Lime products including quicklime and hydrated lime, can convey a number of benefits in the treatment of biosolids including: biocidal effect, odour control, and dewatering functionality.
Dewatering – Dewatering biosolids with lime has the potential to reduce operational costs in several areas including: reagent reduction costs, reduced polymer usage, reduction in wash water required, reduction of cartage costs and a reduction in capital costs for solids storage.
Pathogen Control – Pathogen control in biosolids using quicklime is achieved through two key main reactions. As quicklime hydrates, heat is released and effectively will pasteurise the solids. Where the alkaline effect from quicklime or hydrated lime raises the pH above 12, this will disrupt the cell walls and kill off most pathogenic bacteria and a number of viruses.
Rodent and Insect Vectors – Due to the alkaline effect, (high pH) and persistence of lime particles, lime treatment will also provide a barrier to preventing flies, insects and rodents from reinfecting treated biological waste.
Odour Control - Hydrated lime is commonly used for odour control. The solubility of Hydrated Lime provides free calcium ions, which react and form complexes with particularly odorous sulfur species such as hydrogen sulfide and organic mercaptans. It is reported that as a result of this reaction, the waste odours are destroyed and not just masked or hidden.
Additional Resources
Graymont carefully monitors its lime production processes to provide products that meet the required specifications.