Lead removal from aqueous solutions by olive mill wastes derived biochar: Batch experiments and geochemical modelling

Zacharenia Kypritidou, Leila El-Bassi, Salah Jellali, Vasiliki Kinigopoulou, Evangelos Tziritis, Hanene Akrout, Mejdi Jeguirim, Charalampos Doulgeris*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract

In this study, lead removal from aqueous solutions using biochar derived from olive mill solid and liquid wastes has been investigated by applying batch experiments and geochemical modelling. The batch adsorption experiments included the assessment of several key parameters such as the contact time (kinetic), initial concentration (isotherm), pH, adsorbent dose, and the presence of competitive cations, whilst the geochemical modelling focused on the involved adsorption mechanisms using the PHREEQC code. The kinetic studies showed that lead adsorption is a relatively fast process, where intraparticle diffusion is the rate-limiting step. Biochar dose, solution pH and the presence of competitive ions significantly affected the Pb adsorption effectiveness by the biochar. Especially the higher Pb removal percentages were observed in mono-elemental solutions with high biochar dose at mildly acidic solution pH values. The maximum Pb adsorption capacity of biochar was estimated as 40.8 mg g−1 which is higher than various biochars derived from sludge, lignocellulosic and animal biomasses. On the other hand, the geochemical modelling employing the PHREEQC code showed that ion exchange and Pb precipitation are the main reactions controlling its removal from aqueous solutions, whilst surface complexation is insignificant, mainly due to the low surface functional groups on the used biochar.

Original languageEnglish
Article number115562
JournalJournal of Environmental Management
Volume318
DOIs
Publication statusPublished - Sep 15 2022

Keywords

  • Batch experiments
  • Biochar
  • Lead removal
  • Olive oil wastes
  • PHREEQC
  • Sorption mechanisms

ASJC Scopus subject areas

  • Environmental Engineering
  • Waste Management and Disposal
  • Management, Monitoring, Policy and Law

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