Submit Your Full Paper – 18th IWA World Conference on Anaerobic Digestion

Workshop title: Integrating membrane processes into anaerobic systems

Workshop chairs: Ángel Robles, Universitat de València, Spain; Jules van Lier, Delft University of Technology, The Netherlands.

Workshop lecturers: Zouhayr Arbib, FCC Aqualia S.A., Spain; Jeonghwan (Jon) Kim, Inha University, South Korea; Lutgarde Raskin, University of Michigan, USA; Ángel Robles, Universitat de València, Spain; Ran Shang, Biothane-Veolia, The Netherlands; Jules van Lier, Delft University of Technology, The Netherlands.

Event description: Different anaerobic membrane-based alternatives are being regarded as a core technology for moving towards new, highly efficient, and cost-effective, green alternatives for wastewater treatment. For instance, AnMBRs have shown their potential for treating: a) low-strength wastewater in mild or even cold climates by introducing a membrane filtration system for complete retention of biomass; and b) industrial wastewaters commonly associated with extreme conditions such as the presence of refractory compounds and/or high salinity that adversely affect biomass retention or reduce biological activity.

Regarding alternative configurations integrating membranes, coupling filtering blankets (e.g., UASB) with post-treatment membranes offers new perspectives for wastewater treatment, since the bioreactor provides a pre-elimination of suspended solids by entrapment and biodegradation in the sludge bed and thus, reduces the solids load to the membrane, allowing for low membrane process costs to be achieved, while membrane represents a polishing effluent step high providing of a high-quality effluent. On the other hand, dynamic membrane (DM) technology represents other low-cost treatment alternative for wastewater treatment, where the dynamic cake formed on the supporting material acts as barrier for pollutant removal while keeping reduced process costs.

Hence, this workshop pays special attention on key operating issues limiting the widespread application of AnMBR technology. In this respect, the main goal of this workshop is to provide recommendations for the improvement of membrane-based anaerobic systems for the treatment of industrial and urban wastewaters.

Expected outcomes of the workshop:

Identification of main challenges and needs.
Final discussion around the writing of opinion/summary paper(s) with the main outcomes.

Outline of the workshop:

Time	Topic	Chair/Lecturer
14:00-14:15	Welcome and introduction	Ángel Robles/ Jules van Lier
14:15-15:30	Part 1: AnMBR as core technology within the Circular Economy	YWP Moderator
	AnMBR for widening resource recovery within the industrial sector (20 min + 10 discussion)	Ran Shang (Biothane-Veolia) Jules van Lier (Delft University of Technology)
	AnMBR for widening resource recovery within the urban wastewater sector (20 min + 10 discussion)	Zouhayr Arbib (FCC Aqualia S.A.) Ángel Robles (Universitat de València)
	Discussion and consolidation (15 min)	All
15:30-16:00	Coffee Break
16:00-17:15	Part 2: Alternative membrane-based configurations	YWP Moderator
	Membrane-based polishing steps for anaerobic fluidized bed bioreactor (20 min + 10 discussion)	Jeonghwan (Jon) Kim (Inha University)
	Dynamic membrane bioreactors (DMBRs) to intensify and expand anaerobic digestion applications (20 min + 10 discussion)	Lutgarde Raskin, Tim Fairley-Wax, Steven Skerlos (University of Michigan)
	Discussion and consolidation (15 min)	All
17:15-17:30	Q/A and conclusions	Jules van Lier/Ángel Robles

Carboxylate Platform. The Swiss Knife for Bioresource Recovery

The transition from traditional wastewater and waste treatment plants to more advanced processes that enable the efficient recovery of resources has become a scientific, technological, economic, and social challenge. In this regard, anaerobic digestion plays a crucial role as it not only helps reduce greenhouse gas emissions but also paves the way for new industrial development models.

The “Carboxylate platform” is based on transforming biowastes (hundreds of different molecules) by anaerobic fermentation into a few numbers of volatile fatty acids (VFA), including Lactic acid, which are essential to produce useful chemicals. This presentation will delve into the importance of thermodynamic, kinetic, and stoichiometric principles in guiding anaerobic fermentation towards selective production of VFAs. Our research group has developed a metabolic model simulating the anaerobic fermentation process and predicting the VFA production yields under different conditions. The model has undergone a rigorous validation process, using experimental data, and has consistently shown promising results in predicting the optimal conditions for enhancing the selective production of the desired VFA. Furthermore, we will discuss the current state of the art and several pilot or industrial-scale projects that aim to produce VFAs,

Polyhydroxyalkanoates (PHA), and Medium Chain Fatty Acids (MCFA) from a variety of feedstocks, such as agricultural waste, industrial effluents, and municipal solid waste. Finally, the opportunities of the platform based on lactic acid will be analysed.

