Monday, November 5
Technical Sessions – 1:15-5:00 P.M.
Boiler Water Contaminants and Their Effect on Boiler System Operations
IWC Rep: Wayne Bernahl, W. Bernahl Enterprises Ltd., Elmhurst, IL
Session Chair: Claudia Pierce, Dr., SUEZ Water Technologies & Solutions, Trevose, PA
Discussion Leader: Debbie Bloom, Retired, Wheaton, IL
Technical papers will be presented in the areas of water treatment, cases of corrosion related phenomena, and contaminants excursion requiring mitigating risks planting safety and reliability. The first paper will cover the differences between terminologies in the “water” composition of boiler systems. Terms like “Ultrapure Water” (UPW) and “Industrial water” (Power, Industrial boilers, refineries, cooling water, industrial process streams, mining, oil and gas) will be highlighted to help the audience come to a clearer understanding about these differences and their impact on water treatment decisions. Another paper included in this session is related to Flow Accelerated Corrosion (FAC), a phenomenon quite unique to steam generation systems. This paper will discuss the conditions which contribute to the two forms of FAC (single phase or two phase) as well as the means to reduce its effects, primarily focused in Heat Recovery Steam Generator (HRSG) systems. A paper is also included providing a case study for root cause analysis of pitting and evaluation of the process analytics in place to detect and monitor corrosive contaminants. It discusses the implementation of on-line chloride and sulfate measurements to complement current analytical measurements and provide actionable data to control power plant processes and reduce corrosion. The last paper will cover steam system silica excursion at an ammonia production site. This excursion led to a 17% reduction in continuous ammonia production rate over a 10-day period at two production sites (profit losses of $ 600,000).
IWC 18-13: How Do the Users of Ultrapure Water differ and What Drives Treatment Decisions?
Mike Henley, MD Henley & Associates, Denver, CO
In the water world, the terms “ultrapure water” (UPW), and “industrial water” have different meanings, depending on the application. Essentially, each water name acts as an umbrella term for several types of water.
In UPW there are really three primary categories: semiconductor water, pharmaceutical water, and power water for sub- and super-critical boilers. Each kind requires specific types of treatment to ensure they meet the specifications for use in their respective end use.
For example, in the production of microelectronics water, the goal is a final water quality with a resistivity around 18.2 megohm-cm (at 25°C). To achieve this quality of water, a facility will use treatment technologies such as ion exchange (IX), reverse osmosis (RO), electrodeionization, ultrafiltration, microfiltration, ozone, and UV. Additionally, great care is given to the choice of materials of construction for piping and valves.
Whether one is thinking of UPW or industrial water, one important factor that impacts the water treatment decisions are the different published guidelines. The list of organizations reads like alphabet soup: ASME, ASTM, EPRI, IAPWS, SEMI, and pharmacopeias (USP, JP, EP).
Through the use of data (charts and tables), and practical information, the aim of this paper and presentation is as follows: 1. To provide a breakdown on what the umbrella term UPW means; 2. To examine how water treatment varies and is similar between and within the two categories; 3. To briefly highlight the organizations that develop the standards used by different end user industries and the role each plays; and 4. To help those in the audience come to a clearer understanding about these differences and their impact on water treatment decisions. This information would come from research and from the author’s experience as editor of Ultrapure Water Journal and Industrial Water Treatment for 27 years.
For example, in the production of microelectronics water, the goal is a treated water with a resistivity around 18.2 megohm-cm (at 25oC). To achieve this quality of water, a facility will use treatment technologies such as ion exchange (IX), reverse osmosis (RO), electrodeionization, ultrafiltration, microfiltration, ozone, and UV. Additionally, great care is given to the materials of construction choice for piping, valves, and other wetted surfaces, which is normally PVDF.
The term “industrial water” is also an umbrella term that refers to several categories of treated water, whose applications include power (lower pressure boilers), industrial boilers, refineries, cooling water, industrial process streams, mining, and certain aspects of oil and gas water. Again, each application has differing quality needs, so the treatment methods will vary. For example, some cogeneration power plants, a simple RO or IX system may meet the water quality need.
