Ling, Alison, Ling

Ling, Alison

Ali Ling is an assistant professor at the University of St. Thomas in St. Paul, MN studying engineered circularity, including the scale-up potential of emerging water and waste management alternatives. She bridges concepts across science and engineering disciplines to address questions about how our society interacts with the natural environment. Prior to joining the faculty in 2023, Ali worked for nine years as an environmental engineering consultant, serving clients across manufacturing, mining, and public sectors.

Titles from this speaker

Cost of Removing PFAS from WRRF Effluent and Biosolids

Abstract

This study developed capital and operation and maintenance (O&M) cost estimates and curves to remove and destroy per- and polyfluoroalkyl substances (PFAS) from municipal water resource recovery facility (WRRF) effluent and biosolids. Class 5 cost estimates (-30%/+50%) for the assumed design bases were estimated based on vendor quotes and standard design practices for combinations of technologies pre-screened to be both commercially applied and effective at PFAS separation and/or destruction. Three treatment alternatives were developed for 0.1 to 10 MGD of tertiary treated WRRF effluent and two treatment alternatives were developed for 1.0 to 10 dry tons per day (dtpd) of dewatered WRRF biosolids. Estimated costs for a 10 MGD facility producing 10 dptd biosolids are approximately $79 to $250 million in capital costs and $50 to $20 million in annual operating costs, including consideration of all alternatives developed. Cost per mass of targeted PFAS removed (7 compounds for WRRF effluent and 9 compounds for WRRF biosolids) ranged from $370,000 per pound of PFAS removed from a 50 dptd WRRF biosolids treatment facility to $8 million per pound of PFAS removed from a 0.1 MGD WRRF effluent treatment facility. These costs do not include any retrofits needed to add tertiary treatment upstream of PFAS separation processes for WRRF effluent or to achieve 15%-25% solids content prior to PFAS destruction processes for WRRF biosolids.

This study developed capital and O&M cost estimates to remove and destroy per- and polyfluoroalkyl substances (PFAS) from municipal water resource recovery facility (WRRF) tertiary effluent and dewatered biosolids. Estimated costs for a 10 MGD/10 dtpd facility are approximately $79 to $250 million in capital costs and $50 to $20 million in annual operating costs. 20-year costs per mass of PFAS removed ranged from $370,000 per pound to $8 million per pound of PFAS removed.

SpeakerLing, Alison

Presentation time

16:30:00

17:00:00

Session time

15:30:00

17:00:00

SessionPFAS Impacted WRFs: Knowledge Update

Session locationRoom S401d - Level 4

TopicDisinfection and Public Health, Intermediate Level, PFAS, Research and Innovation, Utility Management and Leadership

Author(s)

Ling, Alison

Author(s)A. Ling 1; B. Vermace 2 ; A. McCabe 3; K. Wolohan 4; D. Dursun 5; M. Blate 6; M. Abu-Orf 6; S. Kyser 7; A. Ling 1;

Author affiliation(s)Department of Civil Engineering, University of St. Thomas 1; Barr Engineering Company 2 ; Barr Engineering Company 3; Barr Engineering Company 4; Hazen and Sawyer 5; Hazen and Sawyer 6; Hazen and Sawyer 6; Minnesota Pollution Control Agency 7; Department of Civil Engineering, University of St. Thomas 1;

