Biopolymer Hydrogel Based on Acid Whey and Cellulose Derivatives for Enhancement Water Retention Capacity of Soil and Slow Release of Fertilizers

Abstract

This study describes the development of a renewable and biodegradable biopolymer-based hydrogel for application in agriculture and horticulture as a soil conditioning agent and for release of a nutrient or fertilizer. The novel product is based on a combination of cellulose derivatives (carboxymethylcellulose and hydroxyethylcellulose) cross-linked with citric acid, as tested at various concentrations, with acid whey as a medium for hydrogel synthesis in order to utilize the almost unusable by-product of the dairy industry. The water uptake of the hydrogel was evaluated by swelling tests under variations in pH, temperature and ion concentration. Its swelling capacity, water retention and biodegradability were investigated in soil to simulate real-world conditions, the latter being monitored by the production of carbon dioxide during the biodegradation process by gas chromatography. Changes in the chemical structure and morphology of the hydrogels during biodegradation were assessed using Fourier transform infrared spectroscopy and scanning electron microscopy. The ability of the hydrogel to hold and release fertilizers was studied with urea and KNO3 as model substances. The results not only demonstrate the potential of the hydrogel to enhance the quality of soil, but also how acid whey can be employed in the development of a soil conditioning agent and nutrient release products.

Controlled‐release alginate‐bentonite polymer gel granules of emamectin benzoate and control efficacy against Spodoptera frugiperda

“…The gaps of polymer matrix without emamectin benzoate were smaller compared to those of the samples loaded with emamectin benzoate. As a large amount of water penetrates the hydrogel matrix and is displaced within it, diffusion of active compounds from the polymer gel is promoted 34,35 . After absorbing water, the polymer gel particles swell, leading to an increased gap size in the polymer granules.…”

“…As a large amount of water penetrates the hydrogel matrix and is displaced within it, diffusion of active compounds from the polymer gel is promoted. 34,35 After absorbing water, the polymer gel particles swell, leading to an increased gap size in the polymer granules.…”

Smart Polymer Hydrogels as Matrices for the Controlled Release Applications in Agriculture Sector

“…via grafting using acrylic monomers. Insitu incorporation of micronutrient (boron) on acrylic acid grafted guar gum-based hydrogel [19], acrylic monomers grafted chitosan hydrogel [20], urea loaded cellulose [21], carboxymethylcellulose-hydroxyethylcellulose cross-linked with citric acid [22], etc. can also be used as matrices for the controlled release of fertilizers and water in agricultural field.…”

Sodium Alginate-g-acrylamide/acrylic Acid Hydrogels Obtained by Electron Beam Irradiation for Soil Conditioning

“…While the human need for water is approximately 2 L per day, the water required for the production of daily food for each person is 3000 L [1,2]. About 70% of the planet's fresh water reserves are used only in agriculture for irrigation, the application of pesticides and fertilizers or animal husbandry [1,3]. The population growth in recent decades has led to an increase in the demand for drinking water and food.…”

“…Additionally, the obvious climatic changes manifested through the lack of rainfall have forced a return, where was possible, to agriculture based on irrigation and to the development of other systems to replace the old rain-fed crop system. This was one of the reasons of the development of some superabsorbent materials in order to ensure the efficient use of water, and the maintenance and durability of the soil [3].…”