การนำสังกะสีกลับคืนจากกากตะกอนโรงงานอุตสาหกรรมผลิตเส้นใยโดยวิธีการแยกด้วยไฟฟ้าแบบควบคุมศักย์ไฟฟ้า / พิมลพร โตโภชนพันธุ์ = Recovery of zinc from rayon fiber production factory industrial sludge by controlled - potential electrolysis / Pimonporn Tophochanapun
The present research studied a zinc exclusion from solid waste by the use of controlled-potential electrolysis. This work is composed of two sections. In the first section, a solvation of Zn from the sludge using various kinds of solvent at different pH was examined. Then, in the second section, the zinc recovery efficiency from the extractant solution was investigated in term of effects from applied potential, reference electrode as well as electrochemical cell type: 1- and 2-compartment cells. Results of the Zn solvation in the first section indicate that sulfuric acid at pH 1 could extract 97.91% (873.40 mg/L) of Zn²⁺, and it was considered to be the best extractant among the other tested solvents; hydrochloric acid, citric acid and ethylenediaminetetraacetic acid (EDTA). In the second section, 66.72% Zn removal from the H₂SO₄ extractant obtained in the 1-compartment cell after 7 volts potential was applied for 150 minutes. It was found that 0.0993 gram of Zn elemental was recoveried and this accountted for 66.63% Zn recovery. In the 2-compartment cells, 98.05% Zn removal from the H₂SO₄ extraction was achieved within 30 minutes electrolysis. A 0.0299 gram or 20.06% Zn elemental was recoveried along with 0.1648 gram Zn(OH)₂ which was accounted as 72.75% Zn component