Burrowes, Peter

Peter Burrowes is a Senior Fellow Technologist in Residulas Resourve Recovery at JACOBS. Peter obtained his Bachelors degree in Mechanical Engineering from Sheffield University, UK, in 1973 and is a registered professional engineer in Ontario. He is a Life Member of the Water Environmental Federation and has served on several committees at both the Federation level and the local level and serves on the Biosolids Committee and the Bioenergy subcommittee. Peter has worked at JACOBS since 1976 on the planning, permitting, design, construction and implementation of many biosolids projects.

Titles from this speaker

Biosolids Incineration in the Times of PFAS

Abstract

Introduction Biosolids management in North America is significantly focused on beneficial use. As reported by the National Biosolids Data Project 2018 (NBDP, 2018), in the United States (U.S.), approximately 5.8 million dry metric tons of biosolids was generated in 2018 by Publicly Owned Treatment Plants (Water Resource Recovery Facilities or WRRFs), of which 53% was beneficially used (see Figure 1). The biosolids comprising Class B, Class A and exceptional quality EPA 503 designations are primarily used for agricultural applications. PFAS and other contaminants of emerging concern in biosolids are an issue that could impact the future of beneficial use as we know it. With existing (Maine, Connecticut) and other states considering potential of land applications bans, Biosolids Managers are considering alternatives to remove PFAS from biosolids. To date, thermal treatment has been identified as a promising pathway for removing PFAS from biosolids. Research has indicated that thermal oxidation (incineration), pyrolysis and gasification show high potential for removing PFAS from the solids. Other technologies, such as hydrothermal liquefaction, deep well injection and supercritical water oxidation (SCWO) are also in the early stages of development. Thermal oxidation has demonstrated that PFAS is removed from the residual and ash (Winchell, 2024). On-going research is evaluating the fate of PFAS in the gaseous phase. Similarly, pyrolysis and gasification can produce a biochar free from measurable PFAS and on-going research is evaluating the fate of PFAS in the gaseous phase (Williams, 2023). The other emerging technologies are thought to destroy PFAS, but research is required to verify this. Thermal oxidation is an established technology with an estimated 80 facilities in operation. In the U.S., thermal oxidation has traditionally been used to process unstabilized solids, specifically as a disposal method, with a few facilities employing external energy recovery, e.g. to produce electricity. Pyrolysis and gasification are well established in other industries with large facilities that use relatively dry feedstocks with large throughputs. However, pyrolysis and gasification are emerging technologies for biosolids management, because of the relatively lower throughput capacities required and the unique physical and chemical characteristics of biosolids causing heat balance and material handling issues. There are a few vendors around the world that are developing systems right-sized for biosolids management. Development of emerging technologies can take 10 to 20 years to reach commercialization. While industry develops and commercializes these technologies, there is a potential gap that needs to be filled to provide alternatives for existing facilities that have invested in technologies to stabilize biosolids for beneficial uses. Thermal oxidation is one such developed technology that can be added to existing technologies to produce a safe end product. Methodology This paper will present three biosolids stabilization technology process trains based on existing case studies (See Figure 2 for an example) that include thermal oxidation and using heat and material balances, demonstrate process viability, as well as compare economics and environmental factors. Process trains (see Figures 3,4 and 5) will include: - Class B mesophilic anaerobic digestion (MAD), dewatering and thermal oxidation - Class B MAD using WAS only THP, dewatering and thermal oxidation - Class A advanced MAD using thermal hydrolysis upstream of AD, dewatering and thermal oxidation Each of the process trains include state-of-the-art fluidized bed (FB) technology with energy recovery and air pollution control equipment that will meet New Source Performance Standards. Economic factors will include capital investment, operating and maintenance costs and life cycle costs. Environmental factors will include Part 503 Regulations, Part 60, Subpart LLLL regulations and greenhouse gas (GHG) emissions. Discussion The discussion will focus on the thermal oxidation technology that is required for the Class B and Class A AD process trains (see Figures 6 and 7), with an emphasis of meeting MACT emission regulations, as well as the results of the heat and material balances. The impact of the energy requirements for adding thermal oxidation will be presented. AD and advanced AD provide the most energy efficient way of converting biomass into recoverable energy through biogas utilization. So, the addition of thermal oxidation will focus on autogenous operation with a dewatered cake that has reduced volatile solids content due to AD and advanced AD. The impact on GHG emissions the biosolids management alternatives by adding thermal oxidation compared to agricultural land application will be reviewed. Specifically, the generation of nitrous oxide (N2O) by FB technology will be discussed and operational methods to reduce emissions will be presented. Closing This paper will be useful to Biosolids Managers, Water Resource Recovery Facility Managers and Consulting Engineers in understanding the immediate future role that thermal oxidation can fill for utilities that operate anaerobic and advanced anaerobic digesters facilities in providing a beneficial end-use for biosolids if land application is not available.

