Sewer sediment management based on hydraulic modelling and life cycle assessment concept

Gouda, Hazem; Ashley, Richard; Blanksby, John; Oltean-Dumbrava, Crina; Adams, Andy

Abstract

The growth of population, cities and towns all over the world usually results in the over-exploitation of resources and increased pollution. Water service providers (WSPs) are required to provide adequate sanitation to the community, taking into consideration technical, social, economic and environmental issues. Therefore, WSPs are faced with increasingly complex objectives and demands when making decisions related to asset investment. Sewer systems handle two types of water that require drainage: (sanitary) wastewater and stormwater. These two types of water typically convey different classes of solids into the system. The presence of these solids which include sediment in systems causes operational problems: loss of hydraulic capacity, in-pipe septicity and contribute to the pollutants in foul flushes. This leads to significant economic and environmental impact on stakeholders and the area into which storm water is discharged. This paper demonstrates a wide variety of effective strategies for addressing sewer sediment management to improve existing infrastructure and develop new systems using hydraulic modelling and life cycle assessment (LCA) approach.

Sediment management generally relies on low technology practices that are applied by individuals, municipalities and industrial establishments. In the UK the current practices to control sediment in urban drainage catchments entail street, gully and sewer cleaning. Other techniques like (e.g. sediment traps, flushing tanks and flushing gates) have been considered elsewhere as an effective method of controlling sediment deposition in the sewer provided regular cleansing and maintenance are carried out (Ashley et al, 2004). There are six options being considered for the management of sewer sediment for this study. The first two are to control the solids entering the sewer system, three options are considering managing the sediment in the sewers and the final option is to manage the sediment at the end of the pipe at the wastewater treatment plant (WTP). The study has calculated the mass flow analysis (MFA) of solids that enter the sewer system using detailed hydraulic modelling. The dynamic model provides inputs needed by other components of the study in describing the life cycle assessment of sediment management options in sewer systems using life cycle assessment via the SimaPro software. The LCA goal of the reported study is to evaluate the energy use, resource consumption, pollutant emissions and the consequent environmental impacts of alternative solids management scenarios.

• Presentation Conference Type: Conference Paper (unpublished)
• Conference Name: 1st International Conference & Exhibition on Sustainable Water Supply and Sanitation, SWSSC 2010
• Start Date: Jul 25, 2010
• End Date: Jul 27, 2010
• Peer Reviewed: Peer Reviewed
• Pages: 1-14
• Keywords: sewer sediment management, life cycle assessment, sediment modelling, mass balance
• Public URL: https://uwe-repository.worktribe.com/output/976831
• Publisher URL: http://www.hcww.com.eg/ar/swssc/p2.aspx