STUDI KOPRESIPITASI Zn2+ DAN Co2+ MENGGUNAKAN Al(OH)3 SEBAGAI KOPRESIPITAN

Abstract

Research of study copresipitation Zn²⁺ using Al(OH)₃ as coprecipitant has been done. This study aims to determine the optimum conditions for coprecipitation of Zn²⁺ by Al(OH)₃, and influence of foreign ions. This study uses variation pH about 5,0 – 10,0 and 6,0 – 10,0 for Co²⁺;  variation of eluent volume about 8,0 – 14,0; variation of concentrated HNO₃ volume about 1,0 – 5,0; and variation of concentration Cu²⁺ and Ni²⁺ about 0,8; 1,2; 1,6; 2,0 and 2,4, respectively. Measurement concentration of Zn²⁺ using Atomic Absorption Spectroscopy (AAS) with wavelength of  213,9 nm Zn²⁺for 240,7 nm for Co²⁺. The result showed the optimum conditions occur at pH about 8, 12 mL of eluent and 1 mL of concentrated HNO₃ with the absorption capacity of 0,074 mg/g for Zn²⁺ and pH about 8, 12 mL of eluent and 1 mL of concentrated HNO₃ with the absorption capacity of 0,0905 mg/g for Co²⁺. Meanwhile, the presence of foreign ions such as Cu²⁺ has influenced the coprecipitated Zn where concentration of the coprecipitated Zn decreased with increasing the concentration of foreign ions.

Keywords:  coprecipitation, coprecipitant Al(OH)₃, trace metal,  Zn, Co, AAS