I am now reading “Removal of color substances using photocatalytic oxidation for membrane filtration processes” for deeper understanding of what membrane is capable of. The study was aimed to determine the effectivity of UV/TiO2/H2O2 to remove color. So the technique can remove TOC at 38% and color 400 at 89%. The interesting fact was if the dosage of H2O2 is less than 0.016 M, then the system is accelerated, produce better TOC rejection and color removal, over-dosage (more than 0.016) declines the rejection enhancement. I only get this point, it appears that there is a break point dosage at which best removal can be achieved. However, there is no information yet the comparison between only TiO2/UV and TiO2/UV/H2O2 of the efficiency.
So I read this paper, and found something valuable there. Photocatalysis is often used for treating water organic pollutants. Titanium dioxide is usually used because it is stable and inexpensive. This paper stated that one author observed that increasing the initial pH of phenol, increases the decomposition rate, reaching max value at 3.3, then decreasing upon further increase in pH.
There are various methods available to coat TiO2 onto the surface of the membrane. I will explain briefly some of them, and the method I used.
Ion assisted deposition
This method was used for coating on super-hydrophobic porous teflon membrane. The author stated that the coating of TiO2 by the chemical wet process such as a sol-gel method is very difficult. The method involved acceleration voltage, temperature, and oxygen. Heated at 523 K.