1. APPLICATION OF SECONDARY FLOTATION FOR IMPROVEMENT OF CONVENTIONAL ACTIVATED SLUDGE PROCESS SYSTEM
- Author
-
Wang, Lawrence K and Wang, Mu-Hao Sung
- Subjects
Liquids--Clarification ,Paper industry ,Wood-pulp industry ,Sludge bulking ,Sewage--Purification--Activated sludge process ,Case studies ,Technological innovations ,Continuous improvement process ,Water--Purification--Dissolved air flotation ,Petroleum industry and trade - Abstract
Wang, LK, and Wang, MHS (2023). Application of secondary flotation for improvement of conventional activated sludge process system. In: "Environmental Science, Technology, Engineering, and Mathematics (STEM)", Wang, LK, Wang, MHS, and Pankivskyi, YI (editors). Volume 2023, Number 3A, March 2023; pp.80 . DOI: 10.17613/jwrp-0e11 ; Lenox Institute Press, Massachusetts, USA. .....ABSTRACT: Dissolved air flotation (DAF) clarifier can be applied in series between the aeration basin and the existing overloaded secondary sedimentation in a conventional activated sludge process system to separate the living microorganisms before settling. This results in many improvements: (a) solids and hydraulic loadings on an overloaded secondary sedimentation are reduced for preventing sludge rising, increasing the overall clarification efficiency, and saving construction cost on expansion of secondary sedimentation facilities; (b) hydraulic loading on the existing aeration basin is reduced thus increasing retention time without increasing aeration basin size; (c) higher solids content of the wasted sludge from DAF represents cost saving and improved operation of sludge thickening, dewatering and disposal; (d) the return sludge, separated by DAF stay in aerobic conditions at all times and are more active than comparable settled return activated sludge. The oxygen requirement for the mixed liquor suspend solids is also reduced due to recycling of aerobic sludge; and (e) The problems of sludge rising and sludge bulking can be totally solved when using DAF. Pilot scale results and full scale design considerations are both presented in this publication in detail. The authors' research findings can be applied to any flotation process equipment regardless of its shape (circular or rectangular), or its manufacturer as long as the secondary flotation clarifier is properly designed and operated.
- Published
- 2023
- Full Text
- View/download PDF