Powerful models and a wealth of full-scale data are available for designing integrated fixed film activated sludge (IFAS) and moving bed biofilm reactor (MBBR) facilities today that were not available ten years ago. The question now is not "how much media is needed?" but "how can we minimize costs and maximize plant capacity by placing the right amount of media in the right place?" The IFAS facility in Broomfield, Colorado, and the MBBR facility at the Williams Monaco Wastewater Treatment Plant (WWTP) in South Adams County, Colorado, have been in service for over four years. Operators have documented biomass quantities and nutrient profiles within individual zones over the years, and this full-scale data, coupled with pilot-scale and bench-scale test results, has been key to optimizing the plant expansions. The Broomfield Phase 2 expansion is currently under construction, and the Williams Monaco expansion is in the study phase.
The Frisco Sanitation District (District) owns and operates an advanced wastewater treatment (AWT) plant. Phosphorous removal has been the dominant concern at this wastewater treatment plant (WWTP) due to the potential for accelerated cultural eutrophication in Lake Dillon, which is a major recreational and drinking water supply in Summit County for the City of Denver.Peak flows are reaching the combined capacity of the four existing AWT units. Therefore, a pilot study was conducted to determine whether membrane filtration systems could (1) increase overall AWT throughput capacity, (2) meet phosphorous removal objectives, and (3) be cost competitive with conventional AWT treatment. Overall goals for the pilot study and preliminary design study include:Provide a net 1.0 mgd increase in AWT capacity.Achieve average effluent total phosphorus levels of <0.02 mg-P/L.Keep total construction cost, including membranes and all pumping, piping, and support facilities to less than $3,000,000.No increase in staffing requirements for either operations or maintenance (O&M).The pilot unit was a Zenon immersed membrane system. The pilot was operated for three months. Operational data included alum dose, long-term flux rate, backpulse and membrane cleaning frequency, and percent recovery. Permeate quality was tested for total phosphorous levels, turbidity removal, and the impact of pH on phosphorous removal performance.
The Cheyenne Board of Public Utilities (BOPU) needs to meet new ammonia limits and address the likely need for nitrogen and phosphorus removal within the next 10 to 15 years at their Crow Creek wastewater treatment plant (WWTP). Meeting the new ammonia limits and positioning for future nutrient removal presents a special challenge since the BOPU desires to minimize staffing levels at the Crow Creek WWTP. Historically, just one operator has been assigned to this facility.The Crow Creek WWTP's existing trickling filter (TF) system was determined to be not well-suited to meet effluent ammonia limits during the winter months, nor for positioning the WWTP for meeting nutrient limits in the future. Results of a process evaluation determined that the best overall approach for Crow Creek was to abandon the TFs and construct a single-pass, multi-stage moving bed biofilm reactor (MBBR) system ⊗ to reduce biochemical oxygen demand (BOD), ammonia (NH 4 -N), and total inorganic nitrogen (TIN). Phosphorus removal will be added in the future via addition of a tertiary treatment step such as metal-salt addition followed by sand filtration.Full-scale MBBR facilities in a multi-stage configuration similar to that designed for Crow Creek WWTP have been effective in treating municipal wastewater in Europe. However both the BOPU and Black & Veatch (B&V) felt that a site-specific pilot study was warranted. Accordingly, an onsite pilot study was conducted for five months to confirm that the sizing parameters and conditions used for the initial design were sufficient to meet effluent NH 4 -N and TIN removal objectives. This paper presents the project background and pilot study methodology, the results and findings gleaned from the study, and the adjustments made to the final design as a result of the pilot work.
In response to rapid service-area growth, The City of Henderson, Nevada implemented planning efforts for the next expansion of wastewater treatment capacity. As the conclusion of that planning effort prior to facility design, advanced wastewater treatment (AWT) processes were pilot tested for application as a post-biological nutrient removal (BNR) phosphorus removal method to meet strict total maximum daily load (TMDL) limits. The existing solids contact clarifiers and down-flow filters were compared, side-by-side, with pilot inclined plate gravity settler and continuous-backwash up-flow filter technology.The results of the pilot testing indicated that the existing technology requires an alum dose of approximately 70 mg/L to maintain an adequate sludge blanket and produce effective turbidity and phosphorus removal, whether or not a BNR-treated secondary effluent is being treated. The piloted technology allows an alum dosage of approximately 20 mg/L to meet treatment goals on a BNR secondary effluent -a 70 percent savings. The economic evaluation of the two alternatives determined that the plate gravity settler and continuousbackwash up-flow filter treatment process will have at least a 13 percent lower present worth cost compared to installing additional solids contact clarifiers and down-flow filters. KEY WORDSAdvanced wastewater treatment (AWT), tertiary treatment, phosphorus removal, total maximum daily load (TMDL), pilot testing, solids-contact clarifier, filtration, inclined plate gravity settler, continuous-backwash up-flow filter, post-biological nutrient removal (BNR), Las Vegas Wash, Henderson, Nevada.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.