Centre for Development Studies

SODIS(3D): Water treatment units for rural communities using 3-D printing, mathematical modelling

July 2016 - March 2017

Principle Investigator: Dr Emma Emanuelsson Patterson (University of Bath)

Research Team: Aurelie Charles (University of Bath) Jonathan Evans (University of Bath) and Paul Shepherd (University of Bath)

Funding Body: EPSRC GCRF - Institutional Funding

Total Value of Award: £40,472

Overview of the project

There are still 650 million people without safe water in the world despite the achievement of Millennium Goal 7c, to halve by 2015 the proportion of the population without sustainable access to safe drinking water and basic sanitation (see http://www.wateraid.org/uk/what-we-do/the-crisis). Hence, one of the UN Sustainable development goals (N.6) is now “ensuring access to water and sanitation for all”. There is a pressing need to develop decentralised household water treatment (HWT) systems that require little maintenance for rural communities in developing countries that struggle with water quality, disposal and distribution systems, until improvements to the centralised treatment systems are achieved.

The aim of this project is to build on the principles of the SODIS bottle, retaining its simplicity, but making it a more efficient, reliable and lowcost continuous treatment system for long-term use. We will use 3D printing to generate rapid prototypes and test them using a unique indoor solar light set-up that replicates pure sunlight.

Key objectives

The project aims to create a more efficient, reliable, low cost and simple portable HWT system, able to produce sufficient clear drinkable water for a small group of individuals. This is in line with not one, but two of the four strategic objectives: (i) Strengthening resilience and responses to crisis and (ii) Tackling extreme poverty and helping the world’s most vulnerable.  

For this pilot study and prototype development phase, a detailed mathematical model will be developed and verified through physical testing.  The validated mathematical model will then be used to optimise the design, and create a final showcase prototype.  In parallel, a desk-based investigation into the social and cultural context in which such a device would be used, will feed into the design to ensure it is fit-for-purpose in a practical sense, as well as a technological sense.

Methodology to achieve outputs/outcomes 

•    Mathematical modelling to correlate water flow, light intensity and temperature with sterilisation performance 
•    Usage of the latest parametric modelling techniques to generate a range of 3D-printed and computer numerical control (CNC)-milled physical prototypes, exhibiting different geometrical characteristics such as channel width/depth/lengths and flow rates 
•    In parallel, to ensure that the technical developments satisfy the criteria to be adopted and sustained by a local community in rural Africa, the prototype will be understood through the exchange-entitlement mapping (E-mapping) framework which embraces a variety of contextual norms as key factor to implement behavioural change
•    Physically tests of the performance of the prototypes as water treatment units to develop an understanding of the influence of additional physical characteristics such as light level, temperature and flow 
•    To use the results of the physical testing to refine the mathematical model and improve its accuracy, then use the mathematical model to optimise the characteristics needed for an efficient treatment system, and 3D-print an optimised prototype to showcase the project.

Intended outputs and impacts

Expected outputs and outcomes

•    Creation of a prototype water treatment device which could easily be mass-produced and disseminated where needed.
•    Establishment of a new multi-disciplinary collaboration amongst researchers spanning three faculties (science, engineering, H&SS) and one institute (IMI)
•    Preparation of a case study that showcases the findings
•    Leverage results from this pilot study to apply for large-scale follow-on research funding (GCRF-RCUK – future calls and the EPSRC competition calls).

Expected impact on beneficiary country(ies)

This project will focus on Africa which has the lowest uptake of adequate HWT systems (10.6% of the population in 22 Africa region countries) *see note 1*, and 37% of the world population that use an unimproved drinking water source live in Sub-Saharan Africa *see note 2*.  Malawi will be used as a case study due to its geo-political relevance in terms of poor entitlements to safe water and socio-economic opportunities and connections *see note 3*. The expected impact will be in terms of clear drinkable water and therefore less diseases, decreased child mortality, less pressure on health systems and improvements in the long-term prospects for socio-economic opportunities. Also, provided that the pilot study is successful, the expected benefits will be able to be scaled up to include other countries in Sub-Saharan Africa via the continuous support of the African Capacity Building Foundation. 

*Note 1* It has been shown that HWT has been one of the most cost-effective interventions to reach the millennium development goals. Rosa and Clasen. Am.J.Trop.Med.Hyg. 82(2)2010.
*Note 2* WHO/UNICEF , 2008 . Progress on Drinking Water and Sanitation: Special Focus on Sanitation, Geneva, World Health Organization.
*Note 3* African Capacity Building Foundation and Leadership in Environment for East and Southern Africa (LEAD-SEA) in Malawi.

For further information about this project, please contact:

Dr  Emma Emanuelsson Patterson