Transportation of domestic slurry in pipeline systems

Research objectives
This study aims at building a 1-dimensional multiphase flow model to represent the transportation of non-Newtonian domestic slurries in long circular conduits. This enables us to design efficient slurry transport systems for future sanitation concepts.

Project outline
Introduction
New sanitation concepts stem from the need for better nutrient recovery from domestic slurries and water management. And for this, these concepts focus on: source separation, collection, transport and treatment. Traditional sanitation concepts use large amount of water, thereby making the slurries dilute. Where as, new sanitation concepts focus on reducing the consumption of water and possess pressurized pipelines for the transportation of these slurries. This reduction in the consumption of water make the slurry concentrated with solids and therefore they exhibit non-Newtonian behavior. Concentrated slurries can be treated more efficiently.

CFD (Computational fluid dynamics) is an important and a widely used tool to study complex multiphase flows. In this study, CFD is used to model the 3-dimensional flow of the slurries. The results thus obtained, are used to build a simplified 1-dimensional model for practical implementation.

Approach

  1. Rheological characterization (Arjang Alidai, “Domestic Slurry Hydraulics In Transport systems”) experiments will be used to describe the domestic slurry.
  2. Various multiphase and turbulence models will be tested to determine its suitability.
  3. A 3-dimensional multiphase slurry transport model will be developed and validated using a large-scale experimental pipeline (ALPHA loop at Deltares) at different layouts (horizontal and inclined). This will also serve to study the transient intermittent behavior of the system and model them in order to allow for application by practitioners in (re)design of systems.
  4.  The results thus obtained will be used to build a simplified 1-dimensional model to describe the system.

Scientific and social relevance
Transportation of household slurries has vastly been overlooked, but is an integral part to the creation of these new sanitation concepts. They hold the missing link to a more sustainable solution. Implementation of these new sanitation concepts will result in a rational usage of water resources and better wastewater management.