Design of the photocatalyst reactor with a graded-type structure to increase the degradation ability of methylene blue by using titania

The development of the textile industry can have negative impact on water pollution. The permissible concentration of methylene blue pollutants in the waters has a threshold value of about (5-10) mg/L while the textile industry waste has levels of around (20-30) mg/L. The existence of methylene blue in the waters destroys the ecosystem. Therefore, a wastewater treatment technology that can decompose methylene blue is needed. An alternative method that can be applied in the decomposition process is the photodegradation method using a photocatalyst. The photocatalyst reactor for degrading methylene blue pollutants has been successfully constructed. The reactor is constructed with a series of graded-type construction (4 vertical reservoirs) using TiO2 substrate which is coaxially coated against UV lamp tube (TL type) which is mounted horizontally in the middle of the reservoir. Pollutant degradation tests were carried out using 60 liters of methylene blue 20 ppm with a flow rate of 6 liters/minute for 24 hours. The TiO2 substrate is made with materials composition ratio of 3: 1: 3: 1,3 for TiO2, PEG 4000, resin, and hardener. The photocatalyst reactor is equipped with a photodetector (with a light source in the form of an LED) to determine the level of pollutant degradation (concentration/ppm) which has been calibrated using a UV-Vis spectrophotometer (pollutant absorbance level). The test results show that there has been a decrease in the concentration of pollutants from 20 ppm to 11.94 ppm which mean that was able to degrade methylene blue pollutants by 8.06 ppm. Other results showed that the photodegradation rate of methylene blue during the day (10am to 4pm) was higher than other times. So, based on the results obtained, its shows that the implementation of the photocatalyst rector can decompose compounds and reduce water pollution due to methylene blue.