This paper was presented at the WEF Residuals & Biosolids and Innovations in Treatment Technology Joint Conference, May 6-9, 2025.

SpeakerBurrowes, Peter

Presentation time

11:25:00

11:45:00

Session time

08:30:00

11:45:00

SessionSome Like It Hot - Diving into Incineration, Pyrolysis, and Gasification

Session number13

Session locationBaltimore Convention Center, Baltimore, Maryland, USA

TopicAdvanced Thermal Conversion, Biochar, Energy and Carbon Neutrality, Energy Conservation/Management, Energy recovery, Gasification, Greenhouse Gases, incineration, Intensification, Knowledge Transfer, PFAS, PFAS/Emerging Contaminants, pyrolysis, Regulatory Requirements, Thermal Processes

Author(s)

Burrowes, Peter, Bharambe, Gokul, Williams, Todd, Ahanmisi, Ohis

Author(s)P. Burrowes1, G. Bharambe 1,T. Williams 1, O. Ahanmisi1,

Author affiliation(s)Jacobs, 1

SourceProceedings of the Water Environment Federation

Document typeConference Paper

PublisherWater Environment Federation

Print publication date May 2025

DOI10.2175/193864718825159803

Volume / Issue

Content sourceResiduals and Biosolids Conference

Word count8

Fort Worth's Alternative Delivery Biosolids Management Solution

Abstract

INTRODUCTION The City of Fort Worth's (City) Village Creek Water Reclamation Facility (VCWRF) implemented a major change to its biosolids processes using design-build-operate (DBO) delivery. During the summer of 2022, the facility started its new centrifuge dewatering and thermal dryer system and now produces a high-quality dried Class A product, resulting in significant cost savings, reduced odors, more regulatory certainty, flexibility, and greater public acceptance. PROJECT OVERVIEW AND BACKGROUND The VCWRF is a 166 million gallons per day (mgd) activated sludge treatment plant. Prior to the project, it had dewatered its anaerobically digested solids with belt filter presses (BFPs) and added lime to produce Class AB biosolids (Figure 1). Each year the facility land applied approximately 29,000 dry tons of material to approximately 40,000 acres of ranch and farmland in the North Texas area. After a comprehensive master planning process, the City made the decision to convert its biosolids operation to a thermal drying process. This was motivated by multiple factors, including: 1.Odor concerns from dewatered solids. 2.Regulatory uncertainties associated with the lime-stabilized Class AB biosolids previously produced by the VCWRF. 3.Public concerns over biosolids land application that are mostly odor related. 4.Increasing hauling distances to land application sites. 5.Increasing costs of biosolids management. The City chose to implement the project using a DBO approach, and contracted with the selected DBO contractor, Synagro, in December of 2019 after receiving multiple proposals. By the summer of 2022, the facility was successfully operating and producing Class A dried biosolids pellets. FACILITY AND ITS OPERATION The VCWRF biosolids facility is located on a separate property located a mile north of the main plant (Figure 2). Anaerobically digested biosolids are pumped to the biosolids site where they are stored in three storage tanks, the largest of which has a capacity of 5 MG. Biosolids are then dewatered by centrifuge, dried in one of the largest rotary drum dryers ever constructed for a biosolids facility with an evaporation capacity of 14,000 kg/h, and stored in silos for truck loading (Figure 3). Process wastewater is pumped back to the VCWRF for further treatment. Odorous air is treated by two bioscrubber systems for hydrogen sulfide and ammonia, and exhaust gas from the rotary drum dryer is treated by a regenerative thermal oxidizer. The existing dewatering belt filter press and lime facility is still available and maintained as a backup system. PROJECT DELIVERY AND LESSONS LEARNED The City decided to implement the project using a DBO delivery