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Western News - From beloved West African cuisine to Canadian road salt, corrosion study opens new path (westernu.ca)

What does a traditional West African dish have to do with road salt spread across snowy Canadian streets every winter? 

The two subjects are equal passions for chemistry PhD candidate Robert Addai, who works in Western’s Material Science Addition lab and studies how metals corrode when they come into contact with food and road salts. 

It all started with fufu, a common staple in his diet growing up in Ghana. A starchy food that’s common in West African cuisine, traditionally fufu is made by pounding cassava, a tropical root vegetable. That labour-intensive process can take hours.  

The preparation of fufu has evolved, the same way butter and other food staples have become almost exclusively machine produced. Most people now use a metal “fufu pounding machine” that offers the repetitive pounding action in a hands-free form, Addai explained. 

“It is a delicious food, but it takes a lot of time. The machines also works in the form of friction, by pounding. My research is focused on whether metals are released from the machine into the fufu,” Addai said. 

Addai measures the chromium, iron, manganese and nickel present in samples of fufu, by testing a slurry of the food in contact with samples of two types of carefully cleaned stainless steel. After breaking it down in a digester, he analyzes the solution for trace amounts of metals using a specialized tool to quantify metal ions. After reviewing initial results, he found the highest concentrations of iron followed by manganese, chromium and nickel. 

Addai tests fufu made from powder, cassava flour, which is the most common preparation for those making the food in Canada, as well as some homemade samples of traditional fufu made by machine. 

His samples are tested after 30 minutes, 24 hours and one week, since fufu can be cooked for various lengths of time. The release of metals increases with time, Addai has found. In some samples, there are potentially harmful levels of nickel and chromium, which have been linked to possible health effects such as respiratory and cardiovascular issues, as well as some types of cancer. 

Health concerns originally sparked Addai’s interest. He wanted to know if the metals in contact with food enjoyed by his friends and family were playing a role in rates of illness. 

“There are a lot of people, not only in Ghana, but all over the world, especially in the diaspora who are suffering from cancer, heart disease and other illness. Scientifically, we don’t always know the cause. So I wanted to study this (food preparation) from the start to check if some of the diseases are coming from this food,” he said. 

There are other concerns, too, such as the type of metal used to create the fufu machines. 

“They use recycled materials, that can contain a lot of lead,” said chemistry professor Yolanda Hedberg, Addai’s supervisor. She conducts similar research testing for the prevalence of metals in dairy products. 

Addai’s deep dive into fufu led him to similar research on metal corrosion in an environment far from a Ghanaian kitchen: an icy Canadian road. 

Hedberg needed a researcher to work on a new project in the Material Science Addition lab. Addai had the knowledge and the willingness to jump in, Hedberg said.

In addition to investigating metals in contact with fufu, Addai is now looking at different brands of road salt used for melting and grip on the roadways in Canada’s coldest months. Despite straddling two seemingly disparate fields – from fufu to road salts – Addai conducts the same kind of core research in both projects.

Last winter, Addai began running tests on the same squares of stainless steel he used for his cassava research. This time, they were laid out in a parking lot of Western Research Parks for a small pilot project. The metal was left outside for two months and monitored as it was sprayed weekly with nine different varieties of road salt.  

Addai will continue that work next winter, along with other researchers, to look at the environmental effects of popular types of road salt, including the type used by Western’s facilities management team.  

“We hope to recommend the best product, to balance effectiveness with environmental impact,” he said. 

Addai said it can sometimes be tedious to wait for the results of his studies, many of which undergo multiple stages and phases. It takes time to reach the stage of final analysis.  

But challenges in examining the tiniest particles of fufu haven’t dimmed his enthusiasm for the subject – or the food. 

Addai is travelling home to Ghana soon and said he can’t wait to enjoy the fufu made by his loved ones, instead of the version he makes in Canada using cassava flour. 

“I told my family, have the fufu ready,” Addai said with a laugh. 

“It’s the first thing I want to do. I miss it so much.” 

Little Falls looking into using brine for winter road care | News | hometownsource.com

Little Falls is hoping to experiment a bit with the way it treats roads, next winter.

Monday, City Engineer Greg Kimman told the Little Falls City Council that he had been looking into using brine on some city streets, rather than the salt and sand mixture that has been used in the past. Though the matter was a discussion only item and there was no formal vote, the Council was receptive to the idea.

Kimman said the plan, as of now, would be to apply brine to the roughly 20 miles of State Aid streets within the city. That would include First Street, Fifth Avenue Southeast, 11th Street Northeast, 13th Street, Riverwood Drive, 10th Street Southwest and Lindbergh Drive Northwest.

