Pemanfaatan Karbon Aktif Kulit Kacang Tanah untuk Menurunkan Kadar Ion logam Ca2+ dan Mg2+ dalam Air:

Abstract

Peanut shell has a high cellulose content as a carbon source which can be used as a basic ingredient for making activated charcoal. Research on peanut shells used as activated charcoal aims to determine the effect of contact time and pH on reducing levels of metal ions Ca²⁺ and Mg²⁺ in water. The research was conducted using contact time variables (30, 60, 90, 120, and 150 minutes) and pH (4, 5, 6, 7, and 8). Measurement of adsorbed metal levels was determined by using an Atomic Absorption Spectrophotometer (AAS). The research results obtained showed that variations in contact time could reduce Ca²⁺ levels by 77.46% -84.89% and Mg²⁺ by 86.88%-88.91%. Adsorbents with variations in pH can reduce Ca²⁺ levels by 63.48%-88.74% and Mg²⁺ by 90.35%-94.49%. The best conditions for the absorption of Ca²⁺ and Mg²⁺ ions were a contact time of 60 minutes and pH 4. The adsorbent was applied to reduce Ca²⁺ and Mg²⁺ levels in water with different hardness levels. The results of the analysis of water samples from two different locations had Ca²⁺ levels of 94.180 mg/L and 210.20 mg/L, while Mg²⁺ levels were 13.536 mg/L and 17.420 mg/L. The percentages of Ca²⁺ adsorption for the two samples were 96.19% and 77.08%, and the percentages of Mg²⁺ adsorption for the two samples were 21.16% and 10.63%. Carbon from peanut shells activated with sodium acetate has the potential to be used to reduce hardness in water.