[Performance and mechanism of excess sludge reduction in an OSA (oxic-settling-anaerobic) process].

The possible factors of sludge reduction such as sludge decay, energy uncoupled metabolism, anaerobic oxidation with low sludge production were discussed in an OSA (oxic-settling-anaerobic) process. It has been confirmed that sludge decay included hydrolysis and acidogenesis of dead microorganism and particle organic carbon adsorbed in sludge flocs and endogenous metabolism. The concentrations of SCOD, NH4(+)-N, TP in supernatant were increased gradually during sludge anaerobic treatment in the batch experiments.

[Performance of treating wastewater and anti-shockloading in oxic-settling-anaerobic (OSA) process for minimization of excess sludge].

Efficiency of pollution degradation, performance of activated sludge, effect of temperature fluctuation and recalcitrant organic compounds on system stability were investigated in OSA process for minimization of excess sludge. CAS process and OSA process were run with synthetic wastewater for 240 d. The results indicate that the OSA process excels the CAS process as a whole.

[Non-filamentous sludge bulking caused by low concentration of dissolved oxygen and phosphorus deficiency and its control].

Non-filamentous sludge bulking occurred during sludge acclimation in lab-scale bio-reactors and the characteristics, properties and degrading pollutants capability of non-filamentous sludge were analyzed. Both low DO concentration (0 - 0.7 mg/L) and low ratio of P/BOD5 (0.