The brine system is, essentially, salt that’s in liquid form. It is applied prior to a snow event to help it melt as it falls.

“I’d like to try to get a little bit ahead on the snow events just to get ahead of them and make sure we don’t get the snowpack that we’ve had in the past couple of years on some of those roads, just to try to get them a little bit closer to bare pavement,” Kimman said.

As a trial, the city would purchase a brine tank for one of its single-axle trucks. Kimman received a quote of $7,067 from Towmaster Truck Equipment of Litchfield to outfit the truck.

As Morrison County is preparing to build a new county shop in Little Falls, it is possible the facility will give it the capability to make brine in-house. Kimman said he had reached out to the county about using some of its brine, next winter.

If that partnership works out, Kimman said the city, at the end of the winter, would replenish the county’s salt supply with however much was needed for the brine it used. He said it is possible a similar deal could be reached with the Minnesota Department of Transportation (MnDOT), but he wanted to explore working with the county first.

“What we would do is, we would call up the county and say, ‘We would like to get a load of brine,’” Kimman said. “We would go over there, get the brine and then at the end of the year — let’s just say we use 500 gallons of brine. They’d calculate it out and say, ‘OK, 500 gallons equates to 100 pounds of salt.’ At that point, we’d bring 100 pounds of salt over to them, dump it off and they would put it in their salt shed.”

He noted later those numbers were used only as an example, and he didn’t know exactly what the ratio of brine to salt would be.

Council President Jerry Knafla asked what the cost for the brine would be if it were purchased on its own. Kimman said the brine itself is not what is purchased, but rather the equipment to make it.

To make the brine, he said those who have the equipment purchase road salt and mix it with water to get a solution. That is what is loaded into the tanks. It is then spread on the road, it dries as a solution and, when the snow falls, it melts as it comes in contact with the brine.

“The nice thing about using a liquid form as opposed to the granular form, and we’ve all seen it, when you sprinkle it on the road, it bounces all over the place,” Kimman said. “With brine, you put it on the road and that’s where it’s going to stay until it melts and it runs off.”

Though the water eventually evaporates, he said the brine salt from the solution will remain on the roadway. That keeps it pre-treated ahead of a potential snowfall that comes even a week later.

Council Member Dave Glaze asked if the brine does any damage to the roads or lawns with which it might come into contact. Kimman said it would damage a lawn, just as any concentration of salt would — even in the traditional, granular form.

He added that the brine wouldn’t do any more damage than “straight salt.” He reiterated, however, the salt in its granular form bounces when it hits the pavement, whereas the brine stays in its intended location for longer.

“Not to mention, any damage is almost all going to be on the right of way,” added Council Member Leif Hanson.

In terms of damage to the road, Kimman said, again, the brine would not be any more harmful than regular salt. Salt can oxidize the top of the pavement in either form.

Glaze asked if the brine was going to cost more than the salt and sand mix the city uses currently. Kimman estimated it might be a “little bit more,” mainly due to the purchase of the saddle tanks for the truck. Using the salt alone for the brine instead of the mix would also be a slight increase in cost.

“But then you won’t be using any sand?” Glaze asked.

“I wouldn’t say that,” Kimman said. “We’ll be reducing the amount of sand that we use, but we’ll still be using some sand.”

That is due to the fact, in the first year at least, only the State Aid roads will be treated with the brine.

Knafla said this past winter he received several complaints about the roads “and how terrible they were.” Residents asked him why they weren’t getting plowed, or why there was so much snow buildup.

“I think trying something like this on certain, select roads that are the most highly traveled roads throughout the city, trying it to see if it does reduce the amount of buildup that we have there and eliminate some of those complaints (is a good idea),” Knafla said.

Glaze agreed.

Council Member David Meyer said he received complaints about the amount of sand that was on the streets in the spring. He thought trying brine to minimize that was a good plan.

Hanson said one of the streets he travels on most is Fifth Avenue Southeast, which would be one of the roads treated with brine under the current plan.

“If something like this can improve that intersection at Fifth Avenue and Ninth Street, which is just brutal, I’m for trying something different,” Hanson said.

Canadian cities' salt levels are unhealthy for water life | CTV News

A number of Canadian cities have exceeded acceptable chloride levels in watersheds in recent years, raising concerns about the impact on freshwater wildlife and other species.

The problem largely stems from road salt and saline solutions, which have a chemical compound of chloride to keep roadways safe during winter weather.

Chloride has both long- and short-term impacts on wildlife, and some experts believe it is adversely affecting fish, frogs and aquatic ecosystems across Canada.

