Recycling Natural Fibre to Superabsorbent Hydrogel Composite for Conservation of Irrigation Water in Semi-arid Regions

• Published in: Waste and biomass valorization 2021-12, Vol.12 (12), p.6433-6448
• Main Authors: Saha, Abhisekh, Gupt, Chandra Bhanu, Sekharan, Sreedeep
• Format: Article
• Language: English
• Subjects: Arid regions; Arid zones; Conservation; Distilled water; Drying; Engineering; Environment; Environmental Engineering/Biotechnology; Food security; Hydrogels; Industrial Pollution Prevention; Inorganic salts; Irrigation; Irrigation water; Loam soils; Moisture content; Original Paper; Plant growth; Recycling; Renewable and Green Energy; Saline solutions; Semi arid areas; Semiarid zones; Silt loam; Soil amendment; Soil conditions; Soil degradation; Soil stresses; Soil water; Waste Management/Waste Technology; Waste materials; Waste utilization; Water absorption; Water availability; Water conservation; Water scarcity; Water stress; Wetting
• ISSN: 1877-2641; 1877-265X
• DOI: 10.1007/s12649-021-01489-9

Purpose Effective management of the issues related to increasing water scarcity in semi-arid regions needs special attention to minimize the negative influence of water stress conditions and prevent soil degradation to ensure global food security. Methods The present study develops an eco-friendly, low-cost superabsorbent hydrogel composite (SHC) through recycling natural fibre using graft polymerization method. Effectiveness of the synthesized SHC for conservation of irrigation water was investigated by measuring its water absorbency in different salt, and pH solutions, reswelling capacity, and the soil–water retention curve (SWRC) of SHC amended soil. Results The synthesized SHC showed water absorbency of 342 g/g in distilled water, indicating its suitability for agricultural application. The SHC showed excellent re-swelling characteristics for more than eight alternate wetting–drying cycles. The sensitivity of SHC to different inorganic salt solutions was investigated, which showed its water absorbency higher than 90 g/g at the maximum salinity level permitted for plant growth. The addition of SHC in silt loam soil showed an increase in water availability of 56%, 81%, and 125%, with the SHC concentrations of 0.1%, 0.2%, and 0.4%, respectively. Conclusion The addition of SHC had reduced the irrigation water requirement by 29% as compared to bare soil at an optimum application rate of 0.2%. The study promotes the use of synthesized SHC for the conservation of irrigation water, as well as soil ecosystem, with an additional advantage of contributing to the mass utilization of waste materials. Graphical Abstract