Tuesday, November 12
Technical Sessions – 8:00 AM -12:00 Noon
ASME-Sponsored Session: Preventing and Remediating Damage Caused by Chemical Excursions in Industrial Boiler Water
IWC Rep: Colleen Scholl, P.E., HDR, Whitewater, WI
Session Chair: Vickie Olson, Honeywell Process Solutions, Sandy Springs, GA
Discussion Leader: Kirk Buecher, METTLER TOLEDO Thornton, Inc., Billerica, MA
Upsets in boiler water cycle chemistry can create the need for extensive repairs and down time for boilers and other areas of the steam cycle. Prevention is critical to avoid this, including setting alarm limits and managing water treatment. Cleaning boilers at the best time after upsets can minimize the damage. The papers in this session cover these issues and also include a case study of a chemistry excursion in a high-pressure steam generation system.
Consider Attending: W1, W3, W7, W8, W10, W11, W15, W17, W18, W21
IWC 19-29: Proper Use of Alarm Limits for Steam Cycle Chemistry Control
David Daniels, M&M Engineering, a Division of Acuren Inspection, Inc., Leander, TX
Steam cycle chemistry limits are often developed using a series of three Alarm Levels that increase in severity of actions to be taken. We will discuss the origin of the Action Levels, on what they were based, and how to properly use these for both determining when to shut down and startup a power generating boiler.
Discusser: Larry Hale, METTLER TOLEDO Thornton, Inc., Billerica, MA
IWC 19-30: Determination of the Time to Clean Industrial Boilers Based Upon Upset Feedwater Conditions
Edward Beardwood, Beardwood Consulting & Technologies, Inc., London, ON, Canada
The hydrocarbon and chemical processing industries operate a large number of low and medium pressure industrial and waste heat recovery steam generators. They are typically in the 150 to 600 psig range, while some may be as high as 900 psig. For simplicity we will define medium pressure as 600 to 900 psig and low pressure less than 600 psig. As the feedwater impurity concentrations increase and cycled percent recovery of said impurities decrease in the boiler water, the potential for tube metal overheating, resulting in reduced efficiency and eventual metallurgical failure increases. Some failures can be catastrophic, while others result in very costly forced outages. The former is related to increasing the total operating cost (TOC) of the thermal process, while the later results in much higher lost opportunity costs. It is these two costs that make up the total cost of ownership (TCO) associated with the forced outage failure. Most low and medium pressure steam systems suffer from poor quality feedwaters that are associated with;
• Chemical and physical corrosion within the condensate and feedwater system.
• Condensate process inleakage
• Poorly operated;
– Thermal mechanical deareation equipment
– Clarification and filtration equipment
– Ion exchange equipment
An assessment method to predict a time for a scheduled outage that would be used for chemical cleaning of the generator based upon the actual operating feedwater quality is required to avoid forced outage repairs. Should feedwater impurity concentrations be inconsistent and variable, due to the nature of the upsets, then the assessment becomes somewhat difficult. Therefore, a risk-based assessment that is applied to the poor feedwater quality that can be experienced over the operating period of a steam generator would be useful. This paper will provide and discuss an assessment method to predict when to schedule a chemical cleaning of steam generators to avoid tube failures and forced outages.
Discusser: Rick Szilagyi, WesTech Engineering, Inc., Salt Lake City, UT
IWC 19-31: Low pH Excursion in 1500 psi Steam Generation System at an Ethylene Plant
Aizaz Ahmed, NOVA Chemicals Corporation, Calgary, AB, Canada; Chris Garton, Nalco Champion, An Ecolab Company, Sarnia, ON, Canada
Water treatment of steam generation system in industry is mainly managed by following available guidelines from ASME or other recognized organizations. However, there is very little information available on managing excursions from the recommended control limits. Operating steam systems outside the recommended control limits pose risk to equipment in steam system as well as to the systems utilizing steam. Under extreme conditions, an excursion may become a safety risk to plant and workers. In absence of well-defined guidelines to deal with excursions, plant operators mostly rely on their understanding of water chemistry and support from water treatment service providers. The understanding and expertise of water treatment varies a lot from plant to plant, so as the responses to deal with the upsets and excursions.
This case study presents a low pH excursion event at an Ethylene production plant to illustrate the challenges faced by plant operators to manage these events working with competing pressure and targets to maintain production rates. The paper highlights potential risks operating at low pH, challenges in following recommendations for recovery, possible gaps in monitoring and control practices hampering timely responses and some recommendations for improvement.
