Details

Autor(en) / Beteiligte

• Coutinho de Paula, Eduardo
• Gomes, Júlia Célia Lima
• Amaral, Míriam Cristina Santos

Titel

Recycling of end-of-life reverse osmosis membranes by oxidative treatment: a technical evaluation

Ist Teil von

• Water science and technology, 2017-07, Vol.76 (3-4), p.605-622

Ort / Verlag

England

Erscheinungsjahr

2017

Quelle

MEDLINE

Beschreibungen/Notizen

• The adverse impacts caused by the disposal of thousands of tonnes per annum of reverse osmosis (RO) membranes modules have grown dramatically around the world. The objective of this study was to evaluate the technical feasibility of recycling by chemical oxidation of end-of-life RO membranes for applications in other separation processes with specifications less rigorous. The recycling technique consisted in to cause a membrane exposition with oxidant solutions in order to remove its aromatic polyamide layer and subsequent conversion to a porous membrane. The recycling technique was evaluated by water permeability and salt rejection tests before and after the oxidative treatments. Initially, membranes' chemical cleaning and pretreatment procedures were assessed. Among factors evaluated, the oxidizing agent, its concentration and pH, associated with the oxidative treatment time, showed important influence on the oxidation of the membranes. Results showed that sodium hypochlorite and potassium permanganate are efficient agents for the membrane recycling. The great increased permeability and decreased salt rejection indicated changes on membranes' selective properties. Scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), atomic force microscopy (AFM), and contact angle characterization techniques revealed marked changes on the main membranes' physical-chemical properties, such as morphology, roughness and hydrophobicity. Reuse of produced effluents and fouling tendency of recycled membranes were also evaluated.