Advances in medicine have made maintaining health and curing diseases possible with the use of pharmaceuticals such as antibiotics. However, the increasing use of these drugs have brought about concerns on the negative impact of pharmaceutical residues on the environment. Pharmaceutical residues mainly enter the environment through excretion, either as the original pharmaceutical compound, or as a by-product of that compound. If wastewater sludge is not treated properly, these compounds may make their way into rivers and oceans, or through the spreading of contaminated biosolids fertilizers on agricultural land. Thus, the public has voiced concern about human waste fertilizer dangers due to pharmaceutical residues.
These residues can either come in the form of the active ingredient, or derivatives of their metabolites after they have been excreted by the body. Human medications are not the only contributors; veterinary pharmaceuticals can also add to the residues found in wastewater. If not properly addressed, the use of recycled wastewater with pharmaceutical residuals may contaminate the soil and groundwater and negatively affect the ecological balance.
To address this issue, wastewater treatment plants (WWTPs) use multi-process methods to treat sewage sludge residuals. Normally, WWTPs have primary, secondary, and tertiary levels of filtration to turn the wastewater into biosolids that is suitable for agriculture. The primary treatment is a physical separation of solid materials from the sewage resulting in the production of a liquid effluent and solid sludge (biosolids). Secondary treatment involves biologic treatment of the wastewater byproducts. Tertiary treatment uses chemical and/or ultraviolet processes.
Pharmaceutical residues do not cause human waste fertilizer dangers because most chemicals are degraded during the treatment phase. There are studies that have shown that biosolids can contain substances like polybrominated diphenyl ethers (PBDEs, flame retardants), certain kinds of antibiotics, anti-inflammatory medications, lipid regulating, anti-epileptic, and anti-depressant pharmaceuticals, the antimicrobial compounds triclosan and triclocarban, bisphenol A and other plasticizers. However, the concentrations are low and range from a few parts per billion (ppb) to a few parts per million (ppm) to cause any hazard.
With advances in technology, along with continuing research in partnership between universities and the federal government, the Ontario Ministry of Agriculture, Food, and Rural Affairs has stated that “the use of biosolids continues to be safe.” The Ministry also focused on the creation of sewage by-laws and promotion of the responsible use and disposal of medications.
In addition, The Water Environment Association of Ontario, a group composed of water industry experts and government representatives, has concluded that using sludge presents little to no threat on health, the environment, and water quality.
This is good news for Ontario’s farmers, who utilize nearly half of the nutrient-rich sludge produced for use on 15,000 hectares of agricultural land. That amounts to nearly 120,000 dry tonnes of treated biosolids which the Ontario government provides them free of charge.
If you are a municipality in Ontario and in need of a biosolids management solution, please feel free to contact us at 1 (877) 479-1388.
Sources:
http://www.omafra.gov.on.ca/english/
https://www.weao.org/
http://www.biosolids.com/benefits.html