Conversion of Chromium Shaving Waste from Leather Processing into Activated Carbon

Abstract

This study aimed to convert chrome shaving waste (CSW) generated from leather processing into valuable materials, such as de-chromed activated carbon and basic chromium sulphate. CSW was de-chromed using three levels of leaching solution of potassium carbonate, hydrogen peroxide, and water (0.25:0.1:5, 0.5:0.2:5, and 0.75:0.3:5, respectively), and the resulting potassium chromate was converted into basic chromium sulphate using sugar reduction method. De-chromed shaving waste (DSW) was pyrolyzed at three temperatures levels (400, 500, and 600 °C) to obtain de-chroming shaving ash (DSA), which then was chemically activated using three levels of potassium hydroxide (3:1, 2:1, and 1:1 of DSA: KOH, respectively). The results showed that up to 21% of de-chroming activated carbon (DAC) was produced, containing 71.22% carbon with a surface area of 731 m2/g, total pore volume of 0.385 cm3/g, and an average pore diameter of 2.106 nm. The produced basic chromium sulphate was suitable for reuse in leather processing. Therefore, this study provides an effective way to convert CSW into valuable materials, reducing the environmental impact of leather processing and promoting sustainability.