyzed by Cary 60 UV-Visible Spectrophotometric method. The correlation coefficient (R2) of the heavy metals lies between 0.99 to 0.98. The compliance of BIS 10500:2012 for the heavy metal concentration in drinking water was verified. From the current study, it was found that EC, TDS, TH and heavy metals such as Aluminum (Al) and Lead (Pb) exceeded the allowed limits as per BIS 10500:2012 revision. The highest values of HPI and WQI from the fifty groundwater samples are 407.97 and 189.79. The highest value of MQI is 3.36 respectively. An attempt has also been made to draw spatial distribution maps for heavy metals having higher concentrations in the study area.
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Lawrence, Glen D., Kamalkumar S. Patel, and Aviva Nusbaum. "Uranium toxicity and chelation therapy." Pure and Applied Chemistry 86, no. 7 (July 22, 2014): 1105–10. http://dx.doi.org/10.1515/pac-2014-0109.

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AbstractUranium toxicity has been a concern for more than 100 years. The toxicology of many forms of uranium, ranging from dust of several oxides to soluble uranyl ion, was thoroughly studied during the Manhattan Project in the United States in the 1940s. The development of depleted uranium kinetic penetrators as armor-piercing incendiary weaponry produced a novel form of uranium environmental contamination, which led to greater susceptibility to the adverse health effects of the toxic heavy metal after its use in various military conflicts. The aerosol from burning uranium penetrator fragments is rapidly dissolved in biological fluids and readily absorbed from the lungs, leading to a wide range of toxic effects. We have studied some chelating agents for uranyl ion, including citrate ion and desferal (desferrioxamine B), which may be effective for minimizing the toxic effects of this insidious heavy metal. Some characteristics of the desferrioxamine complex are presented, along with information about the use of citrate as an effective chelating agent for therapy of uranium toxicity.
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Dissertations / Theses on the topic "Dissolved heavy metal ion"

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Terdkiatburana, Thanet. "Simultaneous removal process for humic acids and metal ions by adsorption." Thesis, Curtin University, 2007. http://hdl.handle.net/20.500.11937/1714.

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Humic substances are macromolecules that naturally occur in all environments in which vegetation matter are present. In general, humic acid is part of humic substances which form the major fraction of the dissolved organic matters in surface water and represents 90% of dissolved organic carbon. Humic acid plays a fundamental role in many ecosystems since it interacts with toxic metal ions present in the system, resulting in a decrease in the bio-availability of such ions. Moreover, the availability of humic acid in water can react with other chemical compounds, such as chlorine to form trihalomethanes (including chloroform) and causes an increasing risk of cancer and may be linked to heart, lung, kidney, liver, and central nervous system damage. Therefore, humic acid removal in water treatment processes is very important in order to achieve the drinking water standards. Heavy metals are significant contaminants in aqueous system. All heavy metals can produce toxicity when ingested in sufficient quantities, but there are several important ones such as lead, mercury, copper, cadmium, arsenic, nickel and silver. These heavy metals are so pervasive and produce toxicity at low concentrations. Moreover, they may build up in biological systems and become a significant health hazard.Adsorption is approved as an effective and simple method for water and wastewater treatment process. Many adsorbents then are developed for use in adsorption process such as montmorillonite, peat, activated carbon, etc. In this research, humic acid and heavy metals were mainly selected for adsorption study. In the sorption experiment, several adsorbents such as synthesised zeolite (SZ), natural zeolite (NZ), powdered activated carbon (PAC) and fly ash (FA), were selected to examine the application of HA and heavy metals both in individual and simultaneous adsorption, The characteristics and interactions of the adsorbents with HA and heavy metals were systematically studied by batch laboratory experiments. In the beginning, the adsorption of HA onto SZ, NZ, PAC and FA was investigated and their adsorption capacity was compared. The equilibrium adsorption of HA on SZ, NZ, PAC and FA was found to be 84.1, 67.8, 81.2 and 34.1 mg/g, respectively, at 30 oC and pH 5.0. Dynamic adsorption data show that these adsorbents could reach their adsorption equilibrium after 50 hours. From pH analysis, HA adsorption is favoured at low pH and an increase in pH will lead to the reduction of HA adsorption. SZ and NZ adsorption capacity were affected by the changing of solution temperature; however, in PAC and FA sorption study, there was no significant effect observed. Two heavy metal ions (Cu, Pb) removal by the adsorbents was then conducted. The results showed that the equilibrium sorption capacity of Cu and Pb ions on SZ, NZ, PAC and FA were 43.5, 24.2, 19.7, 28.6 and 190.7, 129.0, 76.8 mg/g, respectively at 30 oC and a pH value of 5. The appropriate pH for Cu and Pb removal was found to be 5 and 6. In most dynamic cases, these adsorbents needed at least 50 hours to reach the adsorption equilibrium. Only adsorption on FA required more than 150 hours to reach the equilibrium.In simultaneous adsorption experiments, the influences of HA and heavy metal concentration (in the range of 10 to 50 mg/L for HA and 10 to 30 mg/l for heavy metals) on the HA-heavy metal complexation were investigated. The results demonstrated that increasing HA concentration mostly affected Cu adsorbed on SZ, FA and PAC and Pb adsorbed on SZ, NZ and PAC. For HA adsorption, the adsorption rate decreased rapidly with increased initial metal ion concentration. Moreover, the adsorption of heavy metals increased with increased heavy metals concentration in the presence of HA. In the presence of heavy metal ions, the order of HA adsorption followed PAC > FA > SZ > NZ. According to the results, the individual and simultaneous adsorption of HA and heavy metals on each adsorbent achieved a different trend. It mainly depended on the adsorption property of both adsorbates (HA and heavy metals) and adsorbents (SZ, NZ, PAC and FA) and also the operation factors such as pH, concentration, temperature and operation time. Even though this experiment could not obtain high adsorption performance, especially in coadsorption, as compared with other adsorbents, the adsorbents in this study represented a higher adsorption capacity and provide the potential for further development.
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Terdkiatburana, Thanet. "Simultaneous removal process for humic acids and metal ions by adsorption." Curtin University of Technology, Dept. of Chemical Engineering, 2007. http://espace.library.curtin.edu.au:80/R/?func=dbin-jump-full&object_id=18564.

