title: Performance of thermally activated dolomite for the treatment of Ni and Zn in contaminated neutral drainage.
abstract: Intensive research is ongoing for developing low-cost and highly efficient materials in metal removal from contaminated effluents. The present study evaluated dolomite [CaMg(CO3)2], both raw and modified by thermal activation (charring), for Ni and Zn treatment in contaminated neutral drainage (CND). Batch adsorption testing (equilibrium and kinetics) were conducted at pH 6, to evaluate the performance of initial vs. modified dolomite, and to assess potential mechanisms of metal removal. Charring of dolomite led to a rigid and porous material, mainly consisting of CaCO3 and MgO, which showed a sorption capacity increased sevenfold for Zn and doubled for Ni, relative to the raw material. In addition, Freundlich model best described the sorption of the both metals by dolomite, whereas the Langmuir model best described their sorption on charred dolomite. Plausible mechanisms of metal removal include cation exchange, surface precipitation and sorption processes, with carbonate ions and magnesium oxides acting as active centers. Based on these results, charred dolomite seems a promising option for the efficient treatment of Ni and Zn in CND.
authors.affiliation: Technology Center for Industrial Waste (CTRI- Centre Technologique des Résidus Industriels), 425 Boul. du College, Rouyn-Noranda, QC J9X 5E5, Canada; Research Institute on Mines and Environment (RIME), University of Quebec in Abitibi-Temiscamingue (UQAT), 445 Boul. de l'Universite, Rouyn-Noranda, QC J9X 5E4, Canada; College of Abitibi-Temiscamingue, 425 Boul. du College, Rouyn-Noranda, QC J9X 5E5, Canada.
authors.forename: Iuliana Laura
authors.initials: IL
authors.lastname: Calugaru
authors.affiliation: Research Institute on Mines and Environment (RIME), University of Quebec in Abitibi-Temiscamingue (UQAT), 445 Boul. de l'Universite, Rouyn-Noranda, QC J9X 5E4, Canada. Electronic address: Carmen-Mihaela.Neculita@uqat.ca.
authors.forename: Carmen Mihaela
authors.initials: CM
authors.lastname: Neculita
authors.affiliation: Technology Center for Industrial Waste (CTRI- Centre Technologique des Résidus Industriels), 425 Boul. du College, Rouyn-Noranda, QC J9X 5E5, Canada; Research Institute on Mines and Environment (RIME), University of Quebec in Abitibi-Temiscamingue (UQAT), 445 Boul. de l'Universite, Rouyn-Noranda, QC J9X 5E4, Canada.
authors.forename: Thomas
authors.initials: T
authors.lastname: Genty
authors.affiliation: Research Institute on Mines and Environment (RIME), University of Quebec in Abitibi-Temiscamingue (UQAT), 445 Boul. de l'Universite, Rouyn-Noranda, QC J9X 5E4, Canada.
authors.forename: Bruno
authors.initials: B
authors.lastname: Bussière
authors.affiliation: Technology Center for Industrial Waste (CTRI- Centre Technologique des Résidus Industriels), 425 Boul. du College, Rouyn-Noranda, QC J9X 5E5, Canada; College of Abitibi-Temiscamingue, 425 Boul. du College, Rouyn-Noranda, QC J9X 5E5, Canada.
authors.forename: Robin
authors.initials: R
authors.lastname: Potvin
keywords: Activated dolomite; Contaminated neutral drainage; Ni and Zn removal; Sorption