การนำกลับไอออนแพลเลเดียมจากของเสียอุตสาหกรรมผ่านเยื่อแผ่นเหลวที่พยุงด้วยเส้นใยกลวง / กีรตินาท อาจญาทา = The recovery of palladium ion from industrial waste via hollow fiber supported liquid membrane / Keeratinat Artyata
This work investigates the recovery of palladium and stannous ions from flexible printed circuit board industrial waste via hollow fiber supported liquid membrane by using LIX 84-I dissolved in organic solution as the extractant. The hydrochloric acid was used as the stripping solution. The experiments were examined in functions of pH of feed solution, types of diluents, extractant concentration, the concentration of hydrochloric acid, system temperatures, equal flow rates of feed and stripping solutions. The optimal condition for recovery palladium and stannous ions was attained at pH of feed solution equal to 3.0 by using 0.06 M LIX 84-I dissolved in kerosene as the extractant, hydrochloric concentration in stripping solution of 6 M, system temperature of 25 OC, flow rates of feed and stripping solution are equal to 100 ml/min. The extraction percentages of palladium and stannous are 100 and 16 % and the stripping percentages are 100 and 0 %, respectively. The aqueous mass transfer coefficient (k[subscript i]) and the organic mass transfer coefficient (k[subscript m]) were determined. The mass transfer coefficients of the aqueous phase and organic for palladium ions are 3.11 x 10⁻³ and 1.75 x 10⁻⁴ cm/s, the mass transfer rate controlling step is diffusion of palladium complex through the liquid membrane. In case of stannous ions reported are 5.7 x 10⁻⁵ and 2.18 x 10⁻⁴ cm/s, the mass transfer rate controlling step is diffusion of stannous ions through the film layer between feed solution and liquid membrane. The both of palladium and stannous were determined the order of reaction (m) by used the kinetic theory, both are equal to 1.0. In addition the model predictions of palladium and stannous ions in the feed solutions at different time, were found fit well with experimental data at LIX 84-I concentration more than 0.02 M.