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Humic substances are macromolecules that naturally occur in all environments in which vegetation matter are present. In general, humic acid is part of humic substances which form the major fraction of the dissolved organic matters in surface water and represents 90% of dissolved organic carbon. Humic acid plays a fundamental role in many ecosystems since it interacts with toxic metal ions present in the system, resulting in a decrease in the bio-availability of such ions. Moreover, the availability of humic acid in water can react with other chemical compounds, such as chlorine to form trihalomethanes (including chloroform) and causes an increasing risk of cancer and may be linked to heart, lung, kidney, liver, and central nervous system damage. Therefore, humic acid removal in water treatment processes is very important in order to achieve the drinking water standards. Heavy metals are significant contaminants in aqueous system. All heavy metals can produce toxicity when ingested in sufficient quantities, but there are several important ones such as lead, mercury, copper, cadmium, arsenic, nickel and silver. These heavy metals are so pervasive and produce toxicity at low concentrations. Moreover, they may build up in biological systems and become a significant health hazard.
Adsorption is approved as an effective and simple method for water and wastewater treatment process. Many adsorbents then are developed for use in adsorption process such as montmorillonite, peat, activated carbon, etc. In this research, humic acid and heavy metals were mainly selected for adsorption study. In the sorption experiment, several adsorbents such as synthesised zeolite (SZ), natural zeolite (NZ), powdered activated carbon (PAC) and fly ash (FA), were selected to examine the application of HA and heavy metals both in individual and simultaneous adsorption, The characteristics and interactions of the adsorbents with HA and heavy metals were systematically studied by batch laboratory experiments. In the beginning, the adsorption of HA onto SZ, NZ, PAC and FA was investigated and their adsorption capacity was compared. The equilibrium adsorption of HA on SZ, NZ, PAC and FA was found to be 84.1, 67.8, 81.2 and 34.1 mg/g, respectively, at 30 oC and pH 5.0. Dynamic adsorption data show that these adsorbents could reach their adsorption equilibrium after 50 hours. From pH analysis, HA adsorption is favoured at low pH and an increase in pH will lead to the reduction of HA adsorption. SZ and NZ adsorption capacity were affected by the changing of solution temperature; however, in PAC and FA sorption study, there was no significant effect observed. Two heavy metal ions (Cu, Pb) removal by the adsorbents was then conducted. The results showed that the equilibrium sorption capacity of Cu and Pb ions on SZ, NZ, PAC and FA were 43.5, 24.2, 19.7, 28.6 and 190.7, 129.0, 76.8 mg/g, respectively at 30 oC and a pH value of 5. The appropriate pH for Cu and Pb removal was found to be 5 and 6. In most dynamic cases, these adsorbents needed at least 50 hours to reach the adsorption equilibrium. Only adsorption on FA required more than 150 hours to reach the equilibrium.
In simultaneous adsorption experiments, the influences of HA and heavy metal concentration (in the range of 10 to 50 mg/L for HA and 10 to 30 mg/l for heavy metals) on the HA-heavy metal complexation were investigated. The results demonstrated that increasing HA concentration mostly affected Cu adsorbed on SZ, FA and PAC and Pb adsorbed on SZ, NZ and PAC. For HA adsorption, the adsorption rate decreased rapidly with increased initial metal ion concentration. Moreover, the adsorption of heavy metals increased with increased heavy metals concentration in the presence of HA. In the presence of heavy metal ions, the order of HA adsorption followed PAC > FA > SZ > NZ. According to the results, the individual and simultaneous adsorption of HA and heavy metals on each adsorbent achieved a different trend. It mainly depended on the adsorption property of both adsorbates (HA and heavy metals) and adsorbents (SZ, NZ, PAC and FA) and also the operation factors such as pH, concentration, temperature and operation time. Even though this experiment could not obtain high adsorption performance, especially in coadsorption, as compared with other adsorbents, the adsorbents in this study represented a higher adsorption capacity and provide the potential for further development.
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3

Satofuka, Hiroyuki. "Studies on heavy metal ion-binding peptides : Application for heavy metal ion detection and detoxification." 京都大学 (Kyoto University), 2002. http://hdl.handle.net/2433/149818.

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Rozycki, Torsten von. "Computational investigations of divalent heavy metal ion homeostasis." kostenfrei, 2009. http://nbn-resolving.de/urn:nbn:de:gbv:3:4-359.

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Lozenko, Sergii. "Heavy metal ion sensors based on organic microcavity lasers." Phd thesis, École normale supérieure de Cachan - ENS Cachan, 2011. http://tel.archives-ouvertes.fr/tel-00744846.