Whether one is thinking of UPW or industrial water, one important factor that impacts the water treatment decisions are the different published guidelines from organizations such as the ASME, ASTM, EPRI, IAPWS, SEMI, and pharmacopeias (USP, JP, EP).
Through the use of data (charts and tables), and practical information, the unique (novel) aim of this presentation is as follows: 1. To provide a breakdown on what the two umbrella terms: Industrial Water and UPW mean; 2. To examine how water treatment varies between and within the two categories; 3. To briefly highlight the organizations that develop the standards used by different end user industries and the role each plays; and 4. To help those in the audience come to a clearer understanding about these differences and their impact on water treatment decisions. This information would come from research with end users or similar experts, and from the author’s experience as editor of Ultrapure Water Journal and Industrial Water Treatment for 27 years.
IWC 18-14: Flow-Accelerated Corrosion- What Is It and What To Do About It
Dennis McBride and Phil Walker, Burns & McDonnell, Kansas City, MO
A corrosion process, referred to as Flow Accelerated Corrosion (FAC), has been determined to be the cause of multiple catastrophic failures in power plants resulting in significant unplanned outages, expense, and even fatalities. Through the knowledge of where FAC can occur and the use of proper chemistry and metallurgical selections, these failures, as well as future fatalities, can be avoided.
IWC 18-15: Case Study: Monitoring and Controlling Corrosion Using On-Line Chloride and Sulfate Measurement
Burt FitzHugh, Tennessee Valley Authority, Drakesboro, KY
Power plants constantly combat corrosion caused by chlorides and sulfates under high pressure water and steam conditions. Paradise Fossil Plant Unit3 is an 1150 MW supercritical generating unit, using a once-through boiler and implementing the associated tight controls over water/steam quality according to Oxygenated Treatment regimen. Even with continuous monitoring of cation conductivity and sodium to maintain them at acceptable levels, pitting was observed on the Low Pressure Turbine blades during maintenance leading to expensive repairs and longer downtime. The root cause for this pitting was traced to excessive chloride and sulfate in the water/steam cycle.
This paper provides a case study for root cause analysis of this pitting and evaluation of the process analytics in place to detect and monitor corrosive contamination. It discusses the implementation of on-line chloride and sulfate measurement to complement the current analytical measurements and provide actionable data to control power plant processes and reduce corrosion.
IWC 18-16: Boiler Silica Excursion Results in Production Loss & Potential Plant Shutdowns at an Ammonia Production Site
Ray Titsing, BSc., BEd., Suez Water Technologies and Solutions, Oakville, ON, Canada
Silica is the most ubiquitous and plentiful component of the Earth’s crust. The vast majority of minerals that contain silica have very low to extremely low solubility in water. Despite this fact, the widespread presence and shear abundance of silica make it a pervasive contaminant in typical raw water sources utilized by industry. Due to its complex and dynamic chemical and physical-chemical properties, silica poses unique challenges when treating water for silica removal.
Silica removal from water destined for use in industrial high pressure steam turbine drives, in particular, requires special attention. Silica in these systems can deposit on steam turbine blades, causing problems ranging from losses in turbine efficiency, to mechanical balance issues, to unexpected shutdowns. In some cases, silica deposits can be removed using high pressure water washing, while others require sand blasting or washing using hazardous chemicals such as hydrofluoric acid. In the most severe cases, deposits cannot be effectively removed requiring complete replacement of the affected blades. Silica removal by the boiler pretreatment systems is, therefore, required to ensure the safe and reliable operation of critical steam turbine drives.
While there are well-established means of removing silica from water, a single, unexpected silica excursion has the potential to be quite serious. This is particularly true for those who are inexperienced in dealing with this type of excursion. Even those experienced in dealing with silica may not be prepared for an unprecedented excursion. Changes in both the amount and characteristics of raw water silica content can be caused by changes in natural water flows, weather, temperature, amount of precipitation, wind patterns, and even the health and diversity of local plant populations. In places where silica was never an issue in the past, silica excursions may become the new “normal.”
