Chemical extraction and quantification of extracellular polymeric substances in unspiked-metaldehyde and spiked-metaldehyde of rubber aerobic granular sludge and molasses aerobic granular sludge

Abstract

The building blocks of biofilm are called extracellular polymeric substances (EPSs), and they are composed of biopolymers. The optimal properties of EPSs include chemical interactions, resistance to dehydration, and resilience in the face of hazardous shock loads. It is necessary to have an understanding of EPSs extraction, composition, and the biomatrix's reaction to contaminants. This research aims to conduct chemical extraction to determine the amounts of EPSs found in unspiked-metaldehyde and spiked-metaldehyde rubber aerobic granular sludge (<i>r</i>AGS) and newly invented molasses aerobic granular sludge (<i>m</i>AGS). The <i>r</i>AGS was produced by feeding synthetic wastewater into sequencing batch reactors (SBRs). The <i>m</i>AGS was developed by adding the <i>r</i>AGS with different volumes of molasses wastewater. The EPSs were successfully extracted and identified by quantifying the number of proteins and carbohydrates present in each <i>r</i>AGS and <i>m</i>AGS condition. Hydroxyl, carboxyl, and amino groups showed that <i>r</i>AGS and <i>m</i>AGS EPSs contained carbohydrates and proteins. The compositions of the EPSs showed a strong correlation with the concentrations of metaldehyde in the spiked-metaldehyde <i>r</i>AGS and <i>m</i>AGS samples. When the total EPSs are taken into consideration, both <i>r</i>AGS and <i>m</i>AGS that are formed are effective treatments for metaldehyde treatment in wastewater.