A microwave-activated coal fly ash catalyst for the oxidative elimination of organic pollutants in a Fenton-like process

Pappu

Journal of Cleaner Production

2019

Geopolymer belongs to a new class of emerging materials for a number of applications owing to the advantages such as low cost; higher compressive strength; improved fire & acid resistance as well as reduced greenhouse gas emission. In this work, we explore the effective utilization of marble waste as a reactive filler and binder for the development of fly ash based geopolymer hybrid composite materials using extrusion process. The effect of marble waste content on the physicochemical and mechanical characteristics of prepared hybrid materials was studied through various characterization techniques. The geopolymerization was conducted at two different molarities of

Section: Raw Materials Properties and Characterizationmentioning

confidence: 99%

Synthesis and characterization of new class of geopolymer hybrid composite materials from industrial wastes

Pappu

Journal of Cleaner Production

2019

“…Fenton-like catalysts based on zeolites modified by other metal oxides have been recently studied [29]. The CFAZs have attracted the attention of researchers as catalysts for Fenton oxidation processes because they contain iron oxides in the form of magnetite, maghemite, and hematite, which are transferred from the raw coal ash [30,31]. In addition, they can be modified with different metal oxides to improve their catalytic properties [32,33].…”

Section: Introductionmentioning

confidence: 99%

Studies on the Potential of Nonmodified and Metal Oxide-Modified Coal Fly Ash Zeolites For Adsorption of Heavy Metals and Catalytic Degradation of Organics for Waste Water Recovery

et al. 2020

A nanocrystalline zeolite of Na-X type (CFAZ) was synthesized by ultrasonic-assisted double stage fusion-hydrothermal alkaline conversion of lignite coal fly ash. Modified CFAZ with magnetic nanoparticles (MNP-CFAZ) was obtained by adding presynthesized magnetic nanoparticles between the synthesis stages. CFAZs loaded by particles of copper (Cu-CFAZ) and cobalt (Co-CFAZ) oxides were prepared by postsynthesis modification of the parent CFAZ, applying a wet impregnation technique. The parent and modified CFAZs were examined for their phase composition by X-ray diffraction, morphology by scanning electron microscopy, and surface characteristics by N2 physisorption. Comparative studies have been carried out on the adsorption capacity of the starting CFAZ and its derivatives with respect to Cd2+- and Pb2+-ions from aqueous solutions. Adsorption isotherms of Cd2+-ions on the studied samples were plotted and described by the adsorption equations of Langmuir, Freundlich, Langmuir–Freundlich, and Temkin. The best correlation between the experimental and model isotherms for the parent and modified CFAZ was found with the Langmuir linear model, assuming a monolayer adsorption mechanism. Parent and modified CFAZs were also studied as catalysts for heterogeneous thermal Fenton oxidation of methylene blue. At 90 °C, the higher catalytic activity exhibits the nonmodified sample, but with the decrease in temperature to 60 °C, the modified samples are more effective catalysts.

“…Every year, up to 600 million tons of fly ash are emitted by China and costs a lot to deal with. Fly ash is a type of cheap industrial solid waste, and the accumulation of it will cause a large amount of arable land and farmland to be occupied. − The erosion of rain will pollute groundwater, and the dust generated by wind will endanger people’s health . Fly ash is a byproduct of coal combustion in coal-fired power plants with a good pore structure, which is widely used in ecological sewage treatment, industrial catalyst preparation, and soil remediation.…”

Section: Introductionmentioning

confidence: 99%

Formation of Fly Ash Catalysts and Selection of a Matrix Binder and Its Application in Denitration

et al. 2020

The development of high-efficiency and low-cost new catalysts is an extremely attractive topic. In this study, two different matrix bentonite-modified fly ash catalysts were successfully prepared, and the compressive strength of the catalyst was studied by using unsaturated dynamic and static triaxial technology. The axial compressive strength of FC (fly ash catalysts added with Ca-based bentonite) was greater than that of FN (fly ash catalysts added with Na-based bentonite). The catalyst reached 978 kPa. The prepared catalyst was characterized by X-ray diffraction analysis, Fourier transform infrared spectroscopy, scanning electron microscopy, and specific surface area analysis (BET) of the catalyst. In addition, denitration performance of different catalysts was explored, and the reaction conditions were optimized. The results demonstrate that when the mixing ratio of fly ash and calcium-based bentonite in the FC is 4:1, the compressive strength is relatively high, and the denitration rate reaches about 82%.