TY - JOUR
T1 - Control of Microthrix parvicella and sludge bulking by ozone in a full-scale WWTP
AU - Levén, Lotta
AU - Wijnbladh, Erik
AU - Tuvesson, Malin
AU - Kragelund, Caroline
AU - Hallin, Sara
PY - 2016
Y1 - 2016
N2 - Bulking and rising sludge are common problems in wastewater treatment plants (WWTPs) and are primarily caused by increased growth of filamentous bacteria such as Microthrix parvicella. It has a negative impact on sludge settling properties in activated sludge (AS) process, in addition to being responsible for foam formation. Different methods can be used to control sludge bulking. The aim of this study was to evaluate the dosage of on-site generated ozone in the recycled AS flow in a fullscale WWTP having problems caused by M. parvicella. The evaluation of the experiment was assessed by process data, microscopic analysis and microbial screening on the experimental and control line before, during and after the period of ozone dosage. The ozone treatment resulted in decreased abundance of M. parvicella and improved the settling properties, without impairing the overall process performance. Both chemical oxygen demand (COD)-and N-removal were unaffected and the dominant populations involved in nitrification, as analysed by fluorescent in situ hybridization, remained during the experimental period. When the ozone treatment was terminated, the problems with sludge bulking reappeared, indicating the importance of continuous evaluation of the process.
AB - Bulking and rising sludge are common problems in wastewater treatment plants (WWTPs) and are primarily caused by increased growth of filamentous bacteria such as Microthrix parvicella. It has a negative impact on sludge settling properties in activated sludge (AS) process, in addition to being responsible for foam formation. Different methods can be used to control sludge bulking. The aim of this study was to evaluate the dosage of on-site generated ozone in the recycled AS flow in a fullscale WWTP having problems caused by M. parvicella. The evaluation of the experiment was assessed by process data, microscopic analysis and microbial screening on the experimental and control line before, during and after the period of ozone dosage. The ozone treatment resulted in decreased abundance of M. parvicella and improved the settling properties, without impairing the overall process performance. Both chemical oxygen demand (COD)-and N-removal were unaffected and the dominant populations involved in nitrification, as analysed by fluorescent in situ hybridization, remained during the experimental period. When the ozone treatment was terminated, the problems with sludge bulking reappeared, indicating the importance of continuous evaluation of the process.
KW - Activated sludge process
KW - Filamentous bacteria
KW - Fluorescent in situ hybridization
KW - Nitrogen removal
UR - http://www.scopus.com/inward/record.url?scp=84959317749&partnerID=8YFLogxK
U2 - 10.2166/wst.2015.560
DO - 10.2166/wst.2015.560
M3 - Journal article
C2 - 26901730
AN - SCOPUS:84959317749
SN - 0273-1223
VL - 73
SP - 866
EP - 872
JO - Water Science and Technology
JF - Water Science and Technology
IS - 4
ER -