Ozone-biological activated carbon as a pretreatment process for reverse osmosis brine treatment and recovery.
Ozonation was used in this study to improve biodegradability of RO brine from water reclamation facilities. An ozone dosage ranging from 3 to 10 mg O(3)/L and contact times of 10 and 20 min in batch studies were found to increase the biodegradability (BOD(5)/TOC ratio) of the RO brine by 1.8-3.5 times. At the same time, total organic carbon (TOC) removal was in the range of 5.3-24.5%. The lab-scale ozone-biological activated carbon (BAC) at an ozone dosage of 6.0mg O(3)/L with 20-min contact time was able to achieve 3 times higher TOC removal compared to using BAC alone. Further processing with Capacitive Deionization (CDI) process was able to generate a product water with better water quality than the RO feed water, i.e., with more than 80% ions removal and a lower TOC concentration. The ozone-BAC pretreatment has the potential of reducing fouling in the CDI process.
Lee
Lai Yoke
LY
Centre for Water Research, Division of Environmental Science & Engineering, Faculty of Engineering, National University of Singapore, Singapore 117576, Singapore.
Ng
How Yong
HY
Ong
Say Leong
SL
Hu
Jiang Yong
JY
Tao
Guihe
G
Kekre
Kiran
K
Viswanath
Balakrishnan
B
Lay
Winson
W
Seah
Harry
H
D001673:Biodegradation, Environmental; D002244:Carbon / Q000032:analysis*; D009995:Osmosis; D010126:Ozone / Q000737:chemistry*; D012492:Salts / Q000032:analysis*; D018508:Water Purification / Q000379:methods*
D012492:Salts; C017082:brine; D010126:Ozone; D002244:Carbon