Preparation Of Carboxyl Modified Jute And Its Adsorption Performance For Aniline In Water

In recent years, water pollution accidents occur frequently with the rapid development of industry, which cause serious harm to the environment and human beings. In the disposal of burst water pollution, the adsorption technology plays a big role. The absorbent which has been used in the emergency response are required of high efficiency, low cost, wide applicability and ease operation. Jute fiber is an ideal raw material for producing absorbent. The jute has a lot of active groups, so a simplified process and a mild reaction conditions may make it an ideal adsorbent.In this paper, the modified jute with carboxyl was prepared by esterification reaction with raw jute using N, N dimethyl formamide as dissolvent and pyromellitic anhydride as modifying agent. Factors of preparing the carboxyl modified jute such as reaction time, reaction temperature, acid anhydride dosage, acid anhydride type and reaction media type were optimized by aniline adsorption using single factor experiment and response surface methodology. The jute samples before and after modification were characterized by FTIR and BET techniques. The experiments showed that the optimum preparation conditions of carboxyl modified jute were as follows: the jute 1.0 g, DMF 40 m L, acid anhydride dosage 4.0 g, reaction temperature by microwave 125 ° C, reaction time 25 min. With the FTIR analysis, the carboxyl groups was successfully introduced into the surface of jute. The BET results showed the specific surface area of modified jute did’t change.In order to test the adsorption properties of carboxyl modified jute for aniline, static experiments were conducted. In the experiments, the factors including p H, initial aniline concentration, treatment time and treatment temperature were investigated, the regeneration experiments was conducted and the adsorption mechanism was discussed. The results showed the optimum p H for aniline adsorption was in the neutral range. Adsorption equilibrium was achieved in 60 minutes, and the adsorption kinetics followed a pseudo-second-order kinetic model. With the increase of initial concentration and temperature, the aniline adsorption increased. The regeneration tests showed the adsorption capacity of carboxyl modified jute did’t change after regeneration four times. The Langmuir model appeard to fit the aniline adsorption process better. The negative value of the standard entropy(ΔG0) and the positive value of the standard free energy(ΔH0) indicated an endothermic and spontaneous nature of the adsorption interaction. The adsorption of carboxyl modified jute adsorption aniline included hydrogen adsorption and electrostatic adsorption.In order to research the aniline treatment process, experiments were conducted in a fixed bed. The factors including the adsorption bed height, influent flow rate and initial concentration were investigated, and recycling use of the adsorption device was tested. The results showed that the aniline removal effects enhanced with the increase of the bed height, and with the decrease of the flow rate and the initial concentration. experimental device could be fast and efficient regeneration, and the removal effects unchanged after regeneration 3 times; BDST model and Thomas model were well used to fit the aniline dynamic adsorption process, the model parameters provided reliable information for practical application. One adsorption reactor for dealing with sudden water pollution was designed, and its application was discussed.