"In the spring, where we might have amphibians, frogs, salamanders, coming into small, shallow pools of water along ponds, along roadways or in the forest, they may end up in salty water. That really limits their ability to survive," Donald Jackson, professor in the department of ecology and evolutionary biology at the University of Toronto, told CTVNews.ca in an interview.

Humans sometimes use the same water we are polluting as well, but the Canadian government has implemented drinking water objectives to remove unnecessary toxins and salt for consumption.

Even with these objectives, drinking water may be a problematic source of salt – but only for those with certain conditions.

"Although the average intake of sodium from drinking water is only a small fraction of that consumed in a normal diet, the intake from this source could be significant for persons suffering from hypertension or congestive heart failure who may require a sodium-restricted diet," the Guidelines for Canadian Drinking Water Quality report reads.

For freshwater species that live their entire lives in water, removing excessive chloride is not an option.

The Canadian Council of Ministers of the Environment (CCME) created guidelines for municipalities in order to keep rivers, streams and lakes healthy for plants and animals.

According to research from DataStream, a non-profit organization compiling information on Canadian freshwater, a number of cities across Canada had heightened periods of chloride in their watersheds in the past.

The CCME says if chloride content exceeds 120 milligrams per litre (mg/L) of water, it can become a chronic issue to water life. If chloride exceeds 640 mg/L, it is categorized as acute, and can severely impact water species immediately.

In an analysis by CTVNews.ca, data from some cities show chloride levels have surpassed (at times) 1,000 mg/L, far exceeding guidelines to maintain healthy waterways.

WHERE IN CANADA IS CHLORIDE AN ISSUE?

Data shows in many municipalities, the areas where roadways are concentrated are where chloride levels are too high for freshwater species.

The data, collected between 2020 and 2023, shows cities like Ottawa, Toronto, Calgary, Edmonton and St. John's are seeing chloride levels exceed 120 mg/L, enough to have an acute effect on species.

Often the waterways are located within subdivisions or along major roads, where salting occurs regularly in the winter.

Researchers in Nova Scotia determined that urbanization without proper waterway planning is hurting ecosystems

That study, which will be published in the Journal of Hydrology in its June 2023 edition, showcases an analysis of the chloride concentrations in 57 lakes around the Halifax-Dartmouth area.

Using data from the Energy and Environment division of the Halifax Regional Municipality gathered between 2006 and 2011, researchers were able to categorize which watersheds were under greater stress.

The data was collected three times a year and from there, researchers determined a mean for the chloride levels. The highest mean concentration of chloride was found in Dent's Punch Bowl, a small lake found in the middle of a subdivision in Halifax.

According to the article, there was a mean chloride concentration over 120 mg/L, meaning chronic living conditions for species in the lake.

Russel Lake in Dartmouth, N.S., had similar concentrations, with a mean over 120 mg/L and was also located within a subdivision.

Researchers were able to determine lakes along expressways and major collector roads had high mean concentrations of chloride in them.

Recently, the province launched a new water monitoring program to track fluctuating chloride levels in lakes, rivers and streams, among other things.

WHAT HAPPENS WHEN CHLORIDE LEVELS ARE TOO HIGH?

Jackson says the information on which species are harmed by increased chloride levels is minimal. The guidelines for how high the concentration can be before it harms the ecosystems are based on about 30 different organisms with ranging resistance to chloride.

The Canadian Water Quality Guidelines for the Protection of Aquatic Life, last updated in 2011, lists a number of species of fish, amphibians, plants and algae and how long they can survive before their "endpoint" in high chloride concentrations.

Some species, like the rainbow trout, can withstand a concentration of 8,634 mg/L for 96 hours before they will die. Other species, like the freshwater mussel, have only 24 hours to survive at a chloride concentration of 709 mg/L.

Others severely impacted by rising chloride levels include the northern riffleshell mussel (considered endangered by the federal government), the chorus frog, the spotted salamander and fingernail clams.

For each species to survive, Jackson says it is about maintaining a careful balance.

If a scientist were to put a freshwater fish in distilled water, Jackson says, it would die because it lacks the "ions and chloride" that help it maintain the balance of water in and outside its body.

"If you were to put that fish into saltwater, it's also going to die, because it can't balance those ions properly inside the bloodstream and outside the bloodstream," he said.

'EVENTUALLY… WE’LL KILL IT'

Despite the dangers, there is hope in that ecosystems and species have proven to be resilient.

Over time, Jackson says, these organisms have learned to adapt to the increased chloride concentration.

But as the levels get higher at a rapid pace it becomes more difficult for the organisms to reproduce.

