What are Biosolids used for?
Biosolids have many uses. They may be used as a fertiliser and soil improver on crops produced for food or as a base for garden fertilisers and mulch for parks, gardens and the home. As science and technology improves and as biosolids gain acceptance as a valuable resource not a waste, many new and exciting uses are being identified including:
- Co-generation/power production/energy recover
- Land application in agriculture (vine, cereal, pasture, olive)
- Road base
- Land application in forestry operations
- Land rehabilitation (including landfill capping)
- Landscaping and topsoil
- Composting
- Incineration
- Landfill
- Oil from sludge (experimental)
- Jewellery
- Additive to road base
Other uses overseas include:
- Bricks and construction material
- Vitrification (glass manufacture)
- Bio-fuel
- Fuel substitute (cement works)
- Additive to road base
- Jewellery
- Electrical generation – “Power from the Bottom Line”
In Western Australia, biosolids are disposed of or reused in the following ways:
- Incineration lessening disposal requirements, destructing pathogens and toxic constituents and providing energy recovery potential;
- Landfill application or spreading of biosolids on agricultural land, forest land or dedicated land disposal sites;
- Composting where biosolids undergoes biological degradation and can be used as a fertilizers or sol conditioners in agriculture or horticulture;
Are their grades of Biosolids?
There are various grades of biosolids depending on the level of pathogens that may remain after processing as well as the amount of heavy metals contained in the biosolids. Higher grades of biosolids are used for spreading on farms as fertilisers and soil samples are matched with the biosolids to ensure the best mix of nutrients are provided and are the most suitable for the land. Application of biosolids is strictly controlled by regulators such as the Health, Environmental and Water management agencies.