title: Overview of current biological and thermo-chemical treatment technologies for sustainable sludge management.
abstract: Sludge is a semi-solid residue produced from wastewater treatment processes. It contains biodegradable and recalcitrant organic compounds, as well as pathogens, heavy metals, and other inorganic constituents. Sludge can also be considered a source of nutrients and energy, which could be recovered using economically viable approaches. In the present paper, several commonly used sludge treatment processes including land application, composting, landfilling, anaerobic digestion, and combustion are reviewed, along with their potentials for energy and product recovery. In addition, some innovative thermo-chemical techniques in pyrolysis, gasification, liquefaction, and wet oxidation are briefly introduced. Finally, a brief summary of selected published works on the life cycle assessment of a variety of sludge treatment and end-use scenarios is presented in order to better understand the overall energy balance and environmental burdens associated with each sludge treatment pathway. In all scenarios investigated, the reuse of bioenergy and by-products has been shown to be of crucial importance in enhancing the overall energy efficiency and reducing the carbon footprint.
authors: Department of Civil Engineering, Queen's University, Kingston, ON, Canada Department of Geography, Queen's University, Kingston, ON, Canada.
authors: Linghong
authors: L
authors: Zhang
authors: Department of Chemical & Biochemical Engineering, Western University, London, ON, Canada cxu6@uwo.ca.
authors: Chunbao Charles
authors: CC
authors: Xu
authors: Department of Civil Engineering, Queen's University, Kingston, ON, Canada Department of Chemical Engineering, Queen's University, Kingston, ON, Canada.
authors: Pascale
authors: P
authors: Champagne
authors: Department of Geography, Queen's University, Kingston, ON, Canada School of Policy Studies, Queen's University, Kingston, ON, Canada.
authors: Warren
authors: W
authors: Mabee
mesh_terms: D001673:Biodegradation, Environmental; D052918:Environmental Restoration and Remediation / Q000379:methods*; D012722:Sewage / Q000032:analysis* / Q000737:chemistry; D014865:Waste Disposal, Fluid / Q000379:methods*
chemical_list: D012722:Sewage
keywords: Sludge; bioenergy; biosolid; energy recovery; environmental impact; life cycle assessment