title: Optimization of operating parameters for sludge process reduction under alternating aerobic/oxygen-limited conditions by response surface methodology.
abstract: Batch tests were employed to estimate the optimal conditions for excess sludge reduction under an alternating aerobic/oxygen-limited environment using response surface methodology. Three key operating parameters, initial mixed liquor suspended solids (initial MLSS), HRT (hydraulic retention time) and reaction temperature (T), were selected, and their interrelationships studied by the Box-Behnken design. The experimental data and ANOVA analysis showed that the coefficient of determination (R(2)) was 0.9956 and the adjR(2) was 0.9912, which demonstrates that the modified model was significant. The optimum conditions were predicted to give a maximal ΔMLSS yield of 226 mg/L at an initial MLSS of 10,021 ± 50 mg/L, an HRT of 9.1h and a reaction temperature of 29°C. The prediction was tested by triplicate experiments, where a ΔMLSS yield of 233 mg/L was achieved under the chosen optimal conditions. This excellent correlation between the predicted and measured values provides confidence in the model.
authors: State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, PR China.
authors: Shan-Shan
authors: SS
authors: Yang
authors: Wan-Qian
authors: WQ
authors: Guo
authors: Xian-Jiao
authors: XJ
authors: Zhou
authors: Zhao-Hui
authors: ZH
authors: Meng
authors: Bo
authors: B
authors: Liu
authors: Nan-Qi
authors: NQ
authors: Ren
mesh_terms: D000332:Aerobiosis / Q000187:drug effects; D000704:Analysis of Variance; D057919:Biological Oxygen Demand Analysis; D019149:Bioreactors / Q000382:microbiology; D001709:Biotechnology / Q000295:instrumentation / Q000379:methods*; D002244:Carbon / Q000032:analysis; D005947:Glucose / Q000378:metabolism; D008954:Models, Biological; D010100:Oxygen / Q000494:pharmacology*; D011506:Proteins / Q000378:metabolism; D015203:Reproducibility of Results; D012722:Sewage / Q000382:microbiology*; D013696:Temperature; D013997:Time Factors
chemical_list: D011506:Proteins; D012722:Sewage; D002244:Carbon; D005947:Glucose; D010100:Oxygen