Ampliação da oferta de água no semiárido: redução da evaporação e dessalinização

Expanding water supply in the semi-arid region: reducing evaporation and desalination

Abstract

With low and irregular rainfall and high evaporation rates, semi-arid regions are constantly dealing with problems arising from negative water balance. In several rural locations, the aquifer is the primary source of available water; however, most of it is composed of a high concentration of salts. Thus, this article aims to conduct a literature review that presents techniques for inhibiting surface water evaporation and aquifer desalination. Physical, chemical, and biological methods are indicated to reduce the evaporation of surface water bodies. Solutions that use physical coverings are the most advantageous because they provide excellent reductions, which can reach 85%, and because of the ease of access that populations have to the material. For desalination, thermal and membrane processes are presented, where, for brackish waters, reverse osmosis stands out since it provides advantages such as low energy consumption, constant quality of produced water, and a range of salinity reduction more significant than 80 %. Therefore, the techniques for suppressing evaporation and desalination show efficiency, standing out as processes of extreme relevance in reducing water salinity, which is fundamental for supplying diffuse communities.