Study of the Pollution Generated by Wastewater from the Refining of Vegetable Oils

This study concerns the assessment of the pollution generated by three industrial discharges produced by the Lesieur company in Ain Harrouda for the production of vegetable oils, such as process water (PWW), ACID wastewater (AWW), and refining wastewater. (RWW). This wastewater is heavily loaded with pollutants that could pose serious environmental problems. The concentrations of polluting matter in chemical oxygen demand (COD), Biological Oxygen Demand (BOD), and Total suspended solids (TSS), variable in time, could strongly influence the effectiveness of treatment with sludge currently used by Lesieur. In addition, process wastewater and refining wastewater are loaded with fats and oils with varied concentration between3700 and 6000 mg/l. At the same time, wastewater from leg breaking has a concentration varying between 1000 and 6000 mg/L. Additionally, leg-breaking water has a concentration of Total suspended solids (TSS) varying between 10,000 mg/L and 23,000 mg/L. In comparison, process wastewater and refining water have concentrations (TSS) ranging between 4500 mg/L and 8000 mg/L, related to turbidity exceeding 10000 NTU. Furthermore, COD fluctuates between 700 and 3,400 mg/L and suspended matter between 500 and 8,000 mg/L with average pollution loads of 114 and 358 kg/day, respectively. Indeed, the COD/BOD5 ratio for process wastewater varies between 3 and 7. On the other hand, for basic wastewater, this ratio varies between 3 and 20, which could be due to the quality of wastewater with high polyphenol content. Indeed, refining wastewater has a COD/BOD5 ratio that varies between 2 and 4, which shows that organic matter is biodegradable compared to other types of wastewater. The phenol concentration varies over time and goes from 20 to 125 mg/L, while the surfactants have a variable concentration of 20 and 127 mg/L over time, then increases during the summer, taking into account the increase in market demand.