| Summary: | 碩士 === 崑山科技大學 === 環境工程研究所 === 103 === An empirical model (incorporating apparent kinetics) that can be used for simulating variations in substrate residual concentration with different operating conditions of the suspended-growth reactor is formulated. Two effluent-recycled suspended-growth reactors (reactors A and B with H2O2 oxygenation) maintained at the operating temperature of 30 1oC and superficial velocity of 1.0 m/h were also used to treat a non-inhibitory substrate molasses by varying three different organic loading rates (OLR = 1.5, 3.0 and 6.0 kg COD/m3-d) to generate experimental data. Thus, not only the performance and the substrate degradation kinetics of the suspended-growth reactor can be evaluated but the empirical model can also be validated by experiments.
Reactor A was operated by maintaining a fixed hydraulic retention time (HRT) of 4 h but with different influent COD concentrations of 250, 500, and 1000 mg/L (OLR = 1.5, 3.0 and 6.0 kg COD/m3-d). In contrast, reactor B was operated by maintaining a fixed influent COD concentration of 1500 mg/L but with different HRT of 24, 12, and 6 h (OLR = 1.5, 3.0 and 6.0 kg COD/m3-d). At the OLR of 1.5–6.0 kg COD/m3-d, the biomass concentration of the two suspended-growth reactors (5020–10800 mg VSS/L) was evidently higher than that of the conventional activated sludge system, the removal of COD reached above 90%, respectively, the specific substrate utilization rate (0.47–0.64 mg COD/mg VSS-d) increased with an increase in OLR, and the specific oxygen utilization rate (24–48 mg O2/g VSS-h) also increased with an increase in OLR.
From the batch experiments, the obtained Monod kinetic parameter k and Ks were 6.0–9.0 mg COD/mg VSS-d and 52–82 mg COD/L, respectively. Also, the k value increases with increasing OLR. By using the validated empirical model (Monod kinetics), the calculated COD removal efficiencies are 9% deviated from the experimental results. Thus, not only the Monod kinetic parameter values obtained in the present study are very reliable but the proposed empirical model can also be used to predict the treatment performance of suspended-growth reactors appropriately.
|
|---|
