| Phenolic compounds are common contaminants in wastewaters, and phenols are considered as priority pollutants since they are harmful to ogranisms at low concentrations. At present,many researches have been focused on finding an effective way to deal with this kind of wastewater with low cost. For dealing with phenolic wastewater, the common ways are adsorption by adsorbent, extraction by solvent, biology method,chemical method. But these methods have their advantages and disadvantages that mainly concentrate on treatment efficiency and cost. Chitosan as a natural polymer, and its wide array of sources, preparation method is simple, harmless non-toxic, biodegradable. Chitosan has useful functional groups such as hydroxyl and amine, so it can interact with phenols based on electrostatic interactions and hydrogen bonds. However, chitosan is unstable in some acid, and prone to acid hydrolysis, which the application of chitosan as the adsorbent has a restrictive role.This paper mainly embarks from the treatment phenol-containing wastewater via adsorption method, and four types of adsorbents are prepared. (1) Chitosan,vanillin and citral as raw materials, two Schiff's base sobrents were preapared by chitosan react with vanillin aldehyde under microwave radiation by means of orthogonal experimental method, as well as citral. (2) Chitosan beads was synthesized by drop-sphere-forming method at first, then vanillin was grafted to the chitosan beads under microwave radiation, followed by reduction with NaBH4, and obtained a new sorbent, as well as citral. (3) Series of adsorption test on simulated wastewater of phenol, 4-nitrophenol, and 2,4-chlorophenol were studied by Schiff's base. The adsorption capacity and the removal rate as the main evaluating objects. The effects of adsorption conditions, such as the yield of Schiff's base, pH, the kinetic adsorption, thermodynamics, the amount of added sodium chloride and the Schiff's base on the adsorption capacity were investigated. (4) The use of two beads by treating actual phenol-containing wastewater were studied through static adsorption experiment and dynamic adsorption test.The effects of static adsorption conditions, such as the sorts of adsorbents, pH,time, and the amount of the modified chitosan on the removal rate of phenols were studied. (5) The removal rate of phenols as the main target, in combination with COD removal rate, decoloration, turbidity in the dynamic adsorption test, such as the initial concentration of wastewater, pillar altitude and the velocity of effluent on the treatment of wastewater. The desorption characteristics of phenols were carried out on CTSC beads. (6) On this basis, the continuous running control experiment in view of the actual wastewater and the type of wastewater containing phenol were also carried on in order to study on the feasibility and the adsorption effect of CTSC beads which serves as the novel water treatment adsorbent.The experimental results are summarized as follows:1, The optimum conditions were confirmed by orthogonal experiments: for chitosan graft vanillin the reaction time 4min, microwave radiation 480W, the chitosan to monomer mass ratio 1:5, the yield of the chitosan and vanillin was 76.52%; for chitosan graft citral the reaction time 6min,microwave radiation 480W, the optimal volume ratio of ethanol and water is 2:1, the chitosan to monomer mass ratio1:6, the yield of the chitosan and citral was 84.22%.2, The optimum conditions for preparation of chitosan beads were as follows: the centration of chitosan is 2%, the ratio of NaOH and C2H5OH is 2%/10%, and the micro-injector is 200μL. The chitosan beads to vanillin mass ratio is 3:1, the content of free amine and degree of substitution (DS) in CTSV beads were 2.85mmol/g and 54.11% respectively. The chitosan beads to citral mass ratio is 3:1.3, the content of free amine and DS in CTSC beads were 2.63 mmol/g and 57.66%, respectively.3, The experimental results indicated that CTSV and CTSC have better absorption capacity to phenol, p-nitrophenol o,p-chlorophenol than CTS. After chemical modification, the adsorption was upgraded. CTSC has higher absorption capacity to phenols than CTSV. The sequence of absorption capacity by Schiff base was as follows: o,p-chlorophenol> p-nitrophenol > phenol.4, The static adsorption experiment test result showed CTSC beads have the best phenols removal rate and higher absorption capacity to CTS beads, CTS, CTSV beads. The optimum adsorption experimental condition was that the pH value is 7, the stiring time is 180 min under the quantity of 0.3g, phenols removal rate is 51.1%. When the quantity is 0.5g, phenols removal rate up to 61.1%.5, The dynamic adsorption test result showed the optimum dynamic adsorption experimental condition by CTSC beads was that under 25℃, pH value is 6.6, pillar altitude is 300mm, the velocity of effluent is 0.7BV/h, phenols removal rate is 90.4%, COD removal rate is 69.0%, chroma and turbidity can be also removed out. CTSC beads was effectively regenerated by the 5% NaOH solution fed at 3.4~6.8BV/h at room temperature.6, The processing effect of the dynamic adsorption experiment by CTSC beads of the phenol adsorption experiment was better than that of phenol-containing wastewater.The paper chosen two natural aldehyde with rich sources and low prices as graft to chitosan. These material meet with the demands of green chemistry, and its process has been highlightened by its simple operation. Application of these adsorbention materials will be more broad prospects for development.
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