AH HA, SO! INTRODUCTION TO WERF’S OWSO CHALLENGE
Amit Pramanik, Ph.D.
Water Environment Research Foundation
635 Slaters Lane, Suite 300
Alexandria, VA 22314
Additional Information
The collection and treatment of wastewater has evolved over the past century from its first and primary mission to protect public health, to preservingwater qualityand the environment. Over the years, costs have increased as the water quality industry has responded to meet increasingly lower pollutant or other limits. Wastewater utilities are fiscally prudent stewards for their rate-paying customers, continually looking for cost-effective solutions to optimize and sustain wastewater and solids treatment operations, while also seeking to maximize resources such as reclaiming the treated water for subsequent use or producing value-added biosolids for land application. Some facilities produce digester gas for heat or power process equipment; and there is work underway to potentially generate energy from microbial fuel cells, and/or recover other resources.
Operational costs at wastewater treatment facilities have been escalating over the past decade, and especially so in the past few years due to rising energy costs. Energy use accounts for one-third or more of the annual operating cost of these facilitiesto provide wastewater services, and is second only to labor costs. The water and wastewater treatment industry uses nearly 3% of the total electric energy produced in the United States.
Solids operations (i.e., sludge thickening, dewatering, biosolids production) and sludge or biosolids handling, transport and disposal account for a significant portion of these energy costs. Offsite disposal also requires transportation and the availability of land. Biosolids land application is one form of resource recovery (due to their inherently nutrient rich organic material content) and is currently practiced by almost 60% of wastewater utilities in the USA. There is increasing recognition by the water quality industry and others that wastewater containsresources that can be further utilized for energy (e.g., methane gas co-generation) or mined to extract scarce resources (e.g., phosphorus) in addition to its beneficial reuse as a soil amendment.
A paradigm shift now taking place recognizes that there is inherent value in the liquid or solid fractions in wastewater, as opposed to “just” treating the wastewater to protect water quality and public health. There is also a strong connection between energy and water. While this has long been the case, especially for several “forward-looking” facilities, rising energy costs have helped additional utilities and others realize this more recently.
The Water Environment Research Foundation (WERF), a not-for-profit organization that funds and manages water quality research through public-private partnerships with wastewater utilities, corporations, academia, industry and the federal government, has embarked on a 5-year research challenge for the Optimization of Wastewater and Solids Operations (OWSO). Subscribers identify and prioritize research challenges through direct input at meetings, surveys, committees and other forms of outreach. WERF utility subscribers represent over 70% of the sewered population in the US alone. In 2006, three top priority challenges and goals were identified by subscribers which pertain to energy use and sustainability of wastewater facility operations:
- Solids Volume Reduction: Develop cost-effective methods to minimize the volume and quantity of wastewater treatment solids generated, without sacrificing product value and quality.
- Resource Recovery: Identify new resource recovery opportunities for wastewater solids, including biogas production, co-generation of heat and energy, and extraction and reuse of constituents.
- Energy Management: Develop strategies, methods, processes, and tools for cost-effective management of energy use in wastewater operations.
WERF subscribers were clearly articulating a need for cost-effective solutions for wastewater and solids treatment operations when they identified the above research challenges. Therefore, it was logical to integrate these three challenges into one (the OWSO challenge) to build a comprehensive, long-term program with a goal to develop and demonstrate economical and environmentally responsible processes that improve wastewater treatment and solids management operations efficiency and reduce costs by at least 20%. To date, the WERF Board of Directors has approved almost $1 million in research funds for the OWSO challenge and several projects are underway.
The graphic on the next page is a holistic view to integrate WERF’s previous, ongoing, and planned research with that of other agencies or organizations that WERF is currently, or plan to, collaborate with as we work to solve this challenge. There are linkages to two other ongoing WERF challenges (Nutrient Removal and Sensors).
Several ongoing projects that are energy related include:
- Cost-effective Energy Recovery from Anaerobic Digested Wastewater Solids- Researchersapplied a life-cycle assessment approach to develop a spreadsheet model that enables users to compare the relative economic merits of several energy recovery technologies (WERF project number 01-CTS-18-UR).