SourceProceedings of the Water Environment Federation

Document typeConference Paper

PublisherWater Environment Federation

Print publication date Oct 2023

DOI10.2175/193864718825159129

Volume / Issue

Content sourceWEFTEC

Word count10

Pretreatment Perspectives For PFAS Water Treatment

Abstract

1.0 ABSTRACT
The goal of this paper is to demonstrate how Wastewater Based Epidemiology (WBE) can be used after COVID-19 in both Municipal and Industrial wastewater systems to proactively monitor, manage, and avoid risks that could negatively impact the business continuity and resiliency of an organization. The history of WBE will first be reviewed to show how it has been used to maximize public health protection and social well-being while minimizing economic impacts and unintended consequences in public and private settings. The design of a WBE monitoring program for Closed, Semi-Closed, and Open Municipal and Industrial wastewater systems will be evaluated through a couple of case studies. Alignment between WBE programs and an organizations risk management programs, sustainability goals, and ethical considerations will also be explored.
2.0 BACKGROUND
On March 11, 2020, the World Health Organization declared COVID-19 a pandemic, highlighting the need for action and cooperation worldwide (WHO, 2020a; WHO 2020b). What followed was the implementation of restrictive measures such as lockdowns, curfews, quarantines, businesses closures, domestic and international travel bans, social distancing and mandatory respiratory protection (Howard et al., 2020). While effective in controlling COVID-19 transmission, these restrictions came at a major cost in terms of actual expenses and lost economic opportunities, in addition to trade-offs in wellbeing, mental health and personal freedoms (Cindrich et al., 2021; Gostin and Wiley, 2020).
COVID-19 also resulted in the largest WBE mobilization effort in recent history. WBE provides a scalable, cost-effective way to anonymously track population-level biomarkers of drug use, diseases, and infections like COVID-19. (Keshaviah 2021; Daughton 2020a). Figure 1 shows that unlike clinical diagnostic tests which are invasive, costly, time-consuming and focused on individual testing, wastewater monitoring of SARS-CoV-2 provides the opportunity for pooled or group testing of an entire population served by a centralized wastewater collection and treatment system (Daughton, 2020a; Daughton, 2020b). The goal of this paper is to demonstrate how WBE can be used after COVID-19 in both Municipal and Industrial wastewater systems to proactively monitor, manage, and avoid risks that could negatively impact the business continuity and resiliency of an organization.
3.0 RESULTS The application of WBE for public health decision-making support is not unique to COVID-19 and has been applied to various microorganisms and drug compounds for over 70 years as outlined in Table 1.
While initial WBE efforts focused on population-wide surveillance through collection of samples at the water resource recovery facility, targeted testing has become a more recent focus. Targeted testing at Sentinel Sites is the collection of samples from a limited population usually within the collection system, where the population has varying levels of stability and with the objective of implementing public health interventions upon detection of an infection in the community monitored. Examples of targeted settings are outlined in Table 2. Public health interventions upon the detection of a positive results have ranged from individual clinical testing to detect the infected individuals to administration of vaccinations or booster campaigns. Public health interventions to guide where targeted diagnostic testing could be amplified by monitoring smaller, key, confined sub-populations have also been common (Daughton, 2020b; Gawlik et al., 2021; McClary-Gutierrez et al., 2021). This is also reflected in the CDC WBE Design Considerations shown in Figure 2. This paper will expand upon the CDC WBE Design Considerations for both municipal and industrial sites since WBE may not always be the best surveillance approach in all settings. As Figure 3 shows, when determining whether WBE is the appropriate monitoring tool for these targeted settings, it is important for health departments, employers and other stakeholders to evaluate the population size, population stability, target analyte stability, probability of excretion, preservation of confidentiality, and the implementation of public health intervention. For industrial sites, additional considerations of risks, sustainability, and ethics can also be considered. We then evaluated various targeted settings and scored them based on the 6 critical success factors as shown in Figure 4 where the higher the score the higher the likelihood of WBE success in this setting. The rest of this abstract will explore a few of the key topics previously mentioned. The full paper will include a comprehensive review of all key topics previously mentioned.
3.1 System Types Population stability impacts the implementation and intervention strategies. The three general types of systems are Closed, Semi-Closed, and Open as shown in Figure 5. An overview is also outlined in Table 3.
3.2 Risk Management WBE monitoring can be used to proactively monitor, manage, and avoid risks that could negatively impact the business continuity and resiliency of an organization. Overall, risks are typically grouped into Financial, Strategic, Hazard, or Operational Risks (Borkovskaya, 2018). The results from a Risk Assessment are then evaluated in the organizations Enterprise Risk Management or ERM system following established guidelines like ISO-31000 (ISO, 2018) or COSO (COSO, 2017). Figure 6 outlines specific risks experienced by industry during COVID-19. While this example pulled some information from the meat industry (Hashem et. al., 2020; Ijaz, 2021), similar industries that utilize shift workers, in a centralized or remote worksite with shared or common working, resting, living, or transportation arrangements could be exposed to similar risks. Examples of these industries were previously outlined in Table 2.
3.3 Case Studies Various industrial and municipal case studies using WBE monitoring will be reviewed as part of the final paper. Table 4 summarizes an Industrial case study at a remote mining site.
3.4 Sustainability Beyond just mitigating risks, WBE monitoring can also support the sustainability strategy of the organization. Many municipal and industrial organizations are leveraging sustainability principles to ensure that their products and services benefit society. Figure 7 outlines the United Nations Sustainable Development Goals or UNSDG's which are 17 goals adopted by the UN in 2015 as a universal call to action to end poverty, protect the planet, and ensure that by 2030 all people enjoy peace and prosperity (United Nations, 2015). Table 5 summarizes how WBE monitoring aligns with SDG's 3, 8, 9, 11 and 17.
3.4 Ethics There are also certain ethical considerations that need to be evaluated as part of an existing or new WBE Public Health Surveillance Program. Designing and managing an ethical WBE monitoring program is critical to building and maintaining trust between the people or populations being monitored and the organization performing the monitoring. Unethical actions by the monitoring organization can quickly erode this trust and could even open the monitoring organization up to lawsuits if the rights, freedoms, or legal protections of the monitored people or populations are violated. Figure 8 is a summary of the key ethical considerations for collecting, managing and communicating with WBE data.

