**6. Conclusions and recommendations**

The combination of the adaptation of technologies with natural brackish water and solar energy in the area would help mitigate the effects of climate change. In other words, the use of brine is a proposal that provides another source of water for irrigation and reduces the greenhouse effect. The proposed system to produce *A. nummularia* would avoid the production of 1.5 tons of CO2 by using solar photovoltaic energy as the system's energy source.

The use of brine in the cultivation of the halophyte plant *A. nummularia* could generate a forage yield of 825 kg year�<sup>1</sup> , occupying a volume of 75 L plant�<sup>1</sup> week�<sup>1</sup> of brine obtained from the RO plant. This forage obtained with *Atriplex* would contribute positively to the growth of bovines (cow), enhancing the sustainable development of the rural community.

In addition to the environmental benefits, the integrated scheme used in the semiarid region of Arica and Parinacota would produce a new source of food for the agricultural sector, thus, diversifying the fodder for livestock in rural areas and adding value to a waste stream with potential contaminating effects.

The use of brine as irrigation water for halophilic plants is an option to consider compared to conventional forage crops such as alfalfa. *A. nummularia* helps protect soils and subway aquifers, because it has a high salt absorption capacity, avoiding potential contaminating effects on the environment.

The circular economy can be considered as a valuable model to promote sustainable resource management, contributing to the construction of a vision for long-term sustainable development. Within this framework, the study complies with 9 of the 11 strategies of the circular economy.

The reverse osmosis technology produces a percentage of brine equal to that of the product water and researchers seek to improve and optimize the membranes to obtain more product water, in this particular case, it would not be necessary because the brine is used practically 100% in the irrigation of halophytes considering its cultivation in a sandy loam soil, with a pond capacity of 48 mm and a 43% of total porosity of the soil to be cultivated, introducing to this technology a new concept, circular economy, increasing its added value.

Finally, this study opens some potential opportunities for future research, such as the implementation of this type of projects in rural communities, considering the use of saline wastes as a source of water for irrigation, maintaining the circularity of RO desalination plants.
