Use of citric acid for heavy metals extraction from contaminated sewage sludge for land application

2006 ◽  
Vol 54 (9) ◽  
pp. 129-135 ◽  
Author(s):  
D. del Mundo Dacera ◽  
S. Babel
Keyword(s):  
Heavy Metals ◽  
Citric Acid ◽  
Land Application ◽  
Metal Extraction ◽  
Lead Removal ◽  
Inorganic Matter ◽  
Highly Effective ◽  
Removal Of Heavy Metals ◽  
Anaerobically Digested Sludge ◽  
Extracting Agents

Recent studies revealed that organic acids such as citric and oxalic acids seemed to be more promising as chemical extracting agents for removal of heavy metals from contaminated sludge, since they are biodegradable and can attain a higher metal extraction efficiency at mildly acidic pH compared to other extracting agents. Results of a lab-scale study on the efficiency of citric acid in the extraction of chromium (Cr), copper (Cu), lead (Pb), nickel (Ni) and zinc (Zn) from anaerobically digested sludge, revealed that citric acid seemed to be highly effective in extracting Cr (at 100%), Cu (at 88%), Ni (at 98%) and Zn (at 100%) at pH 2.33, mostly at 5 days leaching time except for Cu and Zn, which are at 1 day and 2 h contact times respectively. Lead removal at the same pH was also high at 95% but at a longer leaching time of 11 days. At pH 3, citric acid seemed to be highly effective in extracting Pb (at 100%) at 1 day leaching time, although higher removals were also attained for Ni (70%) and Zn (80%) at only 2 h leaching time. Chemical speciation studies showed that Cr, Cu and Ni in the sludge sample seem to predominate in residual fractions, while Pb and Zn were found mostly bound to organic and inorganic matter forms, hence the potential of the sludge for land application.

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 Effect of Soil Washing Solutions on Simultaneous Removal of Heavy Metals and Arsenic from Contaminated Soil

2020 ◽  
Vol 17 (9) ◽  
pp. 3133 ◽  
Author(s):  
Kanghee Cho ◽  
Eunji Myung ◽  
Hyunsoo Kim ◽  
Cheonyoung Park ◽  
Nagchoul Choi ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Sulfuric Acid ◽  
Phosphoric Acid ◽  
Contaminated Soil ◽  
Contaminated Soils ◽  
Soil Washing ◽  
Metal Extraction ◽  
Simultaneous Removal ◽  
Removal Of Heavy Metals ◽  
Removal Efficiencies

In this study, we investigated the feasibility of using a solution of sulfuric acid and phosphoric acid as an extraction method for soil-washing to remove Cu, Pb, Zn, and As from contaminated soil. We treated various soil particles, including seven fraction sizes, using sulfuric acid. In addition, to improve Cu, Pb, Zn, and As removal efficiencies, washing agents were compared through batch experiments. The results showed that each agent behaved differently when reacting with heavy metals (Cu, Pb, and Zn) and As. Sulfuric acid was more effective in extracting heavy metals than in extracting As. However, phosphoric acid was not effective in extracting heavy metals. Compared with each inorganic acid, As removal from soil by washing agents increased in the order of sulfuric acid (35.81%) < phosphoric acid (62.96%). Therefore, an enhanced mixture solution using sulfuric acid and phosphoric acid to simultaneously remove heavy metals and As from contaminated soils was investigated. Sulfuric acid at 0.6 M was adopted to combine with 0.6 M phosphoric acid to obtain the mixture solution (1:1) that was used to determine the effect for the simultaneous removal of both heavy metals and As from the contaminated soil. The removal efficiencies of As, Cu, Pb, and Zn were 70.5%, 79.6%, 80.1%, and 71.2%, respectively. The combination of sulfuric acid with phosphoric acid increased the overall As and heavy metal extraction efficiencies from the contaminated soil samples. With the combined effect of dissolving oxides and ion exchange under combined washings, the removal efficiencies of heavy metals and As were higher than those of single washings.