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Monitoring of environmental pollutants present at low concentrations requires creation of miniature, low-cost, and highly sensitive detectors that are capable to specifically identify target substances. In this thesis, a detection approach based on refractive index sensing with polymer micro-lasers is proposed and its application to the detection of heavy metal pollutants in water (mercury - Hg2+, cadmium - Cd2+ and lead - Pb2+) is studied. The resonance frequencies of the microcavity are highly sensitive to the refractive indices of the resonator surrounding: the resonances shift by a small amount when the surface refractive index changes, resulting from the interaction of the mode evanescent field with the surrounding medium. This permits label-free detection by coating the resonator with a suitable recognition species. The originality of this work lies in the utilization of active microcavities, or microlasers, created of the dye-doped polymers. Active microcavities offer an enhanced signal/noise ratio as compared to the passive ones and very narrow resonance peaks even at moderate quality factors (Q ≥- 6000). The choice of polymers as an active medium is connected with a number of advantages they offer: as opposite to semiconductors, polymers can be easily functionalized, integrated in microfluidic circuits and are cheaper in processing. Moreover, the use of porous polymer matrices may allow accumulation of analyte ions inside the microcavity and thus enhance the sensitivity. Two possible applications of microlasers are investigated in the thesis: refractive index variation sensing with non-functionalized cavities and heavy metal ion detection with functionalized cavities. In the first case, the sensitivity values have been obtained, comparable with the reported in literature for planar passive microresonators. In the second case, the experimental proofs of specific detection of mercury ions in liquid are presented. The ways of sensitivity improvement are discussed and verified and a foundation is layed for the creation of integrated Lab-on-Chip microfluidic biochemical detector.
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Steinbaugh, Gregory E. "Heavy metal Ion transport utilizing natural and synthetic ionophores." The Ohio State University, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=osu1189785736.

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Ma, Yiu Wa. "Fixed bed removal of heavy metal ions by chelating ion exchange." Thesis, Queen's University Belfast, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.491880.

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Column runs with varied operation conditions of flowrate, feed concentration and particle size have been conducted to observe the sorption of nickel, copper and zinc by the chelating resin. They all show a typical constant-pattern, steep curve in the first part of the breakthrough curve and the slope would dramatically reduce at a breakpoint such that it would take extremely long time to reach 100% breakthrough level. ~ The Modified Bed Depth Service Time (BDST) model incorporated with a timedependent bed capacity has been used together with the Empty Bed Residence Time (EBRT) model to analyze the fixed bed performance under different operating conditions. The Homogeneous Surface Diffusion Model (HSDM) and the Shrinking Core Diffusion . Model (SCDM) have been applied to- model the fixed bed performance. Due to the dramatic change in the slope, the first and second parts of the breakthrough curves need to be modeled separately. Comparing the two models, SCDM is more appropriate to explain the sorption of metal ions into the chelating resin. The research has suggested the existence of a Na-loaded outer shell and a H-loaded inner core in the chelating resin. When the moving boundary progresses from the outer shell into the inner core, there is a remarkable change in the ion exchange process, resulting in different kinetics. This explains the sharp change in the slope of the experimental breakthrough curves. A new version of SCDM has been developed to model the progression of the moving boundary inside the resin for the successive resin layers along the whole resin column so as to predict the column' s solid and liquid phase concentration profiles. The new SCDM has. the flexibility of varying the portion of the outer shell so that the behavior of resins with different resin Na contents can be predicted.
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Jayasinghe, Manori. "Heavy-metal-ion transport in nanoporous selective-membranes theory and experiment /." Cincinnati, Ohio : University of Cincinnati, 2007. http://www.ohiolink.edu/etd/view.cgi?acc%5Fnum=ucin1186764159.

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Thesis (Ph. D.)--University of Cincinnati, 2007.
Title from electronic thesis title page (viewed Oct. 8, 2007). Includes abstract. Keywords: gamma alumina membranes, heavy-metal-ion transport, uranyl, membrane functionalization, nanoporous membranes, steering molecular dynamics, free energy study, liquid-liquid interface, water/hexane interface, tri-butyl phosphate. Includes bibliographical references.
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JAYASINGHE, MANORI I. "HEAVY-METAL-ION TRANSPORT IN NANOPOROUS SELECTIVE-MEMBRANES: THEORY AND EXPERIMENT." University of Cincinnati / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1186764159.

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Sekhula, Koena Sinah. "Heavy metal ion resistance and bioremediation capacities of bacterial strains isolated from an Antimony Mine." Thesis, University of Limpopo, 2005. http://hdl.handle.net/10386/139.

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Thesis (M.Sc.) -- University of Limpopo, 2005
Six aerobic bacterial strains [GM 10(1), GM 10 (2), GM 14, GM 15, GM 16 and GM 17] were isolated from an antimony mine in South Africa. Heavy-metal resistance and biosorptive capacities of the isolates were studied. Three of the isolates (GM 15, GM 16 and GM 17) showed different degrees of resistance to antimony and arsenic oxyanions in TYG media. The most resistant isolate GM 16 showed 90 % resistance, followed by GM 17 showing 60 % resistance and GM 15 was least resistant showing 58 % resistance to 80 mM arsenate (AsO4 3-). GM 15 also showed 90 % resistance whereas isolates GM 16 and GM 17 showed 80 % and 45 % resistance respectively to 20 mM antimonate (SbO4 3-). Arsenite (AsO2 -) was the most toxic oxyanion to all the isolates. Media composition influenced the degrees of resistance of the isolates to some divalent metal ions (Zn2+, Ni2+, Co2+, Cu2+ and Cd2+). Higher resistances were found in MH than in TYG media. All the isolates could tolerate up to 5 mM of the divalent metal ions in MH media, but in TYG media, they could only survive at concentrations below 1 mM. Also, from the toxicity studies, high MICs were observed in MH media than TRIS-buffered mineral salt media. Zn2+ was the most tolerated metal by all the isolates while Co2+ was toxic to the isolates. The biosorptive capacities of the isolates were studied in MH medium containing different concentrations of the metal ions, and the residual metal ions were determined using atomic absorption spectroscopy. GM 16 was effective in the removal of Cu2+ and Cd2+ from the contaminated medium. It was capable of removing 65 % of Cu2+ and 48 % of Cd2+ when the initial concentrations were 100 mg/l, whereas GM 15 was found to be effective in the biosorption of Ni2+ from the aqueous solutions. It was capable of removing 44 % of Ni2+ when the initial concentration was 50 mg/l. GM 17 could only remove 20 % of Cu2+ or Cd2+. These observations indicated that GM 16 could be used for bioremediation of xvi Cu2+ and Cd2+ ions from Cu2+ and Cd2+-contaminated aqueous environment, whereas GM 15 could be used for bioremediation of Ni2+.
National Research Foundation and the University of the North Research Unit
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Books on the topic "Dissolved heavy metal ion"

