Modeling and Optimizing Chromate Photo-Precipitation With Iodide Exciting Under Uv Irradiation Publisher



Rasolevandi T¹ ; Azarpira H² ; Mahvi AH^{1, 3} Show Affiliations
Source: Desalination and Water Treatment Published:2020

Abstract

This study aims to develop a process based on the UV irradiation of iodide (UI) to create reducer agents for photo-precipitation of the chromate. To perform the RSM-based optimization, the R 3.0.3 software was employed. A central composite design function was implanted that could fit and model a standard response surface into the coded experimental data. According to the highest R2 value (multiple R2: 0.9986 and adjusted R2: 0.9974), the lowest P-value (2.2 × 10–16), the lowest AIC (12.27), and the most insignificant lack-of-fit (0.6711) corresponding to the second-order model were chosen for optimization. Based on this model, the stationary for iodide dose (mg L–1), pH, time (min), and initial Cr concentration were 0.3 mg L–1, 7, 50 min, and 0.5 mg L–1, respectively, and photo-precipitation performance reached to 94.42%. Base on this pseudo-first-order kinetic model, the observed rate constant (kobs) and the related rate (robs), respectively altered from 5.67 to 15.21 min–1 and from 0.3317 to 2.372 mg L–1 min–1 by the increase of Cr concentration from 5 to 20 mg L–1. Also, with increasing of Cr concentration from 5 to 20 mg L–1, EEO increased from 5.67 to 15.21 (kinetic model) and from 5.11 to 18.45 (figure-of-merit model) kW h m–1. © 2020 Desalination Publications.