This paper examines an unprecedented steam system silica excursion at an ammonia production site. The excursion led to a 17% reduction in continuous ammonia production rate at two production plants over a combined 10 day period. This resulted in combined profit losses of $600,000. Plant shutdowns and implementation of expensive temporary treatment options were both being seriously considered prior to the excursion subsiding. The paper will detail the specific challenges this excursion generated and what was done at the time to mitigate the potential risks to plant safety and reliability.
IWC 18-Reserve: The Silica Dilemma
Michael Snow, SnowPure Water Technologies, San Clemente, CA
Consider Attending: W-1, W-2, W-5, W-7, W-10, W-12, W-17
Sustainability in Water Treatment Design – Not Just a Differentiator, but the Future for Gaining a Competitive Edge
IWC Rep: Ken Dunn, Solenis-Retired, Mashpee, MA
Session Chair: Michele Funk, Bechtel Corporation, Reston, VA
Discussion Leader: Kenneth Chen, Fluor Enterprises, Inc., Aliso Viejo, CA
It is commonly understood, yet not necessarily accurate, that sustainable designs increase the overall cost of the project. To the contrary, a single sustainable design change, such as fresh water reduction or use of a sustainable technology, can naturally lead to compounding benefits (lower power usage, reduced chemical usage or less environmental impact), and even result in an edge over competitors. This session will illustrate how sustainable designs have intrinsic relationships and can organically cultivate into a technical advantage, and even decrease overall cost. The designs in this session include: biological treatment realizing benefits of reduced chemical usage; an environmentally filming anime-type biocide that reduces truck delivery traffic and lowers dosing equipment capital cost and electrical use; a combined cycle power plant with no wastewater discharge permit that takes a holistic design approach with selection of air cooled condensing technology, while also reducing chemical use for regeneration of the condensate polisher; and a coal fired power plant reusing gypsum fines from wastewater dewatering for wallboard while optimizing greenspace footprint.
IWC 18-17: Sustainable Alternatives to Power Plant Make-up Water: Using Treated Municipal Wastewater
Bridget Finnegan and Michael Pudvay, P.E., Veolia Water Technologies, Inc., Pittsburgh, PA; John He, P.E., Veolia Water Technologies, Inc., Cary, NC; Lucas Davis, P.E., Kiewit Engineering Group, Inc., Lenexa, KS
Using treated municipal effluent as make-up water for power plants presents obvious benefits, including cost reduction and sustainability. The methods and benefits of using treated municipal effluent are compared in this paper for three separate power plants in North America. Each power plant includes a nitrification stage and a solids removal process to treat the municipal effluent before it can be used. However, the stability of the source water and the environmental benefits outweigh the treatment costs.
IWC 18-18: Grey Water for Cooling Water Makeup: Mission Impossible
Brad Buecker and Ray Post, P.E., ChemTreat, Richmond, VA
By choice or mandate, owners and design engineers for many new power and industrial plants are selecting alternatives to fresh water for plant makeup. An increasingly common choice is effluent from a publicly owned treatment works (POTW), commonly known as municipal wastewater treatment plant effluent or grey water. These waters typically contain elevated concentrations of ammonia, nitrite/nitrate, organics, phosphate, and suspended solids, all of which, if left untreated, can lead to a nightmare scenario of microbiological fouling in cooling towers and cooling systems. But with proper pre-treatment and cooling water chemical treatment, these makeup supplies can successfully be utilized. Methods to adapt grey water for use in cooling systems include robust pre-treatment of the makeup, consistent and reliable biocide feed to the recirculating water, and use of all-polymer treatment for scale/corrosion control in place of the phosphate/phosphonate programs of the past. The latter has been gaining impetus due to concerns about the environmental impacts of phosphorus discharge to lakes and rivers.