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Brown, Jennifer. Heavy metal ion adsorption by thiol-functionalized nanoporous silica. Sudbury, Ont: Laurentian University, 1998.

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Butkus, Steven R. Spokane River dissolved metals total maximum daily load: Submittal report. Olympia, Wash: Washington State Dept. of Ecology, Water Quality Program, 1999.

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Butkus, Steven R. Spokane River dissolved metals total maximum daily load: Submittal report. Olympia, Wash: Washington State Dept. of Ecology, Water Quality Program, 1999.

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Ball, C. P. The development of a fibre-optic heavy metal ion sensor based on immobilised dithizone. Manchester: UMIST, 1993.

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Pelletier, G. J. Applying metals criteria to water quality-based discharge limits: Empirical models of the dissolved fraction of cadmium, copper, lead, and zinc. Olympia, Wash: Washington State Dept. of Ecology, Environmental Investigations and Laboratory Services Program, Watershed Assessment Section, 1996.

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United States. National Aeronautics and Space Administration., ed. Mutagenesis in human cells with accelerated H & Fe ions: Final summary of research programs. [Washington, DC: National Aeronautics and Space Administration, 1991.

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Tanner, D. Q. Surface-water-quality assessment of the lower Kansas River basin, Kansas and Nebraska: Distribution of trace-element concentrations in dissolved and suspended phases, streambed sediment, and fish samples, May 1987 through April 1990. Lawrence, Kan: U.S. Dept. of the Interior, U.S. Geological Survey, 1995.

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Tanner, D. Q. Surface-water-quality assessment of the lower Kansas River basin, Kansas and Nebraska: Distribution of trace-element concentrations in dissolved and suspended phases, streambed sediment, and fish samples, May 1987 through April 1990. Lawrence, Kan: U.S. Dept. of the Interior, U.S. Geological Survey, 1995.

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Tanner, D. Q. Surface-water-quality assessment of the lower Kansas River basin, Kansas and Nebraska: Distribution of trace-element concentrations in dissolved and suspended phases, streambed sediment, and fish samples, May 1987 through April 1990. Lawrence, Kan: U.S. Dept. of the Interior, U.S. Geological Survey, 1995.

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Tanner, D. Q. Surface-water-quality assessment of the lower Kansas River basin, Kansas and Nebraska: Distribution of trace-element concentrations in dissolved and suspended phases, streambed sediment, and fish samples, May 1987 through April 1990. Lawrence, Kan: U.S. Dept. of the Interior, U.S. Geological Survey, 1995.

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Book chapters on the topic "Dissolved heavy metal ion"

1

Thomas, Robert J. "Ion Detectors." In Measuring Heavy Metal Contaminants in Cannabis and Hemp, 155–63. First edition. | Boca Raton : Taylor and Francis, 2020.: CRC Press, 2020. http://dx.doi.org/10.1201/9781003004158-14.

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Thomas, Robert J. "Ion-Focusing System." In Measuring Heavy Metal Contaminants in Cannabis and Hemp, 99–106. First edition. | Boca Raton : Taylor and Francis, 2020.: CRC Press, 2020. http://dx.doi.org/10.1201/9781003004158-9.

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Velusamy, Sasireka, Anurag Roy, Senthilarasu Sundaram, and Tapas K. Mallick. "Concern for heavy metal ion water pollution." In Contaminants of Emerging Concerns and Reigning Removal Technologies, 257–84. London: CRC Press, 2022. http://dx.doi.org/10.1201/9781003247869-13.

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Thomas, Robert J. "Principles of Ion Formation." In Measuring Heavy Metal Contaminants in Cannabis and Hemp, 65–69. First edition. | Boca Raton : Taylor and Francis, 2020.: CRC Press, 2020. http://dx.doi.org/10.1201/9781003004158-5.

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Lim, Si-Hyung, and Sungho Yoon. "Sensors and Devices for Heavy Metal Ion Detection." In KAIST Research Series, 213–32. Dordrecht: Springer Netherlands, 2015. http://dx.doi.org/10.1007/978-94-017-9981-2_9.

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van der Veen, Niels J., Richard J. M. Egberink, Johan F. J. Engbersen, and David N. Reinhoudt. "Selective Optode Membranes for Heavy Metal Ion Detection." In Sensor Technology in the Netherlands: State of the Art, 107–10. Dordrecht: Springer Netherlands, 1998. http://dx.doi.org/10.1007/978-94-011-5010-1_16.

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Rajagopalan, V., S. Boussaad, and N. J. Tao. "A Nanocontact Sensor for Heavy Metal Ion Detections." In Nanotechnology and the Environment, 173–78. Washington, DC: American Chemical Society, 2004. http://dx.doi.org/10.1021/bk-2005-0890.ch022.

