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

Abstract

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.