Photocatalytic Degradation of Toluene (Component of Crude Oil) Contaminated Water Using Titanium Dioxide Based Catalyst: A Review

Petroleum industry is one of the fastest growing industry in the world, and it contributes significantly to the profitable development in unindustrialized countries. The wastewater from a petroleum industry consist a wide variety of pollutants like petroleum hydrocarbons, mercaptans, oil and grease, benzene, toluene, ethylbenzene, xylene, phenol, ammonia, sulphide and other organic compounds etc. All these compounds are present as very complex form in discharged water of petroleum industry, which are harmful to the environment and human health directly or indirectly. Pollution of soil-water interface due to the release of hydrocarbons in environment is a major public health concern, and therefore, remediation of these pollutants is needed to reduce risk to human and environment. Various methods such as physical, chemical, biological, and Advanced oxidation processes (AOPs) methods are used to degrade these pollutants from wastewater. The conventional remediation methods can only change the phase of contaminants without destroying them, thereby leading to another pollution problem. This review paper highlights some current treatment methods of toluene contaminated water, and to introduce a proposed method that sought to develop an oleophilic and hydrophobic composite catalyst (ESA-TiO2-FeS2-Kenaf), that would harvest the toluene content, and simultaneously degrade the harvested toluene content using solar light as the energy source.