Human Practices

The team focused on evaluating the feasibility of the 4 proposed project applications: production of PHB on Mars from human waste, integrating PHB production in a wastewater treatment plant, integrating PHB production with leachate treatment, and integrating PHB production in developing countries.

  Landfills

Landfill leachate treatment is an avenue that we considered when looking at possible applications of our project on Earth. Leachate feedstock is rich in organic matter. It is highly toxic water produced during the decomposition of waste, which becomes dangerous to the environment when left untreated and can leak to the groundwater, causing contamination.

Conventional technologies used in leachate treatment do not include the production of value-added products and such technologies appear to be concerned with the simple removal of toxic, undesired components. Leachate transfer involves recycling and combined treatment with domestic sewage, biodegradation involves aerobic and anaerobic processes for waste decomposition, chemical and physical methods involve chemical oxidation, adsorption, chemical precipitation, coagulation/ flocculation, sedimentation/flotation and air stripping. Integrating a PHB-producing stage into conventional leachate treatment would facilitate the production of PHB out of the waste, cutting down the cost of treatment and allowing the facilities to become profitable. One problem associated with this feedstock is that it is a nutrient rich medium, which decreases the rate of PHB production in our bacteria. This would mean that the leachate would have to be treated to remove phosphates and nitrates prior to entering a bioreactor containing the bacteria.

  Wastewater Treatment Plants

Our project was initially aimed at providing a method by which wastewater treatment facilities could take biological material in wastewater and transform it into value-added product in the form of bioplastic. Part of our integrated human practices included a visit to our local wastewater treatment facility. Pine Creek is a new wastewater treatment facility in Calgary which treats sludge to produce methane, and uses the treated product as a fertilizer.

This tour served the purpose to gather information regarding this application. Sludge produced during conventional municipal wastewater treatment is an organic rich material that looks promising for the PHA production industry. Currently, sludge is treated to remove organic matter (lower chemical oxygen demand (COD)) and toxins. Removal of organic matter is achieved by fermentation, where the organic matter is broken down into volatile fatty acids (VFAs), and is afterwards digested by bacteria to produce methane and carbon dioxide. Research was conducted on the use of sludge as a feedstock for PHA production and showed the process to be feasible and at times economical. One of the major downsides of the most common PHA production method is the use of toxic chemical - chloroform in the extraction and purification of the PHA plastic. We also found that, along with the extraction and purification expenses, the profitability of this option was not ideal.

  Developing Countries

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  Space

While the previously mentioned feedstock is a promising source of high volumes of VFAs, the cost of treatment facility implementation and running is high, the level of control for the maintenance of the pure E. coli culture might be considered inadequate, thus lowering the economic feasibility of the project implementation. Additionally, alternative methods of treatment of the above mentioned waste streams were investigated and proven to work, thus making the project idea less novel and necessary in development.

The implementation of the PHA production process in space is a novel solution in the treatment of the solid human waste is space. Currently human waste is left untreated and is transported back to Earth, where is it burned down. NASA have been investigating different ways of utilizing human waste during space expeditions and on Mars, yet the use of human stool in the production of PHA plastic was not yet discussed, thus making the project idea novel and worthy of investigation. Furthermore, the high level of sterility of the process and the pure bacterial culture utilization can be better explained in the space application. The PHA plastic produced in space, can then be used in the 3D printing of worn out parts and other necessary details.

Engagement

Collaborations

SAFETY