Study of a small-scale system for water desalination and filtration: Reverse osmosis using renewable energy and physicochemical analysis of samples

M. de O. Santos, R. A. Menezes Junior, M. M. da S. Sá, M. G. Nascimento, A. C. G. Fernandes, L. S. Gomes, M. da F. Santana, H. da S. Oliveira, L. C. M. Nascimento Júnior, P. C. de O. Queiroz

Reverse Osmosis, Renewable Energy, Water Treatment, Physicochemical Analysis, Small-Scale System, Water Sustainability, Water Fil-tration, Drinking Water, Energy Efficiency

This article addresses the study, development, and evaluation of a small-scale system for water desalination and filtration, using reverse osmosis integrated with a renewable hybrid energy system. The main objective of the research is to propose an efficient and sustainable system for water treatment in areas facing water scarcity, with a spe-cific focus on the interior of the State of Sergipe, Brazil. The methodol-ogy employed combines bibliographic research with experimental research. Water samples were collected and analyzed from an artesian well located in the municipality of Estância, between 2020 and 2022. Water quality analyses were performed in a laboratory environment, before and after the desalination process. The desalination system used employed a small-scale reverse osmosis filter with a flow rate of 16 liters per hour. This water processing system was integrated into a Hybrid Energy System (HES) that uses photovoltaic solar and wind energy to operate the water pump, the cooling system, and the reverse osmosis filter. Furthermore, the study included modeling the energy production for the hydroelectric power plant, based on historical wind speed and solar irradiance data from 1990 to 2020 in regions of the State of Sergipe. The results of the water quality analyses demonstrat-ed the effectiveness of the desalination process. There was a consider-able reduction in chloride concentrations (from 50.13 mg/L to 3.71 mg/L) and sodium (from 43.27 mg/L to 3.42 mg/L). The concentration of total dissolved solids also decreased significantly (from 395.1 mg/L to 30.46 mg/L). Physicochemical parameters such as total hardness (from 300 mg/L to 29.74 mg/L) and apparent color (from 31.9 mg/L to 5.4 mg/L) showed drastic reductions and significant improvement, respectively. The process did not alter the concentration of most of the analyzed metals, sulfates, nitrites, and total selenium, with the excep-tion of manganese, which had its concentration reduced. The pH of the water varied slightly from 7.84 to 6.00, but remained within the ac-ceptable limit for potability according to Brazilian legislation. Re-garding the system's energy demand, estimated at 57.6 kWh/month, the modeling demonstrated that the average monthly photovoltaic energy production was sufficient to meet this need. Wind energy production in the region was considered less viable due to low production and high cost. In conclusion, the study validated the viability of the desalination system under study, powered by renewable energy, as a promising alternative to guarantee access to potable water in a sustainable way in regions with water scarcity. The results in improving water quality and the adequacy of renewable energy supply support the proposal.

10.22161/ijaers.134.8