Evaluating acids and chelating agents for removing heavy metals from contaminated soils

1997 ◽  
Vol 16 (4) ◽  
pp. 274-280 ◽  
Author(s):  
C. Nelson Neale ◽  
R. Y Bricka ◽  
Allen C. Chao
Keyword(s):  
Heavy Metals ◽  
Contaminated Soils ◽  
Chelating Agents

Selection and test of effective chelators for removal of heavy metals from contaminated soils

1995 ◽  
Vol 22 (6) ◽  
pp. 1185-1197 ◽  
Author(s):  
Ting-Chien Chen ◽  
Edward Macauley ◽  
Andrew Hong
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Contaminated Soils ◽  
Chelating Agents ◽  
Heavy Metal Contamination ◽  
Recovery Potential ◽  
Wide Range ◽  
Removal Of Heavy Metals ◽  
Zinc Chelator ◽  
Copper Lead

Heavy metal contamination of soil is a common problem at many hazardous waste sites. Chelating extraction of heavy metals has been proposed as a remediation technique for contaminated soils. A useful method was developed, which assessed 190 ligands for their ability in extraction and recovery of target metals, including cadmium, copper, lead, mercury, nickel, and zinc. Chelator performance was evaluated based on equilibrium calculations with an emphasis on the potential of recovering both the metals and chelating agents. Batch equilibration experiments over 24-h periods were performed to test three chelating agents, S-carboxymethyl-cysteine (SCMC), N-2-acetamidoiminodiacetic acid (ADA), and pyridine-2,6-dicarboxylic acid (PDA), which were deemed suitable for the extraction of cadmium, copper, lead, and zinc from soil. All three chelators demonstrated high extraction capability toward their respective target metals across a wide range of pH, metal, and ligand concentrations. In addition, all three chelators exhibited good recovery potential at moderately elevated pH values. The potential of many chelating agents and their effective pH ranges in the remediation of soils contaminated with heavy metals are reported. Key words: heavy metal, soil, contamination, chelation, remediation.

scholarly journals Comparative Activation Process of Pb, Cd and Tl Using Chelating Agents from Contaminated Red Soils

2020 ◽  
Vol 17 (2) ◽  
pp. 497 ◽  
Author(s):  
Lirong Liu ◽  
Dinggui Luo ◽  
Guangchao Yao ◽  
Xuexia Huang ◽  
Lezhang Wei ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Contaminated Soil ◽  
Contaminated Soils ◽  
Chelating Agents ◽  
Dynamic Equilibrium ◽  
Ethylenediaminetetraacetic Acid ◽  
Speciation Analysis ◽  
Activation Process ◽  
Activation Effect ◽  
Red Soils

Adding chelating agents is a critical technique of heavy metal activation for enhancing phytoextraction through the formation of soluble metal complexes which will be more readily available for extraction. The preliminary, dynamic, equilibrium activation experiments and speciation analysis of Pb, Cd and Tl in contaminated red soils were used to select six chelates with relatively good activation performance from nine chelates, and the effects of dosage and pH on the heavy metals activation were studied systematically. Results showed that the activation of Pb, Cd and Tl by chelates reached equilibrium within 2 h, and the activation process showed three stages. Under neutral conditions, chelates had better activation performance on Pb- and Cd-contaminated soils. Except for S,S-ethylenediamine disuccinic acid (S,S-EDDS) and citric acid (CA), the maximum equilibrium activation effect (MEAE) of ethylenediaminetetraacetic acid (EDTA), N,N-bis (carboxymethyl) glutamic acid (GLDA), diethylenetriaminepentaacetic acid (DTPA) and aminotriacetic acid (NTA) was over 81%. The MEAE of Tl-contaminated soil was less than 15%. The decreasing order of the dosage of chelating agents corresponding to MEAE for three types of contaminated soils was Pb-, Cd- and Tl-contaminated soil, relating to the forms of heavy metals, the stability constants of metal–chelates and the activation of non-target elements Fe in red soil. Under acidic conditions, the activation efficiencies of chelates decreased to differing degrees in Pb- and Cd-contaminated soils, whereas the activation efficiencies of chelating agents in Tl-contaminated soils were slightly enhanced.

Synergistic Effect of Rhamnolipid and Saponin Biosurfactants on Removal of Heavy Metals from Oil Contaminated Soils

2020 ◽  
Vol 57 (2) ◽  
pp. 109-114
Author(s):  
Amirhossein Dolatzadeh khiyavi ◽  
Reza Hajimohammadi ◽  
Hossein Amani ◽  
Hadi Soltani
Keyword(s):  
Heavy Metals ◽  
Synergistic Effect ◽  
Contaminated Soils ◽  
Removal Of Heavy Metals

scholarly journals Chemical Properties of Heavy Metal-Contaminated Soils from a Korean Military Shooting Range: Evaluation of Pb Sources Using Pb Isotope Ratios

2021 ◽  
Vol 11 (15) ◽  
pp. 7099
Author(s):  
Inkyeong Moon ◽  
Honghyun Kim ◽  
Sangjo Jeong ◽  
Hyungjin Choi ◽  
Jungtae Park ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Contaminated Soils ◽  
Management Strategies ◽  
Chemical Properties ◽  
Heavy Metal Concentration ◽  
Soil Samples ◽  
Shooting Range ◽  
Geochemical Properties ◽  
Mineral Phases

