Evaporation and Stabilization of Heavy Metals with Colloid/Interface Properties in EAF Dust-Clay Bodies

2007 ◽  
Vol 544-545 ◽  
pp. 569-572
Author(s):  
Young Min Wie ◽  
Ki Gang Lee
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Metal Ion ◽  
Sintering Temperature ◽  
Clay Content ◽  
Raw Material ◽  
Colloid Interface ◽  
Mixing Ratios ◽  
Eaf Dust ◽  
Total Concentrations

To recycling the EAF dust as a ceramic raw material, the leaching concentrations of heavy metals (Zn, Pb, Cr, Cd) were analyzed with various pH and mixing ratios for EAF dust-clay bodies. The evaporation amounts of the some heavy metals were evaluated by measuring their total concentrations in the sintered bodies of EAF dust-clay mixtures with various mixing ratio and sintering temperature. TCLP test was conducted for evaluating the chemical stabilities of the heavy metal elements. The heavy metals in EAF dust are 'amphoteric metal' and leached a little at pH10. The leaching concentrations of heavy metal ion were effectively decreased by the formation of PSHP when adding the clay to the EAF dust and controlling the pH of the slurry at 12. Evaporation of heavy metal components were increased with increasing the sintering temperature and the contents of EAF dust. The leaching concentrations of heavy metal components were decreased with increasing the clay content and temperature.

Applications of Bentonite to Soil Decontamination

2018 ◽  
Vol 69 (7) ◽  
pp. 1695-1698
Author(s):  
Marin Rusanescu ◽  
Carmen Otilia Rusanescu ◽  
Gheorghe Voicu ◽  
Mihaela Begea
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Laboratory Experiments ◽  
Experimental Studies ◽  
Heavy Metal Concentration ◽  
Polluted Soil ◽  
Raw Material ◽  
Soil Decontamination ◽  
Metal Retention ◽  
Removal Of Heavy Metals

A calcium bentonite from Orasu Nou deposit (Satu Mare Romania) was used as raw material. We have conducted laboratory experiments to determine the influence of bentonite on the degree of heavy metal retention. It has been observed that the rate of retention increases as the heavy metal concentration decreases. Experimental studies have been carried out on metal retention ( Zn) in bentonite. In this paper, we realized laboratory experiments for determining the influence of metal (Zn) on the growth and development of two types of plants (Pelargonium domesticum and Kalanchoe) and the effect of bentonite on the absorption of pollutants. These flowers were planted in unpolluted soil, in heavy metal polluted soil and in heavy metal polluted soil to which bentonite was added to observe the positive effect of bentonite. It has been noticed that the flowers planted in unpolluted soil and polluted with heavy metals to which bentonite has been added, the flowers have flourished, the leaves are still green and the plants whose soils have been polluted with heavy metals began to dry after 6 days, three weeks have yellowish leaves and flowers have dried. Experiments have demonstrated the essential role of bentonite for the removal of heavy metals polluted soil.

scholarly journals Plant-Based Tacca leontopetaloides Biopolymer Flocculant (TBPF) Produced High Removal of Heavy Metal Ions at Low Dosage

Processes ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 37
Author(s):  
Nurul Shuhada Mohd Makhtar ◽  
Juferi Idris ◽  
Mohibah Musa ◽  
Yoshito Andou ◽  
Ku Halim Ku Hamid ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Metal Ions ◽  
Metal Ion ◽  
Metal Removal ◽  
Test Procedure ◽  
Synthetic Wastewater ◽  
Leachate Treatment ◽  
Low Concentration ◽  
Removal Of Heavy Metals