approach, funded in part by a Texas Water Development Board (TWDB) Clean Water State Revolving Fund loan. With the selected DBO approach, risk is shared between the facility owner and the DBO contractor (Figure 4), but the owner loses some control over the details of the work. This provides the DBO contractor with greater flexibility and control over cost and schedule, which for this project allowed the contractor to control cost and schedule to minimize change orders during an unprecedented economic climate: COVID pandemic, the 2021 Texas Freeze, and growing inflation. A dryer facility is more akin to an industrial process than a traditional wastewater facility. In addition, as a DBO the City was not provided with as much detail on the new dewatering and dryer systems during design as would traditionally be provided. Jacobs supported the City's review of the designs, provided construction observation, and reviewed acceptance test procedures and results to support the City's management of the contract and verify that the work was consistent with the DBO contract requirements. Together the project team worked with Synagro to address challenges as they arose, including those related to the material recycle loop, foaming, and other issues. The facility is designed to manage biosolids to 2040 (Table 1). Class A biosolids production was achieved in July of 2022, marking a major milestone for Fort Worth and the DBO team. At that time the facility began formal 'acceptance testing' which consisted of a contractually mandated evaluation to verify that the newly installed infrastructure was working as designed. The City and team continue to address various punch list items to shift fully into the operations phase of the project, but this marks a major milestone for the City and for the residents of Fort Worth. The DBO Contractor is responsible for all operation and maintenance activities at the biosolids facility, including those for existing dewatering infrastructure (belt-filter presses) as well as the new dryer facility. THE PAPER This paper will describe the thermal drying project and lessons learned including: 1.A brief overview of the dryer project's history and motivations, 2.Description of the new facility and its operation, highlighting some of the key features of the drying facility, including systems for heat recovery, efficient water usage, pellet recycling, and use of digester gas as a supplemental heat source. With the new biosolids product, benefits to the City include reduced product odor, significantly less trucking, wider diversity of product use options, better use of digester gas, and operating cost savings 3.Lessons learned through the project's unique delivery approach. For example, collaborating with the TWDB brought significant cost savings for the City but presented other unique challenges. The TWDB did not have pre-existing procedures for design build projects, so TWDB staff worked closely with City staff to satisfy the requirements of both entities. Lessons learned from this collaboration that can benefit other utilities on future TWDB-funded projects will be presented. For example, because of the significant schedule constraints on the project, the project team executed an early package for construction of the building foundations that allowed construction to begin sooner while the rest of the design was completed and reviewed. 4.Operation and maintenance overview of biosolids processing operations, including the operating term and undertakings that the DBO contractor will satisfy during the term of the contract. BENEFIT OF THE WORK The work presented in this paper will benefit WRRF Utilities who seek alternative methods of implementing biosolids management solutions, as well as consulting engineers and the contracting community.

This paper was presented at the WEF/IWA Residuals and Biosolids Conference, May 16-19, 2023.

