There are many interesting facts about biosolids use. For example, biosolids have given communities a chance to make use of an otherwise undesirable waste products found in sewage. But what exactly are biosolids and how are they different from sewage sludge? In general, sludge is the material that is recovered from sewage as it is being processed in the treatment facility. Once the process of treatment is completed, the by-product is referred to as biosolids. Below are some other interesting facts about biosolids use that you may not be aware of.
How are biosolids produced?
Biosolids are the nutrient rich organic materials and the major by-product of the wastewater treatment process. In Ontario, industrial and institutional facilities are required to pre-test and test their wastewater to remove hazardous contaminants before it is discharged to the sanitary sewer system. To ensure their compatibility with the treatment process, the wastewater treatment facility monitors incoming wastewater streams. The wastewater then goes through several processes (physical, chemical and biological) that remove the solids from the water. The solids are then heated during the digestion phase to curb the pathogens and other harmful microorganisms. When treated and processed, the biosolids can be disposed of at landfill sites or used as fertilizers on agricultural fields.
Where do biosolids end up?
There are many management options for biosolids in Ontario. The most common are landfill disposal, incineration and beneficial use on agricultural land of liquid, dewatered or further processed forms of biosolids. Agricultural land application is one biosolids use that is not only beneficial for crops, but also the most environmentally sustainable. In Ontario, land application is the most preferred biosolids management option. More than 80% of Ontario municipalities use this method. Land application takes advantage of the nutrient and soil conditioning value of biosolids. These properties are used to enhance soil fertility and crop growth.
Do biosolids smell?
Among other interesting facts about biosolids is their smell. The odour emitted by biosolids depend on the compounds that are found in the wastewater, as well as the type of treatment it has undergone. Some biosolids may have an “earthy” aroma while others will be described as having a strong ammonia odour. The smell that comes from biosolids is the result of sulfur compounds and ammonia, both of which are plant nutrients. However, the odours can be effectively managed through various physical and chemical processes. Smell can also be minimized by incorporating the biosolids into the soil immediately during application.
What are the benefits of biosolids?
Biosolids have many benefits for the environment. They are used to fertilize fields for growing crops. The agricultural lands where biosolids have been applied show significant improvements in crop growth and yields. Nutrients found in biosolids such as nitrogen, phosphorus, potassium and trace elements such as calcium, copper and iron are necessary for crop production and growth. Biosolids enhance structure, moisture retention and soil permeability. They also add organic matter that helps maintain good soil tilth and reduce the potential for soil erosion. The use of biosolids reduces the need for commercial fertilizers thus helping lessen the negative impact of synthetic chemicals on environment, as well as lowering the cost of production for farmers (some cities offer biosolids for free). Because of carbon sequestration and the reduction of greenhouse gas, the use of biosolids can also help mitigate climate change. Biosolids are also an environmentally desirable solution for covering up landfill space. They can serve as a quality cover material and work best when mixed with dirt and mulch.
If you are a municipality in Ontario and in need of a biosolids management solution, please feel free to contact us on 1 (877) 479-1388.
Sources:
http://www.cwwa.ca
https://www.ontario.ca
http://www.omafra.gov.on.ca