IWRA Executive Office

abstract 627

Nanofiltration as a sustainable Water Defluoridation operation dedicated to large scale pilot plants in the world

Author(s): Maxime Pontie, Hanane Dach, Jérôme Leparc

Keyword(s): desalination, water defluoridation, nanofiltration, fresh water

Article:

Poster:

Session: OS1m Water quality 1

AbstractThis investigation concerns the use of nanofiltration (NF) to remove excess fluoride from drinking

water. The regular ingestion of water with fluoride ions concentration higher than 2mg.L-1 causes serious health

diseases like dental and bone fluorosis all over the world [1].
The nanofiltration (NF) membrane is a type of

pressure-driven membrane which properties is situated between reverse osmosis (RO) and ultrafiltration (UF)

membranes. NF offers several advantages such as low operational pressure, high flux, high retention of multivalent

anion salts and organics compounds with molecular weight above 300 Da, relatively low investment and low

operation and maintenance costs. Because of these advantages, the applications of NF worldwide have increase.

The history of NF dates back to the 1970s when RO membranes with a reasonable water flux operating at relatively

low pressures were developed. Hence, the high pressures traditionally used in RO resulted in a considerable energy

cost. Thus, membranes with lower rejections of dissolved components, but with higher water permeability, would be

a great improvement for separation technology. Such low-pressure RO membranes became known as NF

membranes. By the second half of the 1980s, NF had become established, and the first applications were reported

as detailed in a recent review [2]. Today 10% of brackish waters market in the world is dedicated to nanofiltration

(NF) membranes [3]. While nanofiltration is a relatively new membrane process, it is already widely used for water

treatment in different parts of Europe, Israel and the US. Striving towards improved quality, efficiency and

applicability, research is continuing in an attempt to understand and model the varying parameters involved during

NF. A technique that is often used for the evaluation of membranes is the flux and rejection behaviour of uncharged

and charged solutes [4].

In this work many commercialized RO and NF membranes have been screened in

order to find a suitable membrane for water defluoridation in the future, as illustrated in the Fig. 1. Our work shows

that the more efficient NF membrane for water defluorination are those presenting solution-diffusion mass

transfer.

References : [1] Fluoride SERIE Vol.2, Fluoride and Environment, Elsevier, in press (2006); [2] N.

Hilal, H. Al-Zoubi, N. A. Darwish, A. W. Mohammad, M. Abu Arabi, Desalination, 170 (2004) 281; [3] J.M.

Rovel, State and behaviour of seawater desalination in the future, Proceedings of CHEMRAWNXV, 21-23 june

2004, Paris, 22-28; [4] H.M. Krieg, S.J. Modise, K. Keizer, H.W.J.P Neomagus, Desalination, 171 (2004)

205.

Events

The congress

Programme

Practical Infos

Nanofiltration as a sustainable Water Defluoridation operation dedicated to large scale pilot plants in the world