Reduction of excess sludge in a sequencing batch reactor by lysis-cryptic growth using quick lime for disintegration under low temperature.
In the present study, quick-lime-based thermal-alkaline sludge disintegration (SD) under low temperature was combined with cryptic growth to investigate the excess sludge reduction efficiency in the sequencing batch reactor (SBR). The optimized condition of SD was as follows: T = 80℃, pH = 11, t = 180 min, and the SD rate was about 42.1%. With 65.6% of excess sludge disintegrated and returned to the SBR, the system achieved sludge reduction rate of about 40.1%. The lysis-cryptic growth still obtained satisfactory sludge reduction efficiency despite the comparative low SD rate, which suggested that disintegration rate might not be the decisive factor for cryptic-growth-based sludge reduction. Lysis-cryptic growth did not impact the effluent quality, yet the phosphorus removal performance was enhanced, with effluent total phosphorus concentration decreased by 0.3 mg/L (33%). Crystal compounds of calcium phosphate precipitate were detected in the system by Fourier transform infrared spectroscopy and X-ray diffraction, which indicated the phosphorus removal potential of SD using lime. Moreover, endogenous dehydrogenase activity of activated sludge in the lysis-cryptic system was enhanced, which was beneficial for sludge reduction. SD and cryptic growth in the present study demonstrates an economical and effective approach for sludge reduction.
a Environmental Science and Engineering Center , Harbin Institute of Technology Shenzhen Graduate School , Shenzhen , People's Republic of China.|b Shenzhen Key Laboratory of Water Resource Utilization and Environmental Pollution Control , Shenzhen , People's Republic of China.|c Shenzhen Public Technological Service Platform for Urban Waste Energy Regeneration , Shenzhen , People's Republic of China.
Xiao-Mei
XM
Lv
d Urban and Landscape Planning Research Center , Harbin Institute of Technology Shenzhen Graduate School , Shenzhen , People's Republic of China.
Ju-Sheng
JS
Song
a Environmental Science and Engineering Center , Harbin Institute of Technology Shenzhen Graduate School , Shenzhen , People's Republic of China.|b Shenzhen Key Laboratory of Water Resource Utilization and Environmental Pollution Control , Shenzhen , People's Republic of China.|c Shenzhen Public Technological Service Platform for Urban Waste Energy Regeneration , Shenzhen , People's Republic of China.
Ji
J
Li
a Environmental Science and Engineering Center , Harbin Institute of Technology Shenzhen Graduate School , Shenzhen , People's Republic of China.
Kun
K
Zhai
D019149:Bioreactors; D017610:Calcium Compounds; D010087:Oxides; D010758:Phosphorus; D012722:Sewage; D013696:Temperature; D014865:Waste Disposal, Fluid
D017610:Calcium Compounds; D010087:Oxides; D012722:Sewage; D010758:Phosphorus; C016538:lime
Lysis-cryptic growth; calcium phosphate precipitate; dehydrogenase activity; lime; sludge reduction; thermal-alkaline