Alum sludge as an efficient sorbent for hydrogen sulfide removal: Experimental, mechanisms and modeling studies. (June 2020)

• Record Type: Journal Article
• Authors: Ren, Baiming; Lyczko, Nathalie; Zhao, Yaqian; Nzihou, Ange
• Is Part Of: Chemosphere. Volume 248(2020)
• Publication Date: 2020-06
• Subjects: Adsorption -- Alum sludge -- Breakthrough curves -- Desulfurization -- Fixed-bed reactor -- Mass transfer coefficient; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2020.126010
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: This paper firstly reported a systematic study of using alum sludge (waterworks residue) for H2 S adsorption. Various trials were performed at ambient temperature in a fixed bed column to study the effects of H2 S flow rate, sorbent bed depth on the alum sludge adsorption efficiency of H2 S. The Breakthrough Curves were simulated by the Thomas model, Bed Depth Service Time model and Yoon-Nelson models. The mechanisms of H2 S adsorption onto alum sludge was examined by different physiochemical characterizations of exhausted and raw alum sludge. Moreover, the mass transfer coefficients were determined from mathematical descriptions of breakthrough curves. The alum sludge adsorption capacity was determined to be 374.2 mg of H2 S/g, slightly decreasing with the increasing flow rate and increasing with the increasing bed depth. All the three models successfully predict breakthrough curves which could be used for scaling-up purposes. The microporous structure, alkaline pH and the inherent metal species of the alum sludge promoted the formation of metal sulphate species. This study demonstrated that alum sludge could be used as cost-effective, largely available, and efficient sorbent for H2 S removal. Graphical abstract: Image 1 Highlights: First study of reusing alum sludge for H2 S adsorption. The effect of flow rate and bed depth were investigated. The adsorption mechanisms were proposed. Three kinetic adsorption models were applied for breakthrough behavior simulation. Mass transfer coefficients of the sorbent were determined.