Waste management professionals must prioritize dust control. Staying on top of the matter helps them adhere to environmental regulations and manage human health risks. Here’s a helpful overview of what people in this industry should know about dust control and why it’s important.
Which Waste Management Activities Can Cause Dust?
Some dust-generation activities at landfills or recycling and waste management sites occur due to traffic and processing activities at those sites. This fugitive dust gets suspended in the air and often, but not always, comes from the soil.
One dust management plan for a United Kingdom landfill broke down the expected sources. It identified 10 types of fugitive dust originating from:
- Waste management vehicles and waste-tipping activities at the landfill
- Waste transfer to a nearby recycling facility
- Suspended particles after waste transfer occurs, particularly during dry conditions
- Particles stemming from waste processing, crushing and sorting at the facility
- Soil excavation and overburdening at the waste site
- Uncovered or partially covered waste carried by moving industrial vehicles
- The placement of soil and clay used for landfill capping and restoration
- Excavated aggregates, including sand and gravel, transported to processing areas
- Material stockpiles at waste storage sites, mainly during windy conditions
- The usage of conveyor belts to move waste through processing facilities
This list shows that the people responsible for dust control at a facility must take an all-encompassing approach to assessing the possible trouble spots and mitigating the issues. Controlling dust starts by knowing when, where and why it originates.
The Link Between Effective Dust Collection and Worker Health
Research indicates that waste management workers could face respiratory risks if their employers don’t take the right steps to manage occupational dust.
One study of workers tasked with removing household and roadside waste examined their likelihood of exposure to respirable crystalline silica (RCS) dust. The researchers’ primary conclusion was that overall exposure levels were low. However, they confirmed that factors ranging from the season to the workers’ roles impacted the risk. For example, they said employees who used blowers to handle road waste were at higher risks of breathing in RCS dust.
If a waste management facility handles materials from demolished buildings, people must take precautions to avoid asbestos dust exposure. Buildings constructed before 1980 may contain asbestos. It’s also found in items people may not expect, ranging from hair dryers to theatrical curtains and fire-protection clothing.
If waste management facilities handle such products made before 1980, they should only allow people to work with them after receiving the proper training and while wearing the necessary accessories.
Providing employees with personal protective equipment (PPE) is one essential step in combating dust exposure risks. However, decision-makers should also look at dust-containment products and teach people how to dispose of materials that may contain hazardous dust.
Containers used for hazardous materials must have labels, markings and placards to identify what’s inside. Certain designations exist for inhalation hazards and spontaneously combustible materials. Dust can fall into both categories.
Materials Types and Processing Can Exacerbate Dust
Evidence also shows that the processing methods for certain materials can increase dust-related issues. Plastic dust occurs when handling that material, including moving or crushing it.
People’s dependence on plastic has caused significant environmental issues. One truckload of plastic gets dumped into the ocean every minute. Research also indicates microplastics end up in household dust. Because plastics are so widespread in today’s society, they’re commonly seen in waste management facilities, and people working with them must take precautions.
Metal dust is another issue dealt with in recycling and waste management facilities. However, some common misconceptions are that it is always hazardous and difficult to recycle. Although people must decide whether to recycle it on a case-by-case basis, positive outcomes are possible.
Aluminum, magnesium and titanium are examples of combustible dust that needs specific collection and handling protocols to keep people safe. However, using dust collectors with passive float valves and explosion vents mitigates the risk of combustion.
Knowing which materials and processing techniques most often cause dust in a facility is a practical step in controlling the risks. Some machinery used to handle waste includes integrated dust collectors, which further assists in the efforts.
Choosing Dust Collectors
Dust collectors in facilities are some of the most widely used control measures. Dry dust collectors work when particles enter them and get captured by internal filters. Compressed air periodically knocks the dust off the filters and into a hopper. It then goes into a container that people must empty regularly.
Then, wet collectors capture dust through impingement with water droplets. This method is most effective on smaller particles. The water and dust go into a settling tank where the particles separate due to gravity or get skimmed off the top of the liquid. This dust control option requires keeping the dust concentration in the water below 5% to maintain proper system performance.
Dry collectors are generally best for large airflow systems and heavy loading applications, as well as particles with a dust deflagration index (Kst) value lower than 150. They’re also often more efficient than wet collectors. However, wet collectors are necessary for controlling the risks of combustible dust or dealing with sticky particles and those with Kst values higher than 150.
Internet of Things (IoT) dust collectors are also relatively new arrivals to the market. They give real-time dust collector performance data to users. These options also send maintenance alerts, helping facility managers deal with hopper obstructions and full containers faster.
Examining Other Measures
Although dust collectors installed inside facilities are popular options, other possibilities exist, too. In one example, a demolition company equipped its excavator with an on-board dust suppression system.
Another instance involved a recycling center initially using a sprinkler system for dust suppression. However, that approach proved ineffective because it saturated the materials and caused pooling around machinery. The facility eventually invested in a solution that uses atomized mist for dust control. It installed it near its debris-sorting line, which caused a marked improvement.
Evan Williams, a project designer with Cambridge Companies/Design-Build Solutions, suggests using a misting system in tipping areas, saying it helps with both odor and dust control. He continued, “These systems can typically be designed and installed in a matter of a few weeks.”
Some facilities also use fogging systems, which are different from misting systems due to their smaller droplet sizes. Flash evaporation means materials and the surrounding environment stay dry. Many fogging systems feature water conditioners, particle filters and ultraviolet disinfection systems.
The dust management plan for the United Kingdom facility mentioned earlier also had some relatively low-tech solutions. They included ensuring all loads on trucks have appropriate sheeting covering them before the vehicles start moving. Additionally, the site enforces a maximum speed limit of 15 miles per hour to reduce road dust issues.
Dust Control Is Essential in the Waste Management Sector
This overview explains why people working in waste management or recycling facilities cannot overlook dust control. Staying on top of it creates a healthier work setting and reduces environmental risks within or outside of facilities.
Emily Newton is an industrial writer who specializes in covering how technology is disrupting industrial sectors. She’s also the Editor-in-Chief of Revolutionized where she covers innovations in industry, construction and more.