Page 15 - Jan/Feb 2016 Vol.33 No.6
P. 15
vated sludge process uses a single basin to following disinfection. De-chlorination rates a pre-thickening system to increase
achieve biological and nutrient reduction, occurs in a reactor. the solids retention time in the basin. Class
as well as secondary clarification. Inherent Post Aeration B biosolids are produced in less time than
to an SBR system is the ability to optimize conventional aerobic processes and the
operating conditions within a basin to A low profile cascade aerator reintro- aerobic nature of the system minimizes
achieve a high degree of nutrient reduction duces oxygen into the plant effluent prior the likelihood that offensive odors would
and thus eliminate the cost of constructing to disposal in the receiving stream. The cas- impact the surrounding community. This
secondary clarifiers. cade aerator consists of a number of chan- staged system uses multiple digester and
nel dividers with low head aeration baffles thickening basins and creates a thickened
The City’s new plant includes three and a trapezoidal-shaped inlet flow control sludge with submerged plate membranes.
SBR basins constructed using common gates and weirs. The 24-foot-wide-and-long The system provides a solids retention
walls to minimize the cost and footprint. aerator is installed in a rectangular concrete time of 25 days and a minimum hydraulic
Each SBR is 178 feet long and 85 feet basin and is sized for the peak hydraulic retention time of 15 days. The system is
wide with a volume of approximately 2.5 loading capacity and an effluent dissolved capable of processing 16,230 lbs/d of waste
million gallons. Each basin operates in oxygen concentration of 6.0 mg/L. activated sludge with a volatile fraction of
a batch process containing a cycle with Outfall 80 percent. Minimum volatile suspended
five basic elements to achieve treatment solids (VSS) reduction is 38 percent by
and clarification objectives. The installed Following the post aeration process, weight.
system utilizes jet aeration technology effluent is sampled prior to entering a 36-
that allows separate aeration and mixing inch gravity line that conveys the treated Two belt filter presses were installed
activities. effluent to the permitted outfall located in for dewatering of the aerobically digested
Tertiary Filtration the West Prong of the Little Pigeon River. sludge. Each belt filter press is capable of
The outfall consists of a 30-inch pipe, processing 1,510 dry pounds per hour
SBR treatment is followed by tertiary 30 feet in length, constructed on ballast with a minimum solids capture rate of 95
filters. Three disk filtration units polish the weights in the channel of the receiving percent.
secondary effluent from the SBRs. While stream. Treated effluent is discharged
additional total suspended solids removal evenly across the entire 30 feet of pipe Original, Sustainable, and Innovative
is achieved by the 10-micron polyester through duckbill diffusers on roughly two- Features
cloth filter, the disk filtration units provide foot, nine inch centers.
additional phosphorus removal through Reuse Pigeon Forge is committed to preserv-
chemical precipitation if biological treat- ing its natural resources. To decrease the
ment in the SBRs is insufficient to meet Three vertical turbine pumps were environmental impact of the facility, the
future phosphorus limits. installed at the plant’s reuse water pump project includes a number of unique, sus-
Disinfection station. Two are dedicated to serve the tainable, and innovative features including:
plant for various treatment processes. The • Rainwater is collected from the roof of
Disinfection is achieved using bulk other is designed to pump chlorinated
sodium hypochlorite and two chlorine effluent to the City’s planned reuse the administration building to irrigate
contact chambers. Flow is split evenly network serving locations at recreation landscaping and flowers
between the contact chambers using fixed sites around the community. • The plant is the first in Tennessee to use
weirs. The serpentine flow path creates Biosolids Treatment a drone for aerial inspection of treat-
contact volume of roughly 80,000 gallons ment processes and real-time reconnais-
in each contact chamber. Disinfected Solids stabilization and thickening is sance of plant personnel safety
effluent from each chamber empties provided by an innovative pre-thickened • The innovative pre-thickened aerobic
into a common splitter box that directs aerobic digestion system that is the first digestion biosolids system is the first of
flow to either the reuse pump station or of its kind in Tennessee. The multi-basin its kind in Tennessee
to de-chlorination. Sodium bisulfite is system aerobically digests volatile fractions • By using the sustainable reuse system,
injected to react with the residual chlorine of the waste-activated sludge and incorpo- the plant has decreased potable water
Continued on page 16
De-chlorination Post Aeration Biosolids Treatment
View online at tnpublicworks.com 15
achieve biological and nutrient reduction, occurs in a reactor. the solids retention time in the basin. Class
as well as secondary clarification. Inherent Post Aeration B biosolids are produced in less time than
to an SBR system is the ability to optimize conventional aerobic processes and the
operating conditions within a basin to A low profile cascade aerator reintro- aerobic nature of the system minimizes
achieve a high degree of nutrient reduction duces oxygen into the plant effluent prior the likelihood that offensive odors would
and thus eliminate the cost of constructing to disposal in the receiving stream. The cas- impact the surrounding community. This
secondary clarifiers. cade aerator consists of a number of chan- staged system uses multiple digester and
nel dividers with low head aeration baffles thickening basins and creates a thickened
The City’s new plant includes three and a trapezoidal-shaped inlet flow control sludge with submerged plate membranes.
