The control measures for deterioration of aerobic activated sludge were experimented. Wastewater samples with different pH, temperature, SVI, and MLSS were investigated to detect the cause of sludge deterioration. The results show that after being operated at high S2O3 2(which could lead to a pH decrease) loading in an A/O biological reactor treated for coking wastewater, though the pH was cont...

One approach to reduce nutrient losses from livestock farms is to apply biological waste treatment systems such as biological nitrogen (N) removal or enhanced biological phosphorus (P) removal (EBPR) to reduce the nutrient content of land-applied waste. The EBPR process takes advantage of the ability of P-accumulating organisms (PAOs) to sequester excess P as polyphosphate granules in their cyt...

Free nitrous acid (FNA), which is the protonated form of nitrite and inevitably produced during biological nitrogen removal, has been demonstrated to strongly inhibit the activity of polyphosphate accumulating organisms (PAOs). Herein we reported an efficient process for wastewater treatment, i.e., the oxic/anoxic/oxic/extended-idle process to mitigate the generation of FNA and its inhibition o...

Effectiveness of ozonation before and after biological treatment for removal of recalcitrant organic matter in bleached kraft pulp effluents was compared. Two industrial ECF bleached eucalypt kraft pulp effluents (E1 and E2) were pretreated with 100 mg O3/L. Raw and pretreated effluents were treated biologically in bench-scale sequencing batch reactors, under constant conditions. Following biol...

In this study the Fuzzy Robust Principal Component Analysis (FRPCA) method is used to monitor a biological nitrogen removal process, performances of this method are then compared with classical principal component analysis. The obtained results demonstrate the performances superiority of this robust extension compared with the conventional one. In this method fuzzy variant of PCA uses fuzzy mem...

A novel polyphosphate kinase (PPK) was retrieved from an uncultivated organism in activated sludge carrying out enhanced biological phosphorus removal (EBPR). Acetate-fed laboratory-scale sequencing batch reactors were used to maintain sludge with a high phosphorus content (approximately 11% of the biomass). PCR-based clone libraries of small subunit rRNA genes and fluorescent in situ hybridiza...

Biological Nutrient Removal (BNR) is critical for the preservation of our lakes and streams. Large amounts of waste products are passed through our sewage treatment systems on a continuous basis. Nutrient loads discharged from these systems must be reduced to avoid eutrophication of the receiving waters. Microbes are particularly useful in biodegrading most of the compounds treated by wastewate...

Sludge produced in wastewater treatment plants (WWTPs) reaches around 1% of the wastewater volume treated whilst the processes for sludge handling and disposal represent from 20 to 60% of operating costs. It is widely recognised that sludge for disposal is one of the most critical issues today for WWTPs operators. The tendency of many countries seems to be aimed towards a biowaste prevention wh...