Avaluació del tractament extern per reduir l’embrutiment biològic en membranes polimèriques submergides

Abstract

Water is a precious and necessary good for humans. We make great use of it be it for industry or urban use. In consequence its quality is altered and generates what we denominate waste waters. This water has to be treated to prevent negative impact on the environment. To avoid this there are waste water treatments. Conventional treatments in waste water treatment plants are composed of physic-chemical and biological treatments. But those water treatment plants present limitations that difficult improvement of the process. This limitations can be balanced out by integrating other advanced technologies of waste water treatment that will improve the treatment and generate better quality water diminishing the impact on the environment. One of those systems is called membrane bioreactor (MBR). This process generates much better water quality but has two big inconvenient: the operational cost and the membrane fouling. The membrane fouling is due to particle accumulation on the surface, negatively affecting water filtration. Fouling is detected by the increase in trans-membrane (TMP) pressure. In consequence there is an increment on the energetic cost and when accumulated it can damage the membrane. There exist different measures to help reduce fouling. Systems like the application of airing to create turbulence and detach fouling. Also periodical back wash process to release obstructed pores or chemical washes to recover filter capacity even though it reduces the membrane useful life. All these measures imply direct actions on the membranes. What we study is the option to apply an external peptic treatment that coats the membrane surface, able to prevent bio-fouling from membranes. With this treatment we could reduce back wash frequency, airing flow or even chemical washes. Therefore we can reduce operational costs from this technology increasing its profitability. Comparison between treated membranes and non-treated ones indicates that we can increase its permeability in low fluxes due to coating