Immobilization of Pb Contaminated Soil using Modified Clay

2006 ◽  
Vol 1 (2) ◽  
Author(s):  
J. H. Park ◽  
W. S. Shin
Keyword(s):  
Sequential Extraction ◽  
Sorption Capacity ◽  
Contaminated Soil ◽  
Contact Time ◽  
Natural Soil ◽  
Modified Clay ◽  
Modified Clays ◽  
Mobile Fraction ◽  
Natural Clays ◽  
Reducible Fraction

Natural clays (i.e., montmorillonite and diatomite) modified by iron and manganese oxide were used as immobilization agents for the remediation of Pb contaminated soil. Batch sorption experiments were conducted to investigate the effect of surface modification on Pb sorption. Pb sorption capacity in modified clays was higher than that in natural clays. Pb sorption capacity in modified and unmodified clays was in the order of Mn-diatomite (1.967 mmol/g) > Mn-montmorillonite (0.718 mmol/g) > Fe-diatomite (0.457 mmol/g) > Fe-montmorillonite (0.330 mmol/g) > montmorillonite (0.233 mmol/g) > diatomite (0.025 mmol/g). Effects of modified clay amendment and ageing (or contact time) on immobilization of Pb were evaluated by a toxicity characteristic leaching procedure (TCLP) and sequential extraction. An artificially polluted natural soil (APNS) with Pb (59.72 mmol Pb/kg soil) was used in immobilization experiment. Lead immobilization efficiency in APNS with modified clay was in the order of Mn-montmorillonite (93%) > Mn-diatomite (86%) > Fe-montmorillonite (81%) > Fe-diatomite (80%). Among the tested modified clays, Mn-montmorillonite was the most efficient in Pb immobilization. Results of sequential extraction of Pb from APNS after immobilization with modified clays indicate that mobile fraction (i.e., exchangeable and carbonate fraction) decreased as contact time increased, while less mobile (i.e., reducible) fraction increased from 27% to 60% of the total amount extracted. This indicates that addition of modified clay to APNS transforms Pb in mobile fraction into reducible fraction.

scholarly journals An Assessment of Heavy Metal Contamination in the Nakdong River Around the Weir

Water ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 684
Author(s):  
Hee Won Son ◽  
Sun Hee Shim ◽  
Haeseong Oh ◽  
Jung Hyun Choi
Keyword(s):  
Heavy Metals ◽  
Sequential Extraction ◽  
Environmental Protection Agency ◽  
Heavy Metal Contamination ◽  
Environmental Research ◽  
Residual Fraction ◽  
Nakdong River ◽  
Risk Assessment Code ◽  
The Nakdong River ◽  
Reducible Fraction

In this study, the concentrations and characteristics of copper (Cu), zinc (Zn), and lead (Pb) contamination in sediment samples were investigated using aqua regia extraction and Tessier’s five-step sequential extraction. Based on the concentration of metals, the influence of the Hapcheon-Changnyeong weir on sediments in the Nakdong River was assessed. The origins of the contaminants, their bioavailability, and their mobility were determined using sequential extraction. Greater concentrations of heavy metals were found in samples collected closer to the weir. The largest proportion of Cu was identified in the residual fraction based on sequential extraction, whereas Zn was predominantly found in the reducible fraction. Iron-manganese in the reducible fraction of Zn has the potential to leach back to the water body. In addition, the combined concentration of fractions 1 and 2 of Cu comprised more than 20% of total amount that still has potential to affect the water quality. The results of this study were compared with existing sediment standards set out by the NIER (National Institute of Environmental Research), Canada, and US EPA (United States Environmental Protection Agency) guidelines, as well as the risk assessment code (RAC). The concentrations of heavy metals exceeded the standards set by the Canadian guideline by up to four times in particular samples, highlighting the need for continual monitoring.

