Biomedical subjects

Jacek Makinia

Publications and source records attributed to Jacek Makinia.

3 recordsLinked to original sources

PubMed2005

Long-term simulation of the activated sludge process at the Hanover-Gümmerwald pilot WWTP.

The aim of this study was to obtain a validated model, consisting of the Activated Sludge Model No. 3 (ASM3) and the EAWAG bio-P module, which could be used as a decision tool for estimating the maximum allowable peak flow to wastewater treatment plants during stormwater conditions. The databases used for simulations originated from the Hanover-Gummerwald pilot plant subjected to a series of controlled, short-term hydraulic shock loading experiments. The continuous influent wastewater composition was generated using on-line measurements of only three parameters (COD, N-NH4+, P-PO4 3-). Model predictions were compared with on-line data from different locations in the activated sludge system including the aerobic zone (concentrations of N-NH4+, N-NO3-) and secondary effluent (concentrations of P-PO4 3-). The simulations confirmed experimental results concerning the capabilities of the system for handling increased flows during stormwater events. No (or minor) peaks of N-NH4+ were predicted for the line with the double dry weather flowrate, whereas peaks of N-NH4+ at the line with the quadruple dry weather flowrate were normally exceeding 8 g Nm(-3) (similar to the observations).

Forecasting↗

PubMed2005

Evaluation of empirical formulae for estimation of the longitudinal dispersion in activated sludge reactors.

Tracer studies are widely applied to characterize the hydraulic properties of reactors. In the case of activated sludge reactors, however, tracer test results are difficult to interpret due to internal and returned activated sludge recirculation. Empirical formulae can be considered as an alternative method of estimating the hydraulic conditions within the activated sludge reactor. The aim of this study is to evaluate accuracy of four empirical formulae for the full-scale conditions based on the results of tracer studies performed at the Rock Creek Wastewater Treatment Plant (WWTP) in Hillsboro, OR (USA). Values of the dispersion coefficient, E(L), were first estimated using a 1-D advection-dispersion equation and setting a sum of squares of differences between the observed and calculated tracer concentrations to a minimum. The estimated values of E(L) coefficient remained within the range of 1043-1580 m2/h. The best approximation of dispersion was obtained from the formula of Fujie et al. (1983, J. Ferment. Technol. 63(3), 295). Also the formula of Murphy and Boyko (1970, J. San. Eng. ASCE 96(2), 211) generated E(L) values of the same order as the optimum E(L). The accuracy of these formulae was further confirmed based on the results of studies reported in the literature.

Bioreactors↗

PubMedDate not supplied

Temperature modeling in activated sludge systems: a case study.

A model of temperature dynamics was developed as part of a general model of activated-sludge reactors. Transport of heat was described by the one-dimensional, advection-dispersion equation, with a source term based on a theoretical heat balance over the reactor. The model was compared to several reference models, including a tanks-in-series model and the dispersion model with heat components neglecting biochemical-energy inputs and other activated-sludge, heat-balance terms. All the models were tested under steady-state and dynamic conditions at a full-scale facility, the Rock Creek wastewater treatment plant in Hillsboro, Oregon, using meteorological data from a station located 16 km from the plant. The dispersion model and tanks-in-series model matched in situ temperature data with absolute-mean errors less than 0.1 degrees C. Neglecting biochemical-heat-energy inputs in the activated-sludge reactor underestimated temperatures by up to 0.5 degrees C. The biochemical-heat-energy inputs accounted for 30 to 40% of the total heat flux throughout the year.

Bioreactors↗