Discusser: Michael Bluemle, Ph.D., Solenis LLC, Wilmington, DE
IWC 19-32: Analytical Tools to Manage Phosphate and Caustic Treatment
Randy Turner, SWAN Analytical USA, Wheeling, IL
Phosphate and/or caustic (NaOH) treatment boiler water treatment is often employed to reduce the risk of corrosion should a contaminant ingress occur. It is also used as a secondary or backup boiler water chemistry for all-volatile treatment (AVT) for the same reason. Corrosion can result in boiler tube failures, lost revenue due to lost generation, and expensive repairs potentially costing utilities millions of dollars. When employing phosphate or caustic treatment the pH control range is the pH from the solid alkali without the pH influence of the amine for feedwater pH control. Therefore, the measured pH must be corrected for the influence of the amine to obtain the solid alkali pH which is complicated and challenging. Also, the free sodium hydroxide must be maintained at less than or equal to (≤) 1.0 part per million (ppm) to reduce the risk of caustic gouging. Measuring the free sodium hydroxide at ≤ 1.0 ppm is very challenging in the laboratory due to the influence of carbon dioxide once the sample is exposed to air. To ensure proper dosing, calculations must be based on the mass of the volume of water to be treated at the current operating conditions. This is because the density and mass decrease as the operating pressure/temperature increases. This paper describes analytical calculations for proper and precise control of phosphate and caustic treatment which have been incorporated into an Excel spreadsheet which includes several calculations of which the most important are:
1. Boiler water ammonia corrected pH
2. Sodium to phosphate molar ratio
3. Free sodium hydroxide concentration
4. Amount of phosphate and/or caustic to dose for a specific concentration at the current operating pressure
This tool can also be used to calculate how much caustic must be added to an AVT treated boiler to neutralize acids or alkalis. As a result, these empirical calculations incorporated into an Excel spreadsheet which allows the station chemist to accurately and properly monitor and control the boiler water pH, phosphate, and/or caustic to reduce the risk of costly corrosion and forced outages. This tool has been used successfully to properly respond to contaminant ingress events to neutralize significant acidic conditions resulting from the ingress of acidic salts such as sodium chloride (NaCl).
Discusser: Akash Trivedi, METTLER TOLEDO Thornton, Inc., Billerica, MA
Reverse Osmosis: Expanding the Treatment Capabilities of Membranes
IWC Rep: Dennis McBride, Burns & McDonnell, Kansas City, MO
Session Chair: Mitch Mueller, P.E., Black & Veatch, Overland Park, KS
Discussion Leader: Kurt Blohm, Veolia Water Technologies, Pittsburgh, PA
Since the development of reverse osmosis (RO) membranes, advances in the technology have surpassed limits previously imposed on these applications, expanding its use in the market. Despite these advances, there are still known difficulties and limits to the use of RO membranes. This session will examine ways to overcome some of these known difficulties and limitations to allow a broader range of use for membranes. Papers within this session discuss:
• The optimization of operating conditions and utilization of chemical feeds to control scale and biofouling.
• Evaluating the performance of low-pressure membranes to remove micro pollutants.
• Selection of membrane element components to handle high temperature applications.
Consider Attending: W1, W2, W3, W8, W10, W11, W15, W16, W17, W21, W22
IWC 19-33: The Contrarian Use of Chlorine to Control Biofouling in RO Membranes
Rich Franks, P.E., Alexandra Rubin and Craig Bartels, Ph.D., Hydranautics, Oceanside, CA; Peter Cartwright, P.E., Cartwright Consulting Co., Minneapolis, MN
It is well known that the reverse osmosis membrane’s polyamide chemistry is incompatible with chlorine. This limitation of the polyamide chemistry is sometimes referred to as the Achilles Heel of RO membranes. In many RO systems, the absence of a continuous biocide such as chlorine leads to extreme biofouling, rapid performance degradation, frequent cleanings, extended downtime, and shortened membrane life. However, regardless of this stated incompatibility, there does exist a low level of tolerance before damage to the molecular structure of the membrane causes a noticeable change in RO performance. This tolerance, which is effected by a number of variables, has gradually increased over the years as the membrane chemistry has evolved. Today’s membranes are more highly crosslinked than those of previous generations. These latest chemistries result in lower pressures and better rejection; including better rejection of more challenging constituents such as silica and organics. These better chemistries have the added benefit of being more robust and, therefore, more chemically tolerant. This includes improved tolerance, not only to caustic or acid cleanings, but also to chlorine. Though no membrane supplier promotes these membranes as chlorine tolerant, their improved durability makes the use of chlorine to control biofouling an option worth considering when confronted with extreme biofouling. At least one RO plant is experimenting with intermittent exposure to low levels of chlorine for the purpose of managing biofouling. After a biofilm is allowed to build on the membranes, as evidenced by decreasing permeability and increasing differential pressure, periodic chlorine dosing is initiated. Though the chlorine improves membrane performance, the permeability and differential pressures do not return to their original, baseline values; the intention being to minimize chlorine exposure and maintain some foulant as a protective layer. This paper will present the chemistry behind past and current chlorine limitations. RO membranes exposed to chlorine in the laboratory will be analyzed. The RO system operating data, both before and during chlorine dosing, will also be presented. Analysis of elements extracted from the RO system will be shared in order to further characterize the membrane performance and chemistry after “real world” chlorine exposure.
