title: Optimizing adsorption of crystal violet dye from water by magnetic nanocomposite using response surface modeling approach.
abstract: A magnetic nanocomposite was developed and characterized. Adsorption of crystal violet (CV) dye from water was studied using the nanocomposite. A four-factor central composite design (CCD) combined with response surface modeling (RSM) was employed for maximizing CV removal from aqueous solution by the nanocomposite based on 30 different experimental data obtained in a batch study. Four independent variables, viz. temperature (10-50°C), pH of solution (2-10), dye concentration (240-400 mg/l), and adsorbent dose (1-5 g/l) were transformed to coded values and a second-order quadratic model was built to predict the responses. The significance of independent variables and their interactions were tested by the analysis of variance (ANOVA) and t-test statistics. Adequacy of the model was tested by the correlation between experimental and predicted values of the response and enumeration of prediction errors. Optimization of the process variables for maximum adsorption of CV by nanocomposite was performed using the quadratic model. The Langmuir adsorption capacity of the adsorbent was determined as 81.70 mg/g. The model predicted maximum adsorption of 113.31 mg/g under the optimum conditions of variables (concentration 240 mg/l; temperature 50°C; pH 8.50; dose 1g/l), which was very close to the experimental value (111.80 mg/g) determined in batch experiment.
authors.affiliation: Environmental Chemistry Division, Indian Institute of Toxicology Research, (Council of Scientific & Industrial Research), Post Box 80, Mahatma Gandhi Marg, Lucknow 226 001, India. kpsingh 52@yahoo.com
authors.forename: Kunwar P
authors.initials: KP
authors.lastname: Singh
authors.forename: Shikha
authors.initials: S
authors.lastname: Gupta
authors.forename: Arun K
authors.initials: AK
authors.lastname: Singh
authors.forename: Sarita
authors.initials: S
authors.lastname: Sinha
mesh_terms: D000327:Adsorption; D000465:Algorithms; D000704:Analysis of Variance; D005840:Gentian Violet / Q000302:isolation & purification*; D006863:Hydrogen-Ion Concentration; D007202:Indicators and Reagents; D008280:Magnetics; D008855:Microscopy, Electron, Scanning; D015233:Models, Statistical; D053761:Nanocomposites; D016062:Porosity; D012044:Regression Analysis; D015203:Reproducibility of Results; D012996:Solutions; D013055:Spectrophotometry, Infrared; D017550:Spectroscopy, Fourier Transform Infrared; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*; D014961:X-Ray Diffraction
chemical_list: D007202:Indicators and Reagents; D012996:Solutions; D014874:Water Pollutants, Chemical; D005840:Gentian Violet