A novel approach for the synthesis of vaterite and calcite from incense sticks ash waste and their potential for remediation of dyes from aqueous solution

The dumping of incense sticks ash due to no known application of it makes it an emerging solid waste. The presence of toxic heavy metals may categorize them as hazardous materials but the presence of high Calcium and silica has drawn the attention of the value-added minerals recovery. Here, calcium oxides were recovered from the ISA, by minimizing the solid waste. Incense sticks ash contains nearly 49–55% which acts as a potential candidate as a raw material for calcium carbonate. The synthesis of CCMPs, from ISA, involves pre-treatment that includes: the extraction of ferrous particles, and the removal of aluminum and silica. The synthesized CCMPs were characterized by sophisticated instruments for detailed information where UV–Vis spectroscopy (UV–Vis), exhibited absorption peaks for calcium carbonate at 210 nm, while dynamic light scattering (DLS) was shown that the average particle size is 1280 nm. Fourier transform infrared (FTIR) and x-ray diffraction (XRD) confirmed the microcrystalline nature of the particles, where FTIR showed bands in the 1800-700 cm−1 range. Both FESEM and TEM revealed the rhombohedral shape of the CCMPs whose size varied from 0.5 μm to 6 μm and purity was 94–96%. Finally, calcium carbonate particles efficiency was analyzed for the remediation of methyl red dye from the aqueous solution and about 48% dye was removed within 1 h only.