SpeakerBurrowes, Peter

Presentation time

14:30:00

15:00:00

Session time

13:30:00

16:45:00

SessionSession 13: Case Studies

Session number13

Session locationCharlotte Convention Center, Charlotte, North Carolina, USA

TopicEconomics and Project Delivery

Author(s)

P. Burrowes

Author(s)P. Burrowes1, S. Nutter2, M. Berg3, T. Lyons4, S. Abbe5,

Author affiliation(s)Jacobs Engineering Limited1; Fort Worth Water Department2

SourceProceedings of the Water Environment Federation

Document typeConference Paper

PublisherWater Environment Federation

Print publication date May 2023

DOI10.2175/193864718825158853

Volume / Issue

Content sourceResiduals and Biosolids

Word count8

The R2E2 Experience -- Energy Performance Two Years On at the Green Bay Facility

Abstract

NEW Water, the brand of the Green Bay Metropolitan Sewerage District, has completed a program, with initial planning starting in 2008, to replace its biosolids management system at the Green Bay Facility (GBF) in Green Bay, Wisconsin. The facility is permitted to treat 49 MGD of wastewater and process biosolids from the GBF and waste activated solids from their other wastewater facility, the DePere Facility (DPF). The GBF was constructed in 1975 and included a thermal conditioning system (TCS), belt filter press dewatering and two multiple hearth furnaces (MHFs) to process wastewater solids. This process train was chosen because agricultural land application in Wisconsin was deemed not to be practical. Subsequently, the TCS was shut down and in 2008, NEW Water took over operations of the DPF. The almost 40-year-old GBF did not have sufficient treatment capacity into the future and the equipment required replacement due to its age and increasing maintenance costs. In addition, the existing MHFs would not meet the pending federal Clean Air Act Maximum Achievable Control Technology (MACT) air pollution regulations for sewage sludge incinerators (SSIs) that became effective in 2016. Between 2008 and 2011, NEW Water and CH2M (now Jacobs) developed a Solids Management Facility Plan that evaluated numerous solids processing technologies and process trains to respond to these issues. Seventy-three solids unit processes were considered, some were eliminated and the remaining 52 unit processes were used to develop 17 process configurations. Of these 17 configurations, six alternative configurations were selected and evaluated in detail. The Digestion with Thermal Processing and Electrical Generation alternative was selected and later named the Resource Recovery and Electrical Energy Project, or R2E2. The R2E2 process flow configuration, shown in Figure 1, is an integrated solids processing system comprising mesophilic anaerobic digestion (MAD), dewatering and fluidized bed incineration with waste heat recovery (WHR). MAD was chosen as a first processing step to generate biogas for combined heat and power (CHP). High strength liquid organic wastes are co-digested in the MAD process to enhance biogas production and maximize power production and waste heat utilization. Dewatering using centrifuges, followed by fluidized bed incineration was selected as the most efficient method of managing the biosolids, given there is not land within economical distance of Green Bay for agricultural utilization. The fluidized bed reactor (FBR) is equipped with a partial scalping dryer, utilizing waste heat recovered from the FBR and using thermal oil to ensure autothermal combustion. Phosphorus is recovered from the dewatering centrate to produce a fertilizer product. In addition, beneficial uses of the residual ash are being pursued. The CHP, dewatering and FBR equipment trains were purchased and the balance of plant design completed in 2014. Construction commenced in August 2015 and commissioning and performance testing were completed by the end of 2018. Figure 2 shows operating data from the startup of the two digesters through August 2019. The system has been operating since November 2018, as an integrated system. Figure 3 shows a summary of the system energy distribution and usage at the design year of 2035 at annual average wastewater flow conditions. The R2E2 project is expected to generate more than 65% of the GBF projected electrical power requirements in 2035 using biogas only and up to 85% using supplemental natural gas to the full CHP loads. With the system thermal efficiency of about 60% based on heat recovered, the R2E2 project will meet NEW Water's goal of producing electricity in the most efficient way while maintaining autothermal combustion. The paper will discuss the energy recovery and production performance of the facility during the two years of full operation, including the Covid-19 period. Since operation of both digesters commenced, NEW Water has initiated its program of importing high strength organic waste (HSW) and has been increasing quantities to achieve design quantities. Biogas production has increased, with increased electricity production of green energy. The monthly biogas and natural gas electricity production, together with the monthly HSW imported quantities and generator run times in the first year are shown in Table 1. As part of the energy management system, SCADA options allow determining when is the optimum time to operate the CHP and the number of units to operate to reduce demand and other electrical charges. NEW Water continues to optimize energy production with waste heat recovery and matching plant heating requirements. The presentation will be of interest to municipal plant operators, wastewater utility managers, planners and design engineers who are considering integrated biosolids processing systems to maximize energy recovery and provide resource recovery opportunities.

