Page 68 - Materials Chemistry, Second Edition

Life Cycle Assessment of Beneficial Reuse of Waste Streams
Life Cycle Assessment of Wastewater Treatment

4 Life Cycle Assessment

of Beneficial Reuse of

Waste Streams for Energy

in Municipal Wastewater

Treatment Plants

Dongyan Mu, Sarah Mack,
Roger Ruan, and Min Addy

CONTENTS
4.1 Introduction ....................................................................................................50
4.2 Waste Streams Generated in Municipal Wastewater Facilities ...................... 51
4.2.1 Biosolids ............................................................................................. 51
4.2.2 Scum ...................................................................................................52
4.2.3 Centrate and Other Liquid Waste Streams .........................................52
4.3 Technologies for Renewable Energy from Waste Created in Wastewater
Treatment Facilities ........................................................................................53
4.3.1 Anaerobic Digestion of Biosolids .......................................................53
4.3.2 Pyrolysis and Other Thermal Chemical Processes to Treat Sludge ...55
4.3.3 Scum to Biodiesel ...............................................................................57
4.3.4 Algae Cultivation and Algal Biofuel Production from Liquid
Waste Streams ....................................................................................59
4.3.4.1 Algae Cultivation Stage .......................................................60
4.3.4.2 Algal Conversion Stage ........................................................62
4.3.4.3 Algal Bioproduct Use Stage .................................................62
4.4 Life Cycle Assessment (LCA) of Waste Reuse in Wastewater Treatment
Facilities .........................................................................................................63
4.5 An LCA Case Study of Beneficial Reuse of Waste Streams Within a
Municipal Wastewater Treatment Plant ..........................................................66
4.5.1 A Metropolitan Wastewater Treatment Plant (MWTP) and its
Waste Streams ....................................................................................66
4.5.2 LCA Description .................................................................................67
4.5.3 LCA Results .......................................................................................70
4.6 Conclusion And Discussion ............................................................................72
References ................................................................................................................72

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