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Hayashita, Takashi. "Heavy Metal Ion Separation by Functional Polymeric Membranes." In ACS Symposium Series, 303–18. Washington, DC: American Chemical Society, 1996. http://dx.doi.org/10.1021/bk-1996-0642.ch021.

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Yılmazoğlu, Mesut. "Organic-Inorganic Ion Exchange Materials for Heavy Metal Removal from Water." In Remediation of Heavy Metals, 179–98. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-80334-6_7.

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Wang, Y. N., J. R. Zhang, Z. H. Lu, Y. Fu, and B. D. Wei. "Removal of wastewater-dissolved heavy metals by Na-carboxylate polyarylene ether sulfone." In Advances in Materials Science and Engineering, 9–14. London: CRC Press, 2021. http://dx.doi.org/10.1201/9781003225850-2.

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Conference papers on the topic "Dissolved heavy metal ion"

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Dave´, Nand K. "Mobility of Ra-226 and Heavy Metals (U, Th and Pb) From Pyritic Uranium Mine Tailings Under Sub-Aqueous Disposal Conditions." In ASME 2011 14th International Conference on Environmental Remediation and Radioactive Waste Management. ASMEDC, 2011. http://dx.doi.org/10.1115/icem2011-59283.

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Laboratory lysimeter studies were undertaken to evaluate the leaching characteristics and mobility of Ra-226 and other heavy metals (U, Th and Pb) from pyritic uranium mine tailings under sub-aqueous disposal conditions for assessing the long-term radiological stability of such waste repositories. The experiments were conducted using three types of un-oxidized tailings: fine, coarse and gypsum depleted mill total tailings. The results showed that Ra-226 was leached from surface of the submerged tailings and released to both surface water and shallow zone pore water during initial low sulphate ion concentration of the surface water cover in all three cases. The release of Ra-226 was further enhanced with the onset of weak acidic conditions in the surface water covers of both coarse and gypsum depleted mill total tailings. With additional acid generation and increasing sulphate and iron concentrations, the dissolved Ra-226 concentrations in the water covers of these tailings gradually decreased back to low levels. Pb was also leached and mobilized with the development of moderate acidic conditions at the surface of the submerged coarse and gypsum deplete tailings. No leaching of U and Th was observed.
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Dossary, Hind S., Fahd I. Alghunaimi, and Young C. Choi. "Produced Water Reuse for Drilling and Completion Fluids Using Ion Exchange Resins." In Abu Dhabi International Petroleum Exhibition & Conference. SPE, 2021. http://dx.doi.org/10.2118/207543-ms.

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Abstract Produced water is considered one of the largest by volume waste streams and one of the most challenging effluents in the oil and gas industry. This is due to the variety of contaminants that make up produce water. A variety of treatment methods have been studied and implemented. These methods aim to reduce the hydrocarbon content and the number of contaminants in produced water to meet the disposal, reuse, and environmental regulations. These contaminants can include dispersed oil droplets, suspended solids, dissolved solids, heavy metals, and other production chemicals. Some of those contaminates have value and can be a commodity in different applications such as bromine (Br). Bromine ions can be used to form calcium bromide, which is considered one of the most effective drilling agents and is used extensively in drilling and completion operations. This paper aims to highlight the utilization and the new extraction method of bromide ions from produced water to form calcium bromide (CaBr2). The conventional preparation of calcium-bromide drilling and completion fluids involves adding solid calcium-bromide salts to the water, which can be relatively expensive. Another method can involve the handling of strong oxidants and toxic gas to form solid calcium bromide. The novel method outlined in this paper is a cost-effective and environmentally friendly way of generating calcium bromide from produced water. The method includes processing the produced water to recover bromide ions. This is done by first passing the produced water through a resin bed, including bromine-specific ion exchange resin, where the bromide ions will adsorb/absorb onto the resin, as shown in Figure-1. The second step involves regenerating the resin with regenerant having calcium cations and water to form calcium bromide. The final stage is generating the calcium bromide in the water from the bed of resin by introducing concentrated CaCl2, forming a concentrated solution of water and calcium bromide. The developed solution will be further processed to give drilling and completion fluids. This novel method constitutes a good example of produced water utilization in different applications to minimize waste and reduce the costs of forming highly consumable materials.
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Ribeiro, A., C. Vilarinho, J. Araújo, and J. Carvalho. "Electrokinetic Remediation of Contaminated Soils With Chromium." In ASME 2018 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/imece2018-87552.

