Efficiency of titanium dioxide photocatalytic activity in removing anionic surfactant of sodium dodecyl sulfate from waste water

The over use of surfactants, detergents and their draining have always been a problem for preserving water resources. Surfactants’ physical and chemical properties, especially their poor biodegradability, made them resistant to biological treatments. The aim of the present study was to assess the efficiency of titanium dioxide photocatalytic activity in removing anionic surfactant from the sewage water.

The research was performed using a Basic – applied method. The batch experiment was conducted by using a Photocatalytic reactor in the Environmental Health Research Center, Kerman University within the period of October – December 2013. The Performance of photo catalysis for the removal of anionic surfactant was assessed with variables such as, nano particles (0.25-1.5 g/L), PH (5-7-9), surfactant concentration, and UV irradiation time. Premiere experiments were conducted on synthetic wastewater and under the optimal condition they were continued with samples of real solutions. Surfactant was measured by spectrophotometer.

The maximum removal efficiency (95 %) was achieved with synthetic solution under the optimal conditions of pH =5, nano particle 0.75g/L, initial concentration of surfactant 100mg/L and 60min exposure time. The activity process followed Langmuir - Hinshelwood kinetics. The removal process with real solutions (wastewater beverage chime) failed to 74% under the optimal conditions.

Study showed the high efficiency of photocatalytic processing for the removal of soluble synthetic anionic surfactant under optimal conditions. The efficiency was much lower when used with real-solutions and high anionic surfactant concentrations