Study On The Absorption Of Cd(?) By Waste Paper-montmorillon Aerogel Prepared By Atmospheric Drying Technology

Aerogel is an emerging material that is widely used because of its low density,high specific surface area and high porosity.In particular,compared with traditional aerogels,clay aerogel shows the advantages in simple preparation method,environmentally friendly raw materials and excellent biocompatibility.Clay aerogel has become one of the hot-spot adsorption materials studied in the past two decades.However,the fragile mechanical properties of clay minerals limit their practical application.Therefore,enhancing the mechanical properties of clay aerogel and further improving its adsorption performance are the focus of research.At present,there are few studies on aerogels prepared by directly combining waste paper and clay.In this study,waste experimental paper and the typical clay mineral material-montmorillonite,were used as raw materials to successfully prepared paper fiber-montmorillonite composite aerogel by ambient drying technology.The study investigated the effect of the ratio of the paper fiber of the material component,the type and ratio of the binder and the modifying agent on the properties of the composite aerogel.The adsorption capacity of the modified composite aerogel under acidic conditions was also studied,and the effect of pH on the adsorption of heavy metal ions by aerogel and its influence mechanism were analyzed at the same time.Studies indicated that the proportion of the different components of the composite aerogel in the aerogel affects the properties of the aerogel.When the proportion of montmorillonite was 5 wt%,the ratio of binder polyvinyl alcohol(PVA)was 2 wt%,and the ratio of paper fiber was 5 wt%,respectively,not only could the composite aerogel obtain the best compression resistance,but also the adsorption amount of Cd2+was also the highest among the composite aerogels of different paper fiber ratios.After the composite aerogel was modified,its properties were optimized.In particular,the improvement of the adsorption performance of Cd2+was the most obvious.The adsorption capacity of Cd2+in unmodified composite aerogel(WP-MMT)was 76.35 mg/g,and the adsorption capacity of Cd2+by composite aerogel modified by H2O2(WP-MMT-H2O2)increased to 114.92 mg/g,and the adsorption capacity of Cd2+by the composite aerogel modified by NaOH(WP-MMT-NaOH)changed to 177.90 mg/g.When the pH is lower than 2,the modified composite aerogel would almost no longer absorb Cd2+,but when the pH of the solution was higher than 5.3,the WP-MMT-NaOH could still maintain high adsorption capacity more than 150 mg/g.