Energy and resource‐efficient reverse osmosis system with tunable recovery for brackish water desalination and heavy metal removal

Abstract

The resource efficiency of a conventional domestic reverse osmosis system is low because it operates at a low water recovery and energy efficiency. Besides, the quality of permeate cannot be controlled, leading to unusual taste, which may result in adverse health effects. In this article, a new system design and operational method of a domestic reverse osmosis system have been studied analytically and experimentally. The study shows that it is possible to tune the permeate quality, and a high water recovery can be achieved with this design and operational method. In addition, specific energy consumption can be reduced. This system is particularly useful in the case of low salinity feed with a trace amount of heavy metals. A synthetic feed solution of As+5 in pure water was used as a feed to verify the same. It was observed that a high water recovery (>85%) could be achieved while removing As+5 from the water. With global rise in decentralized desalination systems, the proposed system design and operational method can be used not only to tune the product recovery and quality but also to reduce the specific energy consumption as well. Hence, this work is in line with United Nations Sustainable Development goals (SDGs).