Polyaniline coated hematite sand supported on graphene oxide (HS@PANI‐GO) as a new magnetic material for advanced catalytic oxidation based on sulfate radicals: optimization using response surface methodology

Abstract

BACKGROUND: We report here on the synthesis of a new magnetic and natural material: polyaniline coated hematite sand supported on graphene oxide (HS@PANI-GO) which was used as an heterogeneous catalyst to activate persulfate (PS) for aqueous solution Orange G (OG) degradation. RESULTS:The characterization results have revealed that the hematite sand is rich in iron oxide, and the inorganic particles were well coated with polyaniline and successfully dispersed in graphene oxide. Further, catalytic oxidation experiments demonstrated that HS@PANI-GO material exhibited high activity in the PS activation for the OG degradation. It was found that complete OG removal from aqueous solution was achieved in 90 min at natural pH. In addition, the influence of various reaction conditions such as temperature, concentration of PS, catalyst dose, pH and decomposition time over the HS@PAN-GO/PS system were investigated and optimized. The catalyst HS@PAN-GO could be recycled easily by a magnet with good reusability. Finally, the effects of various parameters such as PS concentration, catalyst dose, initial OG concentration, and contact time, were investigated using the response surface methodology (RSM). It transpires that the experimental elimination of OG is 98.14%, as obtained under optimal conditions, was very close to the predicted value (96.58%) determined by RSM. CONCLUSION: This study provides a promising way for the activation of green oxidant 'PS', by using a new magnetic composite suited for environmental remediation and oxidation catalysis. RESULTS AND DISCUSSIONS CharacterizationThe crystalline structures of the various materials as determined by XRD are shown in Fig. 1. (JCPDS NO 33-0664). According to the XRD profile, the majority of the peaks observed at 2 = 24.19 ∘ , Figure 2. Scanning electron microscopy (SEM) images of (a, b) HS and (c, d) of HS@PANI.

Oxidative degradation of p-chlorophenol by the persulfate-doped Fe–Mn bimetallic hydroxide, the parametrical significance, and systematical optimization

“…In recent years, the advanced-oxidation methods (AOP) have attracted more attention particularly in treating non-biodegradable POPs in the wastewater due to their operational convenience and effectiveness (El Fakir et al 2019, Lv et al 2020, Xiao et al 2020a). Among the oxidants, the utilization of hydroxyl radical (•OH) for the oxidation degradation of some organic compounds is most mentioned in various treatment processes (Laysandra et al 2019, Shokoohi et al 2019, Xiao et al 2020b).…”