Anaerobic Digestion: Its Undisputed Role in Environmental Engineering

Anaerobic digestion of sludge and slurries from wastewater treatment plants has been a core topic in AD conferences for many decades. While sludge stabilization was a primary driver, the concomitant energy recovery positioned anaerobic digestion centrally in greening conventional activated sludge (CAS) systems. What is the status of sludge digestion and what are the current developments in application and fundamental research? What limits the bioconversion and what techniques can be applied to maximize this. Thermal hydrolysis processes (THP) are increasingly applied to maximize biogas production, but THP also impacts AD functionalities, sometimes resulting in less biogas than expected. Can we predict the effects? Do we need alternatives for THP? With enhanced sludge digestion, also the reject waters get more concentrated. While anammox is being implemented to reduce the N load, increasing concerns for non-controlled N₂O emissions and potential cultivation of Legionella at the treatment sites call for alternative approaches. Step away from biology and embracing physicochemical techniques? Recent research has shown that we can also recover the biochemical energy enclosed in ammonia. May this help in further greening the CAS systems? The introductory lecture aims to vitalize one of the most traditional topics in the IWA World Conferences on Anaerobic Digestion.

Workshop title: From microbial ecology to microbiome engineering of anaerobic digestion communities

Workshop chairs: Jo De Vrieze (Ghent University, Belgium), Anna Trego (University of Galway, Ireland)

Workshop lecturers: Ciara Keating (Durham University, UK), Adam Smith (University of Southern California, USA), Ryan Ziels (University of British Columbia, Canada),

Event description: This workshop will focus on the microbial ecology of anaerobic digestion (AD) ecosystems. As the work of the AD scientific community lies at the interface between microbial ecology and process engineering, we want this workshop to serve both process engineers (with potentially minimal experience in ecological concepts), as well as microbial ecologists working on applied aspects of AD. We plan to cover fundamental concepts (e.g., lab techniques, sequencing tools, and analytical tools), as well as emerging technologies and approaches at the nexus of ecology and microbiome engineering. We hope to stimulate discussions around experimental planning, the state and future of the ‘field’, and current knowledge gaps in AD microbial ecology. We plan to include a presentation/teaching component, as well as a hands-on component to our workshop. The goal of this workshop is for participants to leave excited about the benefits of adding an ecological angle to their experiments, and with the scientific foundational knowledge to perform it successfully.

Expected outcomes of the workshop:

Understanding a range of ecological techniques and the types of hypotheses that can be tested with them;
Knowledge on how to design interesting and high-quality ecological experiments that fit into a given budget;
Training on the advantages and disadvantages of various statistical tools for analyzing/interpreting sequencing data;
Capacity to identify strategies to better link microbial ecology to AD process performance.

Outline of the workshop:

Time	Topic	Chair/Lecturer
14:00-14:15	Introduction on the workshop content and objectives	Jo De Vrieze
14:15-14:45	From ecology to engineering: monitoring and steering of AD based on ecological parameters	Ryan Ziels
14:45-15:15	Molecular techniques in anaerobic digestion: potentials and pitfalls	Adam Smith
15:15-15:30	How to finetune your experimental design in relation to molecular techniques	Jo De Vrieze
15:30-16:00	Coffee Break
16:00-16:45	What can I do with my sequencing data? Statistical tools and data sharing	Anna Trego and Ciara Keating
16:45-17:15	From data to predictions: insights in basic modelling approaches	Ryan Ziels
17:15-17:30	Q&A and conclusions	Anna Trego & Jo De Vrieze

Workshop title: Anaerobic conversions for sustainable biorefineries

Workshop chairs: Marta Carballa/ Miguel Mauricio-Iglesias

CRETUS, Department of Chemical Engineering, Universidade de Santiago de Compostela, Spain

Workshop lecturers: Irini Angelidaki (Department of Chemical and Biochemical Engineering, Technical University of Denmark), Robbert Kleerebezem (Department of Biotechnology, Delft University of Technology), Antón Taboada (CETAQUA, Spain), David Bolzonella (Department of Biotechnology, University of Verona, Italy,)

Event description: Anaerobic microbial transformations are key for the circular economy paradigm as they can use a large variety of substrates and convert them into resources with little energy input while yielding products with a dense/high energy content. In the recent years, the variety of products that can be obtained after an initial anaerobic transformation has increased notably and there are several success stories leading to the production of chemicals, feed, energy, biopolymers… This workshop aims at showcasing the possibilities of anaerobic biorefineries and how linking the characteristics of the available substrates with their design is a key aspect for their success.

