Wednesday, November 10, 2021
Technical Sessions
Power & FGD (Water Chemistry to Power Success)
IWC Rep: Derek Henderson, Duke Energy Corporation, Raleigh, NC
Session Chair: Jason Monnell, Electric Power Research Institute (EPRI), Charlotte, NC
Discussion Leader: Dave Guinta, Burns & McDonnell, Kansas City, MO
Time: 8:00 AM – 12:00 Noon
Room: Salt River 3
In this session, we will splash into process design, chemical treatment, and their operational impact to the treatment and management of high-volume water streams in the electric power industry. We will explore biofouling control for cooling water systems, wet FGD Scrubbers additives, and innovative FGD wastewater treatment designs. It will be sure to provide engaging discussions, idea generation, and in-depth details regarding these solutions.
IWC 21-61: Halogen Stable Azole: Effectiveness and Mechanism of Action in Cooling Water Systems
Mary Jane Felipe, Chelsea Eaton, Swamy Margan, and Steven Lee, and William Watson, Baker Hughes, Sugar Land, TX
Time: 8:10 AM
Copper alloys are used in cooling systems because of their excellent heat transfer properties. In the advent of copper alloy corrosion though, releasing the copper ions to the water not only raises an ecotoxicity concern in the effluent discharge but also induces galvanic corrosion to mild steel metallurgies leading to a bigger corrosion problem in the cooling systems. The use of triazole has been the go to chemistry since the 1970’s. Triazoles such as tolyltriazole and benzotriazole are known to effectively form a film on copper metallurgies. The presence of nitrogen and the ring structure enhance film formation at the solid-liquid interface.
In a cooling water system, one of the basic problems to combat is the possible growth of microorganisms. These microorganisms can induce a type of corrosion that is often harder to treat than general corrosion. To mitigate, it is typical to feed halogen-containing biocides like chlorine and bromine. These oxidizing biocides are maintained at a fairly low parts per million level, however, it is very common to feed higher biocide level when the pump is not maintained properly. During biocide upsets, corrosion rates of the copper alloy metallurgies also increases because of the tolyltriazole’s interaction with the halogen containing biocide.
This paper presents a halogen stable azole that forms a film on copper alloy metallurgies even in the advent of halogen-containing biocide upsets in cooling water systems. Corrosion inhibition is investigated using linear polarization resistance monitoring. Further mechanistic studies was done using Tafel polarization and impedance studies. Field data confirmed a 50-85% reaction of chlorine-containing biocide when a typical tolyltriazole inhibitor is used to prevent copper metallurgy corrosion. This data corroborates the data shown in the laboratory.
Discusser: Dan Cicero, Nalco Water, Naperville, IL
IWC 21-62: Design Innovations for the Largest FGD Plant in North America
Evan Claytor and Precious Ukonu, SUEZ Water Technologies & Solutions, Glen Allen, VA; Charles Chappell, TVA, Knoxville, TN; Mark Owens, HDR, Mosely, VA
Time: 9:00 AM
Tennessee Valley Authority (TVA) and SUEZ were faced with the challenging engineering task of designing the largest FGD wastewater treatment plant to date in North America with a flow capacity of 4,400 gpm. In addition, the plant had a requirement for complete system redundancy. Several engineering design innovations occurred which allowed the project to maintain the budget, schedule, and the required operational flexibility. These design innovations are as follows:
- The dual reactor tanks associated with each clarifier.
- A very high rate synthetic media gravity filter
- The elimination of acid feed prior to filtration
- Duplex stainless steel was chosen as the material of construction for the tanks as a less expensive alternative to typical FGD coatings.
Discusser: Bryan Hansen, P.E., Burns & McDonnell, Centennial, CO
IWC 21-63: Effects of WFGD Additives such as DBA on Wastewater Treatment
Suzette Puski, Stantec, Providence, RI
Time: 10:20 AM
Many Wet Flue Gas Desulfurization (WFGD) systems use additives regularly to meet emission limits that were enacted after the scrubber system was designed. Organic acids such as DBA can provide additional benefits beyond the WFGD system by decreasing the load on the bioreactor in wastewater treatment and improving selenium removal.
