Response surface methodology (RSM) and its application for optimization of ammonium ions removal from aqueous solutions by pumice as a natural and low cost adsorbent

Abstract

This research was conducted to study the adsorption of ammonium ions onto pumice as a natural and low-cost adsorbent. The physico-chemical properties of the pumice granular were characterized by X-ray diffraction (XRD), Fourier transforms infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). Modeling and optimization of a NH 4 + sorption process was accomplished by varying four independent parameters (pumice dosage, initial ammonium ion concentration, mixing rate and contact time) using a central composite design (CCD) under response surface methodology (RSM). The optimum conditions for maximum removal of NH 4 + (70.3%) were found to be 100 g, 20 mg/l, 300 rpm and 180 min, for pumice dosage, initial NH 4 + ion concentration, mixing rate and contact time. It was found that the NH 4 + adsorption on the pumice granular was dependent on adsorbent dosage and initial ammonium ion concentration. NH 4 + was increased due to decrease the initial concentration of NH 4 and increase the contact time, mixing rate and amount of adsorbent.

Removal of 4-chlorophenol from aqueous solution by granular activated carbon/nanoscale zero valent iron based on Response Surface Modeling

“…The complete design consisted of 60 runs and these were performed in duplicate to optimize the levels of selected variables (initial concentration of 4-CP, pH, contact time, adsorbent dose, and type of adsorbent). For statistical calculations, the fi ve independent variables were designated as X 1 , X 2 , X 3 , X 4 and X 5 , respectively, and were coded according to the following equation (Yazdanbakhsh and Hashempour 2015, Doddapaneni et al 2007, Moradi et al 2016:…”

“…4-CP was adsorbed on the reactive iron particle surface after being spread through the solution. Then, iron nanoparticles as electron donors were corroded following the occurrence of an effective contact between them and molecular 4-CP (Moradi et al 2016). In addition, hydrogen peroxide could be created by iron corrosion in the presence of oxygen.…”

“…In addition, hydrogen peroxide could be created by iron corrosion in the presence of oxygen. As a result, strong oxidants like OH• species could be produced by the reaction between Fe 2 and hydrogen peroxide (Moradi et al 2016). The 4-CP bond was broken by the organic pollutant degradation with help of the hydroxyl radical as soon as the 4-CP was adsorbed onto the nanoparticle surface (Fig.…”

“…Zero-valent iron is a type of iron which has a strong reducing element (Moradi et al 2016). Compared to Zero-Valent Iron (ZVI), NZVI is more suitable for use since it has a higher specifi c surface area and reactivity (Kassaee et al 2011, Mangal et al 2013.…”

Removal of cephalexin from artificial wastewater by mesoporous silica materials using Box-Behnken response surface methodology

“…In statistics, response surface methodology explores the relationships between several explanatory variables and one or more response variables. The main idea of RSM is the use of a sequence of designed experiments to obtain an optimal response [39][40][41][42][43][44][45].…”