Preparation of Novel Adsorbent Material Based on Common Sea Shells for the Adsorption of Cd2+ Ions

This paper reports the formation of novel adsorbent material based on undulating venus shell (UVS), white conch shell (WCS), conus conch shell (CCS) and abalone shell (AS). These absorbent materials were prepared by grinding the shells followed by high-temperature calcination process. The prepared adsorbents were well characterized by scanning electron microscopy (SEM), X-ray diffraction and Fourier transform infrared (FTIR) spectroscopy. Further, the effects of adsorbent dosage and temperature on the adsorption of Cd2+ by shell powder and related adsorption isotherms were evaluated. The results indicated that the amount of adsorbent and temperature have a great influence on the adsorption process of the four adsorbents. Under optimized conditions, the four shell powders exhibited strong adsorption properties of Cd2+ which was consistent with the Freundlich isotherm adsorption model. The optimal conditions for preparing shell powder adsorbents with the best adsorption performance were determined by evaluating the particle size, calcination temperature and calcination time during the preparation process and the prepared materials were characterized by several techniques. The results demonstrated that the particle size of UVS powder was over 140 mesh at 450 °C with activation time of 60 min. Furthermore, the UVS powder exhibits apparent porous morphology after calcination and thus the specific surface area was markedly increased. Consequently, the adsorption performance was significantly improved.