"As we start increasing those (chloride compounds), really what we're doing is we're making it more difficult for the organism that fish or the plants to maintain that balance," he said. "And eventually we'll overwhelm it and we'll kill it."

Although relatively unseen to the human eye, some of these species are used as food, like mussels and fish, while others provide a balance within ecosystems to keep other species in check.

The largest issue with chloride is that once in the waterway it can not be removed easily. Instead of seeing what Jackson calls a "die off" these species will disappear.

"If it takes a long time, we often don't even recognize that (they are) disappearing," he said.

WHAT CAN BE DONE?

There are some cities across Canada that showed lower levels of chloride in their waterways. Despite being located on an island in the Atlantic Ocean, Charlottetown was one of the municipalities curbing salt.

A spokesperson from the city told CTVNews.ca that it has taken steps to limit salt usage in the winter.

"For example, sidewalks will not be salted when snow can be scraped to reveal mostly bare sidewalks, sunny weather conditions and rising temperatures are forecast for after the snow has been plowed, another weather event is expected in the next 24-36 hours or temperatures are too low for salt to be effective," the spokesperson said.

Some municipalities use more sand or small gravel to ensure traction without chloride.

The City of Winnipeg has used beet juice to help lower the amount of salt used on its roadway since 2020, and according to a city spokesperson, it can improve the "adhesion of the sand and salt to the roadway surface at colder temperatures."

"Beet juice can make up to 60 per cent of the solution we are applying to the roads and is combined with a traditional sodium chloride-based brine. This lessens our chloride loading on infrastructure and the environment while producing a good quality melting solution effective to temperatures below -30 C," the spokesperson wrote in an email to CTVNews.ca.

In the northern parts of the country, chloride is not used often in the winter because it isn’t effective below temperatures of -10 C.

Data from Great Slave Lake near the Northwest Territories shows chloride levels hovered around 10 mg/L in 2021. Since 2014, the information from DataStream shows, chloride levels from around the lake have not reached higher than 84.9 mg/L.  

Northern company's Plowbrush innovating winter road maintenance - North Bay News (baytoday.ca)

Plowbrush helps sweep more snow from streets and is estimated to reduce the amount of salt needed on roads by approximately 40 per cent.

FALCONBRIDGE, Ont. — The white stuff has only recently melted from city streets, but an innovative company based in Falconbridge is ready to help clear (more of) the snow when the temperature drops below zero.

Plowbrush is a company approximately four years in the making, and the snowplow-mounted device it manufactures is simple at face value.

It’s like having a giant push broom behind a snowplow blade.

“It’s a flat blade, and our roads really aren’t that flat,” vice-president of operations Brennan Chaput told Sudbury.com during a recent tour of their facility.

The brush, which includes plastic bristles similar to what you’d see on a street sweeper, lowers and raises pneumatically by the operator.

“When the plow operator wants to use it to sweep, they flip a switch and it puts down pressure on the road and it sweeps,” Chaput said, adding that each brush lasts approximately 1,200 kilometres and is easily switched out for a fresh one.

Plowbrush is a product of Chaput and his father, Rob, who were inspired by friend and Emcon (snowplow contractor) employee Jay Jewett, who came up with the idea. 

The Chaput duo made a few modifications and created the product they have today. The latest, third version, is stronger than past versions, with more cylinders and stainless steel to help prevent rust. 

Last month, they received a $728,433 grant from the province as part of a broader funding announcement which saw $11 million injected into Greater Sudbury’s economy.

One of the selling points for receiving the funds is that Plowbrush is estimated to reduce the amount of salt needed on roads by approximately 40 per cent, by their estimate. More snow is removed by the brush/blade configuration than blades alone, which lessens the need for salt, Chaput said, noting it also helps clear roads more quickly so there’s less driving time required.

The provincial funding has allowed them to purchase a waterjet cutting machine, which will allow them to fabricate their own pieces in-house, including cutting the brush’s bristles to size.

The company had previously outsourced much of this work but came up against a wall when it came to people willing to do the brush work, which they can now do themselves.

The company is currently eyeballing an expansion, Chaput said, as there’s the potential to hire an in-house welder so their product can be fully made in-house at their Falconbridge shop.

A Plowbrush costs approximately $12,000, and they have been sold mainly to Emcon, which uses them in such places as Dryden, Manitoulin Island and Greater Sudbury. The City of Greater Sudbury has purchased one, and there’s one in use in Sault Ste. Marie. 

Their main hurdle now is getting people to give Plowbrush a try, Chaput said. 

“Ideally, we’ll get one on every plow out there, but it’ll take some time.”

