Comparación de métodos de descarga para vertidos de salmueras, provenientes de una planta desalinizadora en Sonora, México

Abstract

One of the alternatives for tackling water shortages for human, industrial and agricultural use is desalination of seawater and brackish water. Desalination involves the separation of dissolved salts from water, by means of several technologies. However, despite the benefits that the technologies offer, an important disadvantage of the process is the amount of brine generated and its environmental impact as a result of its high salinity. In this context, the aim of this study is to compare the techniques available to discharge brines from a desalination plant, through the investigation of adequate disposal methods, in order to propose the best technique, to decrease the environmental impact caused in the study site. For this purpose, a 100 m3/d desalination plant was operated at 85 % product recovery and 15 % retentate. The salinity concentration difference between the feed and retentate (brine) was compared. The results indicate an increase in the retentive salinity with respect to the feed water, from 2931 mg/L to 6756 mg/L of total dissolved solids. This concentration increase shows that it is important to regulate the disposal of brine in order to avoid negative impacts on the receiving ecosystem. For this project, the most adequate method according to the study site was to operate an aquaculture farm for the production of high commercial value shrimp. Hence, this was the proposed integral brine discharge management in the zone of the Yaqui Valley in Sonora, Mexico.