Joint aerobic biodegradation of wastewater from table olive manufacturing industries and urban wastewater

Wastewater generated in the elaboration of table olives has been treated us ing activated sludge from a municipal wastewater plant after adequate accli mation. To avoid bactericide properties of some chemical structures present in this type of effluents, synthetic urban wastewater has been used to dil ute the original wastewater. The main parameters affecting efficiency of bi ological processes have been studied. Thus, initial biomass concentration, temperature up to 303 K (upper working temperature limit = 313 K) and initi al substrate concentration exerted a positive influence on COD degradation rate. The optimum pH was found to be around 7, experiencing a slight inhibi tion on cell activity at pH 4. Under the experimental conditions investigat ed other parameters like polyphenol content, absorbance at 254 nm and total organic carbon were also reduced to some extent. Only nitrates amount was increased after the biological process took place. A kinetic model based on Monod equation was proposed and applied to experim ental results. The maximum specific growth rate was calculated by means of the aforementioned kinetic model. The value of this parameter as a function of temperature was fitted to an Arrhenius expression, mu(max) = 9.43 x 10( 10) exp(72021/RT) h(-1) (R in J mol(-1) K-1 283 K < T < 303 R, pH approxima te to 7-10).