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Soil is a vital natural resource that regulates our environment sustainability and provide essential resources to humans and nature. Nowadays, with an increasingly populated and urbanized world, pollution is widely recognized as a significant challenge to soil and groundwater resources management. The most common chemicals found in soils and water plumb in a dissolved state and considered as potential pollutants are heavy metals, dyes, phenols, detergents, pesticides, polychlorinated biphenyls (PCBs), and others organic substances, such as organic matter. Unlike organic contaminants, heavy metals are not biodegradable and tend to accumulate in living organisms and many heavy metal ions are known to be toxic or carcinogenic. Toxic heavy metals of particular concern zinc, copper, nickel, mercury, cadmium, lead and chromium. Electrokinetic remediation deserves particular attention in soil treatment due to its peculiar advantages, including the capability of treating fine and low permeability materials, and achieving consolidation, dewatering and removal of salts and inorganic contaminants like heavy metals in a single stage. In this study, the remediation of artificially chromium contaminated soil by electrokinetic process, coupled with Eggshell Inorganic Fraction Powder (EGGIF) permeable reactive barrier (PRB), was investigated. An electric field of 2 V cm−1 was applied and was used an EGGIF/soil ratio of 30 g kg−1 of contaminated soil for the preparation of the permeable reactive barrier (PRB) in each test. Results proved that the study of chromium mobility revealed the predominance in its transportation through the soil towards the anode, due essentially to the existence of chromium in the form of oxyanions (chromate and dichromate), which confers a negative charge to the molecule. Chromium removal by electrokinetic remediation was faster in low levels of concentration and the utilization of citric acid as buffer and complexing agent allowed to maintain pH of soil below the precipitation limit for this element. It was obtained high removal rates of chromium in both experiments, especially near the anode. In the normalized distance to cathode of 0.8 it was achieved a maximum removal rate of chromium of 55, 59 and 60% in initial chromium concentration of 500 mg kg−1, 250 mg kg−1 and 100 mg kg−1, respectively. The viability of the new coupling technology developed (electrokinetic with EGGIF permeable reactive barrier) to treat low-permeability polluted soils was demonstrated. Based on the proved efficiency, this remediation technique has to be optimized and applied to real soils in order to validate it as a large-scale solution.
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Zhao, Zhiyong, Daniel F. Downey, and Gordon Angel. "Heavy metal contamination in ion implantation." In The fourteenth international conference on the application of accelerators in research and industry. AIP, 1997. http://dx.doi.org/10.1063/1.52731.

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Len, L. K., S. Humphries, and C. Burkhart. "Grid-controlled metal ion sources for heavy ion fusion accelerators." In AIP Conference Proceedings Volume 152. AIP, 1986. http://dx.doi.org/10.1063/1.36341.

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6

Discenzo, Fred M., Steven A. Kania, Chung-Chin Liu, Laurie Dudik, Aleksandr Vasser, and Benjamin Ward. "Dissolved Wear Metal Monitoring in Lubricating Fluids." In ASME/STLE 2007 International Joint Tribology Conference. ASMEDC, 2007. http://dx.doi.org/10.1115/ijtc2007-44102.

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Lubricating fluids play a critical role in the operation of many machines in commerce, industry, and the military. Failure of a lubricant often results in accelerated metal wear and the release of wear debris in the lubricant. Early detection of abnormal metal wear is important for fault detection and failure prevention. An electrochemical cell can be operated in a lubricating fluid in such a way that the operating characteristics of the cell can provide an indication of the chemistry of the fluid. For example, certain ions in the fluid, such as wear metal ions, will react to particular potential values applied to electrodes in the electrochemical cell. By applying a changing potential across the electrodes in an electrochemical cell and observing the resulting current it is possible to detect and identify the ionic species present in the lubricating fluid. The objective is to provide real-time monitoring of lubricating fluids using an in situ sensor to detect and diagnose conditions leading to machinery failure. A series of experiments have been conducted to confirm the ability of an electrochemical cell to detect wear metal ions in lubricating fluids extracted from machinery. Additional tests have been conducted to test the hypothesis that the presence and amount of wear metal ions corresponds to the type and amount of wear particles in the fluid. Initial laboratory tests have established a positive correlation with wear particles detected in used lubricating oil with ion presence determined using ion chromatography. The results reported indicate that a small, real-time multielement sensor with an electrochemical cell will be able to detect wear metal ions and provide an early indication of unusual material wear. This capability may provide an early warning of atypical wear patterns and provide a cue to an operator or service engineer indicating the type of fault occurring and the specific component experiencing wear or early failure.
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Ramshani, Zeinab, Binu B. Narakathu, Avuthu S. G. Reddy, Massood Z. Atashbar, Jared T. Wabeke, and Sherine O. Obare. "SH-SAW-based sensor for heavy metal ion detection." In 2015 Joint Conference of the IEEE International Frequency Control Symposium & the European Frequency and Time Forum (FCS). IEEE, 2015. http://dx.doi.org/10.1109/fcs.2015.7138901.

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Wang, Shin-Li, Revathi Sukesan, Indu Sarangadharan, and Yu-Lin Wang. "FET Based Heavy Metal Ion Sensor to Detect Mercury Ion from Waste Water." In 2019 20th International Conference on Solid-State Sensors, Actuators and Microsystems & Eurosensors XXXIII (TRANSDUCERS & EUROSENSORS XXXIII). IEEE, 2019. http://dx.doi.org/10.1109/transducers.2019.8808568.

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Usha Rani, K. R., Rajani Katiyar, C. Manjunatha, Nivedita P. Birajadar, Likhita Likhita, and Punith K. "Heavy Metal-Ion Detection in Soil Using Anodic Stripping Voltammetry." In 2020 International Conference for Emerging Technology (INCET). IEEE, 2020. http://dx.doi.org/10.1109/incet49848.2020.9154169.

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Jiang, H., C. Yang, K. Yang, and L. Dong. "A SUB-PPB-LEVEL INTEGRATED ELECTROCHEMICAL HEAVY METAL ION MICROSENSOR." In 2018 Solid-State, Actuators, and Microsystems Workshop. San Diego: Transducer Research Foundation, 2018. http://dx.doi.org/10.31438/trf.hh2018.43.

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Reports on the topic "Dissolved heavy metal ion"

1

Chefetz, Benny, Baoshan Xing, Leor Eshed-Williams, Tamara Polubesova, and Jason Unrine. DOM affected behavior of manufactured nanoparticles in soil-plant system. United States Department of Agriculture, January 2016. http://dx.doi.org/10.32747/2016.7604286.bard.

