An Optimized Protocol for Volatile Suspended Solids Quantification by Loss on Ignition at 550°C and Extraction of Biofilm Extracellular Polymeric Substances using Cation Exchange Resin

Abstract

This thesis provides a refined method utilizing loss on ignition (LOI) at 550 Celsius to accurately measure Volatile Suspended Solids (VSS), Fixed Suspended Solids (FSS), Total Suspended Solids (TSS), and Total Organic Carbon (TOC). A 2001 Draft EPA Method 1684 was referenced and revised using positive control experiments and current studies. The method reporting and detection limits were determined following Environmental Protection Agency Guidelines. LOI at 550&deg;C can be used for soil organic carbon, sludge, sediment analysis, wastewater treatment plant monitoring, and water quality assessment. A sample collection method was developed for periphyton algae samples from Boulder Creek, Boulder, CO for LOI 550&deg;C. Periphyton is primarily made up of diatom algae cells, which produce a microbial extracellular film called biofilm to survive harsh conditions. Environmental biofilms can be used as bioindicators for contaminants in the water and provide potential degradation pathways for toxins. Biofilm is composed of extracellular polymeric substances (EPS) that can be separated into colloidal EPS and bound EPS, consisting of polysaccharides, proteins, lipids, nucleic acids, and divalent metals such as Ca2+ and Mg2+. The second section of this thesis optimizes an EPS extraction method of biofilms utilizing CER (cation exchange resin) by introducing lab-grown biofilm Bacillus Subtilis as a standardized control, allowing reproducibility across labs. Currently, there are no standard controls used between EPS extraction methods.&nbsp;</p