The temperature dependence of the kinetic parameters derived for the aerobic treatment of wastewater from the washing of olives prior to the oil production process

Abstract

A kinetic study of aerobic treatment of wastewater produced from the washing of olives, prior to the olive oil manufacturing process, was carried out at two different temperatures (14 and 28°C) and hydraulic retention times of 6, 12, 18, 24 and 30 h. The wastewater was more efficiently treated at an operating temperature of 28°C. Over 93% of soluble COD was removed at a retention time of 6 h whereas at 14°C, COD removal was only 67% at the same retention time. At 28 °C the maximum specific substrate utilization rate (q _m) was about 11 times faster than at 14°C. The biokinetic parameters μ _m (maximum growth rate of microorganisms), K _s (saturation constant) and k _d (endogenous respiration coefficient) were temperature dependent and showed higher values at 28 °C than at 14 °C. The overall growth yield (Y) was of the same order of magnitude at the different temperatures.

Key words:

• Wastewater
• Washing of Olives
• Aerobic Treatment
• Temperature
• Kinetic Parameters
• Activated Sludge