BIOSOLIDS : Fertilizer from Human Waste

Sounds interesting…What is that?

Biosolids

Biosolids is the term to describe digested human waste. “The users of the Toronto wastewater system generate about 195,000 tonnes of biosolids every year ” [City of Toronto]. That’s a lot of waste! Luckily, there is another route for these biosolids besides being disposed into landfills or oceans or being incinerated and that is: sustainable agricultural fertilizer. 

BENEFITS

As mentioned previously, reusing biosolids can be a step to helping our environment. Instead of taking more space in crowded landfills or harming marine life that comes across our waste in their aquatic homes, it is put in areas where it can serve another purpose. The composition of this material is rich in organic matter and nutrients, and has high capabilities as fertilizer for plants since it increases the health of the soil (e.g. balance moisture). Biosolids provide crucial micronutrients (e.g. zinc, copper, iron) and macronutrients (e.g. nitrogen, phosphorus, potassium). It does this over a span of several years after its application. This also means that there is a smaller need for chemical fertilizers which can cause groundwater contamination. Since biosolids enrich the soil and promote vegetation growth, there is less soil erosion and sometimes actually decreases groundwater pollution of nitrogen and phosphorus. Also, it has potential for new jobs.

CONS

With so many benefits, naturally there are some disadvantages. The first issue most people may be concerned with is odour. Naturally we know that human waste can smell bad, and we could guess what would happen if left out in the open for a long period of time. There are treatments done to it to filter through the waste and reduce the malodour but not all of it disappears, especially if not treated properly. There is always the risk of pathogens and unknown hazardous chemicals if the strict criteria are not met if someone decides to apply it to their own land. One mistake and it could cause widespread harmful effects towards health. It is not easy to reverse the process or effects of using biosolids as fertilizer.

IS THIS THE RIGHT APPROACH?

Biosolids are dispersed into the soil

Using biosolids from sewage treatment plants for agricultural fertilizer is a realistic  and relatively green approach but it will take a lot of effort to get others to accept this agricultural practice, especially changing the some of the deep mindset of Westerners that the negative effects like odour and the thought of using human waste to plant new crops are not worth the effort to change. Stakeholders of this issue are not limited to the citizens, although some feel they are the only one affected by this. Others include: land owners, biosolids generating workers, chemical fertilizing industry workers, government members, and other organizations. They all have a part in this issue and may support different sides. 

 During this time when being environmentally-friendly is an significant subject, using biosolids for fertilizer would be an effective technique of decreasing negative human impacts on earth and improving the agricultural soil and crops.

WORKS CITED

• http://www.toronto.ca/water/biosolids/index.htm
• http://www.cwwa.ca/faqbiosolids_e.asp
• http://www.compost.org/Biosolids_Composting_FAQ.pdf
• http://www.nebiosolids.org/index.php?page=faqs
• http://www.omafra.gov.on.ca/english/nm/nasm/info/brochure.htm

IMAGES

• http://www.melbournewater.com.au/images/sewerage/biosolids_01.jpg    
• http://biosolids.agsci.colostate.edu/Pictures%20Used/Byers/application.jpg    
• http://biosolids.agsci.colostate.edu/Pictures%20Used/Byers/Slide2.JPG 

COMMENTED ON

 Michelle F. 

 Amanda Y.