June 3, 2011

Biosolids - Human Waste as Fertilizer

It's easy to harshly pass judgement on the idea of biosolids - they are, quite plainly, treated sewage.  The idea may seem gross or unsanitary to some, but it's important to remember that learning more should come before decision-making and opinion-forming.

For this reason, it is important to answer: What exactly are biosolids?
As stated above, biosolids are treated sewage, particularly nutrient-rich organic materials that are produced from the treatment of domestic sewage, in a treatment facility of course.  These materials can be processed and recycled to be used as fertilizer, resulting in productive soils and stimulated plant growth.  Biosolids can also be returned to the environment in other ways.

An in-depth look at how biosolids are treated.
(Click here for bigger version.)
The domestic wastewater generated from sewage treatment facilities is used to create biosolids.  Before even reaching the facility, it is possible for pre-treatment to begin, as this is sometimes mandatory for industrial facilities (to make sure they are void of any hazardous contamination).  The incoming wastewater is monitored; if the sewage can be treated and recycled, it is put through biological, chemical, and physical processes to remove solids and separate water.  Disease-causing and -transferring organisms  are controlled through sanitization.

It's the wastewater treatment process that's the reason why we have biosolids in the first place.  This treatment improves the quality of waters around Canada, due to regulations on dumping waste in bodies of water.  The wastewater now must be treated; biosolids recycled or buried in landfills.


Illustrating a positive of biosolids.
POSITIVES:
  • Crop production can be improved due to biosolids used as fertilizer
  • Water quality is protected
  • Landfill space is conserved
  • Cost effective and creates jobs (good for the economy)
NEGATIVES:
  • Health hazard due to possible dangerous chemicals
  • Contamination could easily occur due to improper treatment
  • Decreases property value
  • Odour (described as "distinct" and "like a sewer")


Actress and Halifax native, Ellen Page,
expressed her take on biosolids in NS.
Although the treatment processes biosolids are put through in order to ensure the safety of their use, the lack of knowledge on the material and its exact composition makes many people uneasy.  The use of biosolids caused a "stink" in August of last year when used in Halifax.  Ellen Page, a Halifax native, even came out to speak on the issue, saying: "It's taking industrial waste, waste from hospitals, businesses, households, full of man-made chemicals, highly toxic, proven carcinogens, radioactive material, and they're putting it on our soil.  They're putting it into our ecosystem."  The actress represented the views of many Haligonians, saying she would like to see more research and public input on biosolids.

I feel mixed on the use of biosolids.  I think that I would like to see more research and learn more about waste treatment in general before making a decision on their use. However, I think that biosolids, if completely safe, have a lot of potential in making improvements in the world, and a lot of negative feedback on the use of biosolids most likely comes from bias or misconception, especially the Western view that the use of waste in anything is gross and unsanitary.


Sources:

  • "Biosolids: Fertilizer or Pollution?" Lynchberg College Virginia. Apr. 2008. Web. 3 June 2011. <http://www.sencer.net/Outreach/pdfs/DCSymposium08/Posters/LUbiosolids.pdf>.
  • "Biosolids Management." City of Toronto. Web. 3 June 2011. <http://www.toronto.ca/water/biosolids/index.htm>.

  • "Biosolids.com | About Biosolids: Biosolids Benefits." Biosolids.com. 2002. Web. 03 June 2011. <http://www.biosolids.com/benefits.html>.
  • "CWWA - FAQ - Biosolids." CWWA/ACEPU. 2010. Web. 03 June 2011. <http://www.cwwa.ca/faqbiosolids_e.asp>.
  • News, Cbc. "Biosolids Cause Stink in HRM - Nova Scotia - CBC News." CBC.ca. 16 Aug. 2010. Web. 03 June 2011. <http://www.cbc.ca/news/canada/nova-scotia/story/2010/08/16/ns-biosolids-stink-halifax.html>.