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The overall goal of this project was to elucidate the role of dissolved organic matter (DOM) in soil retention, bioavailability and plant uptake of silver and cerium oxide NPs. The environmental risks of manufactured nanoparticles (NPs) are attracting increasing attention from both industrial and scientific communities. These NPs have shown to be taken-up, translocated and bio- accumulated in plant edible parts. However, very little is known about the behavior of NPs in soil-plant system as affected by dissolved organic matter (DOM). Thus DOM effect on NPs behavior is critical to assessing the environmental fate and risks related to NP exposure. Carbon-based nanomaterials embedded with metal NPs demonstrate a great potential to serve as catalyst and disinfectors. Hence, synthesis of novel carbon-based nanocomposites and testing them in the environmentally relevant conditions (particularly in the DOM presence) is important for their implementation in water purification. Sorption of DOM on Ag-Ag₂S NPs, CeO₂ NPs and synthesized Ag-Fe₃O₄-carbon nanotubebifunctional composite has been studied. High DOM concentration (50mg/L) decreased the adsorptive and catalytic efficiencies of all synthesized NPs. Recyclable Ag-Fe₃O₄-carbon nanotube composite exhibited excellent catalytic and anti-bacterial action, providing complete reduction of common pollutants and inactivating gram-negative and gram-positive bacteria at environmentally relevant DOM concentrations (5-10 mg/L). Our composite material may be suitable for water purification ranging from natural to the industrial waste effluents. We also examined the role of maize (Zeamays L.)-derived root exudates (a form of DOM) and their components on the aggregation and dissolution of CuONPs in the rhizosphere. Root exudates (RE) significantly inhibited the aggregation of CuONPs regardless of ionic strength and electrolyte type. With RE, the critical coagulation concentration of CuONPs in NaCl shifted from 30 to 125 mM and the value in CaCl₂ shifted from 4 to 20 mM. This inhibition was correlated with molecular weight (MW) of RE fractions. Higher MW fraction (> 10 kDa) reduced the aggregation most. RE also significantly promoted the dissolution of CuONPs and lower MW fraction (< 3 kDa) RE mainly contributed to this process. Also, Cu accumulation in plant root tissues was significantly enhanced by RE. This study provides useful insights into the interactions between RE and CuONPs, which is of significance for the safe use of CuONPs-based antimicrobial products in agricultural production. Wheat root exudates (RE) had high reducing ability to convert Ag+ to nAg under light exposure. Photo-induced reduction of Ag+ to nAg in pristine RE was mainly attributed to the 0-3 kDa fraction. Quantification of the silver species change over time suggested that Cl⁻ played an important role in photoconversion of Ag+ to nAg through the formation and redox cycling of photoreactiveAgCl. Potential electron donors for the photoreduction of Ag+ were identified to be reducing sugars and organic acids of low MW. Meanwhile, the stabilization of the formed particles was controlled by both low (0-3 kDa) and high (>3 kDa) MW molecules. This work provides new information for the formation mechanism of metal nanoparticles mediated by RE, which may further our understanding of the biogeochemical cycling and toxicity of heavy metal ions in agricultural and environmental systems. Copper sulfide nanoparticles (CuSNPs) at 1:1 and 1:4 ratios of Cu and S were synthesized, and their respective antifungal efficacy was evaluated against the pathogenic activity of Gibberellafujikuroi(Bakanae disease) in rice (Oryza sativa). In a 2-d in vitro study, CuS decreased G. fujikuroiColony- Forming Units (CFU) compared to controls. In a greenhouse study, treating with CuSNPs at 50 mg/L at the seed stage significantly decreased disease incidence on rice while the commercial Cu-based pesticide Kocide 3000 had no impact on disease. Foliar-applied CuONPs and CuS (1:1) NPs decreased disease incidence by 30.0 and 32.5%, respectively, which outperformed CuS (1:4) NPs (15%) and Kocide 3000 (12.5%). CuS (1:4) NPs also modulated the shoot salicylic acid (SA) and Jasmonic acid (JA) production to enhance the plant defense mechanisms against G. fujikuroiinfection. These results are useful for improving the delivery efficiency of agrichemicals via nano-enabled strategies while minimizing their environmental impact, and advance our understanding of the defense mechanisms triggered by the NPs presence in plants.
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Beltran, Michael R., Vladimir R. Mindin, and Rita V. Drondina. Heavy Metal Ion Removal and Wastewater Treatment by Combined Magnetic Particle and 3-D Electrochemical Technology. Fort Belvoir, VA: Defense Technical Information Center, March 1996. http://dx.doi.org/10.21236/ada363782.

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Yermiyahu, Uri, Thomas Kinraide, and Uri Mingelgrin. Role of Binding to the Root Surface and Electrostatic Attraction in the Uptake of Heavy Metal by Plants. United States Department of Agriculture, 2000. http://dx.doi.org/10.32747/2000.7586482.bard.