IWC 18-19: Innovations in Water Treatments Employing Filming Amine Technology
Wolter Glass, Mexel USA, LLC, Arlington, VA
Filming amines are receiving increased attention for use in cooling water applications from commercial and institutional cooling towers to large power plants with once-through cooling. Once considered only as a chemical to address corrosion, its unique chemistry is now being explored by manufacturers and water treatment professionals. The potential for reducing the environmental impacts of cooling water treatment programs along with energy savings are now being identified. The chemical mechanism of action for filming amines focuses on preventing fouling from a wide range of factors rather than remediating. These innovative uses of existing technology have now been demonstrated in a range of applications with documented results. In addition to the wide use of filming amines for corrosion control, it has also been demonstrated as a biocide and scale control agent. This paper will discuss data from selected projects along with an overview of the chemistry and treatment program options. Research on relative environmental impacts of filming amines compared to common biocides will also be presented.
IWC 18-20: Process Changes to Coal Fired Power Plant Gypsum Dewatering in a Postage Stamp
Julia Mercer, EIT, HDR, Pittsburgh, PA
This paper discusses the results of a coal fired utility’s evaluation to determine if installing new equipment in the gypsum dewatering circuit to make sellable gypsum would be profitable. Proposed equipment includes additional gypsum dewatering equipment (vacuum dewatering drum and conveyors) with ancillary support equipment. The site layout was extremely confined and this paper also discusses the evolution of the general arrangement and how 2×100% redundancy was fit into the small space.
Consider Attending: W-1, W-2, W-5, W-10, W-12
Trace Contaminants: Detection, Removal and Recovery
IWC Rep: Mike Gottlieb, ResinTech Inc., West Berlin, NJ
Session Chair: Donna DeFlavis, Dow, Collegeville, PA
Discussion Leader: Young Chul Choi, Southern Research, Cartersville, GA
Removing trace contaminants from water sources is a challenging but necessary application in a time of limited water supplies and increasing regulatory concerns. This session will present papers on treatment systems used to selectively remove Radium, Uranium and Selenium as well as discuss the importance of accurate Selenium speciation for effective treatment. This session will also discuss recovery and reuse for Uranium.
IWC 18-21: Radium Removal from Potable Water Supplies
Peter Meyers, ResinTech Inc., West Berlin, NJ and Frank DeSilva, ResinTech Inc., Gardena, CA
There has been intense interest in radium removal from potable water supplies in the last few years, driven by the radium MCL issued by the US EPA. Although the compliance cycle for large systems ended a few years ago, the cycle for small community systems ended in Dec 2016. These small systems are now required to take action if test samples exceed the MCL.
Although radium can be reduced by membrane processes such as RO, this treatment method produces a waste stream of significant volume that contains the radium in more concentrated form. Radium is removed by water softening resins so long as hardness ions are also removed but it is not always desirable or cost effective to soften potable water. Certain cation resins have unusually high affinity for radium compared to other cations such as calcium, magnesium, and sodium and can be effectively applied in some single use applications where the total dissolved solids and hardness are modest. For higher Total Dissolved Solids (TDS) and hardness waters, the radium selective complexer hybrid cation provides high throughput capacities for single-use applications.
This paper discusses the relative merits of the various radium removal processes, presents operating data for both the single-use application of cation resin that is highly selective for radium and for the radium selective complexer hybrid. Some of the operational difficulties associated with the use of ion exchange resins for radium removal are also discussed
IWC 18-22: Water Treatment Residuals Management for Uranium Removal Using Ion Exchange Media Re-certification and Reuse in Potable Water Systems
James Arnold, P.E., Water Remediation Technology LLC, Arvada, CO
Uranium removal treatment for groundwater and municipal water systems incorporate recognized ion exchange water treatment technologies to great effectiveness. Once concentrated on ion exchange medias, uranium residuals become a challenging disposal problem involving state and federal regulations for handling, storage, transportation and final disposal. In addition the long-term disposal implications of radioactive residual materials raise other concerns. Uranium water treatment residuals can be recovered by using the spent water treatment media as a direct source material substitute in uranium metal processing and production. The numerous state and federal licensing requirements in handling uranium containing materials complicate the simple substitution. WRT has successfully completed a reuse program for uranium water treatment residuals. Working with the NRC in proposing regulatory changes to the Federal Code along with establishing a willing uranium reprocessing partner, the program includes full recovery of uranium residuals and nearly full reuse of uranium ion exchange media materials for direct replacement in uranium treatment systems.