- Evaluation of Processes to Reduce Activated Sludge Solids Generation and Disposal Researchers are evaluating several technologies and process innovations recently in the market place to reduce or eliminate waste activated sludge. The results of this study will promote a better understanding of the mechanisms behind these technologies and will include a critical evaluation of their performance. This research will result in a spreadsheet model to evaluate these processes and technologies for their technical and economic applicability to specific wastewaters and local conditions (05-CTS-3).
- Evaluation of the Co-digestion of Organic Waste Products with Wastewater Solids to Maximize Anaerobic Digester Performance. Researchers will characterize organic wastes which have the potential to augment biogas production when co-digested with municipal solids. They will conduct laboratory testing of these wastes to confirm their potential to boost biogas production. Later research phases will include pilot scale testing and full-scale demonstrations (TBD – one of the selected OWSO challenge projects).
To follow the progress of research under the OWSO challenge, go to or contact Lauren Fillmore, Program Director at r Amit Pramanik, Ph.D., Senior Program Director at .
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WERF RESEARCHOWSO CHALLENGE OTHER WORK
(Completed/Ongoing) STRATEGIC PARTNERS
Functional Delivery
Focus Mechanisms/
Areas Outputs
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Notes:
- The OWSO challenge integrates three sub-challenges previously identified by Subscribers: Energy Management; Solids Volume Reduction; and Resource Recovery – the latter two were focused on residuals/biosolids.
- The integrated challenge expands resource recovery to include reclaimed water (treated wastewater for reuse), resource recovery of nutrients (e.g. phosphorus) in wastewater, renewable energy (microbial fuel cells), etc.
- A key additional sub-challenge is “unit process optimization” – this “fourth” issue integrates the above sub-challenges in a more holistic manner and benefits from prior / ongoing work.
- The OWSO challenge links to two other WERF challenges (Nutrient Removal and Sensors)
Key WERF Research relevant to the OWSO Challenge
Project # & Title / Brief Description / PI/Organization / Total Cost / Publication Number or Status / Link to Challenge90-4,
Innovative Process Assessment: Sludge Processing, Disposal, and Reuse / Provided an assessment of diverse research/ development projects regarding the treatment and disposal of biosolids. / Richard Kuchenrither, Ph.D., P.E.
Black & Veatch
Kansas City, MO / $100,000 / Completed / Indirect
91-ISP-5,
Polymer Characterization and Control in Biosolids Management / Provided information on optimal usage of chemical conditioners for biosolids dewatering. Assessed automatic polymer feed equipment. Provided a formal protocol for making decisions on selecting polymers and estimating dosing rates. / Steven Dentel, Ph.D., P.E.
University of Delaware
Newark, DE / $299,000 / D43007
Completed / Direct – both solids volume reduction and unit process optimization
91-ISP-5A,
Guidance Manual for Polymer Selection in Wastewater Treatment Plants (Companion report to project above) / Aids wastewater chemists, managers, and operators in the selection of polymers. Systematic processes for polymer selection are divided into modules for each type of polymer application with step-by-step guidance. / Steven Dentel, Ph.D., P.E.
University of Delaware
Newark, DE / Included in above project / D0013
Completed / As above
94-REM-2,
Analysis and Fate of Polymers in Wastewater Treatment / Addressed the impact and fate of polymers used as flocculant agents in wastewater treatment. Evaluated when polymer release to the environment may be harmful. Examined analytical methods to detect polymer. / Steven Dentel, Ph.D., P.E., DEE
University of Delaware
Newark, DE / $269,150 / D00301
Completed / Indirect
95-REM-2
Producing Class A Biosolids with Low-Cost, Low-Technology Treatment Processes / Class A biosolids have been and are now being produced by low-cost, low-technology biosolids treatment processes including lagoon storage, air drying, and cake storage. Project reviewed available literature and municipal agency data about these processes. / Perry Schafer, P.E., DEE
Brown and Caldwell / $439,000 / Completed / Indirect
96-CTS-4,
Investigation of Hybrid Systems for Enhanced Nutrient Control / Investigated and developed basic design and operation criteria for various hybrid nutrient removal systems, and evaluated the use of such systems for retrofitting facilities. / Dipankar Sen, Ph.D., P.E.