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The principal accomplishment of the research supported by BARD was progress toward a comprehensive view of cell-surface electrical effects (both in cell walls [CWs] and at plasma membrane [PM] surfaces) upon ion uptake, intoxication, and amelioration. The research confirmed that electrostatic models (e.g., Gouy-Chapman-Stern [G-C-S]), with parameter values contributed by us, successfully predict ion behavior at cell surfaces. Specific research objectives 1. To characterize the sorption of selected heavy metals (Cu, Zn, Pb, Cd) to the root PM in the presence of other cations and organic ligands (citric and humic acids). 2. To compute the parameters of a G-C-S model for heavy-metal sorption to the root PM. 3. To characterize the accumulation of selected heavy metals in various plant parts. 4. To determine whether model-computed ion binding or ion activities at root PM surfaces predict heavy-metal accumulation in whole roots, root tips, or plant shoots. 5. To determine whether measured ion binding by protoplast-free roots (i.e., root CWs) predicts heavy-metal accumulation in whole roots, root tips, or plant shoots. 6. To correlate growth inhibition, and other toxic responses, with the measured and computed factors mentioned above. 7. To determine whether genotypic differences in heavy-metal accumulation and toxic responses correlate with genotypic differences in parameters of the G-C-S model. Of the original objectives, all except for objective 7 were met. Work performed to meet the other objectives, and necessitated on the basis of experimental findings, took the time that would have been required to meet objective 7. In addition, work with Pb was unsuccessful due to experimental complications and work on Cd is still in progress. On the other hand, the uptake and toxicity of the anion, selenate was characterized with respect to electrostatic effects and the influences of metal cations. In addition, the project included more theoretical work, supported by experimentation, than was originally planned. This included transmembrane ion fluxes considered in terms of PM-surface electrical potentials and the influence of CWs upon ion concentrations at PM surfaces. A important feature of the biogeochemistry of trace elements in the rhizosphere is the interaction between plant-root surfaces and the ions present in the soil solution. The ions, especially the cations, of the soil solution may be accumulated in the aqueous phases of cell surfaces external to the PMs, sometimes referred to as the "water free space" and the "Donnan free space". In addition, ions may bind to the CW components or to the PM surface with variable binding strength. Accumulation at the cell surface often leads to accumulation in other plant parts with implications for the safety and quality of foods. A G-C-S model for PMs and a Donnan-plus-binding model for CWs were used successfully to compute electrical potentials, ion binding, and ion concentration at root-cell surfaces. With these electrical potentials, corresponding values for ion activities may be computed that are at least proportional to actual values also. The computed cell-surface ion activities predict and explain ion uptake, intoxication, and amelioration of intoxication much more accurately than ion activities in the bulk-phase rooting medium.
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Banin, Amos, Joseph Stucki, and Joel Kostka. Redox Processes in Soils Irrigated with Reclaimed Sewage Effluents: Field Cycles and Basic Mechanism. United States Department of Agriculture, July 2004. http://dx.doi.org/10.32747/2004.7695870.bard.

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The overall objectives of the project were: (a) To measure and study in situ the effect of irrigation with reclaimed sewage effluents on redox processes and related chemical dynamics in soil profiles of agricultural fields. (b) To study under controlled conditions the kinetics and equilibrium states of selected processes that affect redox conditions in field soils or that are effected by them. Specifically, these include the effects on heavy metals sorption and desorption, and the effect on pesticide degradation. On the basis of the initial results from the field study, increased effort was devoted to clarifying and quantifying the effects of plants and water regime on the soil's redox potential while the study of heavy metals sorption was limited. The use of reclaimed sewage effluents as agricultural irrigation water is increasing at a significant rate. The relatively high levels of suspended and, especially, dissolved organic matter and nitrogen in effluents may affect the redox regime in field soils irrigated with them. In turn, the changes in redox regime may affect, among other parameters, the organic matter and nitrogen dynamics of the root zone and trace organic decomposition processes. Detailed data of the redox potential regime in field plots is lacking, and the detailed mechanisms of its control are obscure and not quantified. The study established the feasibility of long-term, non-disturbing monitoring of redox potential regime in field soils. This may enable to manage soil redox under conditions of continued inputs of wastewater. The importance of controlling the degree of wastewater treatment, particularly of adding ultrafiltration steps and/or tertiary treatment, may be assessed based on these and similar results. Low redox potential was measured in a field site (Site A, KibutzGivat Brenner), that has been irrigated with effluents for 30 years and was used for 15 years for continuous commercial sod production. A permanently reduced horizon (Time weighted averaged pe= 0.33±3.0) was found in this site at the 15 cm depth throughout the measurement period of 10 months. A drastic cultivation intervention, involving prolonged drying and deep plowing operations may be required to reclaim such soils. Site B, characterized by a loamy texture, irrigated with tap water for about 20 years was oxidized (Time weighted average pe=8.1±1.0) throughout the measurement period. Iron in the solid phases of the Givat Brenner soils is chemically-reduced by irrigation. Reduced Fe in these soils causes a change in reactivity toward the pesticide oxamyl, which has been determined to be both cytotoxic and genotoxic to mammalian cells. Reaction of oxamyl with reduced-Fe clay minerals dramatically decreases its cytotoxicity and genotoxicity to mammalian cells. Some other pesticides are affected in the same manner, whereas others are affected in the opposite direction (become more cyto- and genotoxic). Iron-reducing bacteria (FeRB) are abundant in the Givat Brenner soils. FeRB are capable of coupling the oxidation of small molecular weight carbon compounds (fermentation products) to the respiration of iron under anoxic conditions, such as those that occur under flooded soil conditions. FeRB from these soils utilize a variety of Fe forms, including Fe-containing clay minerals, as the sole electron acceptor. Daily cycles of the soil redox potential were discovered and documented in controlled-conditions lysimeter experiments. In the oxic range (pe=12-8) soil redox potential cycling is attributed to the effect of the daily temperature cycle on the equilibrium constant of the oxygenation reaction of H⁺ to form H₂O, and is observed under both effluent and freshwater irrigation. The presence of plants affects considerably the redox potential regime of soils. Redox potential cycling coupled to the irrigation cycles is observed when the soil becomes anoxic and the redox potential is controlled by the Fe(III)/Fe(II) redox couple. This is particularly seen when plants are grown. Re-oxidation of the soil after soil drying at the end of an irrigation cycle is affected to some degree by the water quality. Surprisingly, the results suggest that under certain conditions recovery is less pronounced in the freshwater irrigated soils.
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