Organics transformation and energy production potential in a high rate A-stage system: A demo-scale study

Shenbin Cao; Dan Lu; KianMing Phua; Wangwang Yan; Chencheng Le; Guihe Tao; Yan Zhou

doi:10.1016/j.biortech.2019.122300

Organics transformation and energy production potential in a high rate A-stage system: A demo-scale study

Bioresour Technol. 2020 Jan:295:122300. doi: 10.1016/j.biortech.2019.122300. Epub 2019 Oct 18.

Authors

Shenbin Cao¹, Dan Lu², KianMing Phua³, Wangwang Yan¹, Chencheng Le¹, Guihe Tao³, Yan Zhou⁴

Affiliations

¹ Advanced Environmental Biotechnology Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, 1 Cleantech Loop, Singapore 637141, Singapore.
² Advanced Environmental Biotechnology Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, 1 Cleantech Loop, Singapore 637141, Singapore; School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore.
³ Public Utilities Board, Water Reclamation (Plants) Department, 40 Scotts Road, #15-01, Singapore 228231, Singapore.
⁴ Advanced Environmental Biotechnology Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, 1 Cleantech Loop, Singapore 637141, Singapore; School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore. Electronic address: zhouyan@ntu.edu.sg.

PMID: 31669872
DOI: 10.1016/j.biortech.2019.122300

Abstract

Current high-rate activated sludge (HRAS) process is an aerobic A-stage process that would cause significant organic loss resulted from the mineralization. In this study, the feasibility of operating a high rate A-stage without aeration (HRNS) was carried out in a demo-scale plant (275 m³/h). The organics transformation and energy production potential in A-stage were explored. The developed A-stage process was demonstrated to be more effective for organics recovery compared to that operated with aeration (53.82% versus 40.94%), despite its relatively low total COD removal efficiency (54.3% versus 63.5% with aeration). Minor organics (accounted for 1.75% of incoming COD) was found to be lost in HRNS process. Moreover, sludge generated from HRNS had higher degradability and higher methane compared to that from HRAS. Overall, this study documented the feasibility of high rate A-stage without aeration, and acted as a guide in achieving energy neutrality or even energy-positive wastewater treatment.

Keywords: Biochemical methane potential (BMP); COD capture; Energy recovery; High rate A-stage; Municipal wastewater; Organics transformation.

MeSH terms

Bioreactors*
Methane
Sewage*
Waste Disposal, Fluid
Wastewater

Substances

Sewage
Waste Water
Methane