Discusser: Ed Greenwood, P.Eng, BCEE, Wood Environment & Infrastructure Solutions, Cambridge, ON, Canada
IWC 19-34: Scale Control in a Boron Rejection System for Seawater Desalination
Caroline Sui, Anna Bandick, and Jeff Melzer, SUEZ Water Technologies & Solutions, Trevose, PA; Joan Estilles, SUEZ Water Technologies & Solutions, Gava, Barcelona, Spain
High pH operation in a second-pass reverse osmosis (RO) membrane seawater desalination system for boron rejection is an effective approach to meet World Health Organization (WHO) specifications for drinking water as well as for specific crop requirements for water used for agricultural irrigation. The regulations for drinking water in some countries could be significantly more restrictive than the WHO’s specifications. High pH operation, however, results in a high tendency to form mineral scales in the system, such as calcium carbonate and magnesium hydroxide.
A large seawater RO (SWRO) desalination plant encountered significant scaling problems in the second pass, brackish water RO (BWRO) system. Frequent cleans in place (CIP) were conducted to remove scales, which was not only costly but also jeopardized the plant’s ability to operate at full capacity.
Our engineering team audited the system, reviewed operating data, conducted comprehensive water and deposit analyses, and performed membrane element autopsies throughout the system to determine possible causes of the frequent CIPs. Thermal dynamic saturation modelling was developed to establish correlations between scale formation and water chemistry and operational conditions. The laboratory study evaluated scale control products for their ability to control deposition and to develop recommended optimum operating conditions.
Strong collaboration between the customer and our company led to implementation of a new antiscalant and the adjustment of the chemical injection parameters in the second pass, achieving significantly more reliable performance with stable permeate flow, decreased differential pressure, and reduced salt passage. Significant annual cost savings were achieved.
Discusser: Andrew Boehmer, P.E., Black & Veatch, Ann Arbor, MI
IWC 19-35: Rejection Performance of Micro-Pollutants by Ultra Low-Pressure Reverse Osmosis membranes
Alan Sharpe, LANXESS Corporation, Birmingham, NJ; Uli Doelchow and Julien Ogier, IAB Ionaustaucher GmbH, Bitterfeld, Germany
This paper investigates the removal of micro-pollutants with an Ultra Low Pressure reverse osmosis membrane. The micro-pollutants studied were hazardous compounds established by the European Union and the EPA, including drugs, herbicides, corrosion inhibitors, contrast agents, and a sugar substitute. This paper presents laboratory and pilot work (via German government funded project). The ULP membrane demonstrated a high rejection performance, supporting its intended use for applications in waste water or drinking water treatment.
Discusser: Bernie Mack, Veolia Water Technologies, Natick, MA
IWC 19-36: Innovative Spiral-Wound Membrane Elements for High Temperature Desalination Applications
Elke Peirtsegaele, MICRODYN-NADIR, Goleta, CA
Water desalination has become one of the most important methods of alleviating water shortages and meeting stricter environmental regulations across the world. While spiral-wound reverse osmosis (RO) and nanofiltration (NF) membrane elements have proven very successful in a variety of desalination applications, more and more applications are emerging that require spiral-wound membrane elements capable of handling high temperatures or extreme cleaning conditions. Because industry-standard RO and NF water elements are limited to a maximum operating temperature of 45°C (113°F), membrane manufacturers are investigating alternative materials to build high temperature elements for applications where standard RO and NF elements cannot be used.
