A STUDY ON THE ACTIVATED PEAT ‘S ABSORPTION OF CU(II), ZN(II), PB(II) IONS BY HCL SOLUTION

Abstract

The sample taken from the peat source in Lien Chieu - Da Nang was activated by HCl solution. The activated peat sample with the size of the particles ≤ 0.5mm was used as an absorption material of Cu²⁺, Zn²⁺, Pb²⁺ ions in water solution at room temperature. In the absorption condition that the tank was stirred and mixed, time to achieve absorption balance was 90 minutes for Cu²⁺, 70 minutes for Pb²⁺, 60 minutes for Zn²⁺ and pH was 5 for the 3 ions. Maximum absorption quantity of Pb²⁺ > that of Cu²⁺ >that of Zn²⁺  and the values were: q_{max (Pb2+)} = 12,84 (mg/g); q_{max (Cu2+)} = 7,12 (mg/g). q_{max (Zn2+)} = 5,46 (mg/g). The absorption affinity of Cu²⁺ was 0,066; of  Pb²⁺ = 0,075; of Zn²⁺ = 0,048. Because the affinity of Pb²⁺ ion > that of Cu²⁺ > that of Zn²⁺, the metal’s  absorption of ions decreases in order : Pb²⁺ > Cu²⁺ > Zn²⁺. The results that we obtained showed that the Langmuir model described quite accurately the absorption of M²⁺ in activated peat. At the same time, it showed the possibility of using activated peat for the purpose of separating heavy metal ions from the water environment.