Demetallization of toxic and heavy metal in Razor Clam, Ensis Arcuatus utilizing catalytic chelation technique

Abstract

Ensis arcuatus is a local seafood and aquatic catches in Malaysia. The toxic and heavy metals content in Ensis arcuatus were recorded below the Malaysian Food Regulation (1985) and EU Food Regulations with the range of initial concentration Pb 0.053±0.030 to.0.074±0.04µg/g, Cd 0.008±0.030 to 0.140±0.240µg/g and Ni 0.003±0.040 to 0.180±0.070µg/g.  In this research, the potential chelating agents which is trisodium citrate to remove toxic and heavy metals in Ensis arcuatus was determined using chelation method, while the optimum conditions used were 600 mg/L, dosage of chelating agents for 1 hours of treatment at temperature 29.5°C. The percentage removal of Pb, Cd and Ni were 21.62% (0.06±0.03µg/g), 31.73% (0.005±0.00µg/g) and 38.07% (0.001±0.02µg/g) respectively . The experimental data revealed that with the presence of catalyst, the percentage removal of the heavy metals  increased.  Experimental result showed that with the present of CaO/Al₂O₃, the percentage removal were increased  It is due to the properties of the CaO that have potential towards the removal of heavy metal. in Ensis arcuatus.  Meanwhile, XRD analysis depicted the active sites were due to the presence of orthorhombic Al₂O₃, monoclinic CaAl_l4O₇/CaO.2Al₂O₃ and cubic Ca₁₂Al₁₄O₃₃ species. BET surface area study illustrated the surface area of 33.22 m²/g.  Finally, FTIR analysis concluded that CaO/Al₂O₃ catalyst at 1000°C treatment showed total removal of metal nitrate species.