title: Improving Settling Characteristics of Pure Oxygen Activated Sludge by Stripping of Carbon Dioxide.
abstract: Increased microbial activity at high ambient temperatures can be problematic for secondary clarifiers and gravity concentrators due to carbon dioxide (CO2) production. Production of CO2 in gravity concentrators leads to septic conditions and poor solids separation. The CO2 production can also be corrosive for the concrete surfaces. Effectiveness of CO2 stripping to improve solids settling was investigated using the sludge volume index (SVI) as the indicator parameter. Carbon dioxide was stripped by aeration from the sludge samples. Results from the study show that aeration also increased the pH values in the mixed liquor while removing CO2 and improving sludge settling. After 10 minutes of aeration at a rate of 0.37 m3 air/m3 water/min, 90% CO2 stripping was achieved. Based on the 30 min settling tests, the SVI increased by 26±1% after CO2 stripping while the pH increased by 0.8±0.1 pH units.
authors.affiliation: Civil and Environmental Engineering Department, Florida International University, USA.
authors.forename: Somshekhar
authors.initials: S
authors.lastname: Kundral
authors.forename: Ratnaji
authors.initials: R
authors.lastname: Mudragada
authors.forename: Ernesto
authors.initials: E
authors.lastname: Coro
authors.forename: Manny
authors.initials: M
authors.lastname: Moncholi
authors.forename: Nelson
authors.initials: N
authors.lastname: Mora
authors.forename: Shonali
authors.initials: S
authors.lastname: Laha
authors.forename: Berrin
authors.initials: B
authors.lastname: Tansel
mesh_terms: D002245:Carbon Dioxide / Q000737:chemistry*; D011232:Chemical Precipitation; D010100:Oxygen / Q000737:chemistry*; D012722:Sewage / Q000737:chemistry*; D014865:Waste Disposal, Fluid / Q000379:methods*; D014874:Water Pollutants, Chemical
chemical_list: D012722:Sewage; D014874:Water Pollutants, Chemical; D002245:Carbon Dioxide; D010100:Oxygen