| Coal gangue is the solid waste produced in the process of coal mining.At present,the main use of coal gangue is used for land reclamation,as well as for power generation,brick,concrete,cement and mineral mining.However,due to the insufficient utilization of coal gangue,the impact of coal gangue dumping on the environment is still serious.The accumulation of a large amount of coal gangue on the ground will cause spontaneous combustion and pollute the atmosphere.At the same time,under the action of rain erosion,heavy metals contained in the coal gangue as precipitation will cause soil pollution and water pollution through weathering and leaching process,endangering the growth of crops and human health.Therefore,highly efficient use of coal gangue to avoid its adverse impact on ecological environment as far as possible is a problem urgently needed to be solved in our country coal industry.With the rapid development of industry,dye wastewater pollution is increasingly serious,its main characteristics are high content of organic compounds,difficult to degrade,and have serious harm to the environment and human health.Therefore,it is essential to seek efficient treatment measures for dye wastewater.In this paper,the traditional alkali fusion hydrothermal method was used to prepare the coal gangue based zeolite under the optimal conditions,and the heterogeneous catalyst was prepared by the support of transition metal.The synthesized zeolite catalyst products were characterized by XRD,SEM,EDS,FT-IR,BET,XPS and other technologies.By investigating the influence of different factors on the adsorption/degradation of basic fuchsin,the experimental conditions were optimized to determine the best experimental parameters,further explore the reaction mechanism and investigate the stability of the catalyst.The adsorption experiments of the synthesized zeolite on the basic fuchsin solution were carried out.Under the adsorption conditions of the initial concentration of the solution 250 mg/L,the dosage of zeolite 0.1000g,the p H=8 and the oscillation time 60min,the adsorption capacity and removal rate of NaA zeolite were 49.66mg/g and 66.21%,respectively.When the oscillation time was gradually increased to 100 min,the maximum adsorption capacity and removal rate were 74.47mg/g and 99.30%,respectively.By exploring the adsorption behavior of zeolite through adsorption kinetics and adsorption isotherm,it is concluded that the fitting curves of pseudo-second-order kinetics model and Langmuir isotherm model are more accurate,with R2of 0.9932 and 0.9594,respectively.Using the synthesized NaA zeolite as the support and Fe（NO3）3·9H2O as the Fe source,Fe-NaA supported zeolite catalyst（Fe-NaA）was prepared by impregnation method,and then combined with H2O2to form a Fenton-like system for catalytic degradation rate of alkaline products.Under the optimal catalytic degradation conditions of Fe3+loading concentration of 1.0g/L,catalyst dosage of 0.0600g,p H=8,initial solution concentration of 250mg/L,H2O2dosage of 1.5m L and reaction temperature of 60℃,The catalytic degradation rate of Fe-NaA zeolite catalyst can reach 89.96%at 60 min of reaction in Fenton-like system.The degradation efficiency of the initial recycling catalyst was 82.21%after five cycles,indicating that the Fe-NaA heterogeneous Fenton catalyst has good catalytic performance and stability.Using the synthesized NaA zeolite as the support,Cu（NO3）2·3H2O as the Cu source and Fe（NO3）3·9H2O as the Fe source,Cu/Fe-NaA supported zeolite catalyst（Cu/Fe-NaA）was prepared by impregnation method,and the Fenton-like system was formed with H2O2to catalyze the degradation of alkaline products.Under the optimal catalytic degradation conditions of Fe3+and Cu2+loading concentration of 1.0g/L,catalyst dosage of 0.0600g,p H=6,initial solution concentration of 250mg/L,H2O2dosage of 1.5m L and reaction temperature of 60℃,The catalytic degradation rate of Cu/Fe-NaA zeolite catalyst for basic fuchsin solution was up to 99.84%after 30 min reaction in Fenton-like system.The degradation efficiency of Cu/Fe-NaA heterogeneous Fenton catalyst was 94.72%after five cycles of recycling,indicating that Cu/Fe-NaA heterogeneous Fenton catalyst had good catalytic performance and stability.This study shows that the production of hydroxyl radical（·OH）in the Fenton reaction system plays a dominant role in the degradation dye.By comparison,the redox cycle of Cu2+/Cu+and Fe3+/Fe2+can accelerate the production of hydroxyl radical（·OH）,trigger a chemical reaction,achieve the maximum degradation rate,and enable the degradation of organic substances in the solution.Therefore,the bimetal Cu/Fe Fenton-like system has the best dye degradation effect,providing a new idea for heterogeneous catalysts. |