This presentation will describe the different additives commonly used in WFGD, monitoring scrubber performance to reduce wastewater discharge, and the impact of additives on Wastewater Treatment system design and performance.
Discusser: Angela Zagala, Nalco Water, an Ecolab Company, Cary NC
IWC 21-64: Enrichments of Anaerobic Selenium Oxyanion Reducers from FGD Wastewater Effluent
Preom Sarkar, Meghan Brandi, Nicholas Means, Djuna Gulliver, and Joshua Miller, NETL-DOE, Pittsburgh, PA
Time: 11:10 AM
While flue gas desulfurization systems are an important technology in mitigating air pollutants, such as sulfur oxide gases, from coal fired power plants, much of the wastewater produced when using this technology contains other pollutants that must be remediated before release back into the environment. Selenium is one of these pollutants of interest because it can cause detrimental ecological consequences even in small amounts. Currently it is known that biological treatment can be utilized to treat FGD wastewater in order to remove selenium, but the microorganisms involved in this process in this relatively extreme environment has not been studied. This project seeks to enrich, identify, and characterize the anaerobic microorganisms in FGD systems that have the capability to reduce selenium oxyanions (selenate and selenite) to elemental selenium and characterize the selenium nanospheres they produce. Presently, we have found a microbial community within the FGD effluent capable of reducing up to 99% dissolved selenate. The community was found to be composed primarily of bacteria from the genera anaerosolibacter and bacillus. This work begins to characterize a little understood microbial system, giving operators an opportunity to optimize FGD effluent treatment technologies.
Discusser: Lisa Kirk, Ph.D., P.Geo., and Seth D’Imperio, Ph.D., Enviromin, Bozeman, MT
Water’s New Flex
IWC Rep: Max Brefeld, TOYOTA MOTOR NORTH AMERICA, Georgetown, KY
Session Chair: John Van Gehuchten, McKim & Creed, Sewickley, PA
Discussion Leader: HG Sanjay, Bechtel, Reston, VA
Time: 8:00 AM – 12:00 Noon
Room: Salt River 7
The water world has been busy over the last year. Technology in the industry keeps improving and, in this session, we will take a look at a few of those innovations. In this catch all session there are new instruments, more uses found for brewery wastes, old water plants finding a new life, and investigating new nonfilter materials. Everyone can find something to like with this talented group of authors.
IWC 21-65: The Value and Challenges of Chlorination/Dechlorination Process Optimization in Power Generation
Vadim Malkov, Ph.D., Hach, Loveland, CO; Mark Flynn, Heorot Power Management, Vernon, CA
Time: 8:10 AM
Quality of the steam cycle water requires special attention and chlorination/dechlorination phase is very important, especially for reclaimed water sources. Ability to accurately measure and control chlorine concentrations allows to minimize membrane maintenance and extend life of the RO filters. Improved management of dechlorination, permitted by efficient ULR chlorine monitoring, resulted in over 30% reduction in SBS usage and halved the frequency of CIP at a power utility. This process optimization is also projected to reduce losses in power production, providing further cost savings.
Discusser: Jason Lemire, P.E., Bowen Engineering, Columbus, OH
IWC 21-66: Using Brewery Waste to Optimize Nitrogen Removal in a Biological Nutrient Removal Facility
Coralynn Revis, P.E., and William Buxton, P.E., HDR, Missoula, MT; Tom Radcliffe and Josh French, City of Bozeman, Bozeman, MT; Theodore Grover, HDR, Bozeman, MT; Bryce Figdore, P.E., HDR, Bellevue, WA
Time: 9:00 AM
Stringent nutrient regulations lead the City of Bozeman, Montana to consider alternative carbon sources for their biological nutrient removal wastewater reclamation facility to further reduce nitrogen in the effluent. Brewery waste from local microbreweries was gathered and tested through a pilot study to evaluate the effectiveness as an external carbon source. Data indicates a reduction of 25-40% of the total nitrogen in the effluent through the use of the brewery waste to further drive the biological reaction.
