title: Removal of malachite green dye from wastewater by different organic acid-modified natural adsorbent: kinetics, equilibriums, mechanisms, practical application, and disposal of dye-loaded adsorbent.
abstract: Natural adsorbent (Cinnamomum camphora sawdust) modified by organic acid (oxalic acid, citric acid, and tartaric acid) was investigated as a potential adsorbent for the removal of hazardous malachite green (MG) dye in aqueous media in a batch process. The extent of MG adsorption onto modified sawdust increased with increasing organic acid concentrations, pH, contact time, and temperature but decreased with increasing adsorbent dosage and ionic strength. Kinetic study indicated that the pseudo-second-order kinetic model could best describe the adsorption kinetics of MG. Equilibrium data were found to fit well with the Langmuir model, and the maximum adsorption capacity of the three kinds of organic acid-modified sawdust was 280.3, 222.8, and 157.5 mg/g, respectively. Thermodynamic parameters suggested that the sorption of MG was an endothermic process. The adsorption mechanism, the application of adsorbents in practical wastewater, the prediction of single-stage batch adsorption system, and the disposal of depleted adsorbents were also discussed.
authors.affiliation: College of Environmental Science and Engineering, Hunan University, Changsha, 410082, Hunan, People's Republic of China.
authors.forename: Hou
authors.initials: H
authors.lastname: Wang
authors.forename: Xingzhong
authors.initials: X
authors.lastname: Yuan
authors.forename: Guangming
authors.initials: G
authors.lastname: Zeng
authors.forename: Lijian
authors.initials: L
authors.lastname: Leng
authors.forename: Xin
authors.initials: X
authors.lastname: Peng
authors.forename: Kailingli
authors.initials: K
authors.lastname: Liao
authors.forename: Lijuan
authors.initials: L
authors.lastname: Peng
authors.forename: Zhihua
authors.initials: Z
authors.lastname: Xiao
mesh_terms: D000327:Adsorption; D027423:Cinnamomum camphora / Q000737:chemistry; D004391:Dust; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D012394:Rosaniline Dyes / Q000302:isolation & purification*; D013696:Temperature; D013816:Thermodynamics; D062065:Wastewater / Q000032:analysis* / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*; D018508:Water Purification / Q000379:methods*; D014934:Wood / Q000737:chemistry
chemical_list: D004391:Dust; D012394:Rosaniline Dyes; D062065:Wastewater; D014874:Water Pollutants, Chemical; C005095:malachite green