Central composite design optimization of zinc removal from contaminated soil, using citric acid as biodegradable chelant

Farrokh Asadzadeh*, Mahdi Maleki-Kaklar, Nooshin Soiltanalinejad, Farzin Shabani

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

29 Citations (Scopus)
3 Downloads (Pure)

Abstract

Citric acid (CA) was evaluated in terms of its efficiency as a biodegradable chelating agent, in removing zinc (Zn) from heavily contaminated soil, using a soil washing process. To determine preliminary ranges of variables in the washing process, single factor experiments were carried out with different CA concentrations, pH levels and washing times. Optimization of batch washing conditions followed using a response surface methodology (RSM) based central composite design (CCD) approach. CCD predicted values and experimental results showed strong agreement, with an R2 value of 0.966. Maximum removal of 92.8% occurred with a CA concentration of 167.6 mM, pH of 4.43, and washing time of 30 min as optimal variable values. A leaching column experiment followed, to examine the efficiency of the optimum conditions established by the CCD model. A comparison of two soil washing techniques indicated that the removal efficiency rate of the column experiment (85.8%) closely matching that of the batch experiment (92.8%). The methodology supporting the research experimentation for optimizing Zn removal may be useful in the design of protocols for practical engineering soil decontamination applications.

Original languageEnglish
Article number2633
Number of pages8
JournalScientific Reports
Volume8
DOIs
Publication statusPublished - 8 Feb 2018
Externally publishedYes

Bibliographical note

Copyright the Author(s) 2018. Version archived for private and non-commercial use with the permission of the author/s and according to publisher conditions. For further rights please contact the publisher.

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