A rapid azo dye decolorization of methyl orange by the foam zero‐valent nickel

Abstract

In this article, foam zero‐valent nickel (FZVN) was put forward as a promising zero‐valent metal for the pretreatment of azo dye wastewater (MO as a model contaminant). The characteristics of FZVN were evaluated by methods of Barrett‐Emmett‐Teller, scanning electron microscopy, X‐ray diffraction, and X‐ray photoelectron spectroscopy. Moreover, influence of key experimental parameters, including oxygen concentration, presence of different acid, pH, and temperature on the MO decolorization were systematically ascertained. Furthermore, possible mechanism of MO removal by FZVN was investigated by using Liquid chromatography‐mass spectrometry (LC‐MS). Results showed that FZVN was a three‐dimensional pore material with a specific surface area of 3 m2 g−1. Moreover, anoxic condition, presence of acetic acid, higher temperatures and acid conditions were beneficial to decolorize MO by FZVN while the decolorization process obeyed the first order kinetic model with an apparent rate constant (kapp) of 0.162 min−1 at pH value of 4 (25°C). The activation energy Ea obtained from the decolorization reaction was 83.1 kJ mol−1. Based on LC‐MS results, the role of FZVN in the decolorization reaction process was suggested as follows: strong reductive, catalysis, and adsorption. © 2017 American Institute of Chemical Engineers Environ Prog, 37: 686–694, 2018

Performance and mechanism of uranium (VI) removal from aqueous solution by zero-valent nickel@hollow glass particles (ZVNi@HGP)

“…The images of ZVNi, ZVNi@HGP and ZVNi@HGP after removal of uranium are shown in figure 2. From figure 2(a), it is evident that ZVNi particles form agglomerated spherical chains, which may be due to the influence of magnetic attraction and high surface energy [22][23][24]. The agglomeration of particles is apparent, preventing the material from effectively removing uranium.…”

Azo-dye degradation by Mn–Al powders

“…This step is needed in order to fulfill legal requirements as well as to enhance the effectivity of posterior biological and chemical treatments. Among other methodologies and materials (Weng et al, 2013) (Weng, 2017) (Liu et al, 2018b), a widely studied decolorizing technology is the use of metallic zero-valent metals (ZVM), which are able to activate the degradation of many types of dye molecules and other pollutants when put in contact with the dyed water (Qin et al, 2015) ( Deng et al, 2018). This can be an important process in sequential biological-chemical methods, as the end products of the degradation reaction are usually less resistant than the original molecule and may be subjected to posterior treatments like aerobic biodegradation (Patel and Suresh, 2006).…”

“…Secondly, the specific physical parameters of the process such as the total surface of the decolorizing material in contact with the dyed water, the agitation or filtration protocols and the geometrical and dynamical parameters of the reactor. The research in new decolorizing metallic materials is focused on improving the effectiveness of the chemical mechanism under different water conditions as well as on designing new production methods to obtain the maximum active surface per gram of material (Deng et al, 2018).…”