Many PFAS-laden waters have concentrations of suspended solids, dissolved organics, or metals that impede operation of granular activated carbon (GAC) or anion exchange (AIX) systems used to remove PFAS from the water phase. This presentation addresses pretreatment considerations ahead of GAC or AIX treatment, challenges associated with process design and implementation, and pretreatment process performance and results and how these affect PFAS removal media performance in the examples outlined.

SpeakerLing, Alison

Presentation time

14:25:00

14:40:00

Session time

13:30:00

15:00:00

TopicAdvanced Level, PFAS, Research and Innovation

Author(s)

Ling, Alison

Author(s)Alison Ling1; Katie Wolohan1; Andy McCabe1

Author affiliation(s)Barr Engineering, Minneapolis, MN1

SourceProceedings of the Water Environment Federation

Document typeConference Paper

PublisherWater Environment Federation

Print publication date Oct 2022

DOI10.2175/193864718825158657

Volume / Issue

Content sourceWEFTEC

Word count7

Description: Regional Supercritical Water Oxidation Facility for PFAS-laden Industrial...

Regional Supercritical Water Oxidation Facility for PFAS-laden Industrial Pretreatment Wastes

Abstract

A regional super critical water oxidation (SCWO) facility has the potential to provide an economically viable, energy-neutral destruction alternative for per- and polyfluoroalkyl substances (PFAS) able to accept multiple concentrated waste streams. SCWO is a physicalthermal process capable of destroying PFAS with the ability to capture energy from the destruction process for energy production, providing the opportunity to turn PFAS destruction from a huge user of electricity to an energy-neutral or even energy-positive endeavor. Energy production is fueled by high-energy waste streams, which could include granular activated carbon (GAC) media, and anion exchange resins (AER), and biosolids. This desktop study outlines conceptual design and economic analysis for regional SCWO infrastructure to handle spent media and foamate from industrial pretreatment systems.

This paper was presented at WEFTEC 2023 in Chicago, IL.

