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).
Installation, Startup, and Operation of World’s First Regenerable Resin System for PFAS Removal
Patrick McKeown. PE1, Steve Woodard. PhD1, Tim Gould2
1ECT2; 2Ahtna Engineering Services, LLC;
The United States Air Force Civil Engineering Center (AFCEC) is conducting on-going response activities to remove and remediate groundwater impacted by poly- and perfluoroalkyl substances (PFAS) at the former Pease Air Force Base in New Hampshire.
AFCEC responded by contracting with Wood Group PLC to conduct a side-by-side pilot test in 2016, comparing the performance of Emerging Compound Treatment Technology’s (ECT2) regenerable ion exchange (IX) resin and bituminous granular activated carbon (GAC). The regenerable resin system was selected for full-scale application, based on system performance and a lower overall lifecycle cost than GAC.
A 200-gpm system was provided to meet the primary project objective of producing treated water with combined PFOS plus PFOA concentrations below the 70 ng/l Health Advisory Level (HAL). The full-scale IX resin system was installed from fall 2017 through spring 2018.
The PFAS remediation system has treated more than 31 million gallons of groundwater having a total average influent PFAS concentration of 55 µg/l. The effluent quality from the IX resin system has been consistently non-detect for PFOS and PFOA, readily achieving compliance with the 70 ng/l HAL target.
Five successful resin regenerations have been performed to date. Operational modifications have been made to address and correct minor challenges with the distillation system, and regenerant recovery and super-loading processes have proven successful. The original superloading media is still operational, having removed and concentrated greater than 99.99 percent of the recovered PFAS mass, and therefore no PFAS waste has needed to be hauled off site to date.
8:45am - 9:30am
A Pilot Scale Evaluation of Coagulant Selection and Dose on HF UF Membrane Performance at the West Boise Water Renewal Facility
Dan Hugaboom1, Ryan Anderson2, Brad Jeppson1
1Carollo Engineers Inc, United States of America; 2City of Boise;
In 2019, the City of Boise completed a pilot study of tertiary coagulation and hollow fiber microfiltration and ultrafiltration (MF/UF) membrane technologies at its West Boise Water Renewal Facility (WBWRF) for phosphorus removal. The work was done to support planning for plant improvements required to comply with anticipated reductions in phosphorus discharge limits from the WBWRF.
The pilot study investigated the performance of a wide range of coagulants and membrane technologies to achieve two primary process goals:
Tertiary treatment train effluent total phosphorous of less than 0.1 mg/L TP-P. Five coagulants were tested across a range of doses to meet the TP goal without overloading the membrane process with coagulated solids. Ferric chloride, ferrous chloride, alum, ACH and RE300 (cerium chloride) were evaluated to achieve a treatment goal of reducing TP from approximately 1 mg/L in the secondary effluent to <0.1 mg/L.
Demonstrate reliable membrane performance. Membrane performance was evaluated using quantitative goals for maximum fouling rates, residuals production and off line chemical cleaning frequency. Three different membrane systems, each with unique design and performance characteristics were evaluated for this application. They include pressurized (cartridge style) UF membrane and two submerged (vacuum driven) systems. The experimental matrix allotted significant amount of time for optimizing backwash, air scour, cross flow and chemical cleaning strategies as well as a range of flux rates.
Below doses of about 5 mg/L (as product), membrane fouling was low and chemical cleaning cycles met goals for maximum allowable frequency, however filtered effluent TP did not consistently meet the goal of <0.1 mg/L. As required dosages increased to meet filtrate TP goals, more energetic and frequent cleaning strategies were necessary to meet membrane performance goals. This presentation will include a detailed analysis of phosphorus removal across the range of coagulants, as well as membrane process performance.
9:30am - 10:15am
The Facility of The Future for the Utility of the Future
Cascade Energy, Inc., United States of America;
The “Utility of the Future” program has given a name to the management and organizational principles that will be needed for wastewater organizations to thrive in the years to come. Features include professional training programs, labor recruiting programs, CMMS programs, improved public and customer relations, collaborative working relationships with regulators, resiliency for extreme events, energy management programs, etc.
But, what about the physical plant? In many ways, most of the new plants being built today would look familiar to a time-traveling engineer from the 1950’s. Part of this is expected – for very good reasons, our industry is slow to embrace new ideas until they are proven out through many years of full-scale use.
My hypothesis is that our industry could create some VERY different facilities if the design requirements were changed. I propose to collect, organize, and share ideas from volunteers from at least 10 separate PNCWA-member engineering firms and vendors who will help answer this question: If you were asked to design a 5 MGD, greenfield facility located near Coeur d’Alene, to meet a 5/5/1 standard, year-round, that would minimize the total carbon footprint of its construction and operation over 30 years, what features would you include? You must select from materials, equipment, and processes that are currently commercially available somewhere in the world, though it does not need to be used currently in the wastewater sector. Ideas for collection and disposal alternatives will also be welcomed.
For the conference, we will present a design summary of each major process area and briefly describe the alternatives and the reasoning for them suggested by the survey participants. The calculations and assumptions for embedded and operational CO2e will be summarized along with the pros and cons of each alternative. The names of volunteers will be shared but will not be associated with specific solutions.
The over-arching goal of the presentation is to provide new ideas to the audience and show what might be achieved when efforts are focused not on lowest first cost but on lowest ultimate impact to the environment.