This study investigates the role of coagulation in enhancing hydraulic performance and permeate quality of UF membranes and provides insight into options for minimizing or ideally eliminating coagulation from UF pre-treatment to SWRO. Results show that coagulation improves UF hydraulic performance mainly by reducing non-backwashable fouling of the membranes. This can be achieved at very low coagulant dose (~ 0.5 mg Fe/L) by coating the membranes with sub-micron particles.
Additionally, the work highlights the applicability of UF membranes with low molecular weight cut-off as the coagulant free future of SWRO pre-treatment. Major benefits in terms of reduced environmental impact is expected when applying membranes with low molecular weight cut-off, as the need for coagulation is eliminated while ensuring longevity of downstream SWRO membranes. In general terms, the research indicates that coagulant consumption can be significantly reduced in UF pre-treatment of SWRO by optimizing operational parameters and applying alternative solutions.
Table of Contents
1. General introduction
2. Seawater reverse osmosis and algal blooms
3. Fouling potential of coagulant in MF/UF systems
4. Optimizing inline coagulation in MF/UF of surface water
5. Fouling potential and removal of AOM in seawater UF
6. Coating UF membranes in seawater reverse osmosis pre-treatment
7. Removal of algal organic matter from seawater with coagulation
8. Seawater reverse osmosis pre-treatment with low MWCO UF
S. Assiyeh Alizadeh Tabatabai (Iran, 1982) received her B.Sc. in Civil Engineering in 2005 from the University of Engineering and Technology, Lahore, Pakistan. After graduation, she joined geotechnical consultants in Tehran and worked on feasibility studies for lines 2 and 4 of Tehran Metro. Soon after that she was admitted to an MSc programme at UNESCO-IHE. In 2007 she obtained her MSc in Water Supply Engineering from the Department of Water Supply and Sanitation. Her thesis entitled "Optimizing inline coagulation to reduce chemical consumption in MF/UF systems" was nominated for a Gijs Oskam award in 2006.
From 2007 - 2009, she was involved in a training and capacity building project, funded from a World Bank loan, for the water and sanitation sector in Iran. In December 2009, she started working on her PhD research at the Department of Environmental Engineering and Water Technology. Her research was part of a larger project "Zero Chemical UF/RO for Seawater Desalination" in collaboration with Norit, Evides, Vitens, RWTH and University of Twente. The project was funded by the Dutch Ministry of Economic Affairs (SenterNovem) and supported by Norit X-Flow.
Assiyeh is actively involved in several water and desalination associations and has served as European Coordinator of the International Desalination Association - Young Leaders Programme from 2011 to 2013. She continues to be on the Young Leaders Programme committee as Technical Coordinator with an active interest in university outreach focused on raising awareness on the desalination industry.