In this study, the geochemical properties of heavy metal-contaminated soils from a Korean military shooting range were analyzed. The chemical behavior of heavy metals was determined by analyzing the soil pH, heavy metal concentration, mineral composition, and Pb isotopes. In total, 24 soil samples were collected from a Korean military shooting range. The soil samples consist of quartz, albite, microcline, muscovite/illite, kaolinite, chlorite, and calcite. Lead minerals, such as hydrocerussite and anglesite, which are indicative of a transformation into secondary mineral phases, were not observed. All soils were strongly contaminated with Pb with minor concentrations of Cu, Ni, Cd, and Zn. Arsenic was rarely detected. The obtained results are indicated that the soils from the shooting range are contaminated with heavy metals and have evidences of different degree of anthropogenic Pb sources. This study is crucial for the evaluation of heavy metal-contaminated soils in shooting ranges and their environmental effect as well as for the establishment of management strategies for the mitigation of environmental risks.

scholarly journals Fractionation of Heavy Metals in Multi-Contaminated Soil Treated with Biochar Using the Sequential Extraction Procedure

Biomolecules ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 448
Author(s):  
Mahrous Awad ◽  
Zhongzhen Liu ◽  
Milan Skalicky ◽  
Eldessoky S. Dessoky ◽  
Marian Brestic ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Organic Matter ◽  
Soil Organic Matter ◽  
Soil Ph ◽  
Contaminated Soil ◽  
Contaminated Soils ◽  
Extraction Procedure ◽  
Sequential Fractionation ◽  
Relationship Of ◽  
The Relationship

Heavy metals (HMs) toxicity represents a global problem depending on the soil environment’s geochemical forms. Biochar addition safely reduces HMs mobile forms, thus, reducing their toxicity to plants. While several studies have shown that biochar could significantly stabilize HMs in contaminated soils, the study of the relationship of soil properties to potential mechanisms still needs further clarification; hence the importance of assessing a naturally contaminated soil amended, in this case with Paulownia biochar (PB) and Bamboo biochar (BB) to fractionate Pb, Cd, Zn, and Cu using short sequential fractionation plans. The relationship of soil pH and organic matter and its effect on the redistribution of these metals were estimated. The results indicated that the acid-soluble metals decreased while the fraction bound to organic matter increased compared to untreated pots. The increase in the organic matter metal-bound was mostly at the expense of the decrease in the acid extractable and Fe/Mn bound ones. The highest application of PB increased the organically bound fraction of Pb, Cd, Zn, and Cu (62, 61, 34, and 61%, respectively), while the BB increased them (61, 49, 42, and 22%, respectively) over the control. Meanwhile, Fe/Mn oxides bound represents the large portion associated with zinc and copper. Concerning soil organic matter (SOM) and soil pH, as potential tools to reduce the risk of the target metals, a significant positive correlation was observed with acid-soluble extractable metal, while a negative correlation was obtained with organic matter-bound metal. The principal component analysis (PCA) shows that the total variance represents 89.7% for the TCPL-extractable and HMs forms and their relation to pH and SOM, which confirms the positive effect of the pH and SOM under PB and BB treatments on reducing the risk of the studied metals. The mobility and bioavailability of these metals and their geochemical forms widely varied according to pH, soil organic matter, biochar types, and application rates. As an environmentally friendly and economical material, biochar emphasizes its importance as a tool that makes the soil more suitable for safe cultivation in the short term and its long-term sustainability. This study proves that it reduces the mobility of HMs, their environmental risks and contributes to food safety. It also confirms that performing more controlled experiments, such as a pot, is a disciplined and effective way to assess the suitability of different types of biochar as soil modifications to restore HMs contaminated soil via controlling the mobilization of these minerals.

scholarly journals Enhanced Electrokinetic Remediation for the Removal of Heavy Metals from Contaminated Soils

2021 ◽  
Vol 11 (4) ◽  
pp. 1799
Author(s):  
Claudio Cameselle ◽  
Susana Gouveia ◽  
Adrian Cabo
Keyword(s):  
Heavy Metals ◽  
Citric Acid ◽  
Organic Acids ◽  
Contaminated Soils ◽  
Electrokinetic Remediation ◽  
Deionized Water ◽  
Soil Specimen ◽  
Removal Of Heavy Metals ◽  
Ph Conditions ◽  
Neutral Metal

The electrokinetic remediation of an agricultural soil contaminated with heavy metals was studied using organic acids as facilitating agents. The unenhanced electrokinetic treatment using deionized water as processing fluid did not show any significant mobilization and removal of heavy metals due to the low solubilization of metals and precipitation at high pH conditions close to the cathode. EDTA and citric acid 0.1 M were used as facilitating agents to favor the dissolution and transportation of metals. The organic acids were added to the catholyte and penetrated into the soil specimen by electromigration. EDTA formed negatively charged complexes. Citric acid formed neutral metal complexes in the soil pH conditions (pH = 2–4). Citric acid was much more effective in the dissolution and transportation out of the soil specimen of complexed metals. In order to enhance the removal of metals, the concentration of citric acid was increased up to 0.5 M, resulting in the removal of 78.7% of Cd, 78.6% of Co, 72.5% of Cu, 73.3% of Zn, 11.8% of Cr and 9.8% of Pb.

scholarly journals Enhanced remediation of heavy metals contaminated soils with EK-PRB using β-CD/hydrothermal biochar by waste cotton as reactive barrier

Chemosphere ◽  
2021 ◽  
pp. 131470
Author(s):  
Yulin Li ◽  
Mengyu Shao ◽  
Manhong Huang ◽  
Wenjing Sang ◽  
Shengyang Zheng ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Contaminated Soils ◽  
Reactive Barrier ◽  
Enhanced Remediation
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