Impact of solution variables on the removal of heavy metals from wastewaters by a recycled iron sorbent

2000 ◽  
Vol 42 (1-2) ◽  
pp. 347-352
Author(s):  
E.H. Smith ◽  
S. Chatterjee
Keyword(s):  
Heavy Metals ◽  
Oxalic Acid ◽  
Metal Speciation ◽  
Surface Finishing ◽  
Complexing Agents ◽  
Lead Removal ◽  
Adsorption Equilibria ◽  
Removal Of Heavy Metals ◽  
Cadmium And Lead ◽  
The Impact

Waste shot-blast fines from surface finishing processes have been demonstrated to be effective for removing heavy metals from solution by adsorption.The technology offers the potential for inexpensive recovery and reuse of a material normally discarded as a solid waste. While metal removals compare favorably with those achieved by commercial sorbents, applications issues such as the impact of background metal-complexing agents require investigation. The presence of oxalic acid, a complexing organic compound, impacted cadmium and lead adsorption in accordance with predictions from metal speciation equilibria; i.e., a small but measurable reduction in lead removal was observed, but cadmium adsorption was relatively unaffected. The effects were repeated in dynamic column experiments, with lead removals reduced by 15 to 20% in the presence of the ligand. Efforts to model adsorption equilibria in the presence of oxalic acid did not fully capture the reduced lead removal, presumably because the model does not consider the complete formation of metal-oxalic acid complexes prior to contact with the sorbent.

scholarly journals Chemical and Biological Leaching Methods to Remove Heavy Metals from Sewage Sludge: A Review

2008 ◽  
Vol 4 (3) ◽  
pp. 509-517
Author(s):  
Lugard N. Ukiwe ◽  
Allinor J.I ◽  
Ejele A.E ◽  
Anyadiegwu C.I.C ◽  
Ibeneme S.I
Keyword(s):  
Heavy Metals ◽  
Sewage Sludge ◽  
Thiobacillus Ferrooxidans ◽  
Extraction Procedure ◽  
Metal Extraction ◽  
High Yield ◽  
Chemical Leaching ◽  
Solids Concentration ◽  
Acid Consumption ◽  
Removal Of Heavy Metals

The removal of heavy metals (HMs) in sewage sludge (SS) is important since sludge is often disposed or applied on farmland to enhance soil fertility. The present study reviewed two conceptual approaches (chemical and biological leaching) of removing HMs present in SS. In the chemical leaching method, traditional acid treatment together with novel methods such as aeration, complexation and sequential extraction procedure have been reviewed extensively. Certain factors influence the removal of HMs in SS. These factors include; pH, leaching agent, redox potential, and contact time. Nitric acid (HNO3), hydrochloric acid (HCl), sulphuric acid (H2SO4), phosphoric acid (H3PO4), ethylenediamine tetraacetic acid (EDTA), as well as Thiobacillus thiooxidans and Thiobacillus ferrooxidans are the most widely studied leaching agents and substrates involved in the chemical and bioleaching processes. However, the bioleaching process has been proposed as a safe, efficient, economical, environmental friendly method to remove HMs in SS due to its simplicity, high yield of metal extraction, low acid consumption, and low sludge solids concentration. Nevertheless, the present review has noted that most researchers are of the opinion that more studies are needed in the bioleaching method in order to enhance its commercial attraction.  

scholarly journals Removal of heavy metals from green mussels (Perna viridis) using pineapple (Ananas comosus) solution as a source of citric acid

2021 ◽  
Vol 919 (1) ◽  
pp. 012041
Author(s):  
F Swastawati ◽  
S R Rizkirana ◽  
Romadhon ◽  
M Muniroh ◽  
Mulyono ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Citric Acid ◽  
Metal Content ◽  
Ananas Comosus ◽  
Perna Viridis ◽  
Green Mussel ◽  
Icp Ms ◽  
Removal Of Heavy Metals ◽  
Excessive Consumption ◽  
Ph Level