Discusser: T.J. Stroebl, Kurita America, Inc., Minneapolis, MN
IWC 21-67: Repurposing Existing Paper Mill Wastewater Treatment Plant For Future Flow
Mayra Giraldo, EIT, Stantec, Atlanta, GA; Nicole Stephens, P.E., Stantec, Raleigh, NC
Time: 10:20 AM
Industrial wastewater treatment systems are designed to accommodate maximum flow and load conditions. It is rare, however, to encounter the question of how to adequately treat flows that are 25 times lower than the existing system’s treatment capacity. This paper will document treatment considerations and recommendations for a pulp and paper mill system following decommissioning of paper machines resulting in a significant flow reduction and shift in wastewater strength.
Discusser: James Beninati, HDR, Pittsburgh, PA
IWC 21-68: Innovative Low Fouling, Chlorine Tolerant Hollow Fiber Nanofiltration Membranes for Micropollutant and Organic Removal
Joris de Grooth, Ph.D., Erik Roesnik, and Umang Yagnik, NX Filtration, Enschede, Netherlands
Time: 11:10 AM
We see in our environment, specifically in our surface waters, more and more persistent chemicals like polyfluoroalkyl substances (PFAS), medical residues, insecticides, pesticides, nano-plastics, anti-biotic resistant bacteria, viruses; in general, micropollutants. This is caused by the fact that traditional wastewater treatment plants do not remove most micropollutants. Common technologies applied for removal of micropollutants include adsorption (activated carbon), advanced oxidation (O3, UV/H2O2) or multi-stage membrane processes, to re-use the effluent or to improve the effluent quality before disposal to surface water bodies. In this paper, an innovative solution for removing micropollutants using hollow fiber nanofiltration (NF) membranes, is presented.
These next-generation hollow fiber NF membranes are found to be suitable for direct treatment of surface water sources and (biologically treated) wastewater. These hollow fiber NF membranes remove color (via natural organic matter [NOM]), low molecular weight organics, micropollutants, and partial hardness, while allowing most monovalent salts to pass through the membrane. The membrane chemistry is based upon poly-ether-sulfone (PES), while the selective nanolayers are created from water-based electrolytes (layer-by-layer). The robust PES membrane in combination with layer-by-layer chemistry allows severe cleaning, e.g., with hypochlorite concentrations up to 200 ppm and a pH in the range of 1-14.
The main benefits of these innovative hollow fiber NF membranes include superior micropollutant and organics removal, fouling resistance, chlorine tolerance, minimal pretreatment, reduced chemical usage, and cleanability at a wide pH range. There is data to substantiate that these benefits translate to significantly low operating costs and lead to considerable CO2 footprint reduction.
The permeate from these hollow fiber NF membranes can be reused directly for a wide range of industrial process, agricultural applications. In combination with advanced oxidation as a post-treatment, the NF permeate can be used for more critical applications including drinking water.
Discusser: Joshua Dewanaga, P.E., SUEZ Water Technologies & Solutions, Bellevue, WA
PFAS #2
IWC Rep: Bradley D. Wolf, P.E., Berkeley Research Group, LLC, Pittsburgh, PA
Session Chair: Russ Huffmyer, McKim & Creed, Sewickley, PA
Discussion Leader: Nicole Bolea, P.E., ECT2, Minneapolis, MN
Time: 8:00 – 11:10 AM
Room: Salt River 2
For this session on Perfluoridated Alkyl Substances (PFAS), the featured papers will cover the following topics; PFAS destruction by novel physical and chemical methods, solutions that have been implemented to address “low hanging fruit” and the sustainability of those solutions at a manufacturing site in North Carolina, a case study that will demonstrate the effective removal of high levels of PFAS compounds at a facility in Australia, and lastly, the development of a technology evaluation for PFAS treatment.
