Track: Waste

Abstract

Huge amounts of municipal sewage sludge, a form of solid waste, are being generated daily  from municipal sewage treatment plants. This sewage sludge if not properly treated can cause landfilling problems that can result in climate change effects due to greenhouse gases emissions. This generated sewage sludge is rich in phosphorous and other nutrients which has potential to be recovered. The current study evaluates the potential to recover phosphorous from municipal sewage sludge using gasification as a thermal method followed by alkali treatment using NaOH. The sewage sludge was first dewatered to 60% moisture content before it was gasified using hot air to convert it into ash for 120 minutes. Gasification at 800 °C was considered as the waste management option for the sewage sludge due to its flexibility and energy efficiency. In this study, 50% of the phosphate was recovered from the sewage sludge ash with a phosphorous nutrient composition of 6.5-7.5 wt. %. Gasification of sewage sludge to recover phosphate oxide and its subsequent alkali treatment to recover phosphate promotes environmental preservation at the same time creating a resource for fertilizer production.Huge amounts of municipal sewage sludge, a form of solid waste, are being generated daily  from municipal sewage treatment plants. This sewage sludge if not properly treated can cause landfilling problems that can result in climate change effects due to greenhouse gases emissions. This generated sewage sludge is rich in phosphorous and other nutrients which has potential to be recovered. The current study evaluates the potential to recover phosphorous from municipal sewage sludge using gasification as a thermal method followed by alkali treatment using NaOH. The sewage sludge was first dewatered to 60% moisture content before it was gasified using hot air to convert it into ash for 120 minutes. Gasification at 800 °C was considered as the waste management option for the sewage sludge due to its flexibility and energy efficiency. In this study, 50% of the phosphate was recovered from the sewage sludge ash with a phosphorous nutrient composition of 6.5-7.5 wt. %. Gasification of sewage sludge to recover phosphate oxide and its subsequent alkali treatment to recover phosphate promotes environmental preservation at the same time creating a resource for fertilizer production.