Discoloration of C.I. Reactive Yellow 145 solution using TiO2 nanoparticles coupled with Sonoelectrochemistry process

Various processes have been utilized for decolorization of textile industries wastewater including physical, chemical, and biological methods. One of the most advanced oxidation processes issonoelectrochemical technology used to decompose and treat dye [1]. In this process, hydroxylradical is released as a result of cavitation phenomenon caused by ultrasonic vibrations inside the liquid in a high temperature and pressure, decomposing the compounds. This attractivecombinatory technology has received a great deal of attention thanks to having the following advantages: adaptability to the environment, usage of clean energy, recovery of heavy metals,treatment of wastes with a high toxicity, no generation of secondary pollution in the environment,and being more economical [2-4]. The aim of this study is to determine the efficiency of thesonoelectrochemical process in the decomposition of C.I. Reactive Yellow 145 from aqueous media. Methods A CCD was used for determining the optimum conditions for discoloration of RY145. Theexperimental results were analyzed using Design-Expert Version8.0.5, and the regression modelwas proposed. The initial pH (2.0-11.0), nano-TiO2 (0.1-1.0 g.L-1), time (300-7200 s) and applied voltage (0.5 – 1.5 V) were selected as four independent variables in the degradation process ofRY145. Result and discussion In figure 1, the response surface and 3D plots were shown as a function of pH (from 4.25 to 8.75) and applied potential (at range 0.825 – 1.475 V) at constant condition of 4800 s and 0.0272 g nanoTiO2. The decolorization percentage increased with increased potential at both acidic andbasic conditions. However, higher rate was again obtained at acidic medium (i.e. pH = 4.25). The OH production rate was increased with increasing potential, and thus, more OH can diffuse from the surface of the electrode into the solution. ConclusionThe degradation of the RY145 was optimized with sonoelectrochemistry system using RSM. The effects of four important operational parameters including pH of solution, Amount of TiO2, time, and potential were evaluated by the response surface and counter plots. Analysis of variance(ANOVA) showed the relative significance of process parameters in decolorization process. This result indicated that pH was the main factor, and the interactions of other parameters werediscussed in detail. Optimization results showed that the optimal conditions for significantexperimental factors were pH= 4.25, applied potential= 1.4 V, TiO2 amount=0.0235 g and contact time= 5700 s. At this conditions, predicted maximum of decolorization efficiency was over 91%. The present results showed that sonoelectrochemistry assisted by CCD have a good potential for dye removal from aqueous solution in the industrial application.

کلیدواژه ها:

Sono- Electrochemical ، Reactive Dye ، Discoloration ، RSM