The presentation will focus on the regulatory environment associated with uranium water treatment residuals, the uranium media reuse concerns and the special requirements in implementing the reuse program for municipal water treatment systems. Some media processing specifics will be discussed along with bulk radionuclide-containing media handling systems for reuse.
IWC 18-23: Compliance with Selenium Aquatic Life Criterion and the Importance of Speciation for Treatment Selection and Monitoring
Ben Wozniak, Jamie Fox, and Russ Gerads, Brooks Applied Labs, LLC, Bothell, WA
It is well-known that for many elements, static water quality guidelines can be over- or under-protective for aquatic life. A variety of site-specific factors may either inhibit or enhance the uptake and bioaccumulation of an element into aquatic organisms like algae, invertebrates, and fish. Regulators have recognized this issue for decades, promulgating guidance for the generation of site-specific contaminant limits and, especially in the case of selenium, tissue-based criteria that may be adopted by states or provinces. The Aquatic Life Criterion for Selenium released by the USEPA in 2016 recommends adoption of a multi-component standard for regulatory management of water quality, including limits on selenium concentrations in water, whole fish, fish muscle, and fish eggs or ovaries. While this recommendation has not been widely implemented by regulators in the US for selenium, provinces in Canada, like British Columbia, have established tissue-based guidelines for local industry. These criteria can add a high degree of complexity to controlling selenium discharge for companies involved in mining activities, particularly if measured tissue concentrations indicate that impairment is occurring. In such cases, investigations into the cause and potential corrective actions (treatment) are typically necessary.
The mobility, treatability, and extent to which selenium is bioaccumulated in aquatic organisms are directly impacted by the molecular forms of selenium in solution. In chemistry terms, the different molecular forms an element can be present as is referred to as “species”. Selenite and selenate (collectively referred to as inorganic selenium) are the most abundant, naturally-occurring soluble selenium species in most aquatic environments. Mining activities may release these species into wastewaters and, if left untreated, receiving waters. While conventional physical/chemical treatments are effective for selenite removal, biological treatment has been identified as the preferred treatment method for selenate by the USEPA. Such treatment systems can, depending on the operating conditions, induce formation of organic selenium species that bioaccumulate at levels significantly greater than those of the initial inorganic selenium species. Proper selection and maintenance of the treatment technology are therefore facilitated by speciation analysis, and in turn increase the likelihood that site-specific selenium criteria will be met. Furthermore, speciation analysis can elucidate the viability of applied preparatory and analytical methods for the measurement of total selenium.
IWC 18-24: Real-time, Continuous & Accurate Selenium Data Ensures a Reliable Selenium Removal Treatment
Vladimir Dozortsev, P.E., Aqua Metrology Systems, Sunnyvale, CA
Maintaining the integrity of a biological remediation process and providing cost-effective treatment of selenium is dependent on obtaining timely and accurate data on selenium speciation at critical remediation process stages. However, traditional methods have struggled to accurately measure concentrations of trace selenium species due to multiple selenium species present in process waters and their highly dynamic equilibrium in the sample solution. A novel online selenium monitor has been developed to determine the levels of dissolved different selenium species and total selenium species in real time.
Maintaining the integrity of a biological process and providing cost-effective treatment is dependent on obtaining timely and accurate data on selenium speciation at critical remediation process stages. However, field-based sampling further laboratory analysis approaches have struggled to accurately measure concentrations of trace selenium species due to the highly dynamic equilibrium of selenium species in the sample solution.