High removal of heavy metals using plant-based bioflocculant under low concentration is required due to its low cost, abundant source, and nontoxicity for improved wastewater management and utilization in the water industry. This paper presents a treatment of synthetic wastewater using plant-based Tacca leontopetaloides biopolymer flocculant (TBPF) without modification on its structural polymer chains. It produced a high removal of heavy metals (Zn, Pb, Ni, and Cd) at a low concentration of TBPF dosage. In our previous report, TBPF was characterized and successfully reduced the turbidity, total suspended solids, and color for leachate treatment; however, its effectiveness for heavy metal removal has not been reported. The removal of these heavy metals was performed using a standard jar test procedure at different pH values of synthetic wastewater and TBPF dosages. The effects of hydroxide ion, pH, initial TBPF concentration, initial metal ion concentration, and TBPF dosage were examined using one factorial at the time (OFAT). The results show that the highest removal for Zn, Pb, Ni, and Cd metal ions were 98.4–98.5%, 79–80%, 97–98%, and 92–93%, respectively, using 120 mg/L dosage from the initial concentration of 10% TBPF at pH 10. The final concentrations for Zn, Pb, Ni, and Cd metal ions were 0.043–0.044, 0.41–0.43, 0.037–0.054, and 0.11–0.13 mg/L, respectively, which are below the Standard B discharge limit set by the Department of Environment (DOE), Malaysia. The results show that TBPF has a high potential for the removal of heavy metals, particularly Zn, Pb, Ni, and Cd, in real wastewater treatment.

Migration Patterns of Heavy Metals in Soil in Wastewater Irrigation Area in the Suburb of Eastern Inner Mongolia

2011 ◽  
Vol 343-344 ◽  
pp. 340-343
Author(s):  
Ri Cha Hu ◽  
Li Bo Sun
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Inner Mongolia ◽  
Metal Ion ◽  
Vertical Direction ◽  
Heavy Metal Concentration ◽  
Water Shortage ◽  
Wastewater Irrigation ◽  
Irrigation Area ◽  
Eastern Inner Mongolia

Based on the soil test of heavy metals in wastewater irrigation area in eastern Inner Mongolia, this paper analyses the content of heavy metals Cr, Cu, Cd, Pb in different layers of soil samples and reveals the internal relations between heavy metal concentration gradient in the vertical direction and soil properties, thus providing a scientific basis to guide sewage irrigation, solve the problem of water shortage in wastewater irrigation area and carry out environmental impact assessment. Soil is an important subsystem in natural environmental systems, through which many pollutants, especially heavy metals, produced by human activities, enter the food chain and ultimately do harm to human health. Currently, heavy metal ion contamination to the soil caused by wastewater irrigation has become one of the focuses in the study of soil chemistry and agricultural environment pollution. For this reason, it is particularly important to study the migration mechanism of heavy metals in soil and to provide a reliable theoretical basis for the prevention and management of soil contaminants.

scholarly journals Heavy metals in pastureland soils situated in A Pastoriza (NW Spain) treated with cattle slurry and NPK fertilizers

2015 ◽  
Vol 5 ◽  
Author(s):  
Natalia Seco-Reigosa ◽  
María J. Fernández-Sanjurjo ◽  
Avelino Núñez-Delgado ◽  
Laura Cutillas-Barreiro ◽  
Antía Gómez-Armesto ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Forest Soils ◽  
Soil Depth ◽  
Available P ◽  
Cattle Slurry ◽  
Nw Spain ◽  
Npk Fertilizers ◽  
Pasture Production ◽  
Total Concentrations

In Galicia (NW Spain), pasturelands cover a broad extension and are mainly used to feed cattle. Farms are managed in an intensive manner, using cattle slurry and inorganic fertilizers to increase pasture production, but also increasing risks of heavy metal pollution. In this work we studied the influence of fertilization practices on total concentrations and in-depth distribution of heavy metals and related elements (As, Cd, Cr, Cu, Mn, Ni, Pb and Zn) in two forest soils (SN1, SN2) and five pastureland soils (P1-P5) fertilized with cattle slurry and NPK, in a broadly exploded farmland area (A Pastoriza, Lugo). Soils SN2 and P4 were developed over slate, whereas soils SN1, P1, P2, P3 and P5 evolved on Candana quartzite. Forest soils presented acid pH (4.58-4.68), high Al saturation (75-90%), and low available P concentration (4.78-11.96 mg kg<sup>-1</sup>), whereas those parameters exhibited better scores in the pastureland soils, due to previous amendment and fertilization practices, thus giving pH 5.17-7.02, Al saturation 0.58-59.24%, and available P 5.24-42.07 mg kg<sup>-1</sup>. Regarding heavy metals, soil depth did not affect significantly to total concentrations, contrary to that happening with parent material, with higher As, Cu, Fe, and Ni concentrations found in soils over slate (possibly due to the presence of pyritic materials). In most cases, heavy metal total concentrations were lower than that considered as reference background levels for soils developed over each of the parent materials, and were always lower than that considered phyto-toxic. In this study, natural soils usually presented heavy metal total contents similar or even higher than that of the fertilized soils (unless Zn in the P4 pastureland), thus indicating that the spread doses of fertilizers did not influence significantly their concentration levels.

