What are BioBullets?

The BioBullet is a novel and effective method of killing zebra mussels. Invented and founded in 2003 [1] , the BioBullet provides a way to effectively kill zebra mussels by encapsulating toxic chemicals into microscopic particles and releasing them into water. While other commonly used chemical treatments are non-specific and can harm other species in the ecosystem, BioBullets present a novel solution that is both effective in controlling mussels and environmentally friendly. With BioBullets, potassium chlorine is encapsulated into microscopic particles that are ingested by the mussels. Using microencapsulated particles is effective method of mussel control, as zebra mussels will easily ingest the particles instead of closing its valves like it tends to when treated with mass chlorine [2] . This method is similar to a Trojan horse, fooling the zebra mussels into eating them. After ingesting the BioBullets through their gills, they are transported to the stomach, where the BioBullets dissolve and release a lethal dose of the toxin. The figure (1) below shows exploitation of mussel's defense system.

Figure (1): Exploiting bivalves filtration ability by encapsulating toxins.
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To create the microparticles, the active ingredient and the encapsulant were mixed and placed in an atomic cooling chamber. As the particles cooled, they formed spheres and would fall to the bottom of the chamber, where they would be further cooled and discharged to a fluid bed processor and coated with a nonionic surfactant to help the particles disperse in water [3] Each microencapsulated particle is about 50 micrometers in diameter, and is made out of 8 different materials, consisting of vegetable oil, silica, and other materials. These materials are used in order to ensure neutral buoyancy of the particle, food-grade surfactants and a tasty coating. By covering the particles with the tasty vegetable fat, mussels are tricked into eating them.

Advantages

By taking advantage of the filtration capabilities of the zebra mussels, it is possible to greatly reduce the amount of toxins needed to kill mussels. Since mussels are efficient filter feeders and concentrate particles within their bodies, their filtration will minimize the lethal concentrations needed to kill them [4] . Furthermore, understanding mussel's filtration tactics provides the opportunity to use water-soluble toxins that were not suited for massive water treatments. With microencapsulation design, the toxins can be designed to degrade rapidly, minimizing pollution of the water and ecosystem as well. Any BioBullets that are not eaten by mussels will dissolve into harmless particles, which will not affect water treatment processes or water quality. According to Aldridge, encapsulation results in 1000x less products than freely dosing treatments[5] . By using BioBullets, only a single treatment rather than continuous dosing over a couple of weeks is needed. As a result, less chemicals are needed.

Figure (2): Micro-encapsulated BioBullets Particles.
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As previously mentioned, encapsulation tend to overcome mussel's defensive valve-closing behavior, there by increasing its susceptibility to the encapsulated active ingredient[6] . Thus, the employment of BioBullets could provide operational, economic and environmental benefits compared to traditional biofouling treatments.

Potential Implications

In the pilot studies, potassium chloride was used as the active ingredient inside the BioBullets. In low doses, it was found to have caused no effect to fish and other organisms. However, it was observed as being toxic to mussels. This is because potassium interfere with the zebra mussels' respiration and cell membranes. [7] . On the other hand, BioBullets leach up to 90% of their KCl within 150 minutes. If it is not consumed by mussels, the concentration rapidly drops to levels safe for other organisms. KCl is also fully approved for use in drinking water treatment.

In Aldridge’s pilot study, it was found that within a single dose of 12 hours, the mortality rate of the mussels was 60% with no other species being harmed. It was not expected to have a 100% kill rate, as the time period was fairly short and there was a possibility that not all mussels were feeding during that period. Thus, BioBullets have the potential to offer a viable alternative to chlorination in the control of zebra mussels. The concept of BioBullets could have the potential to completely change the approach of chlorine treatments and controlling mussel populations. With the introduction of this new product, it is possible that greener technology will reduce toxins and pollution to the environment while effectively controlling the biofouling problem of zebra mussels worldwide.
  1. ^ “About Us”, Biobullets.
    Retrieved From: http://www.biobullets.com/about-us/
  2. ^ Claudi, R. & Mackie, G. L. 1994, Practical manual to zebra mussel monitoring and control. Boca Raton, Lewis Publishers
  3. ^ Aldridge, D. C., Elliott, P., & Moggridge, G. D. (2006). Microencapsulated BioBullets for the control of biofouling zebra mussels. Environmental science & technology, 40(3), 975-979.
    Retrieved From: http://www.protectyourwaters.net/news/data/ZM%20Factoids.pdf
  4. ^ Costa, R., Aldridge, D. C., & Moggridge, G. D. (2011). Preparation and evaluation of biocide-loaded particles to control the biofouling zebra mussel, Dreissena polymorpha. Chemical Engineering Research and Design,89(11), 2322-2329.
    Retrieved From: http://dx.doi.org.ezproxy.lib.ucalgary.ca/10.1016/j.cherd.2011.02.027
  5. ^ “Products”, Biobullets.
    Retrieved From: http://www.biobullets.com/products/
  6. ^ Costa, R., Aldridge, D. C., & Moggridge, G. D. (2011). Preparation and evaluation of biocide-loaded particles to control the biofouling zebra mussel, Dreissena polymorpha. Chemical Engineering Research and Design,89(11), 2322-2329.
    Retrieved From: http://dx.doi.org.ezproxy.lib.ucalgary.ca/10.1016/j.cherd.2011.02.027
  7. ^ Warwick Fisher, S., Stromberg, P., Bruner, K. A., & Boulet, L. D. (1991). Molluscicidal activity of potassium to the zebra mussel, Dreissena polymorphia: toxicity and mode of action. Aquatic toxicology, 20(4), 219-234.
    Retrieved From: http://www.sciencedirect.com.ezproxy.lib.ucalgary.ca/science/article/pii/0166445X9190061D