Traditional Se speciation approaches where a manually collected field sample is shipped to a lab and further analyzed is time-consuming and produces unsatisfactory results. Analysis in the lab is difficult and relies heavily on sample handling and preservation by field personnel. Error associated with sample preservation as well as the relatively long time required for sample processing contribute to significant inaccuracies in Se speciation. Ideally, the sample should be analyzed unpreserved immediately after sampling using a continuous online selenium monitor.
As a result, a novel online selenium monitor has been developed and is commercially available to determine the levels of dissolved selenium species and total selenium species in real time.
The fully automated, self-calibrating, selenium monitor delivers accurate and reliable results (up to 1 ppb or +/- 15%, whichever is higher) with a typical measurement time of 30 minutes for some selenium species. The online monitor ensures sample stability compared to manual sample preservation.
This paper will discuss case studies of comparative results between this novel selenium analysis methodology and current laboratory methods.
Consider Attending: W-1, W-2, W-5, W-10, W-11, W-12
Emerging Tools and Case Studies from Industry to Public-Private Partnerships
IWC Rep: Bill Willersdorf, Veolia Water Technologies, Randolph, NJ
Session Chair: HG Sanjay, Ph.D., P.E., Bechtel, Reston, VA
Discussion Leader: Jo Anna Ordonez, Solenis LLC, Kyle, TX
Recycle, Reuse and Resource Recovery is generally associated with metals, plastic and paper products. However, water is a resource and must be viewed as such. Water Environment Federation (WEF) made a conscious choice a few years back to try and focus on resource recovery by referring to wastewater treatment facilities as Water Resource and Recovery Facilities (WRRF). The term WRRF is still in infancy, but water recycle and reuse is gaining momentum in various sectors including industry, agriculture and landscaping. This session includes papers showcasing emerging tools to evaluate the true cost of water and case studies from energy sector, manufacturing and public-private partnership to facilitate recycle and reuse of water.
IWC 18-25: Upcoming Tools to Help Industry with Making the Business Case for Water Conservation Projects
Brian Moore, Arcadis, Clifton Park, NY
A key barrier that often thwarts many water conservation ideas, exacerbating the above challenges, is the common misconception that water is “cheap”, and the cost for water conservation projects lack the necessary return-on-investment (ROI) to justify implementation. This myth is disbanded by a true cost of water analysis. Influencing cost factors can include:
• The cost of energy used to move or purify water
• Costs of labor to manage water systems
• Regulatory costs
• Costs for heating or cooling water
• The costs of chemicals for pretreatment or other industrial processes
• The cost of wastewater treatment (capital equipment and operating costs) prior to discharge
When total water costs are considered, opportunities to reduce demand for and reuse water can be addressed as critical business decisions, rather than optional, voluntary activities.
The focus of this presentation is a project funded by the Water Research Foundation (WRF) for the development of a complete, universally accepted, and user-friendly tool for industry to accurately calculate the true cost of water, including indirect economic benefits such as water scarcity. This free tool also allows the user to determine a ROI for water saving projects that can help make a business case for water sustainability projects. The tool was developed by industrial water efficiency experts from Arcadis in consultation with 11 industrial and 2 municipal partners to enhance applicability and usability of the tools.
The impetus for the tool, along with all the stakeholders involved, will be discussed to showcase why a tool of this nature can help champion water conservation projects. An overview will be provided of all the individual tools (total of 7) contained within the broader toolbox. However, the presentation focuses primarily on three tools from the toolbox: (1.) True Cost of Water tool, (2.) the Return on Investment Tool, and (3.) the Shadow Price tool (which allows the user to monetize the impact of water stress/scarcity and apply those costs to the two prior tools). This presentation is intended to provide a high-level introduction of the tools.
Those who are interested in a deeper dive into the tools are encouraged to attend the workshop session: “W-6: Evaluating Business Cases for Industrial Water Reuse”. In that workshop the user will learn in detail about the features of each tool, how to use the tools, as well as seeing the tools applied (real-time) for evaluation of real-world case studies.
