An interesting news story about the measurement of air quality on cruise ships appeared recently. Specifically, it dealt with the concentration of ultrafine particulate (UFP) matter in the air on four cruise ships, measured by a researcher from Johns Hopkins University. UFP is invisible matter with diameters of around 100 nanometres (nm), which is about 1,000 times smaller than a human hair, and it is implicated in airway inflammation and effects on other organs in the human body. Being interested in air quality, I looked up the actual study report which you can also read here. Here is my take on the work and meaning… Continue reading
With recent moves to permit sales of cannabis in Canada and some U.S. states, commercial operations are popping up in various locations. Whenever new industries emerge, there are often new environmental impacts to consider and air pollution seems to be an increasingly common problem with cannabis too. Not from smoking, but rather from the greenhouse operations where it is grown under lights in high-density conditions to save space. It turns out that these intensive grow operations can have vented air emissions that are rather smelly, as this one news item describes.
Like all plants, cannabis emits volatile chemical compounds at various stages in its growth. Some work has been reported in research literature, identifying over 200 chemicals in the air, although I suspect that paper missed a lot of odorous sulfur compounds that are often associated with “skunky” smells. A lot of the odor compounds are terpenes or their relatives (e.g. limonene, pinene, linalool), and the paper mentions cymene, benzaldehyde, nonanal, and decanol as key odor chemicals. None of these compounds are particularly hazardous (at least at the normally low concentrations found around plants). None of them are specific to cannabis either. Lots of them are produced by various plants, in varying amounts and combinations. A lot of plant-based essential oils that you can buy contain similar chemicals.
The environmental issue arises if the odor interferes with the neighbouring property and their ability to use and enjoy their property. The Ontario government website has some information about odors and property-owner rights . Under Ontario’s Environmental Protection Act (Section 14) odor-emitting industries can get into legal trouble because they are emitting a “contaminant” that causes an “adverse effect”.
From an engineering point of view, the control of odorous emissions like this is not unlike many other industries with odour concerns, like sewage treatment plants, rendering plants, some food manufacturers, and some chemical manufacturers. The first step is containment, so that odor emissions are not just leaking out of the buildings from a multitude of locations. If everything can be efficiently captured in one or two well-controlled ventilation systems, then emissions controls can be applied to those vent streams before they discharge into the environment.
It’s not clear at this point what type of emission controls are best for both efficiency and cost points of view. Usually there are several possible solutions, so engineers have to figure out which one is the most cost-effective. Standard approaches to odor control run a range of technologies from wet scrubbing to activated carbon capture, to biofiltration and possibly photochemical oxidation. High temperature thermal oxidation is another option, but probably overkill and too expensive for this application. One solution may not fit all commercial operations either. Each location would need a thorough engineering analysis and assessment for a good recommendation, which is something done by chemical and environmental engineers (and some mechanical engineers too). Companies that rushed into production without doing these assessments may get stuck with expensive retro-fits once the Ministry of Environment comes knocking.
So, with every new “industry” there are issues that come up that may or may not have been anticipated by the business people. Those issues will keep regulators and engineering consultants busy for a while.
Some interesting results from my colleague’s research group. I add some further context below the link…
Researchers at Waterloo Engineering have created a powder that could be used to reduce greenhouse gases at factories and power plants that burn fossil fuels. The advanced carbon powder, developed using a novel process in the lab of chemical engineering professor Zhongwei Chen, could filter and remove carbon dioxide (CO2) from emissions with almost twice the efficiency of conventional materials.
My Context/Analysis: Some interesting work in materials science and chemistry. From the published paper (sorry it’s behind a paywall, but I can read it through the university’s subscription), I can see that the amount of CO2 captured is about 1.6 mmole of CO2 per gram of powder, or about 70 mg/g, at flue gas conditions. As the paper points out, this is pretty good for CO2 adsorption, but it is not a miracle cure for all of our problems. To put it in context, in 2016 the U.S. electricity sector emitted something like 1,800,000,000,000 kg of CO2 (from the EPA website). So, if the powder can capture 70 mg per g it would take about 26,000,000,000,000 kg of powder for one year of capture. That’s a lot of powder!! And that’s only for one sector in the U.S. alone (representing about 28% of U.S. CO2 emissions). So, it’s important to continue doing research, find new things and look at potential applications in a wide range of fields. But carbon emissions and climate change is a huge problem and there aren’t any easy answers. Reducing CO2 emissions will generally be better than trying to capture them afterwards, like the three R’s hierarchy (reduce, reuse, recycle).
Interesting research project in our Electrical and Computer Engineering department. Reduces the need for CT scans and their high radiation doses.
Nice to see a Chemical Engineer receive a Nobel prize, for work on random mutagenesis for industrial enzyme selection and improvements. My PhD work was in enzyme applications, though not this particular area.
Dr. Arnold’s research has produced methods now routinely used to create new catalysts. Her work has led to new enzymes for pharmaceuticals, sustainable biofuels, and other environmentally friendly products.
Congratulations Prof. Strickland!
Donna Strickland, an associate professor at the University of Waterloo in Ontario, became the first woman in 55 years and the third ever to win the Nobel Prize in Physics, sharing it with a scientist from the U.S. and another from France for their work in laser physics.
An interesting article about my colleague Prof. Emelko’s research. I’m somewhat jealous that she gets to fly in a helicopter!
Forest fires are sweeping North America with detrimental environmental, economic and human impacts. A research team, led by University of Waterloo Engineering professor Monica Emelko, will receive $5.5 million from the Natural Sciences and Engineering Research Council of Canada’s (NSERC) Strategic Partnership Grant for Networks to provide new knowledge on the impacts of different forest management strategies on drinking water source quality and treatability.
An interesting article about some co-op student efforts in one of our research labs. I learned about Spatial Atomic Layer Deposition, which is an interesting application of nanoscience and materials engineering.
With the help of seven University of Waterloo co-op students, Canada’s first Spatial Atomic Layer Deposition (SALD) system is up and running. At the celebratory ribbon cutting on May 10, 2018, project leader Professor Kevin Musselman said he couldn’t have done it without the co-op students who helped design and build the machine. “I was sitting at my desk the whole time. I don’t think I ever lifted a finger so it was entirely built by the students,” laughs Musselman.
Over the past month I’ve spent some time on research topics related to garbage. Or more accurately, energy from waste, sustainable materials management, circular economy issues, reduction and recycling. To the public, such things may not be as exciting as self-driving cars, but as landfills, oceans, and beaches fill with wastes they are becoming more noticeable and pressing issues.
First, I helped to organize our 5th annual Resource Recovery Partnerships Conference here at Waterloo in late June. Over two days, we had lots of presentations and networking among academic, industrial and municipal government people discussing various issues related to waste reduction and management. Shortly after that, I attended the Air & Waste Management Association’s annual conference, held in Hartford CT. There, I saw a number of interesting presentations on “zero waste”, sustainability, and case studies of projects. Between these two events I learned a few things that I can summarize below: Continue reading
There is a perception out there that Waterloo Engineering is a great place for a practical undergraduate education (I won’t argue with that), but when it comes to more theoretical graduate studies and research in Canada you should look to one of the other big names. I will argue with that, and of course present some data for analysis. Continue reading