Recovering rare earths using algal biofilms

Rare earths are a critical resource that are used in a wide range of applications like computers, electric car batteries, windmill turbines, and other green energy technologies. In spite of the name, they’re not actually that rare. However, they are found at low concentrations and are difficult to separate from one another. To deal with this, ChemE PhD student Mitchell Zak is investigating the use of algae to recover rare earths from mining effluents and other aqueous waste streams by having them adsorb onto the cell wall of the biomass in a process called biosorption.

A major issue with using microorganisms like algae for biosorption is that they have poor mechanical properties and small cell size, which makes it difficult to immobilize and implement in an engineered treatment system.

“To address the immobilization issues, we grow our algae in a much more concentrated form that allows growth to a surface known as a biofilm. My research project, Recovery of Rare Earth Elements Using Algal Biofilms Via Biosorption, focuses on seeing how effective algal biofilms are in terms of overall uptake, kinetics, and selectivity which hasn’t been assessed before,” says Zak.

Through guidance from his two supervisors, Professors Grant Allen and Vlad Papangelakis, and postdoctoral fellow Jens Kastenhofer, Zak is working hard to develop a low-cost and environmentally friendly method to recover rare earths. His hope is that the algal biomass could be used afterwards to produce other value-added products, such as biofuels.

This week, Zak successfully presented his research at the 13th International Water Association Specialist Conference in Melbourne, Australia. Congratulations to Zak on a job well done!


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Wood biochar – a low-cost, high-performance alternative to advanced nanoporous carbon materials

On June 7, Wood Biochar Monolith-Based Approach to Increasing the Volumetric Energy Density of Supercapacitor, an article by Professors Charles Jia and Don Kirk, was published in ACS Publications – a high-impact interdisciplinary journal reporting on energy research.

Energy storage technologies are central to the economy’s electrification and renewable energy utilization and crucial to tackle the climate change challenge. According to the International Energy Association, the world will need 266 GW of energy storage capacity by 2030 to keep global warming below 2 °C. Electrochemical energy storage (EES) systems can constitute a significant portion of that capacity. While the past couple of decades has seen an unprecedented expansion in energy storage material research, it is increasingly recognized that the volumetric performance of EES systems is more relevant to real-world applications. Supercapacitors are particularly attractive for storing energy from intermittent sources, such as solar farms, windmills, and regenerative braking of electric vehicles, due to their fast charging/discharging capability and long cycling life. However, the low energy density and high manufacturing costs hinder their full acceptance and large-scale applications. Three factors determine the volumetric energy density of a device: volumetric capacitance of the electrode material, operating voltage window, and device packing efficiency.

Wood biochar monoliths (WBMs) have a low-tortuosity porous structure and a conductive carbon matrix, a combination desirable for binder-free electrodes with high energy density. Jia and Kirk’s paper reports a novel approach for fabricating high-performance, WBM-based thick electrodes. Their study outlines a practical method to increase the volumetric energy density, demonstrating the potential of WBMs as a low-cost, high-performance alternative to advanced nanoporous carbon materials such as graphene and carbon nanotubes.


Five U of T Engineering projects have received GESeed support

Five U of T Engineering projects have received support from the Global Engineering Seed (GESeed) program in its first round. Among this group are Professor Jeff Brook (Dalla Lana School of Public Health, ChemE), along with Professors Greg Evans (ChemE, ISTEP), Arthur Chan (ChemE) and Jeffrey Siegel (CivMin) who are working with Fort McKay First Nation Sustainability Department, AUG Signals Ltd., on Cleaner Air for an Indigenous Community Heavily Impacted by Energy Development.

For the full list of U of T Engineering GESeed recipients, click here. GESeed was created at U of T Engineering’s Centre of Global Engineering (CGEN) to support the development of community-engaged research that addresses critical challenges in Indigenous communities and developing countries in the Global South.


Using renewable biopolymers (lignin) for dewatering biosludge

Hamed Ghazisaidi (ChemE PhD student) and Vincent Wang (ChemE 2T1 + PEY Co-op, incoming MASc), supervised by Professors Grant Allen and Honghi Tran, as well as Senior Research Associate Dr. Torsten Meyer, are looking for alternative chemicals or additives that can replace petroleum-derived products in wastewater treatment systems with more sustainable and environmentally friendly chemicals.​

Today in the pulp and paper industry, wastewaters are treated using biological treatment systems that often use synthetic polymers to remove water from the biosolids that are produced as a waste byproduct. “Our research looks at the performance of lignin-based materials as dewatering aids; lignin being an abundant polymer that is found in the wood used in the pulp and paper industry,” says Wang.

“We are trying to evaluate their performance and determine how we can make these renewable materials perform better at their role at a lower cost and with lower amounts,” Wang elaborates.

In their research titled, Determining the performance of lignin-based flocculants in biosludge dewatering, Ghazisaidi and Wang also worked in collaboration with Professor Pedram Fatehi from Lakehead University, who provided some of the materials used in these experiments.​

“We hope that our research will allow the pulp and paper and many other industries and municipalities that rely on biological wastewater treatment to move to a more sustainable approach that will help reduce their environmental footprint,” says Ghazisaidi.

