Sustainable Science

Talking Water Reuse Research with James Roberts

by Fennie Easton van der Graaf

James Roberts is a Masters student in Environmental Engineering, Civil Engineering. He investigated the application of primary microscreening and algae photobioreactors (PBR) as treatment processes in decentralized wastewater treatment.Presentation Pic

In general, wastewater treatment facilities mimic natural processes by following three main steps to remove organics and nutrients that would otherwise cause adverse effects to the environment. In natural conditions, suspended organics settle from the water column, dissolved organics are consumed by bacteria, and nutrients are removed by algae. These processes are controlled and intensified in primary, secondary, and tertiarywastewater treatment.

Primary microscreening is a primary treatment technique that sieves out organic particulates instead of settling them, thereby reducing the loading on the secondary treatment in a very compact fashion. Secondary and tertiary treatment is then performed simultaneously using an algae PBR. James’s algae PBR contains an illuminated horizontal plate, over which wastewater is passed. A symbiotic heterogeneous biofilm of bacterial and algal populations naturally grows on the plate, consuming dissolved organics and nutrients from the wastewater flow. The algae in the biofilm produces oxygen that bacteria can use to consume organic pollutants and to convert ammonia to nitrate. I asked James a few questions about this project and his career:

Why is this research novel and real life applicable?

“The combination of the microscreen and algae PBR is a low cost, low energy, high quality but relatively spacious (for algae to grow) option for wastewater treatment. A niche it could fill is in building scale treatment in lower density suburban areas where extra space is available and the cost of the alternative, which is providing collection infrastructure to support centralized treatment, is high. The progress of implementing systems like these is slow however, as it is a significant shift from how treatment is done today.


As far as novel aspects of the research go, these treatment techniques have not been applied at the building scale before, but if you treat wastewater closer to the building that produces it, it’s easier to reuse the water, so there are significant benefits. This research will also be the first to explore the effects of a number of particular conditions on PBR treatment efficiency. This includes using an open vs. closed PBR, high vs. low alkalinity influent wastewater, and varying the timing of wastewater addition to the reactor.

What are environmental concerns that your proposed wastewater treatment technology could be more efficient at overcoming?

“One, we need to remove species that consume oxygen, like ammonia and dissolved carbon, which would otherwise deplete oxygen levels in environment, making it uninhabitable for many forms of aquatic life. Two, we want to limit odours caused by the anaerobic conditions that would ensue. Three, pathogenic bacteria in wastewater can only be removed after organics are removed, otherwise the organics react with the chlorine before it has the opportunity to kill the bacteria. Fourth, if not removed, nutrients like phosphate and nitrate can cause a spring in growth of algae in receiving waters, which also depletes oxygen.”

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How do you practice sustainability in the lab while undergoing your project?

“I am pretty good with reusing pipette tips, the concentrations of the analytes I monitor are fairly high so residual contamination from a used but washed pipette tip isn’t really a problem. I try to reuse gloves: I love the tightness of medium sized gloves but I couldn’t reuse them as much so I switched to extra-large, but at the same time I can’t reuse too much since I use real waste water!”

What are common sustainable practices at the Environmental Engineering Lab?

“Well this doesn’t really answer your question, but I do know that wastewater at UBC is fairly dilute because a lot of labs use tap water for cooling on instrumentation, but there is no recycle line on it so they constantly have tap water running into the drain. It’s been something that UBC has been trying to find on campus and stop. I don’t think we do that in our lab. It’s more expensive to have internalized cooling and UBC, like most utilities, doesn’t charge the full cost of water so we tend to do stupid things with it.”

 What lead you to pursue a career in Environmental Engineering?

“I was in the fourth year of my Integrated Engineering undergrad at UBC and I would have Taco Tuesday talks with my buddy about what to do after graduation. Everything led back to the idea of rebuilding the community, the idea that we don’t know our neighbors as well as we would’ve fifty years ago. How can an engineer help create a sustainable community? Wastewater treatment believe it or not. If treated at the community scale, the water and nutrients in wastewater become a valuable local resource that can be used to revitalize and green the urban realm.”

What has your experience been like in your Master’s program and what advice would you pass to other Master’s students?

“I knew I wanted to do microscreening. Finding a professor to support this project was tough, and so I didn’t have a supervisor for the first 8 months of my Masters. After talking to everyone I could, I managed to secure industry funding from ECO-TEK (company that designed onsite wastewater treatment facility at the UBC Centre for Interactive Research on Sustainability), and get a job there maintaining their facility at CIRS. I then found Dr. Ryan Ziels and he added the algae PBR idea to the project, which I ended up finding more interesting anyways! In terms of advice, I think strong communication with your supervisor is important. Also, keep in mind your project is not the ‘be all end all’ and what you’re researching is probably not what you are going to do with your career, but invest in it and remember what it is within a greater context. Other than that, do activities other than your Masters; I got really into climbing!”

James is currently writing his thesis, but he intends to publicize his research as much as possible. Find out more about James’s research and his experience as a participant in the 2018 UBC Three Minute Thesis competition at

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