Study and Design of a Double-Sloped Solar Distiller, An Environmentally Friendly and Economical Solution for Arid Regions

Abstract

Introduction: Access to drinking water has become a major global challenge, exacerbated by increasing pressures on water resources in arid and semi-arid regions. Faced with this problem, solar distillation technologies are emerging as promising solutions for producing pure water from renewable natural resources, such as solar energy. This work focuses on studying the performance of a double-slope solar distiller, designed and experimentally tested in Algeria.

Objectives: The objective of our work is the design and implementation of a double-slope solar distiller, exploring the materials used as well as the different stages of the design and manufacturing process of the double-slope solar distiller. The positive environmental impact of this solution is also highlighted, especially in isolated areas lacking drinking water.

Methods: The experiments were conducted at the northern Algeria. All experiments were performed using a single solar still with two slopes that we designed ourselves. The experiments took place in the same location, with the same position, but with different start times, different types of water, and, of course, under different weather conditions. To better understand the function of the still, we measured the temperature in several parts of the still, in addition to measuring the wind speed and the solar radiation falling on the still's glass. Two tests were carried out, with different water characteristics.

Results: The production of distilled water is influenced by several factors, including solar radiation, the temperature gradient between the water temperature in the basin and the transparent cover, the geometry of the device, and meteorological parameters. The variation in our daily production was monitored for the two trials conducted. For test n°1: the weather conditions were very favorable for collecting a significant quantity of distilled water; maximum sunshine was observed, which promoted solar distillation. For test n°2: the weather conditions were also favorable for collecting a significant quantity of distilled water, averaging 400 ml.

Once the water was distilled, a considerable decrease in TDS (Total Dissolved Solids) was observed, reaching 75.46%. A slight decrease in pH of approximately 0.8 was also noted, due to the loss of dissolved mineral salts and alkaline substances. A decrease in conductivity of 75.66% was also observed after distillation, due to the removal of inorganic salts. Similarly, a decrease of 74.5% in salinity was observed, due to the separation of pure water from the dissolved salts remaining in the unevaporated portion of the water, which was 0.02% in most tests.

Conclusions: In conclusion, this thesis aims to contribute to the advancement of knowledge on sustainable drinking water production technologies, focusing specifically on the efficiency of a double-slope solar still in a localized context. By providing empirical data and in-depth analysis, our study will serve as a reference for the development and adoption of similar technologies in regions facing water security challenges.