Research on the Morphological of Lead and Zinc in the Smelting Slag

2015 ◽  
Vol 1088 ◽  
pp. 200-205
Author(s):  
Lin Yu ◽  
Dong Wei Li
Keyword(s):  
Heavy Metals ◽  
Sequential Extraction ◽  
Ecological Risk ◽  
Total Content ◽  
Residual Fraction ◽  
Bcr Sequential Extraction ◽  
Lead And Zinc ◽  
Smelting Slag ◽  
Reducible Fraction

In this paper analysed the forms of heavy metals (Zn Pb Cd and As) of the Smelting Slag for Lead and Zinc,using BCR sequential extraction. Different chemical morphological of heavy metals have different activity and harmfulness. Migration and Utilization of heavy metals were decided by the existent form of heavy metals in the soil,which influenced Bioactivity and Toxicity. The results show that the main forms of Zn and Cd are Oxidizable and Residual fraction, and Pb mainly occurred in Oxidizable and Reducible fraction. however, As mainly occurred in Residual fraction, which the percentage of reachs 99.56%. According to the percentage of fractions extracted in total content (As is 0.44%, Zn is 14.7%, Pb is 85.98%, Cd is 48.86%),the latent ecological risk of heavy metals varied in the descending order of,Pb Cd Zn and As.

scholarly journals The Determination of Chemical Forms of Heavy Metals in Shooting Area Contaminated Soil Using Sequential Extraction Method

2015 ◽  
Vol 20 (6) ◽  
pp. 111-116 ◽  
Author(s):  
Gyeonghye Moon ◽  
Hongki Park ◽  
Kyoungkeun Yoo ◽  
Jha Manis Kumar ◽  
Alorro Richad Diaz ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Sequential Extraction ◽  
Contaminated Soil ◽  
Extraction Method ◽  
Chemical Forms ◽  
Sequential Extraction Method

DDT-Contaminated Soil Treatment with Persulfate and Hydrogen Peroxide Utilizing Different Activation Aids and the Chemicals Combination with Biosurfactant

2012 ◽  
Vol 15 (1) ◽  
Author(s):  
Anna Goi ◽  
Marika Viisimaa ◽  
Oleksandr Karpenko
Keyword(s):  
Hydrogen Peroxide ◽  
Contaminated Soil ◽  
Soil Treatment ◽  
Natural Soil ◽  
Persulfate Oxidation ◽  
Oxidation Processes ◽  
Combined Application ◽  
Chemical Oxidants ◽  
Effective Option ◽  
Magnesium Peroxide

AbstractThe efficacy of DDT-contaminated soil treatment with hydrogen peroxide and persulfate utilizing different activation aids and the chemicals combination with biosurfactant was evaluated. The addition of a supplementary activator was able to improve the degradation of total DDT with both the hydrogen peroxide and persulfate oxidation processes indicating a lack of available activator. Ferrous iron added gradually was effectively utilized in the oxidation system with gradual addition of hydrogen peroxide, while chelated metal iron addition promoted the oxidation with more stable persulfate. The treatment with solid carriers of hydrogen peroxide, either calcium peroxide or magnesium peroxide, can be an effective alternative to the liquid one resulting in a higher degradation level of the contaminant. Strong alkalization with elevated dosages of NaOH sustained the persulfate oxidation of DDT. The addition of biosurfactant, rhamnolipid-alginate complex obtained by biosynthesis of strain Pseudomonas sp. PS-17, and EDTA improved the degradation of DDT by both persulfate and hydrogen peroxide oxidation processes indicating that the combined application of chemical oxidants and biosurfactant at natural soil pH has prospects as an effective option for contaminated soil remediation.

Adsorption of CuCl2 on Mg-Al HTlc: Effect of EDTA and Addition Sequences

2012 ◽  
Vol 573-574 ◽  
pp. 150-154
Author(s):  
Yun Bo Zang ◽  
Nai Ying Wu
Keyword(s):  
Aqueous Solutions ◽  
Sorption Capacity ◽  
Contact Time ◽  
Room Temperature ◽  
Copper Ions ◽  
Sorption Process ◽  
Langmuir Model ◽  
Maximum Sorption Capacity ◽  
Maximum Sorption ◽  
Pseudo Second Order

In this study, removal of copper ions from aqueous solutions by synthetic Mg-Al-HTlc was investigated as a function of contact time, EDTA and addition sequences at room temperature. It is found that HTlc could reduced copper ions concentration effectively. The kinetics closely fit pseudo-second order kinetics with necessary time 9 h to reach equilibrium. The sorption process followed langmuir model. The maximum sorption capacity calculated was found to be 39.4 mg/g. The presence of EDTA and addition sequences could affect sorption of Cu(II) onto HTlc.

