KARBON AKTIF AMPAS KOPI HOUSE BLEND TERAKTIVASI H₂SO₄ UNTUK PENGOLAHAN LIMBAH LAUNDRY

Abstract

Direct discharge of laundry wastewater without treatment causes negative environmental impacts due to high levels of Methylene Blue Active Substances (MBAS), phosphate, and ammonia. This study aims to utilize house blend coffee ground waste as a raw material for activated carbon activated with sulfuric acid (H2SO4) to reduce these pollutants. Coffee grounds were pyrolyzed at 200°C for 2 hours and activated with varying H2SO4 concentrations of 10% (AK10), 20% (AK20), and 30% (AK30). The activated carbon was characterized according to SNI 06-3730-1995, including moisture content, ash content, iodine number, functional groups (FTIR), and total carbon content, then applied to laundry wastewater in a batch system (dose 4 g/L, 200 rpm, 60 minutes). The results show that moisture content (0.1477-0.3751%) and ash content (8.9970-9.2211%) of all samples met the SNI standard, while the iodine number (116.96-132.735 mg/g) and total carbon content (43.26-60.27% w/w) did not meet the SNI minimum thresholds (750 mg/g and 65% w/w). FTIR analysis confirmed successful surface sulfonation, indicated by a sharp S-O absorption peak after activation. In the application stage, the highest reduction effectiveness for MBAS was achieved by AK20 at 58.86% (from 30.51 to 12.55 mg/L), for phosphate by AK30 at 29.20% (from 1.736 to 1.229 mg/L, meeting the 2 mg/L quality standard), and for ammonia by AK30 at 11.79% (from 10.94 to 9.650 mg/L, meeting the 10 mg/L quality standard). An activator concentration of 20-30% proved to be the optimum range, although the MBAS parameter did not reach the discharge standard due to the high initial pollutant load. This study demonstrates that H2SO4-activated house blend coffee ground activated carbon has potential as an environmentally friendly adsorbent for the pretreatment of laundry wastewater, with further optimization needed in pyrolysis temperature and contact time.