IWC 21-69: Withdrawn
IWC 21-70: PFAS Mitigation in Chemours – A Different Kind of Challenge
Steven Grise, P.E. and Michael Davis, Ph.D., The Chemours Company, Wilmington, DE
Time: 8:10 AM
Traditional treatment technologies have been challenged to handle the unique nature of PFAS compounds in the environment. Many existing technologies have limited effectiveness due to the physical and chemical properties of the compounds. That said, combinations of existing technologies with creative engineering solutions can be used to mitigate current emissions.
The Chemours Company is committed to being a leader in environmental stewardship and responsible manufacturing, abating air and water emissions of fluorinated organic compounds by at least 99% at its manufacturing sites globally. Our Fayetteville Works manufacturing site in North Carolina has been at the forefront of that effort. We have focused on finding ways to get PFAS air and water emissions from our operations as low as possible, to both meet our commitments and address community concerns. While additional work remains to be done, we believe we have some of the answers to achieving our goals.
This paper will discuss some of the solutions we have implemented. These solutions include the “low hanging fruit” of water minimization, the more challenging aspects of water internalization and thermal oxidation, and the path ahead. The discussion will cover the solutions and the sustainability of our decisions.
Discusser: Katherine Van Sice, McKim & Creed, Sewickley, PA
IWC 21-71: A Multi-Barrier Ion Exchange Process for the Removal of Short and Long Chain PFAS/PFOS Compounds
Rajeev Bhavaraju, LANXESS Pty Ltd., Granville NSW 2142, Australia; Dirk Steinhilber, LANXESS Deutschland GmbH, Koeln, Germany
Time: 9:00 AM
Australia published “ The Intergovernmental Agreement on a National Framework for Responding to PFAS Contamination” in February 2018. This policy agreement provided for a consistent approach to PFAS contamination between the Commonwealth and the Australian States. Australia had recognized the risk of PFAS contamination early on, phasing out fire foams and other materials made with these compounds as far back as 2003. Consequently there are many installations already in place for the removal of these compounds.
This case study will demonstrate the effective removal of high levels of PFAS compounds in impounded waste water waters from the Fiskville County Fire Authority (CFA) Training College in regional Victoria , Australia. The college was closed in early 2015 due to the detection of contaminated water on the site and indications of regional health concerns. Remediation steps were put in place and it is considered the first time in Australia that high levels of PFAS compounds have been removed to the lowest limit of reporting for PFAS .
Multiple stages of water treatment for a 125,000 gallon per day system were required due to the presence of dissolved organics, metals and suspended solids, in addition to the PFAS contamination. Major challenges at this site/project were high levels of PFAS compounds with variable feed composition, that had to be removed to the lowest limit of reporting for PFAS for both short and long chain compounds. On top of this, treated water quality had to meet stringent EPA standards for continuous discharge.
Perfluorobutyrate (PFBA), one of the “short chain” versions of these “forever chemicals” was the most prevalent and was the basis of breakthrough criteria. Short chain PFAS compounds are considered more difficult to remove.
Removal of the PFAS compounds was largely achieved using a robust multi-barrier ion exchange process (IX) in combination with conventional pre-treatment technologies. The IX configuration included a regenerable industry standard macroporous weak base resin followed by a single use highly selective anion resin designed specifically for the removal of these compounds in a lead lag configuration.
This paper will illustrate the use of both regenerable IX technology and highly selective single use resins for the removal of PFAS chemicals to non-detectable and/or very low regulatory limits.
