AU - Dindarloo, Kavoos AU - Sheikh Mohammadi, Hamideh AU - Jamali, Hamzeh Ali TI - Optimization of nitrate removal from drinking water by modified Pumice with magnesium chloride using Box Benken design method PT - JOURNAL ARTICLE TA - hums-jpm JN - hums-jpm VO - 8 VI - 4 IP - 4 4099 - http://jpm.hums.ac.ir/article-1-548-en.html 4100 - http://jpm.hums.ac.ir/article-1-548-en.pdf SO - hums-jpm 4 ABĀ  - Introduction: Nitrate, due to its high solubility in water, causes pollution of groundwater resources, poses a serious threat to human health and causes eutrophication of water resources. The aim of this study was to optimize the use of modified pumice in the removal of nitrate from water. Methods: This experimental study was performed in 2020 on laboratory scale. The experiments were designed using the Box-Benken method. The studied variables included pH (2-4), initial nitrate concentration (50-100 mg/L), contact time (15-45 min) and pumice dose (0.5 - 1.5 gr/L) at three levels. Thus, a total of 29 experiments were designed and performed. Experimental design and statistical analysis were performed using Design Expert 7.0 software. All examinations were performed according to the instructions provided in the latest edition of the Standard Methods for the Examinations of Water and Wastewater. Results: The results showed that the quadratic polynomial equation fitted well with the experimental data. Also, the liner effects of all four variables (including pH, initial nitrate concentration, contact time and modified pumice dose), as well as interactions effects and quadratic effects of each variable on the nitrate removal efficiency from water were significant (P-Value <0.05). The results of numerical optimization showed that the optinal conditions included pH of 2.01, initial nitrate concentration of 70.45 mg/L, reaction time of 44.98 min, and modified pumice dose of 1.21 gr/L. Under these conditions, nitrate removal efficiency, model desirability, and predicted R2 were 89.66%, 100% and 0.82, respectively. Conclusion: According to the results, magnesium-modified pumice can be applied to remove nitrate from water. However, it should be mentioned that the pH of the water, after purification, must be modified with a suitable alkaline substance. CP - IRAN IN - LG - eng PB - hums-jpm PG - 56 PT - Orginal YR - 2021