SpeakerLing, Alison

Presentation time

08:35:00

09:05:00

Session time

08:30:00

10:00:00

SessionApproaches to PFAS Destruction and Centralized Treatment

Session locationRoom S401d - Level 4

TopicPFAS

Author(s)

Ling, Alison

Author(s)A. Ling 1; A. McCabe 2 ; D. Garb 3; S. Viswanathan 4;

Author affiliation(s)Department of Civil Engineering, University of St. Thomas 1; Barr Engineering 2 ; 374Water 3; 374Water 4;

SourceProceedings of the Water Environment Federation

Document typeConference Paper

PublisherWater Environment Federation

Print publication date Oct 2023

DOI10.2175/193864718825159143

Volume / Issue

Content sourceWEFTEC

Word count11

Description: Treatment and Toxicity Takeaways From Two Pharmaceutical Wastewater Treatability...

Treatment and Toxicity Takeaways From Two Pharmaceutical Wastewater Treatability Studies

Abstract

Background
Pharmaceutical wastewaters can present a challenge in meeting either pretreatment or surface water discharge requirements. These wastewaters typically contain active pharmaceutical ingredients (APIs) as well as other organic compounds involved in formulating pharmaceutical products. APIs specifically can have targeted effects on aquatic toxicity that may impact permit requirements. Water quality can vary significantly, depending on facility size and product formulation schedules. Unlike many classes of contaminants, APIs vary widely in chemical structure. The uniting factor for APIs is that they actively interact with biological systems in a targeted manner. As a result, many APIs have downstream aquatic toxicity impacts, sometimes at parts per trillion (ppt) concentrations, so treatment targets for whole effluent toxicity (WET) may need to be considered. Treatment processes commonly deployed for API treatment include granular activated carbon (GAC) adsorption, biological processes, and advanced oxidation. Combinations of technologies can also be effective. Oxidation upstream of either biological treatment or GAC adsorption can improve efficacy by breaking down large organic molecules into smaller by-products that could then be more easily removed by biological treatment and/or GAC (Wu, Zhou, Sun, & Fu, 2018; Lhotsky, Krakorova, & et al., 2017). Biological treatment of complex organic compounds is typically more effective in a fixed-bed system than in suspended growth systems like activated sludge (Dvorak, Lederer, Jirku, Masak, & Novak, 2014; Zearley & Summers, 2012). In a biological activated carbon (BAC) process, the sorption capacity of the activated carbon binds pollutants and enables biodegradation processes that would otherwise be too slow to occur in a similarly sized system without GAC. By making GAC adsorption into a biological process, BAC improves micropollutant removal and reduces carbon changeout frequency (Sbardella, Comas, Fenu, Rodriguez-Roda, & Weemaes, 2018).
Objectives The objectives of this study are to synthesize lessons learned from testing and designing wastewater treatment solutions for two different water sources:
1. Groundwater impacted by pharmaceutical operations
2. Equipment rinse waters from pharmaceutical production lines We evaluated both projects through feasibility and treatability studies and are currently in design and contracting phases.
Treatability Case Study #1 The first case study addressed treatment of groundwater impacted by both APIs and VOCs. The extracted water also contained relatively high concentrations of iron, which complicated treatment processes. We conducted a preliminary feasibility study and suggested the use of iron pretreatment followed by BAC pressure vessels. We then designed and operated a six-month pilot test to evaluate the selected treatment train for its ability to meet pretreatment requirements for the local POTW. The BAC was operated similar to a GAC pressure vessel, with regular backwashing to limit biomass buildup and associated fouling. Orthophosphate present in the source water removed the need for micronutrient supplementation to support biological growth in the BAC vessels. General water chemistry and field parameters were monitored in influent and effluent from each process in the treatment train on a weekly basis throughout the life of the pilot. BAC treatment typically requires several months of acclimation before steady-state conditions and an adapted microbial community is established, which is needed to achieve consistent and predictable degradation of APIs and other constituents. Steady-state conditions, as reflected by consistent removal of bulk parameters COD and iron was achieved after three months. Over 99% removal of VOCs and 85% removal of most APIs measured were measured during steady-state conditions, as