Journal of Pure and Applied MicrobiologyVol. 8 No. Special Edition Nov. 2014

Aquatic Natural Organic Matter (NOM) Removal in Biological Filters

Francisco J. Rodríguez-Vidal

Department of Chemistry, University of Burgos, Spain. Higher Polytechnic School, Av Cantabria s/n 09006 Burgos, Spain.

Received on 06 August 2014 and accepted on 20 October 2014

 

ABSTRACT

The aim of this work was to study the biodegradability of aquatic natural organic matter (NOM) through measurements of the biodegradable dissolved organic carbon (BDOC) in several water samples. Two different bioassays were used to determine BDOC: the Billen-Servais method (inoculum: raw water) and the Joret-Lévi method (inoculum: acclimated sand) and three different types of water were studied in this work: a natural water from the Úzquiza Reservoir (Burgos, Spain), a synthetic water prepared using natural fulvic acids extracted from the Úzquiza Reservoir and a synthetic water prepared using a commercially suppliedhumic acid. The natural water from the Úzquiza Reservoir (Burgos, Spain) showed the most biodegradable NOM whereas the solutions of pure humic substances had a low biodegradability, showing values slightly higher the fulvic acids. The Billen-Servais method (inoculum: raw water) gave substantially lower BDOC values than the Joret-Lévi method (inoculum: acclimated sand) for the three types of NOM studied. Additionally, several filtration tests were performed using columns filled with either sand (a non-adsorbing media) or granular activated carbon: GAC (an adsorbing media), including two operating conditions: sterile filtration and biologically active filtration. GAC filters showed a substantially greater TOC removal than sand filters, due to the high adsorptive capacity of GAC for humic substances; biologically active filters showed a slightly greater efficiency (about 3%) than sterile filters, which was similar regardless of the type of filter used (GAC or sand).

Keywords : Biodegradation assays, Biodegradable dissolved organic carbon (BDOC), Granular activated carbon (GAC) filters, Sand filters,humic substances, Natural organic matter (NOM).