scholarly journals pH-Regulated Carbon Dots Fluorescence Sensor Array Detection of Multiple Heavy Metal Ions Under Stepwise Prediction

2022 ◽  
Author(s):  
Zijun Xu ◽  
Yuying Liu ◽  
Jiao Chen ◽  
Xiyuan Wang ◽  
Hao Liu ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Metal Ions ◽  
Metal Ion ◽  
Heavy Metal Ions ◽  
Sensor Array ◽  
Chelating Agent ◽  
Fluorescence Sensor ◽  
Array Detection ◽  
Multiple Heavy Metals

Abstract As a large amount of heavy metals leaches into water sources from industrial effluents, heavy metal pollution has become an important factor affecting water quality. To enable the detection of multiple heavy metals, we constructed a pH-regulation fluorescence sensor array. Firstly, by adding a metal chelating agent as receptor, metal ions and carbon quantum dots (CDs) were connected to distinguish between Cr6+, Fe3+, Fe2+, and Hg2+ ions. Thus, the lack of affinity between the indicator functional groups and the analyte was solved. Secondly, by adjusting the pH environment of the solution system, an economical and simple array sensing platform is established, which effectively simplified the array construction. In this study, the SX-model was used in the field of fluorescence sensor array detection for metal ion recognition. Based on the strategy of stepwise prediction, combined with the classification and concentration models, the bottleneck of the unified model in previous studies was broken. This sensor array demonstrated sensitive detection of four heavy metal ions within a concentration range from 1 to 50 µM, with an accuracy of 95.45%. Moreover, it displayed the ability to efficiently identify binary mixed samples with an accuracy of 95.45%. Furthermore, metal ions in 15 real samples (lake water) were effectively discriminated with 100% accuracy. A chelating agent was used to improve the sensitivity of heavy metal ion detection and eventually led to high-precision prediction using the SX-model.

Sorption of Heavy Metal on Natural Clay

2018 ◽  
Vol 68 (12) ◽  
pp. 2804-2807
Author(s):  
Mircea Stefan ◽  
Adriana Bors ◽  
Daniela Simina Stefan ◽  
Ionut Alexandru Savu Radu ◽  
Cicerone Marinescu
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Metal Ion ◽  
Background Electrolyte ◽  
Hydroxyl Groups ◽  
Natural Clay ◽  
Equilibrium Isotherms ◽  
Solution Ph ◽  
Constant Ph ◽  
Langmuir Isotherm Model

Sorption of heavy metals on Na-montmorillonite was studied as a function of solution pH and different concentrations of background electrolyte and also a function of added metal ion at constant pH. Equilibrium isotherms have been measured and analyzed using a Langmuir isotherm model. The metal ions were predominantly adsorbed on the permanent charge sites in a easily replaceable state. There was also evident a substantial involvement of the hydroxyl groups on the edges of Na-montmorillonite in specific adsorption of the cations especially at higher pH.

scholarly journals Biosorption and Bioaccumulation Abilities of Actinomycetes/Streptomycetes Isolated from Metal Contaminated Sites

Separations ◽  
2018 ◽  
Vol 5 (4) ◽  
pp. 54 ◽  
Author(s):  
Ivana Timková ◽  
Jana Sedláková-Kaduková ◽  
Peter Pristaš
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Metal Ion ◽  
Polluted Soil ◽  
Negative Effects ◽  
Wide Range ◽  
Specific Uptake ◽  
High Concentrations ◽  
Further Development ◽  
Soil And Water

