Effect of bacteria inoculation in solidification/stabilization matrices for fibreboard wastewater sludge

Fiberboard factories are rapidly growing to fulfill the increasing demand for timber production. Therefore, due to this rapid growth, there is a need to address wastewater sludge disposal concerns. This is crucial because the sludge contains a high concentration of contaminants that endanger the environment and public health. This study aims to treat the sludge by determining the potential of bacteria inoculation in the Solidification/Stabilization (S/S) method based on compressive strength, heavy metal leaching, and Chemical Oxygen Demand (COD) concentrations. The materials used in sludge remediation were Portland cement to act as a binder and Sphingobacterium spiritivorum . This study involves compressive strength testing, leaching tests using Toxicity Characteristics Leaching Procedure (TCLP), COD, and heavy metals concentrations analysis using Inductively Coupled Plasma Mass Spectrometry (ICP-MS) equipment in accordance with U.S. Environmental Protection Agency guidelines (U.S. EPA). After bacteria inoculation, data shows an increase of approximately 4.4% in compressive strength test. COD concentration level reduces by around 1.5% but heavy metals concentration increases except for Chromium (Cr) and all elements still exceed the permissible limits. Based on the overall results, the method of bacteria inoculation in S/S method revealed the potential to remediate wastewater sludge.