PENURUNAN NILAI COD LIMBAH CAIR INDUSTRI BATIK DENGAN METODE FOTODEGRADASI TERKATALISIS OLEH LAPIS TIPIS TiO2; THE DECREASING COD LEVEL OF BATIK INDUSTRY WASTEWATER BY PHOTODEGRADATION METHOD CATALYZED BY TiO2 THIN FILM

Sejati, Bina Karunia, Endang Tri Wahyuni

2015 | Disertasi | FMIPA

In this research, preparation, characterization and application of the TiO2 thin film as photocatalyst on the photodegradation of batik indsutry wastewater for decreasing COD level was carried out. The preparation of TiO2 thin film was done by DC reactive sputtering with the condition electrode voltage 4 kV, sputtering current 15 mA, vacum pressure 5×10-4 torr, deposition time 210 minutes, substrate temperature 250°C and the ratio of Ar/O2 gas pressure varied 85/15, 80/20, and 75/25%. The resulted TiO2 thin films were calcined at 300°C. In addition to calcination temperature 300 °C, calcination temperature 350 and 400 °C were applied at TiO2 thin film;85/15%. The COD level of batik waste was determined by titrimetic method. Identification of organic matter as contributor of COD was performed by FTIR and XRD. Photodegradation process was conducted by batch system in a closed reactor that was equipped by UV lamp. In this process, the influence of thickness of TiO2 film and irradiation time on the photodegradation effectiveness was evaluated. The results showed that incresing pressure argon gas, gave thicker TiO2 film and the resulted phase structure tended to be rutile. The XRD characterization showed that the higher temperature of calcination, phase structure of crystal transformed into rutile phase. Photodegradation process catalyzed by TiO2 thin film could decrease COD level from 864 mg/L (initial level) to 464 mg/L at the optimum conditions of the thickness of TiO2 film 774 nm and the UV irradiation time 18 hours.

Kata Kunci : TiO2 thin film; DC reactive sputtering; photodegradation, wastewater; COD