Mild winter didn’t exactly save towns money for snow removal | News | journalinquirer.com

While the state saw a milder than usual winter this year, the increased price of salt, the timing of the storms in the region, and overtime expenses still ended up costing many towns roughly the same amount to keep roads clear.

Still, some municipalities did see some savings over previous years, but many already have plans for those funds.

In Tolland, Town Manager Brian Foley said the Department of Public Works had budgeted $146,416 for snow removal overtime for fiscal year 2022-23.

“We also budgeted $149,655 for treated salt and winter sand, as well as another $8,500 for contracted services for seasonal help with the clearing of snow from the Birch Grove Elementary School, as well as for supplemental snow plow drivers when needed,” Foley said.

“The sand and salt account has been completely depleted, while there is a balance of approximately $5,405 remaining in the contracted services line,” he said.

Foley said that the $5,405 along with the approximate $95,232 remaining in unspent overtime will be used to offset any shortfall for next season, as budget cuts are expected for the upcoming year.

Dwight Ryniewicz, director of Public Works in Vernon, said that town usually buys about 4,000 tons of salt a year, but had some left over from last year so only bought 3,000 tons for this past winter. About 500 tons of salt still remains of the stockpile, he said.

Ryniewicz said the town didn’t pre-treat roads as much as in previous years because most storms started out as just rain, which would have washed away the salt-brine liquid used to pre-treat roads.

Nonetheless, the town did exceed its overtime budget of $77,000 by 30% because the storms that the region did get were mostly overnight, he said.

When temperatures rose during the day and fell again after sunset, town workers also would have to treat parking lots and roads after the precipitation froze again, Ryniewicz said.

The town of Vernon budgeted about $100,000 for salt and spent all that was budgeted, using another $54,000 in Town Aid Road Grants that come from the state, he said.

Ryniewicz said the cost of salt increased in the last year, and there is only one supply contractor bid in the area through the Capitol Region Council of Governments, or CRCOG.

South Windsor Town Manager Michael Maniscalco said his town also did not receive much snow, but the duration and timing of precipitation coupled with sharply falling temperatures caused the town to use more salt than usual.

South Windsor’s remaining salt, which is stored in a shed under a cover, will be saved for next winter, he said.

Maniscalco said the town has spent $147,245 of the current snow removal budget, which originally started at $430,630.

The remaining $283,385 will be transferred to cover overages in other budget line items, he said.

Maniscalco added that any money still leftover would be swept into the town’s general fund balance.

Suffield Public Works Director Chris Matejek said the mild winter ended up saving his department about $100,000 compared to last year. The savings came in the form of less overtime and less money spent on outside contractors.

This winter the department spent about $67,000 on overtime for employees, compared to $100,000 last winter, and spent about $77,000 on contractors, compared to $147,000 last winter.

Matejek said the milder weather meant the department didn’t need to purchase as much salt or use as much fuel, but the savings were offset by inflation.

Although the department saved money, he doesn’t see the situation as leading to “extra” money. He’s not going to take that $100,000 and buy something else. However, the department does need some new equipment, such as a dump truck, to keep the fleet from growing too old, and any savings now could help obtain that down the road when town leaders analyze the budget, Matejek said.

While the figures aren’t tabulated yet in East Hartford, Mayor Mike Walsh said his town likely spent less money for snow-related costs this season compared to last. Overtime savings are difficult to track because the costs would be shifted to other tasks, he said.

“We house all overtime as one number, so that includes leaf collection, cleaning up parks in the spring, and snow removal,” Walsh said.

Walsh said any surplus in road salt means savings, since the town can buy less next season.

East Windsor Finance Director Amy O’Toole said that town doesn’t have a separate snow removal fund. Money used for snow removal is allocated under road maintenance.

There is currently $185,000 remaining in the original $300,000 road maintenance account, O’Toole said. East Windsor also has $130,000 allocated for salt and sand, and $126,000 of that was spent this winter.

“What we don’t spend in the salt and sand line, we spend out of the road maintenance for either drainage projects or road maintenance,” O’Toole said.

Coventry Town Manager, John Elsesser said he is not clear yet on how much money they may have left over, but he knows that next year there will be a full shed to start out with.

“Between three-quarters and a full shed is standard,” Elsesser said.

“I talked with our public works director, and we have some obligations for purchasing additional salt,” he said. “You have to commit to a certain amount, so we’ve ordered that.”

Elsesser said the town would use any excess money to purchase items requested for next year to get them out of the budget proposed for next fiscal year and minimize any potential increase.

