Humified insoluble solid for efficient decontamination of nickel and lead in industrial effluents

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• 作者：Andr茅s Calder铆n Garc铆a ; Fern ; o Guridi Izquierdo ; Nelson Moura Brasil de Amaral Sobrinho ; Rosane Nora Castro ; Le ; ro Azevedo Santos ; Luiz Gilberto Ambrosio de Souza ; Ricardo Luis Louro Berbara
• 关键词：Heavy metals ; Vermicompost ; Retention ; Wastewater
• 刊名：Journal of Environmental Chemical Engineering
• 出版年：December, 2013
• 年：2013
• 卷：1
• 期：4
• 页码：916-924
• 全文大小：952 K

文摘

The aim of the present study was to evaluate the ability to retain heavy metals cations (Ni²⁺ and Pb²⁺) from humified insoluble solid (HIS) that remains after the humic substances (HS) are extracted from a vermicompost (VC) in industrial wastewaters. HIS has ionizable functional groups and carbon types belonging to oxygen structures (di-OAlkylC, OAromatic, COOH, CO) with potential to establish interactions with heavy metals cations in aqueous dissolution. The kinetic study showed a pseudo-second-order behavior of retention, and the adsorption was best described when data were analyzed using the Freundlich isotherm. The Q_max for Ni²⁺ and Pb²⁺ was 34.1 mg g^鈭? (HIS) and 151.1 mg g^鈭? (HIS). Scanning electron microscopy (SEM) confirmed the retention of heavy metals on the HIS surface; additionally, the spectra of HIS with retained metals indicated the involvement of the oxygen groups in the interaction with metals. The effectiveness of HIS to retain Ni²⁺ and Pb²⁺ was determined in retention studies with industrial effluents in lab conditions with 5 g, 10 g and 20 g, pH 7, contact time: 150 min and T = 25 掳C. Tests made with industrials wastewater 鈥淔actory of White Ceramic鈥?showed that the extraction capability of Ni²⁺ and Pb²⁺ was 98% and 96%, respectively. These results demonstrate for the first time, the ability of the (HIS) material to be used as remover of heavy metal cations.