This work aims to prepare a novel phosphate-embedded silica nanoparticles (P@SiO₂) nanocomposite as an effective adsorbent through a hydrothermal route. Firstly, a mixed solution of sodium silicate and sodium phosphate was passed through a strong acidic resin to convert it into hydrogen form. After that, the resultant solution was hydrothermally treated to yield P@SiO₂ nanocomposite. Using kinetic studies, methylene blue (MB) dye was selected to study the removal behavior of the P@SiO₂ nanocomposite. The obtained composite was characterized using several advanced techniques. The experimental results showed rapid kinetic adsorption where the equilibrium was reached within 100 s, and the pseudo-second-order fitted well with experimental data. Moreover, according to Langmuir, one gram of P@SiO₂ nanocomposite can remove 76.92 mg of the methylene blue dye. The thermodynamic studies showed that the adsorption process was spontaneous, exothermic, and ordered at the solid/solution interface. Finally, the results indicated that the presence of NaCl did not impact the adsorption behavior of MB dye. Due to the significant efficiency and promising properties of the prepared P@SiO₂ nanocomposite, it could be used as an effective adsorbent material to remove various cationic forms of pollutants from aqueous solutions in future works.

Organic pollutants such as phenolic compounds have received global interest since they are harmful, toxic, and carcinogenic. This work aimed to synthesize copper sulfide nanoparticles in digenite phase (Cu_1.8S) via sol–gel method and apply it as a photocatalyst to remove a phenolic contaminate, bromophenol blue (BPB) dye, from water. The copper sulfide nanoparticles were prepared by the sol–gel technique under different conditions, such as reaction temperature, reactant concentration, and aging time, in the presence of a stabilizing agent (cetyltrimethylammonium bromide, CTAB). The synthesized nanoparticles were then described using different characterization techniques. Then these nanoparticles were applied as a photocatalyst for the degradation of bromophenol blue (BPB) under different conditions, including photo-irradiation time, catalyst dosage, dye concentration and power lamp. The aimed copper sulfide digenite nanoparticles (Cu_1.8S) were obtained at a 3 h aging time, exhibiting a cubic crystal structure and a size of 8 nm in a 3-dimensional closed-packed structure model with an energy band gap of 1.82 eV. This material has the ability to absorb visible light and thus can be a superior candidate for photocatalysis, demonstrating strong photocatalytic activity towards the degradation of the phenolic dye (i.e., BPB). Excellent results were achieved at a contact time of 3 h, 7 ppm of BPB, 50 mg catalyst dose, and 32 W power lamp. As a consequence, about 96.7% of the contaminants were removed. The photocatalytic degradation was found to obey the Langmuir postulate and exhibit pseudo first order kinetics.

CaCO3 nanoparticles synthesized from CaCl2 and Na(2)CO(3)using a new, simple and fast technique. Factors affecting on the particle size such as concentration of Ca2+ and CO32-, PEG weight dissolved in Ca2+ solution, flow rate, temperature, media type, PEG weight dissolved in the used medium, concentration of CO32-, stirring speed, medium volume and additive dissolved within Ca2+ solution investigated. The obtained particles were characterized by SEM, XRD, EDS, IR and TGA. The characterization clarified that the particles prepared were spherical with size range of 19-30 nm, ultra-pure and the crystal was calcite. Moreover, the preparation system was redesigned to be continuous preparation system. The histogram showed that the CaCO3 nanoparticles obtained were homogenous in size (30 nm). Finally, the obtained nanoparticles were used in preparation of nanoporous PVC film with pores size range 80-120nm