Analisis Limbah Karbon Aktif Filter Depot Air Minum sebagai Adsorben untuk Penurunan Logam Besi pada Air Sumur Bor

Abstract

The limited supply of clean water around the Medan Industrial Area encourages people to use drilled well water which is susceptible to contamination by heavy metal contaminants, especially iron (Fe) which has levels exceeding the threshold of 0.2 mg/L according to the Regulation of the Minister of Health of the Republic of Indonesia No. 2 of 2023. This study utilized granular activated carbon waste from drinking water depot filters as an adsorbent, through a washing process using 0.5 M HCl, drying at 110°C for 2 hours and thermal reactivation at 500°C, 600°C, and 700°C for 2 hours. Characterization of the physical properties of activated carbon was carried out by testing the water content and ash content before and after thermal reactivation, while surface morphology characterization was carried out using a Scanning Electron Microscope (SEM) before and after reactivation at the best temperature (700°C). The adsorption test was conducted using a two-stage batch method: the first stage tested variations in reactivation temperature on a well water sample with a concentration of 58.4 mg/L, and the second stage tested variations in adsorbent weights of 4g, 6g, 8g, and 10g at the best temperature of 700°C with an Fe content of 12.7 mg/L. Fe levels before and after the adsorption process were measured using Atomic Absorption Spectrophotometry (AAS) at a wavelength of 248.3 nm. The results showed that thermal reactivation at 700°C and an adsorbent weight of 10 g was able to reduce Fe levels by 99.92% with an Fe content of 0.009 mg/L. This study demonstrates that waste activated carbon from drinking water depot filters can be reused as an adsorbent, producing Fe levels <0.2 mg/L (Regulation of the Minister of Health of the Republic of Indonesia No. 2 of 2023).