“We’re looking at having a good use of funds for necessary things to save taxpayers money in future,” he said. “We’re buying as much salt as possible because we expect prices will continue to go up. Kind of like keeping your oil tank full.”

Somers also contracts annually for road salt through CRCOG and has a special revenue account for road maintenance.

Public Works Director Todd Rolland said the town’s expenses from that account includes winter road salt, tree trimming and removal, road patching, crack sealing, guide rail repairs, road line stripping, sign repair and replacement, drainage structure and catch basin repair work, catch basin cleaning, and engineering for larger projects.

For years when winters aren’t too bad, he said, Somers uses the money it didn’t spend on road salt for road maintenance projects, as there is always more work to be done.

Rolland said the town does not break out separately what is left over in snow removal expenses.

Windsor Town Manager Peter Souza said his town appropriated $397,000 for snow removal this past winter between two accounts.

A state grant funded $145,000 and the remaining $252,000 was budgeted in the general fund balance.

Between the two accounts, $156,000 remains. Souza said the $61,000 left in the general fund would be transferred to the town’s unassigned fund balance.

The $95,000 in state funds could be used to replenish salt supplies for the upcoming year.

Salt that wasn’t used this winter will also be stockpiled for the next season.

Journal Inquirer Staff Writers Collin Atwood, Susan Danseyar, Matthew P. Knox, Joseph Villanova, and Jamila Young contributed to this story.

Atlas Salt drill results point towards impressive economics (thearmchairtrader.com)

Atlas Salt [TSXV:SALT] has drilled 305.5 metres of a massive salt deposit which sits in an eastern step-out at its Great Atlantic project. This is grading at 95.56% of sodium chloride. The drill hole is being hailed as "truly extraordinary" by CEO Roland Howe, both in terms of shallowness, thickness and grade profile. There is very high purity salt near the bottom of the drill hole.

Atlas Salt owns 100% of the Great Atlantic salt deposit strategically located in western Newfoundland in the middle of the robust eastern North America road salt market, a market which STILL amazingly imports expensive salt from South America for winter road gritting.

The project features a large homogeneous high-grade resource located immediately next to a deep-water port. Atlas is also the largest shareholder in Triple Point Resources as it pursues development of the Fischell’s Brook Salt Dome approximately 15 kilometres south of Great Atlantic in the heart of an emerging clean energy hub.

At the end of January Atlas Salt released a PEA which includes a pre-tax internal rate of return (IRR) of 22%; NPV of $909 million and payback in 4.2 years after commencement of operations. The base case is for a 2.5 million tonnes per year (Mtpa) production for a 30-year mine life with a mine and processing design to accommodate expansion up to 4 million tonnes per year and capable of extending the mine life beyond the 30-year standard production model.

The stock has already been one of the best-performing picks in The Armchair Trader's small cap venture portfolio.

Freshwater ecosystems are becoming increasingly salty. Here's why this is a concern (theconversation.com)

Freshwater ecosystems around the world are becoming saltier and saltier. Many human-driven factors contribute to freshwater salinization, including: irrigation, oil extraction, potash mining, and road de-icing.

As a result, salts enter waterways. But as bad news never comes alone, the salts are often accompanied by a toxic cocktail of other pollutants, whose combined toxicological effects are largely unknown.

Although the problem of rising freshwater salinization went largely unaddressed for many decades, it has gained considerable attention during the last 20 years.

Scientists around the world are working together to understand the ecological impacts of increasing salinization on aquatic biodiversity and food webs. Our ultimate goal? To examine the adequacy of water quality toxicity thresholds for the protection of aquatic life.

Salinization, a major problem

Canada is home to a majority of the world’s freshwater resources, mostly concentrated in the provinces of Ontario and Québec, where close to 5 million tons of road salt are applied annually to de-ice roads.

Combined with climate change and increasing frequency and duration of drought in many regions of the world, the problem is getting worse. This is a major concern. Why? Because the availability of freshwater resources will become a critical factor for humanity over the next 50 years.

Researchers from around the world mobilized

We recently presented a series of articles in a special issue on freshwater salinization in the journal Limnology and Oceanography Letters, published last February.

In this special issue, we focus on sodium chloride (NaCl), the same molecule found in table salt, as a key agent of freshwater salinization. We highlight a series of co-ordinated field experiments, conducted by researchers in North America and Europe, that have addressed the impacts of freshwater salinization on zooplankton (microscopic crustaceans) at a regional scale.

Zooplankton are an ecologically critical group in aquatic food webs and are often used as indicators to detect environmental change due to their sensitive ecological tolerances.

