Management of reverse osmosis concentrate by solar distillation

Abstract

Disposal of rejected brine is a fundamental part of reverse osmosis desalination technology, it presents negative influences on the marine ecosystem, due to the high salt content and the presence of other harmful chemicals in the concentrate. Solar distillation is such a promising technology for brine management. The main goal of this study is to treat high salinity solution of reverse osmosis desalination brine and to recover valuable resources while producing freshwater. The implementation of the study is through two phases: the first phase includes desalination by reverse osmosis process to produce fresh water and the concentrated brine, while the second phase consists of recovering solid salts using the solar distillation. Thus, different experiments of desalination by reverse osmosis pilot and solar distillation were carried out under the optimal experimental conditions. The obtained results showed that Chlorides are the most dominant constituents in the composition of brines, while the daily water productivity contributed to around 80% of the total productivity of the solar system (volume of the water produced/m2/day) and the amount of salt crystallize by solar distillation represents 35 grams per liter of brine, this salt has a great demand for several sectors such as agriculture, industry, and others.

Feasibility Study of a Reverse Osmosis Desalination Unit Powered by Photovoltaic Panels for a Sustainable Water Supply in Algeria

“…Indeed, all solar desalination systems integrate solar technologies that can provide a sustainable solution to meet drinking water needs in areas with clean water scarcity and water consumption in the industry [4]. Water desalination processes are classified into two categories, namely thermal processes (distillation: multiple-effect MSF (Multi-Stage Flash) [5][6][7][8] or MED (Multi-Effect distillation)) [9] and membrane processes (RO, electrodialysis) [10][11][12].…”