Stearns & Wheler, LLC / $111,000 / Completed / Indirect
96-CTS-5,
Benchmarking Wastewater Treatment Plant Operations – Collection, Treatment, and Biosolids Management / Derives performance standards for wastewater treatment operators to help focus their efforts, improve operations, and reduce costs. Highlights approaches, processes, and results that have been used by others to accomplish these objectives. / Roger Patrick
WaterResearchCenter (WRC) / $335,334 / D73001
Completed / Indirect
96-REM-1,
Biosolids Management: Assessment of Innovative Processes / Identified and reported on development, status and cost effectiveness more than 110 innovative biosolids processing and management technologies. Format was also used in recent EPA report to update technologies. / Albert Pincince, Ph.D., P.E.
Camp, Dresser & McKee
Cambridge, MA / $72,000 / D83004
Completed / Direct –solids volume reduction
97-REM-2,
Pathogen Destruction Efficiency in High Temperature Digestion / Compiled information available worldwide on high temperature digestion studies. Developed practical and economical high temperature (mesophilic/ thermophilic) digestion protocols to yield Class A biosolids products and augment existing processes to further reduce pathogens. / Donald Gabb, Ph.D., P.E.
East Bay Municipal Utility District
Oakland, CA / $576,478 / Completed / Direct – several aspects
97-REM-4,
Investigating the Effects of Electrical Arc Pretreatment of Biosolids / Investigated the feasibility of electrical arc pretreatment of biosolids as a potential innovative dewatering process prior to chemical conditioning and dewatering. Addressed fundamental and applied aspects of its operation. / Steven Dentel, Ph.D., P.E., DEE
University of Delaware
Newark, DE / $200,462 / D00314
Completed / Indirect
98-CTS-1,
Biotechnology/Industrial Ecology – A Look into the Future for Wastewater Treatment / The project brought together talented and experienced visionaries for a workshop to address entirely new approaches and processes for wastewater treatment. It identified possible directions for future development of technologies and processes for wastewater treatment. / WERF / $60,000 / D93015
Completed / Direct and Indirect – resource recovery and other aspects
98-CTS-5,
Emerging Treatment Technologies for Water Reclamation (Membrane Bioreactors: Feasibility and Use in Water Reclamation) / Explored the feasibility and application of membrane bioreactor (MBR) technology to reduce costs and increase practicality of water reclamation for use. Summarizes advantages and limitations of MBR process, and addresses the potential of MBRs for water repurification, configuration issues for full-scale development, compliance and preliminary cost estimates. / Samer Adham, Ph.D.,
MWH / $286,000 / D13000
Completed / Direct – resource recovery (liquids)
98-REM-3,
Thickening and Dewatering Processes: How to Evaluate and Implement an Automation Package / Evaluated state of current practices, screens and field tests selected automation processes. Provided information to improve dewatering operations to cut the cost of dewatering biosolids in POTWs and in downstream operations. / Robert Gillette, P.E., DEE
Carollo Engineers / $754,901 / D13006
Completed / Direct – several aspects
99-WWF-1,
Research Priorities for Debottlenecking, Optimizing, and Rerating Wastewater Treatment Plants / Project convened an expert workshop to identify and frame a comprehensive research agenda that would develop and demonstrate tools for process capacity assessment and debottlenecking in wastewater treatment / WERF
Paul M. Sutton / $75,000 / D93008
Completed / Direct and indirect – several aspects, inc. unit process optimization
99-WWF-3,
Methods for Wastewater Characterization in Activated Sludge Modeling / Identified the most critical wastewater and biomass components and the relevant coefficients to be quantified for the most common uses of the model. Provided guidance to potential model users on the use of default and/or estimated values for the remaining parameters. / Henryk Melcer, Ph.D., P.E.
Brown and Caldwell / $1,111,680 / Completed / Indirect
00-CTS-8,
Membrane Technology: Feasibility of Solid/Liquid Separation in Wastewater Treatment / Provided a comprehensive assessment of membrane applications and identifies a method to evaluate the use of membrane technologies for specific treatment applications. Results from this research will allow for a direct comparison of membrane technologies with more conventional methods of solid/liquid separation. / Glen Daigger, Ph.D., P.E.
George Crawford, P.E.
CH2M-Hill / $434,674 / Completed / Direct – several aspects
03-CTS-15,
Feasibility of Membrane Technology for Biological Wastewater Treatment - Phase II Website Update / Update above online resource / As above / As above / Completed / As above
00-CTS-10T,
Minimizing Biomass Production from Biological Treatment / Identified and evaluated methods to reduce biological solids in aerated biological reactors. Helped determine whether cost savings can practically be realized by reducing the ultimate amount of waste requiring treatment and disposal. / David H. Stensel, Ph.D., P.E.