The main conclusions of these experiments are as follows:

• Water quality guidelines in Canada and the United States (standards) do not adequately protect freshwater zooplankton, which could lead to an increase in the abundance of algae, which the zooplankton feed on. This is because when zooplankton abundance decreases, especially for large grazers such as Daphnia, phytoplankton can proliferate under conditions of reduced predation;
• Salinization of freshwater systematically leads to a loss of abundance and diversity of zooplankton in all regions; and
• Individuals of the same zooplankton species do not all exhibit the same tolerance to salinity. Thus, this variation may interfere with our ability to predict community-level responses. Water quality guidelines may therefore need to be adjusted to become more region-specific.

A matter of regulation

Many questions remain unanswered. However, what we do now know is that long-term water quality guidelines (Canada: 120 mg Cl⁻¹L⁻¹; United States: 230 mg Cl⁻¹L⁻¹) and in the short term (Canada: 640 mg Cl⁻¹L⁻¹; United States: 860 mg Cl⁻¹L⁻¹) for chloride concentrations are too high to protect aquatic life in Canada and in the United States. For reference, a pinch of salt in a pot of water corresponds to approximately 0.3 mg of Cl⁻¹/L⁻¹. In other words, adverse effects are observed at much lower concentrations. Regulations in Canada and the United States should therefore be reviewed. In Europe, the water quality standards for salinity for the protection of aquatic life in freshwater ecosystems are mostly absent.

The importance of taking concrete action

Water quality guidelines for the protection of aquatic life are generally established using laboratory tests (called toxicological tests) on a single species.

However, aquatic habitats harbour a complex array of predators, prey, competitors, and pathogens, the interactions of which can limit our ability to predict the responses of communities and species to pollutants .

Thus, the collective research published in this special issue also highlights the importance of understanding ecological responses in multi-species communities in natural settings to assess the responses of freshwater life to human impacts.

Overall, we should develop alternative applications and technologies that are more sustainable and efficient.

We also need to establish more appropriate water quality guidelines to improve controls on salts entering our freshwater environments to reduce adverse effects on aquatic life and the quality of our freshwater resources.

Can sugar melt snow like salt? Which other substances can? » Science ABC

Going sledding, making snowmen, and having snowball fights are some ideal ways to enjoy winter weather. However, you might not feel the same way when that snow covers your driveway, roads, and roofs. It is frustrating and time-consuming to clear out all that snow!

Salts can help us tackle these problems.

Rock salt, also known as Sodium chloride or Brine, and other anhydrous salts like magnesium chloride and calcium chloride, are used in bulk quantities by the government to melt road snow during winter. The salts used for melting snow on pavement are commonly known as ‘Deicers’ or ‘Road Salts’. They cannot be consumed like edible salts.

Water freezes at 0⁰C, and at this temperature, ice and water, i.e., the solid and liquid states, are in equilibrium with each other. When we add salt (any salt) to water, it dissolves in it and causes a phenomenon called ‘Depression in Freezing point’.

This is a colligative property shown by solvents like water. Hence, the water that was supposed to freeze at 0⁰C  will now freeze at a lower temperature (say -10⁰C), depending on the salt concentration. So, if the atmospheric temperature is 0⁰C, snow will melt instead of remaining in its solid form.

The snow during winter storms is not 100% solid. It is soft to the touch, which signifies that the water has not completely frozen. The deicers get dissolved in these small water cavities and melt the snow. A small concentration of salt is enough to melt a large chunk of snow. Road salts form a major commercial product in countries with annual snowy winters, like the USA, Canada, United Kingdom, etc. The United States annually utilizes NaCl and other Chloride-based road salts worth roughly 24 million dollars.

Can Sugar Melt Snow?

At the freezing point of water, molecules of water lose their kinetic energy and solidify, forming a crystalline structure. As more and more molecules are attracted, they become compact and develop a strong attraction due to Hydrogen bonding. As seen in the figure, there is a relative decrease in the intermolecular distance when water goes from liquid to ice.

This intermolecular distance is disrupted when we add any soluble solutes, like salts. Molecules that dissolve in water overcome the attraction between water molecules and get squeezed between them. As a result, the attraction between like molecules decreases, and it takes even lower temperatures to solidify.

Sugar, i.e., sucrose, readily dissolves in water, so it can also cause a depression in the freezing point of water. However, sucrose doesn’t dissociate into its constituent ions, but instead remains as an uncharged disaccharide. On the other hand, salts ionize into their constituent ions, e.g., MgCl2 –> Mg²⁺ + 2Cl^–, and easily displace themselves between water molecules.

Depression in the freezing point depends on the number of solutes present in the solvent: the more solute particles, the greater the lowering of the freezing point.

