The use of a pumice stone in removal of petroleum hydrocarbons from industrial wastewater through coagulation and flocculation

Background: Petroleum hydrocarbons that are released from industrial processes cause damage to aquatic life and degrade ecosystems by accumulating in the food chain, allowing living organisms to produce toxic secretions. Methods: In this study, a pumice stone was used to remove total petroleum hydrocarbons (TPHs) from industrial wastewater in the south refinery company in Iraq/Basrah by coagulation and flocculation processes using the design of experiments (DOE) approach using the method of analyzing screening designs and measurement of the samples using GC instrument. Results: The maximum removal was 99% at pH 3, coagulation dose of 0.5 g, and time of 60 min, and a comparison was made between the DOE and the multiple linear regression (MLR) to determine the effectiveness of the system used, which proved its incredible effectiveness. Conclusion: According to the results, a great convergence between the actual and prediction results of removal was found, while MLR was very far from the actual and predicted removal results. The high efficiency of pumice stone was found in removing petroleum hydrocarbons from the industrial wastewater of the South Refineries Company. Pumice stone is widely available in the market and cheap economically.