Discusser: Harsh Ashani, Wilson Engineers, Tempe, AZ
IWC 21-72: Developing Technology Evaluation for PFAS Treatment
Kristen Jenkins, P.E., OLI Systems, Inc., Parsippany, NJ ; Beth Landale, P.E., GHD, Farmington Hills, MI; Ryan Thomas, Ph.D., GHD, Niagara Falls, NY; Alessandra Murphy and Daniel Beck, GHD, Detroit, MI; Kishor G. Nayar, Ph.D., GHD, Houston, TX; Grant Trigger, B.Eng., JD, RACER Trust, Detroit, MI
Time: 10:20 AM
Revitalizing Auto Communities Environmental Response (RACER) Trust manages the environmental remediation and facilitates redevelopment of the former General Motors (GM) Powertrain manufacturing facility site at Willow Run in Ypsilanti, Michigan. Currently the water generated from a groundwater collection system is sent to the local Publicly Owned Treatment Works (POTW). The groundwater contains per and polyfluoroalkyl substances (PFAS), and Perfluorooctane sulfonate (PFOS) in particular was present above the Michigan water quality standard. Conventional alternative treatment technologies for the detected PFAS were evaluated in order to develop a cost-effective treatment process, which included granular activated carbon (GAC) and ion exchange (IX). Results of bench testing and alternatives evaluation for these conventional technologies were presented in a 2019 IWC paper and presentation.
Both GAC and IX technologies result in a PFAS containing residual which may require regeneration, including PFAS destruction through incineration, or careful management in a landfill to prevent re-release to the environment. Therefore, since 2019, developing technologies have been evaluated with the objective of identifying a treatment alternative that results in destruction or complete mineralization of the PFAS. The paper will present the following developing technologies, including the results of bench and/or pilot testing completed during 2020:
- Cyclopure’s Dexsorb® adsorbent with PFAS destruction by ball milling
- Plasma
- Wet air oxidation
- Alkaline ozonation
For each of the technologies, the treatment technology and results of treatment will be presented, as well as any testing performed to determine whether PFAS has been mineralized or lost through physical transfer.
In addition, during 2020, a pilot was conducted to oxidize iron and settle the precipitated iron along with any other precipitated solids. The objective of this pilot was to collect a sufficient quantity of solids to perform PFAS analysis on the solids. Lab testing results were inconclusive regarding whether PFAS were adsorbing to solids. Therefore, the pilot was performed to determine the fate of PFAS. Adsorption of PFAS to solids may result in restrictions on locations/landfills accepting it for disposal and may increase the disposal cost.
Discusser: Cristina Piekarz, P.E., HDR, Walnut Creek, CA
Water/Wastewater: Cleaning Up The Universal Solvent
IWC Rep: Bill Kennedy, Stantec, Charlotte, NC
Session Chair: Jeff Easton, WesTech Engineering, Salt Lake City, UT
Discussion Leader: Ramesh Kalluri, KALLURI GROUP, INC., Houston, TX
Time: 8:00 AM – 12:00 Noon
Room: Salt River 6
From innovative approaches for pH control to the treatment of complex organic compounds, this session shares methods and practices to aid in your water and wastewater treatment challenges.
IWC 21-73: In Hot Water: Heat Balance Modeling in Two Industrial Waste Water Treatment Systems
Shannon Brown and Eduardo Casanova, Bayer Crop Science, Saint Louis, MO; Karen Budgell, Golder Associates, Lakewood, CO; Elaina Mason, Bayer Crop Science, Muscatine, IA; Erin Milligan, Bayer Crop Science, Kansas City, MO
Time: 8:10 AM
High temperatures in biological waste water treatment (WWT) systems can jeopardize treatment. Microbial breakdown of biochemical oxygen demand (BOD) is accomplished by enzyme catalysis. The predominant reactions occurring within this breakdown are exothermic. While they vary among species, each microbe and associated enzyme has optimal temperature ranges. When temperatures rise too far above this range, enzymatic reactions slow and eventually stop due to denaturing of the enzyme to the point where the active site no longer fits the substrate. Sometimes microbial death will also occur. Therefore, operating temperature range is an important parameter for control of activated sludge WWT processes. Engineering heat balances are performed across these systems to help quantify the heat generated and lost within the process and to identify options for bioreactor temperature control. Heat balances were conducted for two industrial WWT systems that successfully treat pesticide manufacturing effluent. These two WWT systems both operate using aerobic biotreatment, but one operates as a conventional activated sludge process and the other utilizes the UNOX biotreatment process. For these balances, analogous, simplified chemistries were used to represent the bulk chemical oxygen demand (COD) constituents and their reaction. Data regression of operational data was used to determine zero order kinetic terms that would suit the bulk chemistry. Combined with first principles, this information was used to create a semi-empirical process model for each system that predicts temperature performance. In this paper, the methodology for using homologous chemistries to approximate the biochemical breakdown of COD in aerobic WWT systems, and incorporation of this information to create system heat balance models is explained. Performance data from the two operating industrial WWT systems, with comparison of the relative heat contributions from sensible heat, solar radiation, conductive and convective heat transfer from the environment, work, and heat associated with chemical reaction are detailed. Application of this methodology will allow creation of similar models for other WWT systems.