This paper explains how data is used to determine when more robust element components (i.e. materials of construction) such as feed spacers, permeate carriers, permeate tubes, and outerwraps are needed to develop elements that can handle different levels of elevated temperatures. Elements constructed with these alternative materials fall into four categories based on temperature tolerance:
• Warm temperature operation (up to 60°C continuous)
• High temperature operation (up to 80°C continuous)
• Heat-sanitization (sanitization up to 90°C)
• Extreme cleaning at high pH and high temperature (up to pH 13 and 75°C)
Overall, this paper focuses on why high temperature spiral-wound elements are needed, which applications require these types of elements, and how different element components can be combined to tackle an even broader range of applications than ever before.
Discusser: Dileep Agnihotri, Ph.D., Watersurplus, Loves Park, IL
Tackling the PFAS Challenge
IWC Rep: Brad Wolf, P.E., Berkeley Research Group, LLC, Pittsburgh, PA
Session Chair: Kristen Jenkins, P.E., GHD, Duluth, GA
Discussion Leader: Tyler Butel, AdEdge Water Technologies, Duluth, GA
Per- and polyfluoroalkyl substances (PFAS) are a class of over 5,000 synthetic compounds used in a wide variety of consumer products due to their water and stain repellent properties and thermal resistance. PFAS are very stable compounds, which persist in the environment. Increasing public awareness has led to current and proposed regulations, including drinking water and surface water. Please join us at this session to learn about PFAS, including the history of use, current regulatory status, as well as demonstrated and developing treatment technologies.
Consider Attending: W1, W3, W8, W10, W11, W14, W15, W17, W21
IWC 19-37: My Industry Does Not Make or Use PFAS. So What Is It, and Why Should I Care? An Overview of PFAS Issues for Non-PFAS Industries
Ryan Ames, P.E., Katie Jones, P.E., Leigh-Ann Dudley, P.E. and L. Alex Wall, Dewberry, Raleigh, NC
Industries that do not utilize PFAS directly in their products or processes may still be affected by the presence of PFAS in other products and the environment and anticipated regulations. Per- and Polyfluoroalkyl Substances (PFAS) is a group of synthetic chemicals that is utilized for a variety of applications in industrial processes and consumer products including vapor control in plating processes, grease resistant coatings on fast food wrappers, water resistant coatings and firefighting foam. The chemical characteristics that make them useful in these applications also make them widespread and persistent in the environment because they can be transported in both air and water, degrade very slowly, and are not removed by most conventional treatment technologies. These compounds are receiving a great deal of attention in both the technical and popular literature because of known and potential health effects. Regulation of these chemicals is in its infancy. Some states are regulating the PFAS in drinking water and the release of PFAS into the environment via various pathways. One limit to regulation is that proposed exposure limits are in the parts per trillion range, and analytical methods for detection and accurate quantification of many of these compounds are still being developed. In February 2019 the Environmental Protection Agency (USEPA) issued an action plan for PFAS that discusses how the EPA regulates new PFAS compounds entering the market place, sets a timeline for establishing toxicity values and drinking water regulations for specific PFAS compounds, and groundwater cleanup actions. In addition the action plan addresses development of analytical methods and development of treatment technologies, among other things.
Due to the potential regulatory implications of PFAS, it is important for all industries that use water, incorporate water into products, or discharge wastewater to have an understanding of this emerging regulatory issue. This paper will provide an overview of PFAS chemical characteristics; presence, fate and transport in water; current and anticipated scope of PFAS water regulations, effectiveness of advanced water treatment technologies, and examples of how PFAS concerns could impact non-PFAS industries.
Discusser: James Beninati, P.E., HDR, Pittsburgh, PA
IWC 19-38: An Introduction to Per- and Polyfluoroalkyl Substances and Treatment
Mike Preston, P.E., and Dustin Mobley, P.E., Black & Veatch, Overland Park, KS
Per- and polyfluoroalkyl substances (PFAS) are a class of chemicals used in the manufacture of many industrial and consumer products, including firefighting foams, water-and oil-resistant coatings, cookware, cosmetics, lubricants, inks, and paints. These compounds are very stable and resistant to heat and degradation, making them beneficial for use in industry and in many consumer products. They are also persistent in the environment and bioaccumulative making them a potential health concern.
Production of PFASs started in the 1940’s with the invention of Teflon® and Scotchgard®. Today, there are more than 3,000 PFAS used worldwide. Their use has resulted in the pervasion of PFAS in the environment and in humans.
