title: Treatment of municipal sewage sludge in supercritical water: A review.
abstract: With increasing construction of wastewater treatment plants and stricter policies, municipal sewage sludge (MSS) disposal has become a serious problem. Treatment of MSS in supercritical water (SCW) can avoid the pre-drying procedure and secondary pollution of conventional methods. SCW treatment methods can be divided into supercritical water gasification (SCWG), supercritical water partial oxidation (SCWPO) and supercritical water oxidation (SCWO) technologies with increasing amounts of oxidants. Hydrogen-rich gases can be generated from MSS by SCWG or SCWPO technology using oxidants less than stoichiometric ratio while organic compounds can be completely degraded by SCWO technology with using an oxidant excess. For SCWG and SCWPO technologies, this paper reviews the influences of different process variables (MSS properties, moisture content, temperature, oxidant amount and catalysts) on the production of gases. For SCWO technology, this paper reviews research regarding the removal of organics with or without hydrothermal flames and the changes in heavy metal speciation and risk. Finally, typical systems for handling MSS are summarized and research needs and challenges are proposed.
authors.affiliation: Key Laboratory of Thermo-Fluid Science and Engineering of MOE, School of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi, 710049, China.
authors.forename: Lili
authors.initials: L
authors.lastname: Qian
authors.affiliation: Key Laboratory of Thermo-Fluid Science and Engineering of MOE, School of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi, 710049, China. Electronic address: szwang@aliyun.com.
authors.forename: Shuzhong
authors.initials: S
authors.lastname: Wang
authors.affiliation: Key Laboratory of Thermo-Fluid Science and Engineering of MOE, School of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi, 710049, China.
authors.forename: Donghai
authors.initials: D
authors.lastname: Xu
authors.affiliation: Key Laboratory of Thermo-Fluid Science and Engineering of MOE, School of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi, 710049, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Guo
authors.affiliation: Key Laboratory of Thermo-Fluid Science and Engineering of MOE, School of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi, 710049, China.
authors.forename: Xingying
authors.initials: X
authors.lastname: Tang
authors.affiliation: Key Laboratory of Thermo-Fluid Science and Engineering of MOE, School of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi, 710049, China.
authors.forename: Laisheng
authors.initials: L
authors.lastname: Wang
mesh_terms: D005740:Gases / Q000737:chemistry*; D006859:Hydrogen / Q000737:chemistry; D009930:Organic Chemicals / Q000737:chemistry; D010084:Oxidation-Reduction; D012722:Sewage / Q000737:chemistry*; D013696:Temperature; D014867:Water / Q000737:chemistry*
chemical_list: D005740:Gases; D009930:Organic Chemicals; D012722:Sewage; D014867:Water; D006859:Hydrogen
keywords: Hydrogen; Oxidation; Sewage sludge; Supercritical water; System