IWC 18-26: Municipal Recycle Water Use for High Purity Manufacturing Processes, Lessons Learned
Max Brefeld, Toyota Motor North America, Georgetown, KY; Donald Castete, Toyota Motor Manufacturing Texas, Inc., San Antonio, TX
Hundreds of gallons of water are required to manufacture an automobile. Auto makers continually strive to reduce this volume to control the increasing use and disposal costs of this natural resource. In 2003 Toyota Motor Corporation decided to build a manufacturing facility in the water stressed area of San Antonio, Texas. Reclaim water from the San Antonio Water System (SAWS) was provided to the facility at a reduced cost. Toyota utilized this source of recycled water to meet the needs of all utility and process applications and thus reduced the new facility’s impact on the environment and regional aquafer. There have been many challenges to using reclaim water for high purity manufacturing processes, but since the start of production in 2006, Toyota Motor Mamufacturing Texas (TMMTX) has used the philosophy of continuous improvement (kaizen) to overcome problems and use the water evermore efficiently. In light of the lessons learned, this paper will explore the techneques used by TMMTX over the past 12 years to use SAWS reclaim water to manufacture their vehicles.
IWC 18-27: The Devil is in the Details – A Recycled Water Treatment Plant Case Study
Daniel Sampson, HDR, Walnut Creek, CA
The operating permit of a power plant located in the Western United States requires that the plant produce and use disinfected tertiary recycled water as the primary source of cooling tower makeup and process water. The power plant receives secondary effluent from a nearby wastewater treatment plant and must treat this water such that it meets the standards listed in the plant’s operating permit. Commissioning of the Recycled Water Treatment Plant (RWTP) revealed that the initial design could not produce water meeting the plant’s permit requirements. The RWTP as originally designed and installed could not achieve the required effluent turbidity. While the RWTP conceptual design was sound, detailed design resulted in several systemic issues impacting the system’s ability to meet its treatment goals. Subsequent investigation and bench testing determined that the secondary effluent required appropriate mixing energy, extended reaction time with the coagulant and a lower operating pH than could reasonably be achieved with coagulant feed alone. The original system required modification to add mixing energy control and greater reaction volume to increase residence time and optimize mixing of the coagulant to achieve acceptable effluent turbidity. Other modifications included the addition of a pH control system using sulfuric acid to ensure that coagulation occurred at the optimum pH to minimize coagulant consumption. The low pH of the effluent required the addition of a caustic feed system to minimize potential corrosion in equipment receiving recycled water. This paper discusses the original system startup, subsequent troubleshooting efforts and findings, and the resulting RWTP modifications with their impact. The narrative will allow others to learn from the challenges encountered at the subject plant.
IWC 18-28: Reducing Industrial Water Use Footprint Through a Symbiotic Public – Private Partnership
Brandon Yallaly, P.E., Carollo Engineers, Inc., Boise, ID; Danny Sargent and Jake Davis, Ph.D., City of Chandler, Chandler, AZ
A major industrial factory in Chandler, AZ uses large quantities of potable water and produces high salinity waste streams in their manufacturing process. In order to eliminate sewer discharge of brine from internal factory treatment systems and offset potable demands, the industrial user, in collaboration with the City of Chandler, constructed and operates a brine treatment facility. The process utilizes an innovative combination of proprietary and non-proprietary processes, including chemical softening, HERO® and thermal brine concentration, that combine to reduce waste volumes by over 96%, eliminate sewer discharges, and recovers water for reuse that meets internal factory water quality standards. A large percentage of the salts are removed as solids and landfilled, with the balance of salts contained in a concentrated brine sent to evaporation ponds for final disposal.
This paper will provide an overview of the facility and its sustainable Public-Private Partnership approach and will include a review of performance and lessons learned.
Consider Attending: W-1, W-2, W-5, W-6, W-10, W-12, W-13