Eco-Friendly Hydrogel from Sodium Alginate and Orange Peel for Sustainable Soil Conditioning

Hajaratul Najwa Mohamed; Che Ku Mohd Faizuldin Che Ku Mohd Yassin; Nabihah Abdullah; Norazlina Hashim; Shuhaimi Mustafa; Abdul Fattah Ab Razak

doi:10.22146/ijc.111205

Eco-Friendly Hydrogel from Sodium Alginate and Orange Peel for Sustainable Soil Conditioning

https://doi.org/10.22146/ijc.111205

Hajaratul Najwa Mohamed^(1*), Che Ku Mohd Faizuldin Che Ku Mohd Yassin⁽²⁾, Nabihah Abdullah⁽³⁾, Norazlina Hashim⁽⁴⁾, Shuhaimi Mustafa⁽⁵⁾, Abdul Fattah Ab Razak⁽⁶⁾

(1) Department of Natural Resources and Environment, Faculty of Engineering Technology, University College TATI, Jl. Panchur, Teluk Kalong, 24000 Kemaman, Terengganu, Malaysia
(2) Department of Natural Resources and Environment, Faculty of Engineering Technology, University College TATI, Jl. Panchur, Teluk Kalong, 24000 Kemaman, Terengganu, Malaysia
(3) Department of Natural Resources and Environment, Faculty of Engineering Technology, University College TATI, Jl. Panchur, Teluk Kalong, 24000 Kemaman, Terengganu, Malaysia
(4) Department of Natural Resources and Environment, Faculty of Engineering Technology, University College TATI, Jl. Panchur, Teluk Kalong, 24000 Kemaman, Terengganu, Malaysia
(5) Halal Product Research Institute, Putra Infoport, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia
(6) Department of Food Technology, School of Engineering and Technology, University of Technology Sarawak, Jl. Universiti No. 1, 96000 Sibu, Sarawak, Malaysia
(*) Corresponding Author

Abstract

An eco-friendly hydrogel was developed from sodium alginate (ALG) and orange peel (OP) powder through ionotropic gelation for application as a sustainable soil conditioner. Limonene (LMN) at 1.5 wt.% was incorporated to enhance the functional properties of the hydrogel. Fourier-transform infrared spectroscopy (FTIR) results confirmed the successful integration of OP into the ALG network through the presence of characteristic hydroxyl and carboxyl functional groups, while thermogravimetric analysis indicated improved thermal stability with increasing OP content due to its lignocellulosic reinforcement. Swelling analysis revealed that the incorporation of 5 wt.% OP enhanced the swelling capacity to 95.5% compared to 65.8% for ALG–LMN alone. However, further increases in OP content (10–15 wt.%) reduced swelling, suggesting excessive filler restricted water diffusion and polymer relaxation. Lower OP concentrations (1–3 wt.%) maintained high water absorption and structural integrity. These findings demonstrate that moderate OP incorporation optimizes the balance between water retention and mechanical stability, indicating strong potential of the ALG–OP–LMN hydrogel as a biodegradable and sustainable soil conditioning material that valorizes agricultural waste.

Keywords

hydrogel; sodium alginate; orange peel; soil conditioning

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DOI: https://doi.org/10.22146/ijc.111205