The Research Of Adsorption-Fenton Method For Reactive Printing Wastewater Treatment

Dyeing-printing waste water is mainly from boiled and smelted waste water, dyeing waste water, desizing waste water, printing waste water, mercerizing waste water and bleaching waste water. It not only causes serious harm to human living environment, but also has a lot of damage to human body.In this paper, we choose reactive printing waste water as the original solution. Although the quality of water had been improved after flocculation treatment, the COD value is still high. The advanced treatment is needed to meet the discharge standard. The traditional advanced treatment has some deficiency. Fenton method is a common advanced oxidation technology, since the reaction is affected by a variety of conditions, such as H2O2 concentration, Fe2+ concentration, the effect is unsatisfactory. Coagulation settlement method of dosing condition will change with the change of water quality. The COD removal rate is low, and sludge generated is difficult to deal with. The price of coagulant used in mixed coagulation process is high. Membrane separation method requires a lot of energy to deal with pollutants. Aerobic biological treatment has a significant effect for the removal of BOD, but the color and COD removal efficiency is not high. On this basis, by comparing the results of other researchers, adsorption and Fenton combined method was used for advanced treatment of reactive printing waste water. And the removal rate of COD will be evaluated. The optimum condition for a single adsorbent adsorption was determined firstly, followed by mixed adsorbent adsorption. Finally, the optimum operating condition of Fenton reagent was determined to find the best technical solution.Experimental results showed that:(1) In orthogonal experiment, for the reactive printing waste water after flocculant treatment by FeSO4, bentonite was selected as adsorbent with dosage of 4.0g, pH value of 9, adsorption time of 40 min. The COD value was 868.3mg/L and COD removal efficiency was 55.7%.(2) Mixing three pairwise adsorbents:The best results for mixing were determined as follow:mixing bentonite and activated carbon, the mass ratio as 1/3, the adsorption time as 30 min, pH value as 9, temperature as 15℃. The COD removal rate was 60.6% and the residual concentration of COD was 430.2 mg/L.(3) The optimal experimental conditions of Fenton reagent for oxidation of reactive printing waste water were determined as follows:FeSO4 dosage of 3mol, pH value of 3, reaction time of 120 min. The COD removal rate was 72.3%. The residual concentration of COD was 119.2mg/L.In summary, the adsorption-Fenton method for reactive printing waste water treatment reached a textile industrial water pollutant discharge standards.