summarized in Table 1. In addition, pilot-scale treatment reduced whole-effluent toxicity (WET) impacts to Ceriodaphnia dubia and Pimephales promelas relative to influent water, with treated waters exhibiting no measured toxicity for acute survival, chronic survival, and chronic reproduction endpoints. WET outcomes are summarized in Table 2. The removal efficiencies and WET results were sufficient to meet pretreatment requirements and to secure a pretreatment discharge permit for the system. This treatment was also expected to meet surface water discharge requirements. Lessons learned from pilot operations resulted in several design changes prior to detailed full-scale design, including increased backwashing frequency, inclusion of a backwash clarifier, and an additional iron removal pretreatment step.
Treatability Case Study #2 For the second case study, Barr helped a client develop a management strategy for equipment rinse waters from a planned pharmaceutical product line. The API used in this case had significant aquatic toxicity impacts at parts per trillion levels, and needed to be removed to below those levels prior to sewer discharge. Barr coordinated bench-scale evaluation of seven treatment technologies: - Particulate filtration, - Ultrafiltration - Alkaline degradation, - Granular activated carbon (GAC) adsorption, - Electrochemical oxidation (with and without RO post-treatment), - Thermal evaporation, and - Vacuum distillation. Evaluation for full-scale application included bench testing, coordination of whole effluent toxicity (WET) and respirometry testing of treated waters, and a detailed water balance of the proposed full-scale system. Respirometry testing used the secondary influent and biomass from the local POTW and spiked it with varying levels of pharmaceutical wastewater to gauge the effect of the discharge on activated sludge microbes at the POTW. Particulate filtration, ultrafiltration, alkaline degradation, and GAC adsorption did not demonstrate compliance with City toxicity metrics. Electrochemically oxidized water was close to meeting toxicity metrics alone and did meet metrics when paired with reverse osmosis membrane separation treatment of oxidized effluent. However, electrochemical oxidation was more expensive than the two evaporative technologies evaluated, thermal evaporation and vacuum distillation. Performance of tested treatment options with respect to API removal, WET outcomes, and respirometry outcomes are summarized below in Table 3. Estimated capital and operating costs for thermal evaporation options as well as proposed option for enhanced UF treatment are compared on Figure 2. Costs for each option were evaluated with and without a final concentration step to reduce residual management needs. Relative to other options, thermal evaporation was associated with lower project risks associated with discharge and disposal and had a more favorable cost profile. Vacuum distillation may have been more cost effective if there had been a use for high-purity water produced by the process.
Significance and Takeaways Case Study 1 saw effective removal of VOCs and APIs and sufficient toxicity reduction using iron pretreatment followed by fixed-bed BAC vessels. However, treating wastewater for discharge in Case Study 2 proved either ineffective at meeting toxicity requirements or more costly than thermal evaporation options for zero-liquid discharge. General takeaways relevant to other pharmaceutical wastewater applications include: - Whole effluent toxicity is frequently a limiting parameter for pretreatment requirements in pharmaceutical wastewater. - Individual APIs have different amenabilities to water treatment processes and in some cases, evaporation or disposal can be more cost-effective than water treatment and discharge. - APIs often occur in mixtures with other APIs and/or co-contaminants, which can require multiple treatment processes.

Pharmaceutical wastewaters can be challenging to manage. Active pharmaceutical ingredients (APIs) are often bioactive by design and frequently have aquatic toxicity impacts, sometimes at parts per billion levels. Two pharmaceutical wastewater treatment case studies are presented. In both studies, whole effluent toxicity (WET) was a concern dictating pretreatment technologies required for pharmaceutical wastewater.

SpeakerLing, Alison

Presentation time

09:00:00

09:15:00

Session time

08:30:00

10:00:00

TopicIntermediate Level, Industrial Issues and Treatment Technologies, Microconstituents and Contaminants of Emerging Concern (Non-PFAS), Water Reuse and Reclamation

Author(s)

Ling, Alison

Author(s)Alison Ling1; Allen Prince1

Author affiliation(s)Barr Engineering, Minneapolis, MN1