Optimisation of the design parameters in an activated sludge system for the wastewater treatment of a potato processing plant.

BERTOLA, N; PALLADINO, L; BEVILACQUA, A.; ZARITZKY, N.

JOURNAL OF FOOD ENGINEERING

ELSEVIER SCI LTD

Lugar: Amsterdam; Año: 1999 vol. 40 p. 27 - 33

0260-8774

Aerated biological reactors at a laboratory scale, fed continuously with a model wastewater system, were used to obtain design parameters of an activated sludge process for the wastewater treatment of a potato processing plant. Experiments were performed using di€erent dilution rates (D) ranging between 0.01 and 0.13 h-1 to determine parameters such as: maximum specifc microbial growth rate (Mu max), saturation constant (Ks), coefficient of microbial decay (kd) and true biomass yield (YX/S). Design parameters were calculated from the mass balances of substrate consumption and biomass production under steady state, considering a Monod typeequation to represent the e€ect of substrate concentration on biomass production rate. The values of YX/S and kd were obtained from the linear plot of qS (specific rate of substrate consumption) vs. D. Experimental data regression led to YX/S =ˆ0.45 gVSS/gCOD and kd ˆ0.024 h-1. By non-linear regression of qS vs. substrate concentration (SS) data the following values were obtained Mumax ˆ0.09 h-1 and Ks ˆ0.006 g/l. Critical dilution rate was also calculated; it corresponds to the D value for which the cells of a reactor operating under such conditions are destroyed or are eliminated from the system at the same rate than they are produced.