Biopolymer-Based Hydrogels for Harvesting Water from Humid Air: A Review

Abstract

Despite the shrinkage of water availability worldwide, the water demand has been climbing due to the rapidly increasing human population and the impacts of numerous hydroclimatic factors. To feed the growing population and meet with the exigent need for freshwater, new water sources must be identified and utilized. In recent years, biopolymer-based hydrogels have been explored as a sustainable and inexpensive solution to capture moisture from humid air for water supply. This review summarizes recent advances in the preparation of atmospheric water harvesting hydrogels that are synthesized based on cellulose, chitosan, and/or other biopolymers, as well as their agricultural applications. The properties and performance of different biopolymer-based hydrogels are discussed and compared. Since agriculture accounts for more than 70% of the water consumption, developing a cost-effective hydrogel-based atmospheric water harvesting/supply system could be a promising solution for relieving the elevating water stress in arid and semi-arid regions.

Nanocellulose/wood ash-reinforced starch–chitosan hydrogel composites for soil conditioning and their impact on pea plant growth

“…Concurrently, the total area of the hydrogel sample in the SEM images was quantied. Porosity was then calculated using the eqn (1). XRD (D2 PHASER XRD Analyzer, Bruker-USA) analysis of hydrogel samples was performed to determine the crystal structure of the hydrogel and composite hydrogel samples with a useable angular range of −3-160°2-Theta.…”

“…Thus, there is an urgent need for creative solutions that tackle these problems and advance sustainable farming methods. [1][2][3] Hydrogels are a palpable solution to this problem. Due to their hydrophilic nature and porous structure, hydrogels can retain a large amount of water.…”

Research Progress on Hygroscopic Agents for Atmospheric Water Harvesting Systems

“…Thavalengal et al [31] discuss the principles, advantages, limitations, and potential applications of different AWH technologies. Li et al [32] and Huan et al [33] reviewed some categories of moisture-absorbing materials, which did not cover different types of materials and could not fully show the differences between each type of moisture-absorbing materials. Several articles have reviewed atmospheric water harvesting (AWH) methods [1,[23][24][25][26][27].…”

Significance of biopolymer-based hydrogels and their applications in agriculture: a review in perspective of synthesis and their degree of swelling for water holding

“…Hydrological drought has posed serious impacts on crop yield, which have compelled researchers to discover fresh approaches in this regard. 2 Various technologies have been invented to tackle hydrological drought, such as drip irrigation systems and low-pressure micro-sprinklers. But these technologies are mostly applied for high-value crops and are not economical.…”