Performance Evaluation of Modified Pumice on Removal Nitrate From Aqueous Solution: Kinetic Studies and Adsorption Isotherm

The contamination of nitrate (NO3−) in potable water has become a serious concern in many parts of the world. Increasing nitrate concentrations in drinking water causes two adverse health effects: induction of “blue-baby syndrome” (methemoglobinemia)، especially in infants، and the potential formation of carcinogenic nitrosamines. The objective of this study was to investigate the nitrate removal using modified pumice with iron and determining the adsorption isotherms and kinetic.

This fundamental and practical study was performed in batch conditions and room- temperature. Effects of the process parameters such as contact time، initial concentration and pH were investigated. In this study، Langmuir and Freudlich isotherms was survey to adsorption reactions and to calculate the equilibrium constant. Residual nitrate concentrations determined in 220 and 275 nm using a spectrophotometer (UV /VIS (Shimadzo-1700، Japan.

Results of literature indicated that removal nitrate depend on Freundlich (R2>0. 998). In the study kf was 0. 14 and amount of adsorbed nitrate was qm (mg/g) =0. 65 for mass unit of modified Pumice. The pseudo second-order is found in the best fitness with the kinetic data.

The results indicate that modified pumice with iron can be employed as an effective adsorbed to removal of nitrate from water solutions.