DEVELOPMENT OF TiO2-BASED CATALYST SYSTEM AND PROTOTYPE OF PHOTOREAKTOR FOR DYE REMOVAL IN THE TEXTILE WASTEWATER MODEL

• Main Author: (NIM : 30212001), SUTISNA
• Format: Dissertations
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/31164
• Institution: Institut Teknologi Bandung

<p align="justify">Recently, clean water crisis is a real problem around us. The increase in human population and the rapid growth of the industries have contributed greatly to the pollution of clean water sources which are the primary needs of life support. Several conventional wastewater treatment techniques have been widely developed. But in general they use high technology, the expensive cost, and produce by-products that are not environmentally friendly. Heterogeneous photocatalysis using TiO2 as a photocatalyst is an advanced oxidation processes (AOPs) that is very promising for the mineralization of toxic compounds and dyes under visible and/or UV irradiations. However, there are some drawbacks of using TiO2 powder directly for photocatalytic processes: TiO2 is immersed in water, the need for post-treatment to remove the TiO2 particles from the treated water, which requires energy and time, and the agglomeration probability of TiO2 powder in water when it is suspended. Therefore, a modification has been carried out by superimposing the TiO2 catalyst on the surface of light and transparent polypropylene (PP) using combined electrostatic and heating methods. The coating process was initiated by generating electrostatic charges on PP so that the TiO2 particles can be attached. Nanoparticle binding has been improved by heating and softening the granule surface at a temperature of 100oC. Mass variations of TiO2 and heating time have been performed and obtained that the combination 2 g of TiO2 for every 100 g of PP granules and heating time of 75 min are the optimal parameters in the coating process. The simple theories have been also proposed to explain effect of heating time on coating effectiveness and limitation number of TiO2 particles that can be coated on the granule surface, showing very good agreement between the fitting results and the experimental data. <br /> <br /> The photocatalytic process has enormous potential applications in wastewater treatment. However the implementation of large-scale photocatalytic processes requires the use of a reactor, a device that carries photons, photocatalysts and reactants in a contact. A prototype of flat panel photocatalytic reactor (FP photoreactor) that is stimulated by sunlight has been designed for the processing of the MB dye. The photoreactor consists of reactor panels of hollow glass filled <br /> <br /> with TiO2-coated granules. The reactor panels are arranged tilted and terraced and the wastewater is circulated through the panels. The photoreactor was tested for treating 30 L of Methylene Blue (MB) solution with an initial concentration of 25 mg L-1. We observed that the reactor was able to degrade more than 98% of the MB in the solution after 48 h of solar <br /> <br /> illumination. The performance of the FP photoreactor was also improved by arranging several reactor panels in series. Using four panels, we observed that the complete decomposition of the same MB solution can be achieved within 10 h. The photoreactor has also been able to reduce the levels of biological oxygen demand (BOD) and chemical oxygen demand (COD) levels of the test solution by 82% and 80% respectively. The proposed FP photoreactor is a very promising alternative for use in decomposing recalcitrant organic pollutants in wastewater. The effects of operational parameters such as the initial concentration and the volume of the solution have also been evaluated in this experiment. To evaluate the reusability performance of the photoreactor, the photodegradation of a concentration of 25 mg L-1 (30 L) MB was repeated for as many as four cycles with the same duration using the four-panel photoreactor. During the four <br /> <br /> experimental cycles, the efficiency of the FP photoreactor to degrade MB was only reduced by approximatelly 1,5%. The stability of the photoreactor performance for repetitive use is also confirmed by the standard deviation of the efficiency for the photoreactor for a total of four experimental cycles is equal to 0.64%, indicating that the efficiency of the FP photoreactor remains almost constant. The FP photoreactor developed in this study have enormous potential to be applied in the large scale wastewater treatment in Indonesia, country with high sunlight intensity throughout the year. Comparing to similar reactor prototypes reported by other authors, the FP photoreactor is much simple in installation and immobilization of catalyst, better in cost savings, and easy in catalyst regeneration. This proposed photoreactor is potential for development of commercial scale wastewater treatments.<p align="justify"> <br />