scholarly journals Evaluation of Acid Leaching on the Removal of Heavy Metals and Soil Fertility in Contaminated Soil

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Chen-Yao Chu ◽  
Tzu-Hsing Ko
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Seed Germination ◽  
Soil Fertility ◽  
Sequential Extraction ◽  
Contaminated Soil ◽  
Contaminated Soils ◽  
Germination Rate ◽  
Extraction Procedure ◽  
Acid Leaching

Heavy metal-contaminated soils were leached with various acid reagents, and a series of treatments was assessed to understand soil fertility after acid leaching. Aqua regia digestion and a five-step sequential extraction procedure were applied to determine heavy metal distribution. The average total concentrations of Zn, Cd, Cu, and Pb for contaminated soil were 1334, 25, 263, and 525 mg·kg−1 based on the ICP/AES quantitative analysis. Other than Pb extracted by H2SO4, over 50% removal efficiency of other heavy metals was achieved. A five-step sequential extraction revealed that the bound-to-carbonate and bound-to-Fe-Mn oxides were the major forms of the heavy metals in the soil. The addition of organic manure considerably promoted soil fertility and increased soil pH after acid leaching. Seed germination experiments demonstrated that after acid leaching, the soil distinctly inhibited plant growth and the addition of manure enhanced seed germination rate from 35% to 84%. Furthermore, the procedure of soil turnover after acid leaching and manure addition greatly increased seed germination rate by 61% and shortened the initial germination time. Seed germination in untreated soil was superior to that in acid-leached soil, illustrating that the phytotoxic effect of acid leaching is more serious than that of heavy metals.

scholarly journals Fractionation and Mobility of Lead in Klity Creek Riverbank Sediments, Kanchanaburi, Thailand

2015 ◽  
pp. 1-10 ◽  
Author(s):  
Teerawit Poopa ◽  
Prasert Pavasant ◽  
Vorapot Kanokkantapong ◽  
Bunyarit Panyapinyopol
Keyword(s):  
Sequential Extraction ◽  
Lead Concentration ◽  
Sediment Contamination ◽  
Risk Level ◽  
Medium Risk ◽  
Sequential Extraction Method ◽  
Contamination Levels ◽  
Living Organisms ◽  
Reducible Fraction ◽  
Polluted Zone

The sequential extraction method was employed to investigate the distribution and chemical fractions of lead (Pb) in Klity Creek sediments, Kanchanaburi, Thailand with the main objective to define the lead mobility in sediment and potential bioavailability in relation to sediment contamination levels. Samples were collected from a total of twelve sampling sites distributed from upstream of the polluted zone until the final downstream point at Srinakarin Reservoir. The results showed that the background value of total lead concentration in the sediments from this area was higher than those reported from other locations in Thailand. Sequential extraction results revealed that lead was mainly associated with the reducible fraction especially in the polluted zone in the vicinity of the ore dressingplant. This is different from the distribution of lead fractions upstream and downstream of the polluted area, i.e. reducible fraction was the major component upstream whereas strongly dissociated fractions (oxidizable and residual) were the major components for the downstream samples (at Srinakarin Reservoir). A significant amount of the lead fraction in the study area was rather mobile, suggesting it as readily available to living organisms. Most samples exhibited a medium risk level with Risk AssessmentCode (RAC) values of more than 10%.

scholarly journals Bio-sorption for Effective Removal of Chromium (VI) from Wastewater Using Moringa Stenopetala Seed Powder (MSSP) and Banana Peel Powder (BPP)

2020 ◽  
Author(s):  
Tolera Seda Badessa ◽  
Esayas Wakuma ◽  
Ali Mohammed Yimer
Keyword(s):  
Sorption Capacity ◽  
Contact Time ◽  
Metal Ion ◽  
Ion Concentration ◽  
Banana Peel ◽  
Order Kinetic ◽  
Moringa Stenopetala ◽  
Kinetics Of Adsorption ◽  
Banana Peel Powder ◽  
Adsorbent Dose

