Treatment of secondary sludge using free nitrous acid to enhance performance and economics of a wastewater treatment plant (2014–2017)
This project aims to reduce sludge production, enhance bioenergy recovery and improve biological nutrient removal in wastewater treatment plants. It is based on the cell-lysing effect of free nitrous acid that was recently discovered by our team. We will develop options to apply this technology both as a pretreatment to anaerobic digestion, achieving an estimated 20% improvement in solids destruction and biogas production, and as an in-line process for smaller plants achieving a similar level of sludge reduction. In both applications, the performance and economics of the plants will be significantly improved. Free nitrous acid can be readily generated from wastewater, and is environmentally benign and degrades harmlessly after use.