Analysis of Water Absorption in Eco-Friendly Bricks Derived from Biosolid Waste to Support Sustainable Development Goals (SDG-12)

Biosolid waste, a byproduct of biological wastewater treatment, is an organic, yellowish-brown material rich in compounds such as silica, calcium oxide, magnesium oxide, potassium oxide, and ferric oxide. It is produced in large quantities with no economic value. This study explores the use of biosolid waste in combination with coal fly ash and cement to produce bricks. Fly ash was varied in concentrations of 10%, 20%, 30%, 40%, and 50%, while cement content ranged from 10% to 30%. Bricks were treated with a drying time of 7, 14, 21, and 28 days before testing for water absorption. The optimal brick composition, meeting Indonesian National Standard (SNI 15-2094-2000), was found to be 30% fly ash, 25% cement, and a 28-day drying period, resulting in a water absorption rate of 19.39%.