Initial-rate based method for estimating the maximum heterotrophic growth rate parameter (μ _(Hmax))

摘要

Currently, the method most used for measuring the maximum specific growth rate (μ Hmax) of heterotrophic biomass is by respirometry, using growth batch tests performed at high food/microorganism ratio. No other technique has been suggested, although the former approach was criticized for providing kinetic constants that could be unrepresentative of the original biomass. An alternative method (seed-increments) is proposed, which relies on measuring the initial rates of respiration (r _(O2ini)) at different seeding levels, in a single batch, and in the presence of excess readily biodegradable substrate (S _S). The ASM1-based underlying equations were developed, which showed that μ _(Hmax) could be estimated through the slope of the linear function of r _(O2_ini)·(V WW+v ML) vs v _(ML) (volume of mixed liquor inoculum); V WW represent the wastewater volume added. The procedure was tested, being easy to apply; the postulated linearity was constantly observed and the method is claimed to measure the characteristics of the biomass of interest.