BiOsmoBackwash: a New Approach to Counter Biofouling in Membrane filtration

Completed

Not Energy Related
Energy Efficiency(Industry)

Basic and strategic applied research
Applied Research and Development

ENGINEERING AND TECHNOLOGY (Chemical Engineering)
ENGINEERING AND TECHNOLOGY (Mechanical, Aeronautical and Manufacturing Engineering)

Not Cross-cutting
Sociological economical and environmental impact of energy (Environmental dimensions)

Dr A Correia Semiao
Sch of Engineering and Electronics
University of Edinburgh

Standard

EPSRC

01 September 2017

31 May 2019

21 months

£100,949

Civil eng. & built environment

Scotland

NC : Engineering

Dr A Correia Semiao, Sch of Engineering and Electronics, University of Edinburgh

Project Contact, Scottish Water

Clean drinking water is vital for human life. Water is also essential to agriculture, energy and manufacture. The United Nations recently reported an expected increase in demand for water of 55% by 2050. The reliable and sustainable provision of clean water for all is urgently needed worldwide, and is the focus of one of the Sustainable Development Goals established by the UN (Goal 6). In a scenario where conventional water resources are becoming increasingly insecure and contaminated, the development of new improved and resilient water treatment technologies is imperative to meet the UN's target. This proposal takes an important step towards a solution involving membrane filtration in water supply.Nanofiltration (NF) and reverse osmosis (RO) membrane processes are increasingly popular as they supply high quality water, including drinking water, from any available water source. A high pressure feed water is filtered through the membrane, producing permeate, i.e. clean water, whilst contaminants are retained on the feed side. Membranes are however known to foul due to an accumulation of contaminants on the membrane surface. Biofouling in particular, is caused by the accumulation, adhesion and growth of microorganisms on the membrane surface leading to dangerously reduced quality and flow of permeated water, increased operational and energy costs and membrane life reduction.Chemical cleaning regimes, such as chlorination, are used to combat membrane biofouling. These processes are inefficient and they require process downtime. They can also modify the properties of the membrane, ultimately reducing its life.This project will demonstrate a simple, novel cleaning technique to prevent biofouling formation on NF and RO membranes. We will explore the regular introduction of a burst of high salinity - a High Salinity Pulse (HSP) - into the input feed flow of the membrane. The HSP causes a high osmotic pressure difference to occur between the feed and permeate sides of the membrane. As a consequence, the direction of water permeation through the membrane temporarily reverses, flowing from the permeate side to the feed side. The membrane is backwashed and adhered microorganisms removed from the surface, avoiding growth and subsequent biofilm formation. This will maintain water production quantity and quality at lower operational and energy costs and extend the usable lifespan of a membrane, having an immediate transformative effect on industries where NF and RO membranes are used, which include the water, wastewater, aquaculture and food & drink industries.

28/09/17