Discusser: Robert Thompson, Jacobs Engineering, Houston, TX
IWC 21-74: Landfill Leachate- “Like a Box of Chocolates You Never Know What You Are Going to Get!”
Ron Ruocco P.E. Stantec, Charlotte, NC
Time: 9:00 AM
Landfill leachate under federal guidelines is classified as industrial wastewater. Cost effective off-site or on-site alternatives are needed for treatment or mitigation preventing health issues from polluting ground water, surface water, and/ or local environments. Attention to planning for adequate leachate management, particularly for leachate discharges to publicly owned treatment works (POTW), often does not receive the necessary budget resulting in disruption to landfill operations, unexpected operating and capital costs, or even emergency expenditures! Changes in water quality standards for metals, and emerging contaminants such as nutrients, pharmaceuticals, and PFAS compounds are pressuring POTWs to discontinue acceptance of untreated landfill leachate altogether! Adequate budgeting for leachate management is essential for proactive, cost effective planning to predict, design, and implement necessary changes in alternatives for leachate treatment systems. This paper looks at the factors influencing the ever changing, landfill leachate characteristics, potential regulatory drivers, and examples of treatment systems currently used for landfill leachate as well as modifications that may be needed in the future.
Discusser: Christine Smith, Purestream Services, Salt Lake City, UT
IWC 21-75: Biofiltration Advances for Treatment of Trace 1,4-Dioxane Concentrations
Phoebe Zheng, P.E., Chao Zhou, P.E., and Brian Petty, P.E., Geosyntec Consultants, Huntington Beach, CA
Time: 10:20 AM
1,4-dioxane is an emerging contaminant frequently detected in drinking water and wastewater, particularly in industrial wastewater from certain industries. Due to its properties, 1,4-dioxane is not removed by most water and wastewater treatment processes, and pretreatment options are currently limited to advanced oxidation processes (AOPs). However, AOP systems are complex and expensive to install and operate, and interfered by the other parameters (COD, color, TSS, etc.) present in these wastewaters. Biofiltration can potentially provide a simpler, affordable, yet effective alternative to AOPs, with metabolic treatment potentially more advantageous in operation. This paper presents the results of a two-year bench study of 1,4-dioxane removal by biofiltration. Effects of operating conditions, including biofiltration media, EBCT, and addition of a supplemental substrate were evaluated.
Discusser: Tat Ebihara, AECOM, Lombard, IL
IWC 21-76: Chemical Replacement – Managing pH with Carbon Dioxide in Place of Sulphuric Acid
Chris Milligan, PE, MSc., BSc., Adrian Beirise, PE, MSc., BSc., and Tyler Elm, MBA, MRM, BSc., Chartwater, BlueInGreen, Fayetteville, AR
Time: 11:10 AM
Proven in older forms over decades in drinking water treatment, today’s CO2 technology is being applied to a wider array of industrial wastewater applications with both economic and safety payouts for replacing strong acids such as sulfuric. Four case studies presented highlight the value proposition of using CDOX® gas-dissolution technology to control permitted wastewater stream pH in power, mining, fertilizer manufacturing, and food industry markets.
Discusser: Charan Tanneru, Tetra Tech, Houston, TX