Seguiment d'un bioreactor anaeròbic de membrana amb membranes reciclades

Abstract

In a context of increasing water scarcity and intensifying extreme climate events —

particularly in the Mediterranean region—, it is urgent to accelerate the implementation of

sustainable and resilient strategies for water resource management, contributing to

the goals of the circular economy and the Sustainable Development Goals (SDGs). Climate

change, population growth, and competition over water use are placing pressure on

conventional supply systems and challenging existing infrastructures. Faced with

growing water scarcity and rising demand, desalination plants have become a strategic

source of water production, although they entail high energy and environmental costs.

In this context, advanced treatment technologies and water reuse emerge as key pillars

to ensure water security in a more sustainable and cost-effective manner. Anaerobic

membrane bioreactors (AnMBRs) are seen as a promising alternative, combining high

effluent quality with low sludge production and the potential for energy recovery.

This work is part of the Osmo4Lives project, which aims to give a second life to reverse

osmosis (RO) membranes at the end of their service life. The objective is to convert them

into ultrafiltration (UF) and nanofiltration (NF) membranes and evaluate their

performance in a submerged AnMBR system treating synthetic wastewater.

The system was monitored continuously over a period of seven weeks, collecting

performance and stability data every 10 minutes at the LEQUIA facilities in Girona.

Recycled membranes from reverse osmosis treatment plants and anaerobic granular

sludge were used. In addition, membrane fouling and salt accumulation in the reactor were

monitored.

The results revealed proved the possibility to recycle RO membrane for their use in AnMBR.

It also showed the differences among the various membrane types, showing that

fouling did not pose a major concern. In the case of nanofiltration (NF) membranes,

significant differences were observed compared to ultrafiltration (UF) and microfiltration

(MF) membranes, particularly in terms of permeate flux and electrical conductivity,

which were notably lower. Furthermore, NF membranes required a much higher

transmembrane pressure than UF and MF membranes

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