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1

Removal of Chromium Contaminated Soils by Electro-Kinetic Method

100%

Jameel S. R. , Saeed K. A. , Hawal L. H.

Journal of Ecological Engineering

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2024

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tom Vol. 25, nr 9

182--189

EN

Chromium-contaminated soil is a serious environmental problem that threatens human health and the environment. Electrokinetic technology is used as a promising solution to treat these soils, as it relies on applying an electric field to remove pollutants from the soil. In this study, four experiments were conducted, where experiments have shown that the use of wheat straw as an available, cheap, economical and efficient adsorbent material to prevent the occurrence of reverse osmosis. The results showed that the percentage of removal increased with the increase in the acidity of the medium, that is, as the pH decreased. This is due to an increase in the movement of pollutants as the soil particles become more positively charged, which enhances Attract negative heavy metal ions. This leads to increased movement of heavy metal ions into soil pores, making them more susceptible to transport under the influence of an electric field. The results proved that when using a disinfection solution with a pH of 2, it gave a higher result compared to pH 7 and 12, where the percentage of removal was 78.3%, 62.6 %, and 51.9% respectively. The dissolution of these metals can be enhanced by adding oxalic acid at a constant voltage gradient 1.2 v/cm and an initial concentration of 200 mg/kg. It was noted after the end of the experiment that the percentage of removal reached 81.9%, as the concentration of metals on the cathode side was higher than on the cathode side. The anode, and this is due to the migration of metals under the influence of electromigration to the cathode side, where the chromium concentration was 47 mg/kg at the cathode side, 27 mg/kg at the anode side.

2

Cadmium Removal from Contaminated Soil by Electro-Kinetic Method

100%

Hawal L. H. , Al-Sulttani A. O. , Hamza J. N.

Journal of Ecological Engineering

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2023

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tom Vol. 24, nr 1

79--86

EN

For this study, an electro kinetic method used to eliminate cadmium from the polluted soil. This method is useful at low permeability medium. Several experiments were conducted with variable operating circumstances, using different pH purging solutions. Rice husks were used in this work as an adsorbent medium available and free of charge to counteract the reverse osmosis process that occurs and affects the work efficiency. The final results after the end of the practical experiments of this process showed that the percentages of the removal process began to increase after the pH gradually decreases. The pH of the solution for the three experiments conducted was 3, 6 and 9, respectively. The best removal rate was 68% in this process at pH 3 ; when compared with the second and third tests at pH 6 and 9, the removal ratios were 58% and 51.5%, respectively. It was discovered that the cadmium removal rate began to decrease along with voltage. At 30 volts the removal rates were 68%, whereas 20 volts they were 66%. Rice husks have been shown to be an effective adsorbent for counteracting reverse osmosis. Therefore, it can be successfully used as an adsorbent medium.

3

Electro-Kinetic Remediation of Nickel from Contaminated Soil Using Bio remedies Banana Peels and Surfactant-Enhanced

100%

Hawal L. H. , Al-Zubaidi L. , Allah S. A.

Journal of Ecological Engineering

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2021

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tom Vol. 22, nr 5

214--220

EN

Pollution of the soil by different types of heavy metals is one of the most important problems of the environment. The present study used an electro-kinetic remediation, which is one of the important advanced techniques for the removal nickel from contaminated sandy soil. The study includes many experiments with different pH electrode purging solutions (distilled water at pH of 3, 5 and 7). Anionic surfactant (sodium dioctyl sulfosuccinate, AOT) was used for washing soil as surfactant-enhanced remediation. Bio remedies banana peels (BP) were utilized as eco-friendly, low cost and adsorbent materials to avoid reverse osmosis that effects on the removal process. The results indicated that the greatest removal efficiency (65.2%) was achieved at the pH of purging solution (3) in comparison with pH of (5 and 7). This means that when the pH of the purging solution decreases, the removal efficiency increases. Using AOT as a soil-washing solution increased nickel dissolution and desorption from surface of the soil. Then, the AOT micelles containing nickel easily migrated to the cathode chamber by flow of the electro osmotic; thus, the removal efficiency increased (74.8%). In conclusion, the use of AOT is effective in enhancing nickel removal through the electro kinetic remediation. Bio remedies using banana peels is considered as a successful adsorbent material to avoid the reverse osmosis flow, this will give a new thought for the application these products as adsorption medium.

4

Adsorption of Lead Ions from Aqueous Solutions onto Rice Husks, Continuous System

100%

Hawal L. H. , Al-Sulttani A. O. , Kariem N. O.

Journal of Ecological Engineering

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2021

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tom Vol. 22, nr 10

269--274

EN

The continuous system of lead adsorption on rice husks was investigated in this paper. A fixed bed study was performed in many tests to investigate the influence of pH, the adsorbent height, the initial concentration of lead, the flow rate and processing time on the lead adsorption process. The results demonstrated that the lead removal capacity decreased when the pH value of the solution and the flow rate increased. The lead removal capacity increased due to the decreased initial concentration of lead. The results showed that the removal capacity increases along with the processing time and the adsorbent height in column. The largest removal was (81%) at pH of 4, the adsorbent height (50 cm), the initial concentration of lead (10 mg/l), the processing time (90 min.) and the flow rate (10 ml/min.). As a result, rice husks can be used to remove the lead instead of expensive commercial adsorbents, due to its availability, inexpensive and perfect adsorption property.

5

Chromium Elimination from Contaminated Soil by Electro-Kinetic Remediation, Using Garlic Peels Powder

100%

Hawal L. H. , Al-Sulttani A. O. , Kariem N. O.

Journal of Ecological Engineering

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2021

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tom Vol. 22, nr 7

252--259

EN

In this paper, an electro-kinetic technique was applied to remove chromium from contaminated soil. This technique is appropriate for the soils with low permeability. Various experiments were carried out under different operating conditions, including various purging solutions. Garlic peels powder (GPP) was used in this study as a cheap adsorbent substance to avert the flow of reverse osmosis, which may affect the removal percentage. The results proved that the removal percentage increased as the pH of the purging solutions decreased. The first three experiments were performed with purging solution at pH of 4, 6, and 8 respectively. The highest removal percentage was 66.3% at pH of 4 compared to the other two experiments at pH of 6 and 8, where the removal percentages were 53.3% and 49.7%, respectively. This paper showed that the percentage of chromium removal decreased along with the voltage. The removal percentage at 1.5 V/cm was 66.3%, while at 1 V/cm was 61%. Garlic peels powder (GPP) is considered as an effective adsorbent material to avert the reverse osmosis flow. Therefore, the use of this material in this study will give a new impression on the application of these products as an absorbent medium.