Study Of The Preparation And Adsorption Properties Of The Ion-Exchange Resin-Based Spherical Activated Carbon

The dyeing wastewater is one of the most difficult wastewater to deal with, as a result of enriching some kind of compounds selectively, the adsorbents is widely used in the field of wastewater treatment. As one of the most important industrial adsorbents, the activated carbon has many advantages. With the expansion of application fields, there's a higher requirement for the performance of activated carbon. It's also contributed to the research and development of special properties of different varieties of activated carbon. More than a determined molecular structure, Ion exchange resin has little or is almost free of impurities, meanwhile, the spherical activated carbon possess several advantages, such as a controllable pore size distribution and reproducible performance, as a result, the research of ion exchange resin as carbon precursor material becomes one of the hot spot in recent years.In this paper four kinds of ion exchange resins were used to prepare spherical activated carbons by different processes respectively, this paper studied the impacts of the types of ion exchange resins, the carbonization process, the activation and crafts on the iodine and methylene blue quantity of spherical activated carbon based on ion exchange resin; Use the spherical activated carbon prepared as adsorbent in adsorbing different kinds of dyes to study the adsorption properties of ion-exchange resin-based spherical activated carbon in simulated dye wastewater.Thermo gravimetric analysis was used to analyze the thermal decomposition behavior of the resin; Light microscope, Scanning electron microcopy were used to study morphology, crystallite size of spherical activated carbon'surface, the acidic functional groups and pore structures were evaluated by the quantity of iodine and methylene blue absorbing on spherical activated carbon and acid-base titration. Conventional equipment was built as a simple and practical dye concentration on-line monitoring devices to study the adsorption isotherms and adsorption kinetics of the spherical activated carbon for dyes.The main results are summarized as following:(1) the carbonization temperature ranges can be separately identified by analyzing the thermal decomposition behavior of ion exchange resins. The carbonization temperature of resin D001 is about 600℃;The carbonization temperature of resin D201,BK001,BK201 is about 500℃. Compared with the other three resins, spherical activated carbon made from resin D001 perform better, so the resin D001 is ideal for charring experiments.(2) The optimal carbonization process of resin D001 was determined by the analysis of the quantity of iodine and methylene blue absorbing on spherical activated carbon. The ion-exchange resin-based spherical activated carbon was finally made at the carbonization temperature of 600℃, the carbonization heating rate of 3℃/min,the carbonization time of 120min, the activation of the heating rate2℃/min, the activation temperature 800℃, the activation time of 30min, the amount of water vapor in the activation process is at the m(H2O)/m(C)=6. Under these conditions, the iodine and methylene blue values of ion-exchange resin-based spherical activated carbon were 484.7mg/g and 87.84mg/g respectively.(3) By studying the spherical activated carbon adsorption of the dye molecules, we know that there are two different ways. In low concentration of dyes, it is single-layer adsorption; While for the high concentration of dyes, along with time prolonged, the dye in the gap of the spherical activated carbon, the surface of the monolayer adsorption of the dye has produced a multi-layer adsorption. Among them, the absorption isotherm of spherical activated carbon to dye Reactive Blue 222 meets Freundlich equation. The dye Acid Red 114 and Reactive Blue 19 adsorption isotherm is consistent with Freundlich equation, the dye Basic Blue 41 adsorption isotherms using Langmuir characterization is more than appropriate; Spherical activated carbon adsorption behavior of the dye Acid Red 114,Basic Blue 41,Reactive Blue 222 adsorption rate equation can be described well by pseudo-two absorption rate equation, as for the dye Reactive Blue 19,its adsorption behavior can be described well by pseudo-one absorption rate equation.