Abu Dhabi's strategic tunnel enhancement programme: odour extraction system approaches

Abstract

The Emirate of Abu Dhabi has experienced tremendous growth since the mid-1970s resulting in significant overloading of its existing sewerage system. Master planning determined that the best long-term wastewater collection and conveyance solution was construction of a deep tunnel sewer system. Implementation of this massive project faced numerous challenges, including the goal of no odours and limited odour control facilities. To accomplish this, the consultant team examined a unique approach of a single odour control system installed at the proposed downstream tunnel pumping station. Rigorous analysis utilising computer-based models confirmed the viability of this approach. However, other approaches including multiple satellite (localised or regional) odour extraction systems were considered. To better understand entrained air forces at vortex drops, and to confirm the preferred odour extraction approach, physical modelling of drop structures and overall tunnel system was implemented. Results and findings concluded that a regional odour extraction system approach was preferred over a single (centralised) extraction approach. This paper focuses on the process of selecting the preferred odour extraction approach and preliminary capacity sizing of regional systems.

The importance of sewer biofilms

“…Naturally, the focus on sewer design and construction has been on the function of the sewer networks with respect to safe transport of water to fulfill this vital role within urban infrastructure. However, over the years, the understanding of sewer function has been expanded, so that expectations of the urban drainage systems is now also to help minimize the impact of urban activities on the natural environment and to prevent odor from waste water in the urban environment . In light of increasing expectations, it is necessary now, more than ever, to design robust sewer networks to fulfil the expected design life of 50–100 years.…”