Preparation Of Rare Earth Lanthanum Loaded Fly Ash Porous Ceramic And Application In Water Treatment

Industrial solid waste Fly ash can cause serious environment pollution.In this study,porous ceramics were prepared from fly ash as the main raw material,and La-loaded fly ash-based porous ceramics were prepared by loading rare earth lanthanum on the surface of porous ceramics.The La-modified porous ceramics are used to adsorb Cr(VI)wastewater,aiming at achieving waste utilization as well as achieving balanced utilization of Lanthanum.The fly ash porous ceramic was prepared using fly ash as raw materials by attempting to add pore former.The influence of the recipe and the sintering schedule on the performance of porous ceramics was studied.Optimum technology parameter was adding 40% poreforming agent,4% sodium tetraborate,4% montmorillonite and 1.81 of fly ash siliconaluminum ratio at 980? sintering for 30 mins.the fly ash porous ceramic exhibited comprehensive properties: porosity is above 58%,the fracture stress is above 161 N,amount of feldspar about 86%.The porous ceramic substrate was modified by impregnation method using ruthenium chloride as a modifier.The optimum modification process of La-loaded fly ash-based porous ceramics is as follows: the cerium chloride solution with a pH of 1.49 and a concentration of 0.41 mol/L is kept at 30 ?,immersed for 32 h,and calcined at 450 ? for 30 mins.By studying the mineral composition,crystal structure,surface functional groups,and atomic binding energy changes during the modification process,it is found that the loading mechanism of the rare earth element La is mainly carried out by ion exchange surface with the Na element of the plagioclase in the porous ceramic.The La element achieves loading in the form of hydroxylation.The adsorption kinetics and adsorption thermodynamics of La(VI)wastewater adsorbed by La-modified porous ceramics showed that the adsorption of Cr(VI)by La modified fly ash-based porous ceramics is an endothermic reaction,and the adsorption law accords with the Langumir isotherm adsorption model.The adsorption behavior of adsorbed Cr(VI)accords with the quasisecondary kinetic model.The results of backwashing regeneration experiment showed that the concentration of Cr(VI)wastewater with a concentration of 60mg/L after backwashing activation regeneration was 0.2916mg/g,which was 48.45% of the adsorption capacity of La original modified porous ceramics.