Therefore, although sugar can melt snow, it cannot do it as effectively as salts.

Why Are We Looking For Alternatives?

After the snow melts, it is cleared either by the steady stream of vehicles or the flow of water into the nearest drainage system. However, the problem is that the salt on the road can negatively impact the environment.

Most road salts are chloride-based salts. Chloride is a nemesis for vehicles, as it initiates corrosion-induced degradation. Chloride absorbs moisture, thus speeding up the rate of corrosion.

The salts that remain in the water enter nearby water bodies and can disrupt aquatic ecosystems. Water bodies near cities are usually freshwater resources like rivers, lakes, and ponds; if salts enter these reservoirs, they reduce dissolved oxygen (DO) and endanger aquatic life. Increased salinity results in a toxic algal bloom by killing algae-eating zooplankton.

One might think that salts are everywhere in the environment, especially chloride salts, which are essential for living cells. Yes, this is true, but to give you some perspective, these salts are used by the millions of tons each year. Hence, the amount of salt entering the environment untreated is beyond permissible levels. Therefore, we need to look for alternative salts or snow-melting systems that cause less harm to the environment.

What Are Some Other Alternatives?

Commonly used chloride alternatives are:

• Beet sugar
• Glycols
• Molasses
• Corn-derived polyols like mannitol, sorbitol, maltitol
• Hydronic, electric and infrared lamps.

Brine salt is found naturally, while other chloride salts can easily be extracted from minerals. Hence, to minimize the effects of these salts, additives are added instead of bulk-producing new salts.

These additives are bio-based, so they degrade easily in the environment. Beet sugar, glycols, and molasses have been proven to show good deicing properties. Agro-based additives, especially corn-derived polyols like mannitol, sorbitol, and maltitol, have proven to be suitable additives to brine salt, which bring about a good depression in the freezing point of water.

Apart from chemicals, machines can also melt snow. Spraying steam and hot water on accumulated snow proves to be effective and eliminates the manual task of removing snow. Hydronic, electric and infrared lamps are found to do the same for pavement surfaces, sidewalks, and bridge decks.

Finding alternatives for chloride salts has been challenging researchers, mainly for 2 reasons: cost and energy. The additives mentioned above are costly to produce in such bulk quantities and machines are energy-intensive tools. Thus, finding a perfect alternative that ticks all the boxes is an ongoing challenge.

A Final Word

Snow is melted by manipulating its freezing point depression, often through the use of soluble solutes like salts and sugars. The concentration and atmospheric temperature also play an essential role in the effectiveness of these deicers. Commercial NaCl deicer can’t melt ice below -10⁰C. Hence, various salts and additives are added to melt snow in extreme temperatures, while having a less harmful environmental impact.

These hidden dangers lurk in massive snow piles left by plows | Watch (msn.com)

Having trouble finding road salt on the Avalon Peninsula? Here's why | CBC News

Winter hasn't slipped away just yet, but some living on Newfoundland and Labrador's Avalon Peninsula have found it difficult to locate one of the season's hottest commodities — road salt.

The culprit? Tens of thousands of faulty road salt bags, says Morgan Winter, vice-president of Avalon Coal Salt and Oil.

The Bay Roberts company provides a lot of the province's salt, typically found at gas stations and grocery stores in large, bright orange bags.

This year, Winter says, he thought he had his business's inventory in the bag. But it turns out he was sandbagged by the company's manufacturer.

He says the company discovered in the fall that it had been supplied tens of thousands of faulty 10-kilogram bags. Winter estimates the faulty bags made up about 50 per cent of what the company ideally likes to have in its inventory.

When the company went back to its supplier, says Winter, it discovered the lead time to get new salt bags would be longer than anticipated. Although the company also sells five-kilogram and 20-kilogram salt bags, Winter says the 10-kilogram bags are their best seller.

"If I don't have a bag to put the salt in, that slows down everything," said Winter. "We pretty much sold through everything we had in inventory, I want to say, two or three weeks ago."

"We don't operate that way. Normally we would have a 50 to 75 per cent cushion on what we would sell."

For those on the hunt for salt, Winter says 20-kilogram salt bags may be available at large retailers and hardware stores, and he even suggests seeking salt from his competitors.

The best places to go for salt are large building centres like Home Hardware, Kent and Home Depot, he said, as salt is likely in low supply at many gas stations.

Winter looks at this year's supply shortage as a learning lesson, one that can help prevent future slip-ups.

"We will be pre-ordering in April, and I would think we'll start ordering a two years' worth of inventory at a time just to get ahead of this problem."