This research funded by the Effective Energy and Chemical Recovery in Pulp and Paper Mills Research Consortium and NSERC is currently in the editing stages of being published.


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July 4, 2022: Appointment of Associate Chair, Undergraduate Curriculum Development

I am very pleased to announce the appointment of Professor William R. Cluett as the inaugural Associate Chair, Undergraduate Curriculum Development (UGCD) for a three-year term from July 1, 2022 to June 30, 2025.

Will joined the Department of Chemical Engineering & Applied Chemistry in 1986. He has served the Department and the Faculty in a number of academic leadership roles, most recently having just completed a three-year term as Director of the Division of Engineering Science. In 2018, he was awarded the President’s Teaching Award, the highest honour for teaching at the University of Toronto. In 2020, he received the OCUFA Teaching Award and, in 2021, he was awarded the Medal for Distinction in Engineering Education from Engineers Canada. He is a Fellow of the Chemical Institute of Canada (FCIC), the American Association for the Advancement of Science (FAAAS), and of Engineers Canada (FEC). He is a registered professional engineer (PEng) in the Province of Ontario.

In this new role, Will will focus on supporting the department’s strategic goal to be a leader in creating a modern chemical engineering curriculum that will continue to attract the brightest minds from around the globe to our undergraduate program. Some of the key functions of the Associate Chair UGCD are to manage curriculum review and changes; oversee curriculum and calendar updates; manage the CEAB accreditation process; and serve on the Faculty’s Standing Committee for Undergraduate Curriculum.

I would like to add that Associate Chair UGCD is one of two positions created to replace the role of Associate Chair Undergraduate Studies in order to focus on supporting our students in post pandemic times and working towards our department’s goal of curriculum modernization.

Please join me in congratulating Will on his new appointment.

I also wish to take this opportunity to thank Professor Tim Bender for his six years of exemplary service to our Department as the Associate Chair, Undergraduate Studies. Tim’s leadership has been instrumental as he navigated our undergraduate program delivery during some exceptionally challenging times over the past two years.

Please join me in thanking Tim and wishing him all the best as he maintains his support for the Department through the development and implementation of continuous improvement processes in his new role as the Chair of the Support Services Committee (formerly Technical Services Committee).

Sincerely,

Ramin


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July 4, 2022: Appointment of Associate Chair, Undergraduate Student Experience

I am very pleased to announce the appointment of Professor Jennifer Farmer as the inaugural Associate Chair, Undergraduate Student Experience (UGSE) for a three-year term from July 1, 2022 to June 30, 2025.

Jennifer joined the Department of Chemical Engineering & Applied Chemistry in July 2016 as an Assistant Professor in the Teaching Stream after obtaining her PhD from York University in Organic Chemistry, specializing in palladium catalysis. Jennifer infuses her passion for chemistry into our chemical engineering program by providing students with a strong foundation in applied chemistry knowledge and practical skills through experiential learning. Her work in this area has led to several papers in chemical and engineering education journals and conference proceedings. Jennifer’s commitment in supporting students goes beyond the classroom, serving as a faculty liaison for several student clubs involved in providing student hands-on experience with chemical processes, sustainability, building community and fostering inclusion. She has served the Department and the Faculty in various capacities, including Chair of the Undergraduate Scholarships and Awards Committee since October 2018. She is a Fellow of the Chemical Institute of Canada, Canadian Engineering Education Association, and the American Society for Engineering Education.

In this new role, Jennifer will focus on ensuring an outstanding experience for our undergraduate students. Some of the key functions of Associate Chair UGSE are to manage the operation of undergraduate student support services; develop undergraduate enrolment planning and targets; manage undergraduate teaching assignments; schedule undergraduate courses; oversee students’ degree requirements and convocation; plan for undergraduate laboratory needs; and prepare undergraduate budget.

I would like to add that Associate Chair UGSE is one of two positions created to replace the role of Associate Chair Undergraduate Studies in order to focus on supporting our students in post pandemic times and working towards our department’s goal of curriculum modernization.

Please join me in congratulating Jennifer on her new appointment.

I also wish to take this opportunity to thank Professor Tim Bender for his six years of exemplary service to our Department as the Associate Chair, Undergraduate Studies. Tim’s leadership has been instrumental as he navigated our undergraduate program delivery during some exceptionally challenging times over the past two years.

Please join me in thanking Tim and wishing him all the best as he maintains his support for the Department through the development and implementation of continuous improvement processes in his new role as the Chair of the Support Services Committee (formerly Technical Services Committee).

Sincerely,

Ramin


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June 28, 2022: Appointment of Associate Chair, Continuing Professional Development

Dear all,

I am very pleased to announce the appointment of Professor Charles Jia as Associate Chair, Continuing Professional Development (ACCPD) for a 3-year term from July 1, 2022 to June 30, 2025.