The following conference paper was presented at Residuals and Biosolids 2021: A Virtual Event, May 11-13, 2021.

SpeakerBurrowes, Peter

Presentation time

11:00:00

11:15:00

Session time

11:00:00

11:45:00

SessionThermal Process Optimization

Session number6

Session locationSimu-Live

TopicBiogas Energy, Biosolids To Energy, Resource Recovery

Author(s)

P. BurrowesW. AngoliB. BartelP. WestcottN. QuallsJ. BeckenS. Graziano

Author(s)P. Burrowes1; W. Angoli2; B. Bartel3; P. Westcott4; N. Qualls5; J. Becken6; S. Graziano7

Author affiliation(s)Jacobs 1; New Water; Green Bay Metro Sewerage Dist 2; New Water; Green Bay Metro Sewerage Dist 3; NEW Water Green Bay Municipal Sewerage District 4; New Water; Green Bay Metro Sewerage Dist 5; New Water; Green Bay Metro Sewerage Dist 6; Jacobs 7;

SourceProceedings of the Water Environment Federation

Document typeConference Paper

PublisherWater Environment Federation

Print publication date May 2021

DOI10.2175/193864718825157954

Volume / Issue

Content sourceResiduals and Biosolids Conference

Word count15

Tuas WRP: A Resource Recovery Factory

Abstract

PUB, Singapore’s National Water Agency, is implementing Tuas Water Reclamation Plant (Tuas WRP), which will be one of the most revolutionary facilities of its kind in the world with resource recovery in the form of NEWater and energy. Two of the key objectives of Tuas WRP are to: Minimise energy usage and maximise energy recovery. Harness synergies from water-energy-waste nexus by integrating used water and solid waste treatment under a single facility: Tuas Nexus. This paper will address how the design achieves these objectives.

PUB, Singapore's National Water Agency, is implementing Tuas Water Reclamation Plant (Tuas WRP), which will be one of the most revolutionary facilities of its kind in the world with resource recovery in the form of NEWater, Industrial Water and energy. Two of the key objectives of Tuas WRP are: - Maximise water recovery - Minimise energy usage and maximise energy recovery - Harness synergies from water-energy-waste nexus by integrating used water and solid waste treatment

SpeakerNewbery, Colin

Presentation time

15:30:00

15:50:00

Session time

15:30:00

17:00:00

SessionRefining Wastewater Effluent for Purification: Reuse-nutrient Removal-nexus II

Session locationRoom S404a - Level 4

TopicIntermediate Level, Municipal Wastewater Treatment Design, Nutrients, Potable Reuse, Water Reuse and Reclamation

Author(s)

Newbery, Colin

Author(s)C. Newbery 1; G. Bharambe 2 ; P. Burrowes 3; M. Wong Wei Qiang 4; A. Chia 5; N. Sundaramurthi 4; L. Wee Siang 4; M. Mun 2; J. Tan 2

Author affiliation(s)Jacobs 1; Jacobs 2 ; Jacobs 3; PUB, Singapore’s National Water Agency 4; PUB, Singapore’s National Water Agency 5; PUB, Singapore’s National Water Agency 4; PUB, Singapore’s National Water Agency 4; PUB, Singapore’s National Water Agency 1; PUB, Singapore’s National Water Agency ;

SourceProceedings of the Water Environment Federation

Document typeConference Paper

PublisherWater Environment Federation

Print publication date Oct 2023

DOI10.2175/193864718825159133

Volume / Issue

Content sourceWEFTEC

Word count7