Surface Modification Of Foam Material And Its Research And Application In Sewage Treatment

The latex sponge and PBAT foam were used as the basic carrier of the adsorbent and the surface was coated and modified by solution dipping method in this paper.The influence of the initial concentration,pH,reaction temperature and time of the simulated wastewater on the removal of pollutants by the foam adsorbent were mainly studied.The experimental data was also fitted with adsorption isotherms and kinetics to explore the adsorption mechanism.The research content was mainly divided into the following two parts:The latex sponge was modified by chitosan,tannic acid and silane coupling agent to prepare an oleophobic sponge adsorbent that can adsorb different kinds of charged dyes and Cu²⁺.The static adsorption capacity of the latex sponge before and after modification to methyl orange(MO)(negative charge),rhodamine B(RB)(neutral),methylene blue(MB)(positive charge)and Cu²⁺under different initial concentration,pH,and reaction temperature were investigated,and simulations of adsorption kinetics and isotherms were performed.The modified latex sponge improved the overall adsorption capacity along with the initial concentration and reaction temperature increased,the adsorption capacity of the adsorbent expanded;when the pH was low,it was beneficial to adsorb MO and RB,and when the pH was high,it was favorable for the adsorption of MB and Cu²⁺.Adsorption kinetics and isotherm data showed that the isotherm dates of pure latex sponge conformed to the Langmuir isotherm model,while the isotherm dates of TA/CS@KH550 modified latex sponge conformed to the Freundich isotherm model,but both of them were more fitted with the pseudo-second-order adsorption model,which was dominated by chemical adsorption.The PBAT open-cell foam doped with iron pillared bentonite was prepared by using sugar as a pore-forming agent and solution phase separation method,and then combined with the solution dipping method to coat the surface of the foam with a PAM/SiO₂coating,which made the PBAT foam have super-hydrophilic performance.The modified PBAT foam was characterized by scanning electron microscopy,XRD,infrared spectroscopy,thermal weight loss and contact angle.The static adsorption effect of superhydrophilic iron-pillared bentonite-doped PBAT open-cell foam on methylene blue and Cu²⁺was studied,which was affected by the initial concentration of the solution,pH,and reaction temperature and time.The adsorption isotherm fitting of the modified PBAT foam showed that the adsorption conformed to the Langmuir model and was biased towards monolayer adsorption.The adsorption kinetics fitting of the modified PBAT foam showed that the adsorption process was more in line with the pseudo-second-order adsorption model,with chemical adsorption dominated.The modified PBAT foam has a certain adsorption effect on Cu²⁺,but its cyclic adsorption capacity was weak,and it has a good cyclic adsorption function for the cationic dye methylene blue due to the existence of the photodegradation reaction.The photodegradation efficiency of MB was still more than 95% after five cycles of adsorption.The super-hydrophilicity imparted by the PAM/SiO₂ coating made the modified PBAT foam also have good application potential in oil-water separation.