Charles joined the Department of Chemical Engineering & Applied Chemistry in September 1994 as an NSERC PDF after obtaining his Ph.D. from McMaster University and was promoted to Full Professor in July 2007. He has served the Department in various capacities, including Associate Chair-Graduate Studies from January 2012 to July 2015. He is a Fellow of the Canadian Academy of Engineering and a Fellow of the Chemical Institute of Canada.

In this new role, Charles will focus on enhancing and expanding our professional development programs by building on our Mater of Engineering (MEng) curriculum; creating internship opportunities for MEng students in coordination with the Engineering Career Centre; launching new MEng emphases; increasing MEng enrolment; and creating micro-credentials and other continuing professional development courses in collaboration with the School of Continuing Studies.

Please join me in congratulating Charles on his new appointment.

Sincerely,Ramin


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Traffic-related pollution in Toronto: Prof. Jeff Brook featured in The Narwhal

Professor Jeff Brook has studied traffic-related air pollution for over 20 years and is now the principal investigator on a team developing interactive tools that allow users to combine air pollution modelled on a map with socioeconomic data from the census.

This story is part of Toronto’s Climate Right Now, a collaboration with The Local about vulnerability and adaptation in Canada’s largest city. Read the full news story.


Curbside dining: SOCAAR featured in The Toronto Star

With curbside patios out in full force along Toronto city streets, Professor Greg Evans says that the air quality pros outweigh the cons when it comes to outdoor dining. Read the full story by The Toronto Star
titled ‘How unhealthy is it to eat in a curbside patio next to traffic? Most CaféTO diners can breathe easy.’


Recovering nickel from mining waste

Leonardo Shen

Shen pictured conducting his research in the lab.

The mining industry in northern Ontario, particularly in Sudbury, has been the economic backbone of this region. As the mining operations generate profits, they also produce large amounts of waste in the form of pyrrhotite tailings, which has become an environmental burden. Under the supervision of Professor Vlad Papangelakis, Heping (Leonardo) Shen (ChemE PhD student) is finding ways to alleviate the economic burden of neutralizing pyrrhotites through a project entitled, nickel recovery from pyrrhotite tailings using a two-step microbially catalyzed process.

“According to 2010 estimates, the total dry weight of pyrrhotite tailings had reached between 50 – 100 million metric tonnes. They are now stored under water, which is more of a containment rather than a treatment. This is not sustainable, as dissolved oxygen in the water will slowly but surely oxidize the buried wastes causing what’s called the acid-mine drainage. During this process, massive acid production will occur, lowering the pH of the water body below 3, which is enough to eliminate almost all living organisms in surrounding ecosystem. An environmentally friendly and economically viable process needs to be developed to ensure the sustainability of the mining operations in this area,” details Shen.

Current treatment of pyrrhotite is associated with enormous costs in neutralization because of the acid production. However, Shen discovered a silver lining!

“A very small amount of nickel (up to 1 wt%) is entrapped in those wastes and recovering this valuable metal could potentially alleviate economic burden. Some acidophilic (acid-loving) microbes like Acidithiobacillus ferrooxidans and can help in the digestion of those solid wastes, liberating the nickel for recovery,” explains Shen.

This is a process called bioleaching, which has several advantages compared to conventional pyrometallurgical (i.e. burning solids) processes. Most notably, it produces no air pollution and requires significantly less energy input.

Leonardo Shen's research equipment

The bioreactor Shen used for his continuous ferrous bio-oxidation experiments.

“If we think the pyrrhotite tailings with nickel entrapped as the enemy to be broken apart, then ferric ions (Fe3+) are the soldiers we deploy. Once the enemy (pyrrhotite) is attacked (leaching), our soldiers are sadly spent … together with freshly released iron from the pyrrhotite they become ferrous ion (Fe2+),” analogizes Shen.

“Now is the time for our microbes to shine! Normally in acidic conditions the conversion of ferric ions (Fe3+) to ferrous ion (Fe2+) is extremely slow, but microbes like At. ferrooxidans can greatly accelerate this process, making sure there’s always enough soldiers to attack the enemy. The only problem is that those microbes will also convert released elemental sulfur to sulfuric acid when there’s oxygen, and we want to minimize that,” explains Shen.

Shen’s approach separates the ferric ion attack and the ferric ion regeneration into two steps, removing the released elemental sulfur in between via simple solid-liquid separation. By doing this, his method avoids the mass production of acid and benefits from the accelerated reaction speed from the microbes.

With the growing need for nickel in EV-battery manufacturing and the depletion of high-grade nickel ores on a global scale, the mining industry is turning its eyes to low-grade ores and wastes, like pyrrhotite tailings. The process Shen is developing and the mechanistic understanding he has learned from developing this process compliments this industrial-focus shift, as well as strengthens sustainability of mining operations in northern Ontario.

Shen’s research was conducted in collaboration with fellow ChemE researchers Dazhi Ren, Srinath Garg, and Christine Romano. Their work has been published in the COM2020 proceedings in 2020 and is set to be published at the IBS conference, which will take place at the end of this year. Their project is funded by the Ontario Ministry of Research and Innovation and Ministry of Northern Development and Mines, Genome British Columbia, and NSERC.


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