These discoveries have prompted a greater focus on PFAS from research institutions, regulatory agencies, and the public. In 2016, the US EPA established health advisory levels for two long-chain perfluorinated compounds – perfluorooctanoic acid (PFOA) and perfluoroctane sulfonate (PFOS) – of 70 ng/L, measured individually or combined. Several US states have issued more stringent guidelines. Recent legislative action is moving toward designation of these compounds as hazardous substances under the CERCLA designation which would result in EPA regulations and significant industrial impacts.
This presentation will present an overview of the chemistry and applications of PFAS, a review of regulations and current efforts to curb PFAS exposure and contamination, and current methods for removal of PFAS from water.
Discusser: Mike Weatherill, Purolite Corporation, Collingwood, ON Canada
IWC 19-39: A Review of Recent Experimental Studies on PFAS Treatment
Francisco J. Barajas-Rodriguez, Ph.D. and Craig Holloway, P.E., AECOM, Austin, TX
Per- and poly fluoroalkyl substances (PFAS) pose health risks to the public which come with long-term exposure. State advisory limits range from 70 parts per trillion (ppt) down to as low as 13 ppt. Since PFAS presence is widespread, treatment of PFAS-impacted water becomes a dominant priority for many industrial entities. PFAS are highly stable due to the strong carbon-fluoride bonds and are highly miscible in water which make their treatment challenging. Therefore, conventional destructive techniques are ineffective, and most treatment options rely on specialized separation strategies.
AECOM is currently involved in the development and testing of strategies to treat PFAS impacted water. One approach treats PFAS in groundwater landfill leachate by implementing a permeable barrier. Batch and column experiments demonstrated and optimized in-situ PFAS removal from the groundwater by evaluating different adsorptive organic media mixed with soil. These media included wood shavings and high organic content biochars. Removal capacities were quantified from batch tests and breakthrough curves were obtained from the column study. The biochar-amended media consistently displayed superior removal of PFAS (up to 100% in batch tests) whereas the wood shavings amendment did not improve PFAS removals.
The second PFAS-treatment approach consists of electrochemical oxidation of PFAS. This technology utilizes a proprietary anode which is highly selective for PFAS destruction and requires the addition of sodium sulfate to increase the electric conductivity. Bench-scale experiments in a 5-gallon, prototype reactor have been performed using laboratory PFAS-spiked water, contaminated groundwater, and ozone-fractionation process-effluent water, in which the PFAS concentrations were 100 parts per billion (ppb), 400 ppb, and 100 ppb, respectively. All experiments indicated destruction of >99% of PFAS, with reaction times from 8 to 80 hours.
These approaches highlight the diversity of applications within the PFAS-treatment realm. Currently, removal techniques that rely solely on separation, such as granular activated carbon and ion exchange resin, are more mature and widely implemented. However, for scenarios such as landfill leachate plume migration containment, the use of biochar or other media mixed with soil may constitute a more cost effective, and even sustainable approach. Lastly, the search for reliable technologies capable of ultimately destroying PFAS is important, and electrochemical oxidation can play a role as a potential tool and alternative to treat these contaminants in combination with separation techniques.
Discusser: Jim Knepper, Jacobi Carbons, Inc., Columbus, OH
IWC 19-40: Perfluoridated Alkyl Substances: A Historical Overview
Peter Meyers and Tom Smith, Jr., ResinTech, Inc., West Berlin, NJ
The first fluoropolymers were invented in the 1930’s and found wide commercial acceptance as non stick coatings for cookware. Both PFOA and PFOS were invented shortly thereafter with the first commercial uses being fire retardant foams and water repellents for fabrics. Since then, many other commercial uses have been found for PFAS compounds.
Per- and polyfluoroalkyl compounds, commonly known as PFAS, are a large family of synthetic chemicals that are recognized as emerging contaminants. PFAS are found in a wide range of products we use every day, including fire retardants, water repellents, car waxes, and even food packaging. The two most studied and produced compounds are PFOA and PFOS, but quite a few other PFAS compounds have been identified as problematic.
As a group, PFAS compounds do not biodegrade but do bioaccumulate. They are water soluble and very mobile. They are found in groundwaters near landfills, airports, military bases, car washes, and various manufacturing sites. Although some are not especially dangerous, others have been shown to cause serious health issues.
The EPA has issued a health advisory of 70 ppt for PFAS, has established an action plan, and is actively working to set a federal MCL for various PFAS compounds.
In this overview presentation, we present information regarding the origin of these compounds, a brief history of how they came to be a recognized health risk, and the current best practices for removing them from our potable water supplies.
Discusser: Krystal Perez, P.E. and Andrew Ryder, Worley, Kirkland, WA
We’ve Got the Power!