Abstract Chromium is an extremely toxic metal in the form of Cr (VI) that causes severe environmental and health problems. Therefore, the aim of this study was to remove chromium ions from wastewater by using cost effective and environmentally friendly bio-sorbents; Moringa stenopetala Seed Powder (MSSP), and Banana Peel Powder (BPP) and to evaluate its adsorption capacities as bio-sorbents. FT-IR characterization of the adsorbents showed that there was a change in the functional groups of the structure of both adsorbents before and after the adsorption that might be due to the adsorption processes taken place on the surface of adsorbent. Adsorption experiments were carried out as batch studies with different contact times, pH, adsorbent dose, initial metal ion concentration, and temperature. Results showed maximum removal efficiency for Cr (VI) at 120 minutes contact time, adsorbent dose of 20 g/L and pH 2 by MSSP and pH 4 by BPP. The percentage removal of Cr(VI) increased with increasing adsorbent dose( from 5g/L to 20 g/L) and contact time (from 60 min to 120 min). Freundlich isotherm model showed a better fit to the equilibrium data than the Langmuir model. The kinetics of adsorption for chromium was well represented by pseudo-second order kinetic model and the calculated equilibrium sorption capacity of the model showed good agreement with the sorption capacity obtained from Experimental results.

scholarly journals Efficacy of Vermiremediation to Remove Contaminants from Soil

2021 ◽  
Vol 11 (29) ◽  
Author(s):  
Ebenezer Olasunkanmi Dada ◽  
Modupe Olatunde Akinola ◽  
Stephen Olugbemiga Owa ◽  
Gabriel Adewunmi Dedeke ◽  
Adeyinka A. Aladesida ◽  
...  
Keyword(s):  
Environmental Health ◽  
Contaminated Soil ◽  
Organic Contaminants ◽  
Crop Production ◽  
Organic Wastes ◽  
Natural Soil ◽  
Inorganic Contaminants ◽  
Growth And Survival ◽  
Financial Interests ◽  
Academic Publications

Background. In addition to improving soil fertility and crop production, earthworms have been found to be useful in the removal of contaminants from soil, known as vermiremediation. Previous studies on vermiremediation have focused primarily on organic wastes, with relatively less attention paid to inorganic contaminants. In addition, some basic terms used in environmental health studies have often not been properly clarified. Objectives. The present study is a review of the state of the literature on the effectiveness of using earthworms to remediate organic and inorganic (metal) soil contaminants. Earthworms’ actions in remediation of organic and inorganic contaminants are described. Some terms that are used interchangeably in environmental health are clarified. The challenges and limitations of vermiremediation are highlighted. Methods. A systematic literature search was conducted to access online academic publications indexed in Google Scholar, PubMed, Scopus, Clarivate Analytics (Web of Science), ScienceDirect, ResearchGate and Springer Link. A total of 165 publications on the subject matter were accessed, out of which 47 were used for the review. Discussion. Empirical and theoretical information from the literature showed evidence of the significant contributions of earthworms to the removal of soil organic contaminants and metals. Earthworms indirectly facilitate the conversion of organic contaminants by promoting microbial and enzyme activities. Some organic contaminants are directly taken up through dermal and intestinal absorption and accumulated by preferential sequestration in sub-organismic and tissue fractions of earthworms. Metals are directly removed and accumulated by the mechanism of detoxification and sequestration, via metallothioneins induction. The terms ‘contaminants’ and ‘pollutants’ have different meanings and should not be used interchangeably. Although vermiremediation presents an ideal clean-up technique, it is limited in application to only mildly contaminated soil environments. Ethical concerns should not pose a serious issue because vermiremediation simply takes advantage of earthworms’ natural soil-conditioning abilities. Many vermiremediation processes, especially of organic wastes, are harmless to earthworms, improving the soil for their growth and survival. Conclusions. Vermiremediation presents a good long-term biological option to clean up mildly contaminated soil. It may be deployed as a secondary measure to rid the soil of residual contaminants after applying physicochemical remediation techniques to an overtly polluted soil environment. Competing Interests. The authors declare no competing financial interests.

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