Resources Recovery from Mussel shells for the Synthesis and Application of CaO nanoparticles for the Adsorption Remediation of Crystal Violet Contaminated Water

Background: In consideration of the need for effective solid waste management through resource recovery and advanced environmental application techniques, we investigated the potential of mussel shell as a precursor for the synthesis of calcium oxide nanoparticles due to their high content of CaCO3.

Method: Calcium oxide nanoparticles were fabricated from mussel shell wastes (using sol gel method), characterized and applied in the adsorption remediation of crystal violet contaminated water.

Results: The nanoparticles have an average particle size of 2.94 nm, pore volume of 0.254 cc/g and BET surface area of 302 m2/g. It showed intense FTIR and UV absorption at 1400 cm-1 and 238 nm respectively. The band gap and pH at zero charged were also evaluated as 7.1 and 7.2 eV respectively, which indicated that the particles absorb in the UV region and favour the adsorption of crystal violet dye in the basic pH. An increase in temperature decreases the efficiency of the nanoparticles towards the removal of the dye while the removal was favoured by increasing the dye concentration, dosages of the adsorbent, time and ionic strength. The maximum removal efficiency of almost 100% was observed after 1 hour period of contact and at the adsorbate concentration of 100 ppm.

Conclusion: The nanoparticles showed an average of 98% recovery capacity after three times re-used and they are thermally stable above 600 °C.