Nitrate sorption on activated carbon modified with CaCl2: Equilibrium, isotherms and kinetics

Chemical Industry and Chemical Engineering Quarterly

卷:21

Tessaro Isabel Cristina¹  Zanella Odivan²  Féris Liliana Amaral² 

[1] Federal University of Rio Grande do Sul, Department of Chemical Engineering, Brasil + Federal University of Rio Grande do Sul, Laboratory of membrane separation process, Brasil;

[2] Federal University of Rio Grande do Sul, Department of Chemical Engineering, Brasil + Federal University of Rio Grande do Sul, Laboratory of separation and unit operations, Brasil;

关键词: nitrate;    isotherms;    kinetic;    activated carbon;    modified surface;   

DOI  :  10.2298/CICEQ130830001Z

来源: DOAJ

【 摘 要 】

In this study, nitrate (NO3-) removal from aqueous solutions was investigated using granular activated carbon (GAC)modified with CaCl2. Batch sorption studies were performed as a function of sorbent dose, initial nitrateconcentration and pH. Sorption was maximized between pH 3 and 9. Studies on the effect of pH showed that theion exchange mechanism might be involved in the sorption process. The percentage of nitrate removed increasedwith increasing sorbent concentration, and the ideal sorbent dose was found to be 20 g•L-1. Four isothermmodels-Langmuir, Freundlich, Redlich-Peterson and Sips-were used to fit the experimental data. TheRedlich-Peterson isotherm model explained the sorption process well and showed the best coefficient ofdetermination (0.9979) and Chi-square test statistic (0.0079). Using the Sips isotherm model, the sorption capacity(qe) was found to be 1.93 mg nitrate per g of sorbent. Kinetic experiments indicated that sorption was a fastprocess, reaching equilibrium within 120 min. The nitrate sorption kinetic data were successfully fitted to apseudo-second-order kinetic model. The overall results demonstrated potential applications of modified GAC fornitrate removal from aqueous solutions.

【 授权许可】

Unknown