Overview and details of the sessions of this conference. Please select a date or location to show only sessions at that day or location. Please select a single session for detailed view (with abstracts and downloads if available).
Nicole Brower, Nicolas Brouillard, Alexandre Crozes, Lindsey Smoot
University of Idaho; , , ,
Upgrades to the Pullman Wastewater Reclamation and Reuse Facility (WRRF) require a system capable of achieving secondary and tertiary total phosphorus (TP) effluent concentrations of less than 1 mg/L and 0.1 mg/L respectively. The upgrade will consist of an enhanced biological phosphorus removal (EBPR) system as a secondary treatment process to achieve the target secondary effluent TP concentration, followed by a chosen tertiary treatment alternative. Tertiary treatment alternatives explored are as follows:
Micro-Algal Phosphorus Removal Chemical Phosphorus Removal Reclaimed Water Application
Utilization of BioWin modeling software, hand calculations, peer-reviewed literature, and a decision matrix generated a final design recommendation to meet the effluent requirements listed above. The final design will consist of an EBPR system in conjunction with struvite precipitation and chemical phosphorus removal. Struvite precipitation will target phosphorus removal of the anaerobic digester centrate being recycled to the front of the plant and chemical phosphorus removal will be employed for tertiary treatment.
Upgrades to the current facility will include:
Addition of an anaerobic zone for EBPR on each treatment train Design of a side stream fermenter for VFA supplementation Design of struvite precipitation process Design of chemical phosphorus removal system
8:45am - 9:30am
Long Term Treatment Performance of High Efficiency Sidestream Phosphorus Removal/Recovery System
Mudit Gangal1, Tim Hendrickx2, Willie Driessen2
1Ovivo USA LLC, United States of America; 2Paques BV;
High Phosphorus concentration sidestreams such as centrates, filtrates etc. can lead to significant operational and process problems at WWTPs by building up in the system via recirculation, leading to nuisance struvite formation and deposition.
This Phosphorus load can be removed much more efficiently and cost effectively in a sidestream treatment system versus removal in the mainstream. The Phospaq process is an aerated reactor that offers the capability to remove or recover Phosphorus in the sidestream via controlled struvite precipitation using Magnesium Oxide and has been implemented in over 11 different municipal and industrial facilities globally.
This paper discusses the long term performance of the process at two full scale wastewater treatment plants. The first plant is the Olburgen WWTP in the Netherlands where the process is implemented ahead of a granular sludge deammonification process for a blended municipal and industrial sidestream. Data from over 10 years of operation of this facility is presented where over 80% Phosphorus removal was consistently achieved with effluent PO4-P values below 20 mg/l. Experience with optimizing the Magnesium dosage is also discussed along with impacts of the same on the downstream deammonification system. The second plant is the Lomm WWTP in the Netherlands where the system was implemented after an anaerobic granular sludge process, where over two years of operation data are presented including effluent PO4-P values < 15 mg/l which were consistently achieved with struvite production of over 1,500 lbs/d, in the form of crystals of diameter approximately 0.7 mm, that met EU fertilizer requirements for land application as a commercial fertilizer substitute.
The Phospaq process thus offers a comprehensive and cost effective solution for utilities looking to address Phosphorus/Struvite issues at their plant while providing the option of recovering the Phosphorus as Struvite based slow release fertilizer product which could serve as a potential revenue source for the utility.
9:30am - 10:15am
Lessons Learned from a Decade of Phosphorus Recovery
Brett Laney, Peter Schauer
Clean Water Services, United States of America;
For more than a decade, Clean Water Services has been utilizing Ostara’s recovery technology to reduce the cost of meeting the stringent effluent phosphorus limits in our NPDES permit. In the ten years of operating the struvite recovery facilities, we found the initial focus of reducing in-plant phosphorus recycle and generating revenue from fertilizer sales was too narrow. To be successful and maximize the potential of the new technology, we had to evaluate and make process decisions with the entirety of the plant in mind. How we manage and track phosphorus from influent to effluent, pre-digestion thickening thru digested sludge dewatering, became critical to plant stability and cost of phosphorus treatment. For example, the implementation of the WASSTRIP process significantly changed the operation of the WAS thickening process by reducing required thickening centrifuges online but also increases the mass of released phosphorus that must be managed to prevent shock loading on the liquids treatment process.
This presentation will cover the positive and negative impacts our efforts to maximize recovery have had on the phosphorus mass balance through the treatment processes. A phosphorus mass balance will be used to illustrate the overall impacts from each of the decisions and demonstrate:
Impacts to the stability of the biological phosphorus removal system
chemical phosphorus removal versus biological phosphorus removal,
recycle flow management
operation and efficiency of the phosphorus recovery facility
Understanding these processes allowed us to make informed decisions that account for operational and economic impacts. Each of these changes to the phosphorus mass balance has had positive and negative impacts to the rest of the plant unit processes. We will discuss how these impacts are mitigated and used to our advantage to optimize phosphorus recovery and improve stability in the BPR process.