Fog collection - materials, techniques and affecting parameters - A review

Abstract

Water scarcity has shown a great challenge during the past decades with millions suffering from lack of potable water. Although, people try to benefit from the water naturally existing in air by two sources: fog and humid air. In this paper, we mainly allot the work on fog water. Fog collection is undergone using fog mesh collectors. There are lots of methods to rate the quality of fog water collection. Most used method is the quantity of water collected in kilograms for a one square meter harvester mesh per one hour. However, sometimes water contact angle on a flat surface of the mesh's material is also reliable. Both give an indication of hydrophobicity or water repellency which is significant for high fog collection efficiency. In addition, drop falling velocity and deposition time of water on the harvester measured in seconds are both indications for fog collection efficiency but rarely used. The scope of this article is to make a helpful guide for fog harvesting technology with the parameters that control the efficiency of this water resource. In addition, there is a detailed review in the chemistry of some of the previous researches on fog water collection inspired by natural existing plants and animals that survive in arid zones where only fog or humid air is found. Concerning the fog harvesting surface material, there will be a comparison between different essential parameters as mentioned above or other general indications. Some of the procedures to create the material will also be explained.