A perspective on hydrothermal processing of sewage sludge

Wan-Ting Chen; Md Akiful Haque; Taofeng Lu; Aersi Aierzhati; Gregory Reimonn

doi:10.1016/j.coesh.2020.02.008

A perspective on hydrothermal processing of sewage sludge

Curr Opin Environ Sci Health. 2020 Apr:14:63-73. doi: 10.1016/j.coesh.2020.02.008. Epub 2020 Mar 10.

Authors

Wan-Ting Chen¹, Md Akiful Haque¹, Taofeng Lu¹, Aersi Aierzhati², Gregory Reimonn¹

Affiliations

¹ Department of Plastic Engineering, University of Massachusetts Lowell, Lowell, MA, USA, 01854.
² Department of Agricultural & Biological Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, USA, 61801.

Abstract

The US annually produces 79 million dry tons of liquid organic waste including sewage sludge. Anaerobic digestion can only reduce the sludge volume by 50% in mass, leaving the other half as a growing waste management and hygienic problem. Hydrothermal processing (HTP), a set of several chemical digestion processes, could be used to convert sewage sludge into valuable products and minimize potential environmental pollution risks. Specifically, hydrothermal carbonization and hydrothermal liquefaction have been extensively studied to sustainably manage sludge. Two of the main reasons for this are the high upscalability of HTP for public waste management and that it is estimated that HTP can recover eleven times more energy from waste products than landfilling. An integration of HTP with anaerobic digestion or recycling the soluble organics (in the HTP aqueous products) into the HTP process could lead to a higher overall rate of energy recovery for municipal sewage sludge.

Keywords: Anaerobic digestion; Environmental health; Hydrothermal processing; Sewage sludge; Sustainability; Wastewater treatment.

Publication types

Review