PEMANFAATAN BOTTOM ASH PLTU SEBAGAI MEDIA FILTER UNTUK MENGOLAH LIMBAH TAHU

Liquid waste from the tofu industry is a significant source of water pollution,
containing high levels of organic materials that can harm aquatic ecosystems. On the
other hand, Coal-Fired Power Plants (CFPP) produce a large amount of bottom ash,
which is still underutilized. This study aims to explore the potential of bottom ash
from the Nagan Raya CFPP in Aceh as an economical and environmentally friendly
alternative filter medium for treating tofu wastewater. The main focus is to evaluate
the effectiveness of bottom ash in reducing Chemical Oxygen Demand (COD), Total
Suspended Solids (TSS), and neutralizing pH. The method employed is a quantitative
experimental approach using a layered filtration system consisting of gravel, coir,
sand, and bottom ash as the adsorbent. The contact time between the wastewater and
the filter medium was varied for 2, 4, and 6 hours, with a control filter without
bottom ash. Initial samples showed TSS levels of 560 mg/L and a pH of 3.8, which
are far below the quality standards. The results indicate that the use of bottom ash
significantly improves wastewater quality, with the highest TSS removal efficiency
reaching 82.85% at a contact time of 6 hours, reducing TSS to 96 mg/L. The highest
COD reduction occurred at a contact time of 2 hours, with an efficiency of 24.8%.
Bottom ash was also effective in neutralizing the wastewater, raising the pH to a
neutral range (6.2 – 7.0). These findings suggest that bottom ash from CFPP has great
potential as a filter medium for tofu wastewater.
Keywords : Bottom Ash, Filter Medium, Contact Time, Tofu Liquid Waste.