Effects of sequential ozonation and adsorption in the removal of water-soluble fraction of crude oil, leading to total organic carbon and toxicity reduction for rainbow trout larvae

Document Type : Original Article


1 Department of Environmental Health Engineering, School of Health, Shahid Sadoughi University of Medical Sciences, Yazd, Iran

2 Environment Research Center, Isfahan University of Medical Sciences, Isfahan, Iran


Aims: The purpose of this study was to evaluate the performance of the sequential application of ozonation and activated carbon processes in the elimination of water-soluble crude oil and thereby reducing total organic carbon (TOC) and toxicity for the rainbow trout larvae. Materials and Methods: A series of water-soluble fractions of crude oil, 5-100 ml/l, were prepared. Groups of ten rainbow trout fish larvae were exposed to the solution for 24, 48, and 96 hours. Toxicity (LC 50 : Median lethal concentration) and TOC tests were performed for the solutions before and after their treatment by sequential ozonation and activated carbon adsorption. Results: The LC 50 (96 hours) and TOC of the sample before the treatment process were 60 mg/l and 55 mg/l, respectively. After adsorption by 10 mg/l activated carbon, followed by ozonation with a concentration of 1 mg/l, the LC 50 increased to 145 mg/l and TOC reduced to 36 mg/l. Those values, after treatment with 30 mg/l activated carbon, followed by 7 mg/l ozone, reached 196 mg/l and 28 mg/l, respectively. In the experiment, ozonation by 1 mg/l ozone was applied, and then adsorption was carried out by 10 mg/l activated carbon, and the LC 50 was 149 and TOC was 35 mg/l. In the experiments with 7 mg/l ozone followed by 30 mg/l activated carbon, LC 50 reached 204 mg/l and TOC reduced to 28.5 mg/l. Conclusions: Primarily ozonation of crude oil polluted waters followed by adsorption by activated carbon can increase the removal efficiency of the process, which results in significant TOC and toxicity reduction.


Volume 1, May
May 2012
Pages 1-5
  • Receive Date: 06 February 2023
  • Accept Date: 06 February 2023