Photo-catalytic degradation of dye by using raw and pre-treated ilmenite / Lee Ru Bin

• Main Author: Lee , Ru Bin
• Format: Thesis
• Published: 2018
• Subjects: GE Environmental Sciences; TA Engineering (General). Civil engineering (General)
• Online Access: http://studentsrepo.um.edu.my/11113/1/Lee_Ru_Bin.pdf; http://studentsrepo.um.edu.my/11113/2/Lee_Ru_Bin.pdf; http://studentsrepo.um.edu.my/11113/

Ilmenite is a natural mineral ore made up of TiO2 and iron. Most of the commercial TiO2 products are extracted and purified from ilmenite mineral. Recently, raw ilmenite has shown a great potential to be used as photo-catalyst for degradation of a harmful dye such as Reactive Black 5. However, the high concentration of Fe ions in ilmenite become the major drawbacks for dye photo-degradation because the presence of excessive Fe ion may lead to fast electron recombination rate. Therefore, pre-treatment on the ilmenite by reducing the content of Fe has been developed to increase the effectiveness for the photo-degradation of dye. Ilmenite has been pre-treated via single step chloride leaching process by using HCl as the leaching agent in order to remove an excessive amount of Fe ions. This is because chloride leaching process generates less waste as compared to sulphate leaching process and the by-product, iron chloride (FeCl2 and FeCl3) can be used for iron extraction. Comprehensive studies on different parameters, such as HCl concentration, temperature, time, and calcination temperature has been conducted in order to control the specific architecture of pre-treated ilmenite. Pre-treated ilmenite with low Fe content (0.76 - 7.15 atomic% of Fe) was successfully produced through chloride leaching process. It is interesting to observe that pre-treated ilmenite demonstrated complete (100%) dye degradation within 30 min but the raw ilmenite only able to achieve 40% of dye degradation efficiency. In this study, it was demonstrated that an appropriate low amount of Fe ions in pre-treated ilmenite plays an important role as an effective dopant by decelerate the recombination centre.