Researchers find that polyester fibre has similar effluent treatment efficiency to ultra or micro filtration methods.
With growing populations, water scarcity has become an important issue. Discharge of untreated or insufficiently treated water is a concern in many countries.
Activated sludge systems for municipal wastewater treatment are widely used, but they require a large amount of land for the construction of sedimentation tanks. Coupling conventional biological systems with microfiltration(MF) or ultrafiltration (UF) membranes, known as membrane bioreactor (MBR) technology, presents a number of advantages in terms of low footprint, high effluent quality and low sludge production. However, the cost of membranes and the fouling that occurs, have limited the application of MBR applications in wastewater treatment. Hence low cost treatment systems that provide high and stable effluent quality need to be developed.
Investigating the issues, researchers from Turkey report in SCI’s Journal of Chemical Technology and Biotechnology that instead of using UF and MF membranes, low-cost cost coarse mesh or fabric can be used as a support material for the formation of a dynamic layer. This layer is responsible for the retention of coarse and fine particles in the reactor. Cleaning such dynamic membrane (DM) layers can be done using physical processes such as backwashing and water rinsing; this contributes to reducing the costs. However these too have problems such as severe clogging.
To try and mitigate these problems, researchers from Turkey investigated the impact of the type of support material on the performance of DM layer. Two hollow fibre supports were considered; polyester fabric and glass fibre. These two supports were used for the treatment of synthetic municipal wastewater. Biological treatment and filtration performance were evaluated. A number of analytical techniques were used to investigate the performance of these DM layers.
It was found that similar treatment efficiencies were obtained with each membrane. The removal efficiencies compared well with that seen in UF membranes, indicating that polyester fabric and glass fibre could provide technically feasible DMs.
Researchers say that further investigation should focus on scaling up DM with hollow fibre support materials to gain a better insight into treatment and filtration performance of these materials.
Journal of Chemical Technology and Biotechnology: DOI:10.1002/jctb.6426