Innovative procedure of chemical cleaning for RO membranes to reduce the energy consumption in the operation of a BWRO plant

Antonio Casañas González, Alejandro Ramos Martin, Federico Leon Zerpa, Nicolau Chirinza

https://doi.org/10.5004/po2024125

Innovative procedure of chemical cleaning for RO membranes to reduce the energy consumption in the operation of a BWRO plant

Antonio Casañas González¹*, Alejandro Ramos Martin¹, Federico Leon Zerpa¹, Nicolau Chirinza²

¹ Institudo de Estudios Ambientales y Recursos Naturales (iUNAT), Universidad de las Palmas de Gran Canaria, Spain
² Faculdade de Ciencias e Tecnologias da Universidade Zambeze

*Corresponding author

https://doi.org/10.5004/po2024125

ABSTRACT

This study presents an innovative chemical cleaning procedure for reverse osmosis (RO) membranes designed to reduce operating pressure and energy consumption in a brackish water reverse osmosis (BWRO) plant. Our objective was to develop a method to effectively combat the fouling caused by the feedwater on the first-stage membranes. We analysed over 17,000 h of operational data from a BWRO plant that features a well intake, a transfer pump, antiscalant dosing, and a conventional physical pretreatment system with sand and cartridge filters. The plant's two-stage RO system consists of 40 pressure vessels in the first stage and 20 in the second, each containing six BWRO elements. After 12,500 h of operation, significant fouling occurred on the first-stage membranes. We performed a basic clean-in-place (CIP) procedure using NaOH at a pH of 11–12 to restore the permeate flow rate. This research demonstrates how a refined cleaning protocol can significantly improve the performance and energy efficiency of desalination processes.

Keywords: Energy use; Reverse osmosis membranes; Brackish water; Chemical cleaning