SBR basins constructed using common gates and weirs. The 24-foot-wide-and-long The system provides a solids retention
walls to minimize the cost and footprint. aerator is installed in a rectangular concrete time of 25 days and a minimum hydraulic
Each SBR is 178 feet long and 85 feet basin and is sized for the peak hydraulic retention time of 15 days. The system is
wide with a volume of approximately 2.5 loading capacity and an effluent dissolved capable of processing 16,230 lbs/d of waste
million gallons. Each basin operates in oxygen concentration of 6.0 mg/L. activated sludge with a volatile fraction of
a batch process containing a cycle with Outfall 80 percent. Minimum volatile suspended
five basic elements to achieve treatment solids (VSS) reduction is 38 percent by
and clarification objectives. The installed Following the post aeration process, weight.
system utilizes jet aeration technology effluent is sampled prior to entering a 36-
that allows separate aeration and mixing inch gravity line that conveys the treated Two belt filter presses were installed
activities. effluent to the permitted outfall located in for dewatering of the aerobically digested
Tertiary Filtration the West Prong of the Little Pigeon River. sludge. Each belt filter press is capable of
The outfall consists of a 30-inch pipe, processing 1,510 dry pounds per hour
SBR treatment is followed by tertiary 30 feet in length, constructed on ballast with a minimum solids capture rate of 95
filters. Three disk filtration units polish the weights in the channel of the receiving percent.
secondary effluent from the SBRs. While stream. Treated effluent is discharged
additional total suspended solids removal evenly across the entire 30 feet of pipe Original, Sustainable, and Innovative
is achieved by the 10-micron polyester through duckbill diffusers on roughly two- Features
cloth filter, the disk filtration units provide foot, nine inch centers.
additional phosphorus removal through Reuse Pigeon Forge is committed to preserv-
chemical precipitation if biological treat- ing its natural resources. To decrease the
ment in the SBRs is insufficient to meet Three vertical turbine pumps were environmental impact of the facility, the
future phosphorus limits. installed at the plant’s reuse water pump project includes a number of unique, sus-
Disinfection station. Two are dedicated to serve the tainable, and innovative features including:
plant for various treatment processes. The • Rainwater is collected from the roof of
Disinfection is achieved using bulk other is designed to pump chlorinated
sodium hypochlorite and two chlorine effluent to the City’s planned reuse the administration building to irrigate
contact chambers. Flow is split evenly network serving locations at recreation landscaping and flowers
between the contact chambers using fixed sites around the community. • The plant is the first in Tennessee to use
weirs. The serpentine flow path creates Biosolids Treatment a drone for aerial inspection of treat-
contact volume of roughly 80,000 gallons ment processes and real-time reconnais-
in each contact chamber. Disinfected Solids stabilization and thickening is sance of plant personnel safety
effluent from each chamber empties provided by an innovative pre-thickened • The innovative pre-thickened aerobic
into a common splitter box that directs aerobic digestion system that is the first digestion biosolids system is the first of
flow to either the reuse pump station or of its kind in Tennessee. The multi-basin its kind in Tennessee
to de-chlorination. Sodium bisulfite is system aerobically digests volatile fractions • By using the sustainable reuse system,
injected to react with the residual chlorine of the waste-activated sludge and incorpo- the plant has decreased potable water
Continued on page 16
De-chlorination Post Aeration Biosolids Treatment
View online at tnpublicworks.com 15
