Ekstraksi Sulfat dan Validasi Metode Penentuan Sulfat Pada Pasta Timbal Aki Bekas Secara Turbidimetri di PT X Pasuruan

Abstract

This study optimized the conditions for extracting sulfate from PbSO4 using a NaOH solution and validated a turbidimetric method for quantifying sulfate in spent battery lead paste. Thermal-assisted extractions were performed using NaOH concentrations of 2, 4, 6, and 8 M. The extracted sulfate was quantified turbidimetrically via BaSO4 precipitation from the reaction of Ba2+ and SO42- ions. Evaluation of calibration curve linearity and sensitivity identified 6 M NaOH as the optimum concentration. The method was successfully validated against SNI 6989.20:2019 standards, demonstrating excellent linearity (R2 = 0.999), precision (RSD = 0.35%, Horwitz CV = 7.30%), sensitivity (calibration gradient = 4.7777), a low detection limit (LOD = 2.19 ppm), and high accuracy (recovery: 91.07% 101.07%). Application of this validated method to spent battery lead paste samples yielded an average sulfate content of 59.83 ppm (5.98%) and a corresponding sulfur content of 19.94 ppm (1.99%)