Abstract Green mussel is a type of shellfish that is widely consumed by humans. Excessive consumption of green mussels can be harmful to health because they are prone to contain heavy metals. One of the methods to reduce the heavy metal content of green mussels is to use citric acid in the pineapple solution. The Green mussel was soaked in pineapple solution for 30 min, 60 min and 90 min. The content of heavy metals such as Pb, Cd, and As was analyzed by ICP-MS. The results showed that after soaking green mussels in pineapple solution for 30 minutes, they reduced 85% Pb, 80,95% Cd, and 53,23% As. The duration of soaking green mussels in pineapple solution for 30 minutes overall had a better quality than soaking for 60 and 90 minutes, with a moisture content of 74,43 + 0,39 (%), protein content 15,21 + 0,35 (%), pH level 6,74 + 0,10, organoleptic with a confidence interval of 7,48<μ< 7,54.

Preparation and application of Fe3O4@Acetamidoxanthate as a unique nanosorbent in heavy metal removing

2021 ◽  
pp. 1-11
Author(s):  
Mohammad Moein Mohareri ◽  
Mehdi Ghaffari ◽  
Elham Sattarzadeh ◽  
Saeed Kakaei
Keyword(s):  
Heavy Metals ◽  
Chelating Agents ◽  
High Efficiency ◽  
Fourier Transforms ◽  
Metal Extraction ◽  
Removal Of Heavy Metals ◽  
Ft Ir ◽  
Temperature Time ◽  
Widespread Interest ◽  
Nano Adsorbent

Chelating agents are one of the most important substances in metal extraction, but separation is the main problem in the use of these agents as an adsorbent. After the adsorption of metals by an external magnet, magnetic NPs provide the possibility of easy collecting and isolating the adsorbent nanomaterial for many applications. Given the immense importance of magnetic NPs, there has been widespread interest in accessing the above adsorbent. In the present study, an attempt was made to synthesize acetamido xanthate which was coupled to NPs and has the potential to be used as a nano-adsorbent for the removal of heavy metals. This novel nano sorbent was characterized by scanning electron microscopy (SEM), Fourier transforms infrared (FT-IR), and Nuclear Magnetic Resonance (NMR) spectroscopy. The effect of some parameters such as temperature, time, pH, and the amount of adsorbent on the extraction reaction was investigated. The optimized condition for extraction of cerium was temperature of 30°C, pH = 8, reaction time of 45 minutes using 7.5 mg of the prepared nanosorbent, that in such condition the yield of reaction achieved up to 97%. The prepared adsorbent showed high efficiency in the adsorption of heavy metals specifically.

Enhanced Electrokinetic Removal of Heavy Metals in MSWI Fly Ash Assisted by Cation Exchange Membranes

2011 ◽  
Vol 84-85 ◽  
pp. 626-630 ◽  
Author(s):  
Xi Peng ◽  
Bin Quan Jiao ◽  
Lin Yu ◽  
Dong Wei Li ◽  
Ke Yang
Keyword(s):  
Heavy Metals ◽  
Fly Ash ◽  
Cation Exchange ◽  
Electroosmotic Flow ◽  
Metal Extraction ◽  
Mswi Fly Ash ◽  
Assisted Extraction ◽  
Removal Of Heavy Metals ◽  
Trial Test ◽  
Exchange Membrane

Since MSWI fly ash enriches heavy metals and many toxic components and these components would potentially leach when the ashes are land filled, it is regulated as hazardous waste in many countries. Electrokinetic removal, an electrochemically assisted extraction method, has recently been adopted as a new method for removal of heavy metals from MSWI fly ashes. But the generation of metal hydroxide precipitation near the cathode decreased conductivity of electrokinetic removal system and limited metal extraction from the sample area. In this study, cation exchange membrane was used in electrokinetic removal experiment to improve this method. After 192 hours of electrokinetic removal, about 15%Cd,20%Pb, 30% Zn, and 10% As was removed from 2.850kg MSWI fly ash. It showed positive effect compared to the trial test. But there still exists some problems, such as low removal efficiency. Further work should be done to solve it.Moreover, the high conductivity in fly ash limits the current , which in turn causes low electroosmotic flow. While electroosmotic flow is the main factor leting the heavy meatals release from fly ash, it would become the focus in further experiment to look for ways increasing the electroosmotic flow in sample cell.

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