IWC Rep: William Kennedy, P.E., Stantec, Charlotte, NC
Session Chair: David Riedel, P.E., Arcadis, Philadelphia, PA
Discussion Leader: Bridget Finnegan, EIT, Veolia Water Technologies, Pittsburgh, PA
In this session we will focus on some of the new(-ish) water and wastewater treatment challenges that the power industry is currently facing. We go beyond the buzz-acronyms of CCR, FGD and ELG to talk about boron, WET testing, and others. Come to this session and get energized!
Consider Attending: W1, W3, W4, W8, W9, W10, W11, W13, W15, W17, W21
IWC 19-41: Landscape of Whole Effluent Toxicity Requirements in the Power Industry
Krystal Perez, P.E., Worley, Kirkland, WA; Jeff Thomas, Electric Power Research Institute, Cincinnati, OH; Shaun Roark, Ph.D., Jacobs, Denver, CO; Elizabeth (Ellie) Traudt Middleton, Ph.D., NiPERA Inc., Durham, NC
Whole effluent toxicity requirements are a challenging subject relevant to many facilities’ National Pollutant Discharge Elimination System permits. This paper shares the results of a recent literature survey conducted by the Electric Power Research Institute that was focused on capturing key permit information across multiple facilities. This work provides new insights into what the industry is seeing with regards to toxicity-based permit requirements. This paper summarizes key findings related to the extent of toxicity-related permit issues for the power industry.
Discusser: John Van Gehuchten, P.E., McKim & Creed, Sewickley, PA
IWC 19-42: Electricity Dispatch of Thermoelectric Power Generation Under Short-Term Water Consumption Constraints: An ERCOT Case Study
Erik Shuster, National Energy Technology Laboratory, Pittsburgh, PA; Yash Kumar, Aranya Venkatesh, Ph.D., Rachel Hoesly, Ph.D., and Arun Iyengar, Ph.D., KeyLogic Systems, Pittsburgh, PA
LOAD (Linear Optimization and Assessment of Dispatch) model optimizes hourly power generation by minimizing generation costs and constraining water use. In this study, it allowed for analysis of impacts of water stress in ERCOT’s operations during the 2018 summer season. Imposition of water constraints in drought-prone Southern Texas indicates fuel switching, electricity price increments, coal plant cycling and localized shifting of generation in the region. The study provides a framework to evaluate potential of NETL’s R&D program in water-conserving cooling and treatment technologies.
Discusser: Katie Bland, P.E., Burns & McDonnell, Kansas City, MO
IWC 19-43: Addressing Root Causes of Wastewater Treatment Performance Issues
Thomas Higgins, P.E., Ph.D., Worley, St. Augustine, FL; Tatsuji Ebihara P.E., Ph.D., AECOM, Chicago, IL
Power plant wastewater treatment plants employing conventional mixers have difficulty achieving stringent metals limits due to formation of colloidal particles that pass through clarifiers and granular media filters. Case studies are presented where adjusting pH setpoints, changing to low-shear mixers and pumps and relocating sludge recirculation to the same tank as ferric addition promoted generation of high density solid that improved metals removal performance.
Discusser: Derek Henderson, P.E., Duke Energy, Raleigh, NC
IWC 19-44: Technology and Treatment for Boron Removal
Dr. Jeffery Easton, P.E., Ph.D., WesTech Engineering, Inc., Salt Lake City, UT; Dr. John McLennan, Ph.D., University of Utah, Salt Lake City, UT
Low-level boron removal from wastewater is a rising challenge for industry, and an upcoming regulatory pressure for many. Boron is a difficult constituent to remove or treat with traditional methods and processes. It is highly soluble in most forms and presents significant removal difficulty due to its small size and often uncharged nature. Traditional treatment technologies such as precipitation, coagulation, flocculation, sedimentation, filtration (including membranes) and common ion exchange have little or no effect on boron compounds in low concentration.
This paper presents an overview of existing and new treatment technologies for the removal of boron from wastewater. Specifically-adapted technology is required to make boron separations possible. Therefore, it is beneficial for engineers to know what technologies are available when approaching a new boron removal requirement and how to apply those technologies. Boron removal methods such as boron-specific ion exchange, boron specific membranes, boron sorbents and hybrid boron removal technologies are presented for consideration. Data and predictive model simulations are offered to guide the design of lab and pilot studies in order to determine full-scale applicability of select technologies.
Discusser: Ereka Hunt, Kiewit, Lenexa, KS