In this work, we report on the fabrication of nanocomposites based on superparamagnetic iron oxide nanoparticles (SPIONs) in combination with hydroxyapatite (HAp) as a platform for drug delivery and magnetic hyperthermia application. First, the influence of experimental conditions such as co-precipitant, bath temperature, and pH on the morphology and magnetic properties of SPIONs was investigated. Then, the superparamagnetic particles were coated with the hydroxyapatite layer for further loading of anticancer drugs, determining the optimal thickness of the HAp shell. The composite was fabricated by the wet chemical process and was characterized by optimizing the experimental conditions of the wiring synthesis to obtain the superparamagnetic spherical material with a high HAp loading as a platform for drug uptake. SEM and TEM studies confirmed the round shape of the magnetic core up to 15 nm in size with a well-defined HAp shell. After checking the material’s superparamagnetic properties, the temperature dependence on time and alternating magnetic field strength was tested and optimized in hyperthermia experiments.

Hydroxyapatite (HAp) adsorption granules with average size of 2 × 10 mm was fabricated from HAp powder and polyvinyl alcohol (PVA) additive by sintering for removing of Cd2+ ions from aqueous solution. The effect of some factors on the Cd2+ adsorption efficiency and capacity was investigated. The removal efficiency and capacity reached 86.5 % and 4.33 mg/g, respectively, at condition: HAp granule mass of 0.3 g, initial Cd2+ concentration of 30 mg/L, contact time of 40 minutes and pH 0 of 5.7 at 30°C. The experimental data was described by Langmuir and Freundlich isotherm models; pseudo‐first order and pseudo‐second order kinetic equations.

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Global challenges in removing heavy metal ions from aquatic reservoirs require novel solutions, especially the application of environmentally friendly materials. This paper presented the efficient removal of Fe3+ and Pb2+ ions from wastewater by apatite ore-based nanostructures. The synthesized material exhibited a nanostructure with high thermal stability, high porosity and negative surface potential, suitable for heavy metal removal in wastewater. The adsorption measurements performed in varying conditions (pH, mass of the adsorbent, and contact time onto the adsorbent) proved that even a few milligrams of the synthesized material could effectively absorb the lead and iron ions from the solution, reaching an effectiveness of about 90%. The maximum adsorption capacity followed the Langmuir isotherm model, estimated at 341 mg.g− 1 for Pb2+, and 1092 mg.g− 1 for Fe3+. Experiments conducted with industrial and craft-village’s wastewaters confirmed the high potential of the nanostructural chemically modified apatite as an efficient and affordable material for the removal of various pollutants from aqueous solutions in practical conditions.

Groundwater wells in Triassic sediments of Dong Giao formation in Kien Khe, Hanam include 6 wells in an area of 4km2. To evaluate the ability of sustainable exploitation, meeting the demand of water supply, the scientific calculation is very important and necessary. This layer is rich in water, good quality, meeting large water supply requirements. However, if the regime and volume of exploited water cannot be determined, it may cause degradation, depletion or change of water quality of the reservoir. In order to have a scientific basis for exploitation, we have conducted exploration with many types of work (field surveys, geophysical measurements, exploratory drilling, water absorption experiments, sampling analysis, calculation , synthesis of assessment and design of exploitation). Calculation results show that the exploitation of 6 wells with the flow of 1,500m3/day in the study area is reasonable, safe, meeting the requirements of both volume and quality for water supply and sustainable development.