Chitosan Wrapping Fly-ash On The Treatment Of Industrial Wastewater

In this paper, Fly ash and chitosan were selected as raw material which is prepared Chitosan Wrapping Fly ash adsorbent and Chitosan Wrapping Modified Fly ash adsorbent. The simulated dye wastewaters of reactive acid and direct dyes were sellected as references, the adsorption properties of the adsorbents were tested, and degradation ratio was a main evaluated index. Combining to the detection COD removal ratio, research the effects of pH, adsorbent dosage, oscillation time, and dye type on the degradation ratio and adsorption effect under the room temperature.The results showed that: (1) The best method among acid,base and roast modifications to fly ash was Ca(OH)₂ modification. Based on FTIR data, the characteristics of modified fly ash were showed that the activity of Al₂O₃, SiO₂ was aroused and the high temperature activation reduced the adsorption resistance from water film. (2) By contrast with the adsorption capacity of dye from aqueous solution on fly ash and chitosan, it showed that the application of chitosan was restricted by its poor water-soluble, and its adsorption speed was slow. Because of its big dosing, fly ash was not widely practiced. So that, the study of the composite of fly ash and chitosan to deal with dyes effluent was of more development prospects. (3) By optimizing conditions, chitosan and fly ash had been made up compound adsorbent, 1:20 rate, which was applied in activity, direct and acid dyes wastewater. The compound adsorbent got a higher degradation rate and COD removal. Under the conditions of pH= 4, it had the best treatment of the majority of dyes. The direct dyes degradation rate was more than 99%, and the best degradation rate of reactive dyes was more than 95%. But the degradation rate of acid dyes generally was worst than the firstwo wastwater, however, acidic cheng adsorbent was also up to 99%. COD removal rate was almost equal to the processing rate of the reactive dye that could reach 90%, the acidic and direct dyes degradations were more than 80%. (4) Prepared by further treatment effect more desirable CWMF adsorbent, with reactive dyes as the research object, proved by experiments both in the degradation rate and the removal of COD were further enhanced. On the active brilliant blue experiments CWMF dosage was only CWF 1/4, the degradation rate increased to 98.1% from the 96.8%, COD removal rate from the original 92.3% to 95.4%. SEM and FTIR analysis showed that chitosan adsorbent could cover a plenty of flyash and the surface was more rough than before, and the reaction group same as the CWF were -OH,-NH₂. So it could be seen that CWMF research for printing and dyeing wastewater provided more favorable treatment data support and innovative ideas.