Adsorption Of Phenol By Biomass

The peanut shells and rice straws were preferred for raw material, and each of which was treated to four adsorbent by physical or chemical method. The adsorption method was used as the way to deal with the phenol in solution. The main results as follows:the adsorption capacity of adsorbents (raw material, carbonated material, modified material) adsorb phenol were explored. The influence of pH, adsorption time, ionic strength, dosage, temperature and primary concentration to adsorption effect were investigated in static tests. The adsorption theory could be known by the fitting results of adsorption kinetics and thermodynamics, which were based on the data of adsorbing time test and different initial concentrations test. The experimental results show that:1、 When the pH of the solution was7, the process of peanut shells adsorbing phenol reached balance after360min. For rice straws, the pH was4and the time was360min. With raising the ionic strength, the removal efficiency was obviously decline. According to Langmuir model, the maximum amounts adsorption of rich straws was6.7mg/g, and the adsorption of peanut shells absorbing phenol meet Freundlich model. By substituting experimental data into kinetics models, the first-order kinetics model could better describe the kinetics of adsorbent adsorbing phenol.The thermodynamic calculations results indicated that the process of rice Straws adsorbing phenol was spontaneous and endothermic.2、 The suitable carbonization temperature was defined by using adsorbent of different temperature for test. The results show that:when the pH of the solution was7, the process of carbonated peanut shells adsorbing phenol could reach balance after240min. For carbonated rice straws, the pH was8and the time was240min. With raising the ionic strength, the removal efficiency was obviously decline. Both of the two adsorbing processes meet the isothermal adsorption characteristic of the two kind of adsorbent adsorbing phenol conformed to both Langmuir equation and Freundlich equation, the maximum amounts adsorption of carbonated peanut shells was54.07-57.04mg/g. The maximum amounts adsorption of carbonated rice straws was28.43~33.35mg/g. Both of the two adsorbing processes meet the second-order kinetics model, The thermodynamic calculations results indicated that the process of the two kinds of adsorbent adsorbing phenol were spontaneous and exothermic. 3、 The modified peanut shells and modified rice straws were prepared by using N,N-dimethylformamide as reaction medium and using chloroepoxy propane、dim ethylamine and pyridine as modifying agent. The results show that: when the pH of the solution was10, the process of modified peanut shells adsorbing phenol could reach balance after120min. For modified rice straws, the pH was10and the time was240min. With raising the ionic strength, the removal efficiency was obviously decline. Both of the two adsorbing processes meet the isothermal adsorption characteristic of the two kinds of adsorbent adsorbing phenol conformed to both Langmuir equation and Freundlich equation, the maximum amounts adsorption of modified peanut shells was84.49~108.76mg/g. the maximum amounts adsorption of modified rice straws was51.10~91.50mg/g. Both of the two adsorbing processes meet the second-order kinetics model. The thermodynamic calculations results indicated that the processes of the two kind of adsorbent adsorbing phenol were spontaneous and endothermic.