Experience with integrated ultrafiltration/reverse osmosis systems in industrial applications in Spain

Abstract

While fresh water resources are increasingly limited, efforts are taken aiming at a more efficient use of those resources and the value of water reuse, not only due to environmental but also due to economic aspects. This is especially true for the industrial sector, with a high potential to save water by reuse. This is expected to be even more critical in the coming future as the price of the water increases and the access to good quality water sources near the industries decreases. Reverse osmosis (RO) technology has been used in the industrial sector for decades for various purposes such as softening, ultra pure water production, or water reuse. But like in other applications such as desalination, in industrial applications, membrane fouling remains as one of the main causes for poor RO plant performance. This implies frequent downtime for cleaning and maintenance and shorter membrane life time, leading to significant operational costs. Therefore, the selection of a proper pretreatment is essential to produce a high quality feed water for the RO system in order to ensure a more sustainable and reliable operation. In the past decades, ultrafiltration (UF) has become more popular for RO pretreatment in the municipal and lately in the industrial sector too. Ultrafiltrate water is virtually free of particles, colloids, and suspended solids. Therefore, plugging of RO feed channels is minimized and the RO cleaning frequency can be noticeably reduced. In comparison with conventional filtration (e.g. sand filtration), UF requires significantly lower footprint, produces a higher and more consistent water quality regardless of variations in the feed quality, and usually needs less power and chemicals. This paper will review the design and operational data of a number of successful full-scale integrated membrane systems (UF followed by RO) installed in different types of industries and treating diverse water sources.

Keywords:

• Ultrafiltration
• RO pretreatment
• Integrated membrane systems
• Reuse
• Industrial water treatment

Notes

Presented at the International Conference on Desalination for the Environment, Clean Water and Energy, European Desalination Society, 23–26 April 2012, Barcelona, Spain