Expected outcomes of the workshop:

Increased awareness of the participants of the many products/resources that can be obtained where anaerobic transformations are a key step.
Demonstration of real success cases where these technologies have reached a mature state
Gathering the community working on the development of biorefineries to identify common hurdles and opportunities

Outline of the workshop:

Time	Topic	Chair/Lecturer
14:00-14:15	Welcome and introduction	Marta Carballa
14:15-15:30	State of the art: from biogas to biomethane and other value-added products	Irini Angelidaki
	State of the art: the carboxylate platform up to PHA and medium-chain fatty acids	Robbert Kleerebezem
	Team activity: creating new value chains I	Moderated by chairs
15:30-16:00	Coffee Break
16:00-17:15	Team activity: creating new value chains II	Moderated by chairs
	Success case 1: Economics and business case for VFA production from sewage sludge and OFMSW	Antón Taboada
	Success case 2: Production of PHA and nutrient recovery from waste streams	David Bolzonella
	Other success cases in biogas and carboxylate platform	To be announced
17:15-17:30	Q/A and conclusions	Miguel Mauricio-Iglesias

Enhancing Anaerobic Processes through Understanding Microbial Community Structure and Function

Despite the promise of anaerobic biotechnology, its full-scale application to treat certain organic waste streams and recover resources remains limited, suggesting that new approaches are needed to expand its use. This presentation will show the development of new anaerobic bioprocesses by applying knowledge of microbial community structure and function and sustainable technology design practices. This approach will be illustrated by focusing on anaerobic dynamic membrane bioreactor development for treating waste streams containing recalcitrant lignocellulosic compounds.

Controlling Product Formation in Anaerobic Digestion

The thermodynamic end-product of the anaerobic digestion process is methane containing biogas, but many research efforts aim for other products, like volatile fatty acids (VFA), molecular hydrogen, ethanol or lactate. These products represent a higher value in a biobased economy when recovered directly from the fermentation broth or when converted in secondary bioprocesses for the production of medium chain length fatty acids or bioplastics. A prerequisite for development of these processes is the (controlled) absence of methanogenesis to maximize the product yield. In this presentation I will describe how and why product formation in anaerobic fermentations depends on the cultivation conditions imposed. Emphasis will be on the identification of key environmental switching points that determine if (partial) inhibition of methanogenesis will be achieved. To which extent these switching points are independent of the history of the microbial community will be a topic of discussion.

Anaerobic Digestion Technology as a Holistic Option for Integrated Management of Municipal Wastewaters and Kitchen Wastes

The traditional methods of treating urban wastewater are energy-intensive and contribute to carbon emissions. Anaerobic digestion technologies can be used to reverse the negative energy balance of wastewater treatment. By treating municipal organic waste and wastewater together, energy recovery can be further enhanced. The integration of various emerging concepts in this integrated waste management concept, such as carbon redirection, anaerobic membrane bioreactor, lithotrophic denitrification, post-ozonation, and artificial methane production, holds significant promise for resource recovery and sustainability. This integrated concept will also support the resilience of the urban water supply system against global warming by providing reclamation and reuse of high-quality treated wastewater in dual water distribution networks. A holistic approach that includes these emerging technologies in municipal organic waste and wastewater treatment will be explored in this presentation.

Microorganisms Assisting the Green Transition

Microbes play a crucial role in facilitating the green transition towards sustainable and eco-friendly practices. This abstract presents various ways in which microbes contribute to develop technologies for the transition from the fossil based economy to bioeconomy. Microbes are are involved in bioremediation, where they break down and detoxify pollutants in contaminated sites, helping restore ecosystems affected by human activities. Additionally, certain microbes possess the ability to produce biofuels and biochemicals, offering a renewable alternative to fossil fuels and reducing greenhouse gas emissions. Furthermore, microorganisms contribute to sustainable treatment of organic waste. Biotechnologies are contributing to valorisation of residual resources, promoting efficient recycling and nutrient cycling.

In this presenation I will show potential applications from biogas to biomethane which can be supplied to the natural gas grid. Methane can also be used as substrate for cultivation of methanotrophic bacterial with high protein content with good aminoacids composition. Additional products can be obtained from the intermediates of the AD process, such as PHAs or specific volatile fatty acids, alcohols, lactic acids etc. Results of several of these alternatives to heat and electricity will be presented. Current status and future opportunities will be discussed.