Boosting sorption features and eco-safety of cross-linked alginate composites incorporated with stoichiometric and calcium-deficient hydroxyapatites

The archived data were gathered within the research project titled ‘Realizacja Europejskiego Zielonego Ładu poprzez zastosowanie innowacyjnych materiałów hydrożelowych opartych na biopolimerach i wypełniaczach nieorganicznych na potrzeby rolnictwa.’, eng. ‘EU Green Deal realization through the application of innovative hydrogel materials based on biopolymers and inorganic fillers for agricultural needs’, financed by the MSCA4Ukraine project (grant holder Ganna Yanovska), which is funded by the European Union.  (project no. 1233565). The primary objective of this study was to develop and characterize eco-friendly hydrogel composites based on sodium alginate (SA) and two types of hydroxyapatite – stoichiometric (HA) and calcium-deficient (CDHA) – for potential agricultural applications, including soil conditioning and cadmium removal. The hydrogels were synthesized with varying concentrations of calcium chloride (0.25–0.5%) as a cross-linking agent and different HA/CDHA loadings. Comprehensive physicochemical analyses (XRD, FTIR, SEM/TEM, textural analysis) confirmed the successful incorporation of mineral fillers into the alginate matrix and revealed structural differences between HA- and CDHA-based composites. Swelling studies demonstrated that both filler type and cross-linking density strongly affected water uptake and diffusion mechanisms. Biosafety tests using Pisum sativum and Lepidium sativum seeds confirmed the non-toxic nature of the materials. The research was conducted in the period from 1st May 2024 till 1st November 2025 at the Institute of Agrophysics, Polish Academy of Sciences in Lublin (Poland). The collection contains the results of studies on: (1) characteristics of hydroxyapatite and calcium deficient hydroxyapatite, as well as hydrogels contained these fillers, (2) adsorption studies of Cadmium ions, including adsorption mechanisms on the selected materials, (3) swelling studies of hydrogels, (4) evaluation of the ecotoxicity of the developed material and its effects on the growth of plants. ​The attached files have been compressed to *.zip format. The dataset consists of the following files:1) character – raw data on the determination of textural parameters (nitrogen adsorption/desorption isotherm, specific surface area, porosity, pore size distribution), phase analysis, morphology, elemental composition, FTIR analysis of inorganic fillers and hydrogels obtained from them (.odt, .pdf., xls, .xlsx, .tiff, .txt).2) ads – raw data on the measurements of adsorbed amounts of Cd ions (.xlsx).3) swelling – raw data on hydrogels swelling (.xlsx).4) biosafety – root length data of cress (L. sativum) grown (.odt, .xlsx).The data was compiled on the basis of laboratory tests.The results presented in file „character” were obtained using the following research equipment: nitrogen adsorption/desorption analyzer ASAP2405 (Micromeritics Inc.), scanning electron microscope (Quanta 3D FEG, FEI), X-ray phase analysis (XRD) (Empyrean, PANalytical), Transmission Electron Microscope (Tecnai, G2 T20 X-TWIN, FEI), Fourier transform infrared spectrometer (FTIR) (ThermoNicolet iS10). The results presented in file „ads” were obtained using the PH/Ion meter CPI-505 (Elmetron) with ionoselective electrodes (Detector s.c.) The results presented in file „swelling” were obtained using the following research equipment: scales Radwag (AS 110R2 Plus).The results presented in file “biosafety” were obtained with smartphone camera and calliper rule.