Heavy metal pollution is of great concern. Due to expansion of industrial activities, a large amount of metal is released into the environment, disturbing its fragile balance. Conventional methods of remediation of heavy metal-polluted soil and water are expensive and inefficient. Therefore, new techniques are needed to provide environmentally friendly and highly selective remediation. Streptomycetes, with their unique growth characteristics, ability to form spores and mycelia, and relatively rapid colonization of substrates, act as suitable agents for bioremediation of metals and organic compounds in polluted soil and water. A variety of mechanisms could be involved in reduction of metals in the environment, e.g., sorption to exopolymers, precipitation, biosorption and bioaccumulation. Studies performed on biosorption and bioaccumulation potential of streptomycetes could be used as a basis for further development in this field. Streptomycetes are of interest because of their ability to survive in environments contaminated by metals through the production of a wide range of metal ion chelators, such as siderophores, which provide protection from the negative effects of heavy metals or specific uptake for specialized metabolic processes. Many strains also have the equally important characteristic of resistance to high concentrations of heavy metals.

scholarly journals Synthesis of iron phosphate-SAPO-34 composite and its application as effective absorbent for wastewater treatment

2018 ◽  
Vol 238 ◽  
pp. 02003
Author(s):  
Ying Cao ◽  
Lianmei Wei ◽  
Xianzhen Song ◽  
Xixi Yan ◽  
Xiaoyu Liu ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Reaction Time ◽  
Metal Ion ◽  
Low Cost ◽  
Iron Phosphate ◽  
Raw Material ◽  
Crystallization Time ◽  
X Ray Diffraction ◽  
Crystallization Method ◽  
Ft Ir

High-purity FePO4 was purified from iron-based phosphating slag as raw material, and FePO4@SAPO-34 was synthesized by hydrothermal crystallization method under the action of templating agent-diethylamine. The synth esized FePO4@SAPO-34 samples were characterized by x-ray diffraction (XRD), scanning electron microscopy (SE M) and Fourier transform infrared spectroscopy (FT-IR). The effects of different crystallization time on the morpholo gy and crystallization of FePO4@SAPO-34 crystals were investigated. The removal of heavy metal ion wastewater by low-cost FePO4@SAPO-34 was investigated. The experimental results show that when the reaction time is 180 °C an d the reaction time is 72h, the crystallization of FePO4@SAPO-34 is the best. When the dosage is 0.6g, the removal efficiency of heavy metal ions is the highest.

scholarly journals Chemical precipitation of heavy metals from wastewater by using the synthetical magnesium hydroxy carbonate

2020 ◽  
Vol 81 (6) ◽  
pp. 1130-1136 ◽  
Author(s):  
Yue Zhang ◽  
Xiumei Duan
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Ph Value ◽  
Metallurgical Industry ◽  
Chemical Precipitation ◽  
Raw Material ◽  
Low Grade ◽  
Heavy Metal Wastewater ◽  
Removal Efficiencies ◽  
Hydroxy Carbonate

Abstract Heavy metal pollution has become one of the most serious environmental problems today. The preparation of magnesium hydroxy carbonate from low-grade magnesite, and the chemical precipitation of heavy metal wastewater with magnesium hydroxy carbonate as precipitating agent were undertaken. The removal efficiencies of heavy metals were improved by increasing the dose of magnesium hydroxy carbonate, and the applicable dose of magnesium hydroxy carbonate was 0.30 g for 50 mL of the wastewater (6,000 mg/L). The precipitation reactions proceeded thoroughly within 20 min. At this time, the removal efficiencies of heavy metals were above 99.9%. The final pH value was 7.1, the residual VO2+, Cr3+ and Fe3+ concentrations were 0.01, 0.05 and 1.12 mg/L, respectively, which conformed to the limit of discharge set by China (0.5–2.0 mg/L, GB 8978–1996). The precipitate was mainly composed of Fe2O3, V2O5 and Cr2O3, which can be recycled as secondary raw material for metallurgical industry. The treatment of the heavy metal wastewater with magnesium hydroxy carbonate was successful in decreasing the concentrations of VO2+, Cr3+ and Fe3+ in wastewater.

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