title: Simultaneous adsorption of methyl red and methylene blue onto biochar and an equilibrium modeling at high concentration.
abstract: Methyl red, methylene blue and biochar were used to investigate simultaneous adsorption of dyes onto low-cost adsorbent at different concentrations combinations. Langmuir mixed model could describe the adsorption well at low concentrations. However, it could not describe the adsorption anymore when concentrations of methyl red and methylene blue were higher than 255 and 300 mg L(-1) respectively with 0.5 g L(-1) biochar loading. A new model on the interaction among adsorbed adsorbates at equilibrium was developed. It could describe the adsorption at high concentrations well. According to the experimental results, interaction among dyes molecules would replace the competition onto adsorbent to be the main factor influencing adsorption when amount of adsorbed adsorbates were higher than those required to form a monolayer on all the adsorbing sites of adsorbent. The model was further verified by adsorption with other solute such as glucose or NaCl in solution.
authors.affiliation: School of Environmental Engineering, Wuhan Textile University, Wuhan, 430073, PR China.
authors.forename: Guanyu
authors.initials: G
authors.lastname: Ding
authors.affiliation: School of Environmental Engineering, Wuhan Textile University, Wuhan, 430073, PR China. Electronic address: wbuyun@126.com.
authors.forename: Buyun
authors.initials: B
authors.lastname: Wang
authors.affiliation: School of Environmental Engineering, Wuhan Textile University, Wuhan, 430073, PR China.
authors.forename: Lingyu
authors.initials: L
authors.lastname: Chen
authors.affiliation: School of Environmental Engineering, Wuhan Textile University, Wuhan, 430073, PR China.
authors.forename: Shuangjiao
authors.initials: S
authors.lastname: Zhao
mesh_terms: D000327:Adsorption; D001391:Azo Compounds / Q000737:chemistry*; D002244:Carbon / Q000737:chemistry; D002606:Charcoal / Q000737:chemistry*; D004396:Coloring Agents / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008751:Methylene Blue / Q000737:chemistry*; D012996:Solutions; D013816:Thermodynamics
chemical_list: D001391:Azo Compounds; D004396:Coloring Agents; D012996:Solutions; C540010:biochar; D002606:Charcoal; C008492:methyl red; D002244:Carbon; D008751:Methylene Blue
keywords: Adsorption isotherm; Interaction; Modeling; Simultaneous adsorption