Reduction in excess sludge production in a dairy wastewater treatment plant via nozzle-cavitation treatment: case study of an on-farm wastewater treatment plant.
Nozzle-cavitation treatment was used to reduce excess sludge production in a dairy wastewater treatment plant. During the 450-d pilot-scale membrane bioreactor (MBR) operation, when 300 l of the sludge mixed liquor (1/10 of the MBR volume) was disintegrated per day by the nozzle-cavitation treatment with the addition of sodium hydrate (final concentration: 0.01% W/W) and returned to the MBR, the amount of excess sludge produced was reduced by 80% compared with that when sludge was not disintegrated. On the basis of the efficiency of CODCr removal and the ammonia oxidation reaction, it was concluded that the nozzle-cavitation treatment did not have a negative impact on the performance of the MBR. The estimation of the inorganic material balance showed that when the mass of the excess sludge was decreased, the inorganic content of the activated sludge increased and some part of the inorganic material was simultaneously solubilized in the effluent.
Hirooka
Kayako
K
Laboratory of Sustainable Environmental Biology, Graduate School of Agricultural Science, Tohoku University, Japan. hirooka@bios.tohoku.ac.jp
Asano
Ryoki
R
Yokoyama
Atsushi
A
Okazaki
Masao
M
Sakamoto
Akira
A
Nakai
Yutaka
Y
D000383:Agriculture / Q000379:methods*; D019149:Bioreactors; D017076:Computer-Aided Design; D003611:Dairy Products; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007220:Industrial Waste / Q000517:prevention & control*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012722:Sewage / Q000737:chemistry*; D013010:Sonication / Q000295:instrumentation*; D014877:Water Pollution, Chemical / Q000517:prevention & control*; D018508:Water Purification / Q000295:instrumentation* / Q000379:methods
D007220:Industrial Waste; D012722:Sewage