| If the phosphorus,nitrogen and other elements in the water body exceed the standard,it will cause the eutrophication of the water body.In this paper,kitchen waste and bentonite are used as raw materials,and high temperature resistance furnace is used to make ceramsite;the material ratio of ceramsite and the optimal firing process parameters are studied and determined,and the ceramsite part fired under the optimal conditions is tested.Performance;through a variety of characterization methods(X-ray diffraction,Xray fluorescence spectroscopy,nitrogen adsorption equilibrium method,environmental scanning electron microscopy analysis,infrared spectroscopy,thermogravimetric/differential thermal analysis),explored the modification mechanism of ceramsite And the main phosphorus removal mechanism.A static experiment was designed from five aspects: the dosage of ceramsite,the initial phosphorus concentration of the phosphorus solution,the p H of the solution,the coexisting ions,and the coexistence of humic acid to explore its effect on the adsorption and removal of phosphorus by the ceramsite;the adsorption of kitchen waste ceramsite Kinetics,adsorption isotherms and thermodynamics to explore the adsorption reaction process and mechanism.In the study of the influence factors of ceramsite dephosphorization,it was finally determined that the best ratio of kitchen waste ceramsite was kitchen waste: bentonite was14g: 6g.The crushed kitchen waste was dried in an oven at 105°C for 2.5 hours,and then dried in an oven at 105°C.Preheating is performed in an environment of 500℃,and the preheating time is 20 min.Experimental studies have shown that when the firing temperature exceeds 1050 ℃,the ceramsite adsorption effect will become worse as the temperature rises,but the ceramsite structure tends to be more stable;under the same temperature conditions,as the firing time increases The poorer the particle adsorption effect,the more stable the structure.Considering the adsorption effect and structural stability,1050℃ is selected as the ceramsite firing temperature and firing for 10 minutes.Through environmental scanning electron microscopy analysis(SEM)and nitrogen adsorption equilibrium method(BET)characterization,it is determined that the kitchen waste ceramsite has a mesoporous structure.Static experiments show that the more ceramsites in the same proportion are added to the solution with the same initial phosphorus concentration,the smaller the adsorption capacity;the higher the initial phosphorus concentration,the greater the adsorption capacity,and the maximum adsorption capacity is about 25.66mg/g;alkali The adsorption capacity of kitchen waste ceramsite in a natural environment is stronger than that in an acidic environment.The adsorption and dephosphorization effect of kitchen waste ceramsite are all inhibited by the three coexisting ions of Cl-,HCO3-,and F-to varying degrees.The degree of inhibition is HCO3->Cl->F-,while SO42-is very effective for adsorption.Phosphorus has a promoting effect.As the concentration of coexisting ions increases,the inhibitory effect of Cl-on the adsorption of phosphorus decreases,while the inhibitory effect of HCO3-and F-increases.The three kinetic models can basically fit the adsorption process of kitchen waste ceramsite,and the quasi-secondary reaction kinetic model has the best fitting effect.In the adsorption thermodynamic analysis,the Langmuir adsorption isotherm model has the best fitting effect for the ceramsite adsorption of phosphorus.The adsorption process is an endothermic spontaneous reaction.Choosing kitchen waste as the raw material for the preparation of ceramsites solves the problem of mixing kitchen waste and domestic waste for composting or landfilling resource consumption and secondary pollution,and it also interprets the "use waste to treat waste".In addition,the ceramsite has low production cost and can be recycled again after adsorption.It also has a good effect in actual wastewater treatment applications. |
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