University of Washington
Seattle / $282,938 / Completed / Direct – solids volume reduction
00-CTS-10Ta,
Evaluation of Feasibility of Methods to Minimize Biomass Production from Biotreatment – pilot test results / As above – tested and reported on anaerobic membrane bioreactor / As above / Included in above / Completed / As above
00-HHE-5T (Phase I)
Identifying and Controlling Municipal Wastewater Odor Environment – Literature Review / Evaluate state of knowledge and science about odors and odor control for all stages of treatment and disposal of wastewater and residuals. Provides basis to begin multi-phase process to develop efficient, effective odor control technologies at all stages of wastewater treatment and disposal.
Phase 1 involved critical reviews and syntheses of published information (includes conventional and grey literature), findings from recent and upcoming odors-related workshops, as well as electronic databases. / Gregory M. Adams, P.E.
Los Angeles County Sanitation District, and
Jay Witherspoon, Ph.D., P.E.
CH2M-Hill / $1,525,000
(for all phases and addendum) / Completed / Indirect
00-HHE-5T (Phase II),
Identifying and Controlling Odor in the Municipal Wastewater Environment Phase II: Impacts of In-Plant Parameters on Biosolids Odor Quality / Phase 2 collected objective data to demonstrate the influence of anaerobic digestion system design and operating parameters on the odor quality of the final product. Biosolids odor emissions were measured before and after anaerobic digestion and operations and treatment parameters were measured to determine the influence of these parameters on biosolids odor quality. Ten POTWS involved in research effort. / Gregory M. Adams, P.E.
Los Angeles County Sanitation District, and
Jay Witherspoon, Ph.D., P.E., CH2M-Hill / See above / Completed / Indirect
00-PUM-7,
Development of a Cost Determination Protocol for Use in Benchmarking Biosolids Management Programs / Developed a protocol to identify and quantify direct and indirect costs associated with management of biosolids for all reuse and disposal options. Protocol tested and refined at several sites that represent wide range of biosolids management options in diverse geographic areas. / Eliot Epstein, Ph.D.
E&A Environmental Consultants, Inc. / $100,000 / Completed / Indirect
00-CTS-4,
Assessment of Technologies for Screening, Floatable Control, and Screenings Handling / Provides guidance for utilities and designers in selecting screening, floatable control, and screenings handling technologies that are appropriate for CSOs and wastewater under a variety of conditions. / Joseph Perry Stephenson, P.E.
Hydromantis, Inc. / $109,000 / Completed / Direct – unit process optimization
00-CTS-5,
Efficient Redundancy Design Practices / Conducted a web-based survey of redundancy of major treatment plant system components. Alternatives to conventional redundancy, differences in requirements from state to state, and regulatory requirements were identified. / Tony Palmer, P.E.
Instrumentation Testing Association (ITA) / $130,085 / Completed / Indirect
00-CTS-3,
Tools for Rating the Capacity of Activated Sludge Plants / Developed a general activated sludge process evaluation and design protocol that considers all resources of variability (influent wastewater, treatment processes employed, and instream water quality of receiving water). / Chris D. Cox, Ph.D.
University of Tennessee / $172,539 / Completed / Indirect
00-CTS-1,
Bridging Pilot-Scale Design / Synthesized a decade of prior research on secondary clarifiers (including ASCE’s CRTC). Developed guidelines and protocols that treatment facilities can use to evaluate and improve performance of secondary clarifiers. / Eric Wahlberg, Ph.D., P.E.
Brown and Caldwell / $57,404 / Completed / Direct – unit process optimization
01-CTS-32-ET,
A New Tool for Measuring Biosolids Floc Strength / Established a standard method and set of procedures for measuring floc strength. Helps in understanding fundamentals of conditioning and enhance full scale dewatering / Mohammad Abu-Orf, Ph.D.
US Filter NATC / Vivendi Water / $104,342 / Completed / Indirect
01-CTS-1,
Mechanisms of Conditioning, Thickening and Dewatering / Improves understanding of nature of flocs and specific chemical interactions that alter floc properties. Can help in better selection of conditioning chemicals, help to reduce chemical costs and/or lead to improved dewatering techniques. / Matthew J. Higgins, Ph.D.