Sludge reduction and microbial community structure in an anaerobic/anoxic/oxic process coupled with potassium ferrate disintegration.

An anaerobic/anoxic/oxic (AAO) wastewater treatment system combining with a potassium ferrate (KFeO) oxidation side-stream reactor (SSR) was proposed for sludge reduction. Batch experiments showed that optimal KFeO dosage and reaction time for sludge disintegration was 100mg/g suspended solids (SS) and 24h, respectively. Subsequently, an AAO-SSR and a conventional AAO were operated in parallel to investigate effects of KFeO oxidation on process performance, sludge characteristics and microbial community structures.

[Spectral Characteristics of Dissolved Organic Matters in Reject Water from Wastewater Treatment Plants].

Reject water generated from sludge thickening, dewatering and stabilization process contains high-content and complex dissolved organic matters (DOM). The spectral characteristics of DOM in the reject water were investigated by three-dimensional excitation-emission matrix and Fourier transform infrared spectroscopy. Fluorescent DOM (FDOM) from reject water were decomposed into six components by parallel factor analysis, the protein-like C1 (275/355 nm), C4 (235/350 nm) and C6 (275/305 nm) and the humic-like C2 (250, 340/440 nm) , C3 (320/380 nm) and CS (250/465 nm).

Effects of alkalinity on membrane bioreactors for reject water treatment: Performance improvement, fouling mitigation and microbial structures.

Two submerged membrane bioreactors (MBRs) for reject water treatment were operated to investigate effects of sodium bicarbonate (SB) addition on enhancing process performance and mitigating membrane fouling. Results showed that SB addition enhanced average removal efficiencies of COD and NH4-N by 14.6% and 38.

[Study on affecting factors of simultaneous nitrification and denitrification in moving-bed biofilm system].

The phenomenon of simultaneous nitrification and denitrification (SND) has taken place in moving-bed biofilm reactor (MBBR) steadily. The effect of C/N to denitrification effectiveness has been also studied in the experiment. The results of the treatment show that better denitrification efficiency could be obtained by increasing C/N ratio and the removal ratios of TN reached 92.