Bentonite Chitosan Crosslinked Adsorbent Preparation And Performance Evaluation

Chitosan is from the most abundant natural resources named chitin, which is a nontoxic, biodegradarable functional macromolecule material, and it is widely used in foodstuff, medicament, water treatment and life sciences fields. And the scientists pay much attention to other productions prepared from Chitosan. Some Chitosan sorbents are also widely used in water treatment and it has its own advantages. According to the Chitosan's structure and chemical character, it has many -NH2 and —OH which have great absorbing capability. So in this paper, we use the Chitosan to made a new Chitosan gel located on the bentonite which can be hydrated easily in order to enlarge its absorbing surface and quicken its sedimentation speed in water treatment, and most of all, it can enlarge the maximum of adsorbing waste material. And we spend much time on the condition of the preparation of the products in order to find the best preparing condition. And we use the industrial dyestuff and the wastewater of the oil refining to evaluate the performance of the products. And the results indicate: when treating the industrial dyes such as Direct Bordeaux of 400 mg/L, Direct Fast Turquoise Blue GL of 500 mg/L and Direct Fast Blue B2RL of 400 mg/L, the degradation ratio of the Chitosan gel located on bentonite can reach to 95.5%, 96.8 % ,94.0%, and the maximum of the absorption can reach to 46.9 mg ,86.2 mg ,38.7mg per gram according to the industrial dyes mentioned above. And most of all, we can get the good results mentioned above in 2 to 4 minutes adsorption time and in 1 to 2 hour spontaneous sedimentation time without any pretreatment. In addition, we can get the results of COD_cr degradation about 56.1 % and the degradation of suspending solid above 90 % in treating the refining wastewater. In the course of preparation of the production, the Chitosan and cross-linking substance needed is very little and in low concentration. In addition, another cross-linking gel located on the bentonite is prepared using the A1C1₃ and PAM, but this production is not to be named on the same day with the production prepared from Chitosan. At last,...