TY - JOUR ID - 72118 TI - Nitric Acid-activated Nteje Clay: Structural and Bleaching Properties (RESEARCH NOTE) JO - International Journal of Engineering JA - IJE LA - en SN - 1025-2495 AU - Onukwuli, Okechukwu AU - Ajemba, Regina AD - Chemical Engineering, Nnamdi Azikiwe University, Awka, Nigeria Y1 - 2013 PY - 2013 VL - 26 IS - 5 SP - 495 EP - 500 KW - Activation KW - Bleaching KW - Surface Area KW - Characterization KW - Cation exchange capacity KW - Clay DO - N2 - The structural and bleaching properties of nitric acid-activated Nteje clay was studied to investigate its ability to serve as an alternative to the high cost imported bleaching earth. The clay was mined, sun-dried, grinded, and reacted with different concentrations of nitric acid, ranging from 2 mol.L-1 to 15 mol.L-1. The un-activated and activated samples were characterized to study the structural effects of the activation process. The activated samples were employed in bleaching palm oil under controlled conditions of the process variables. The characterization results showed that the surface area, cation exchange capacity (CEC), and oil retention properties of the activated samples were affected by the activation reaction. The surface area increased to about 4 times (288.8 m2.g-1) the initial value (68.5 m2.g-1), while the CEC decreased from 154 to 65 meg.100-1g-1 with acid activation. The bleaching studies revealed that the activated clay samples adsorbed color pigments from palm oil more than the un-treated clay sample, with the bleaching efficiency of the sample activated using 13 mol.L-1 HNO3 increased from 37.82 % to 89.76 %. This study has shown that nitric acid can favourable be employed in activation of Nteje clay to improve its bleaching ability and that the activated samples can serve as an alternative to the imported bleaching earths. UR - https://www.ije.ir/article_72118.html L1 - https://www.ije.ir/article_72118_ddc8e388a79c08ecbfc2eea204368ac2.pdf ER -