Resumen de Micro-pollutants remediation from soil and groundwaer by in-situ treatment technologies
César Alberto Valderrama Angel
Growing industrialization causes continuous increase in micro-pollutants contaminations in soils and groundwater. Most of these organic chemicals like Polycyclic Aromatic Hydrocarbons (PAHs) are persistent in the environment and represent adverse effects on the human health. PAHs are included in the Persistent Organic Pollutants (POPs) group which due to their toxicity has received increasing attention in the last decades. In-situ treatment technologies gained acceptation since 1990 in front ex-situ technologies due to the lower operational cost. For that reason, two in-situ technologies: Permeable reactive barriers (PRBs) and in-situ chemical oxidation (ISCO) were considered for the treatment of soil and groundwater contaminated with PAHs.
The present work has studied as a model system, the elimination process from water of the poliaromatic diazoic compound (Acid red 14). Additionally this compound was selected as a model compound to compare the sorption behaviour of the hyper-cross-linked polymers (MN200, MN300) with granular activated carbon (GAC) as sorbent of reference. Equilibrium experiments reported maximum loading capacities of 108, 65 and 21 g kg-1 for MN300, MN200 and GAC respectively. The kinetic experiments demonstrate the effectiveness of the hyper-cross-linked polymers compared with GAC, while the MN300 resin was close to the 90% of recovery at 600 minutes; MN200 was at 70% and GAC at 45%. Dynamic behaviour and effectiveness of sorbents for dye removal were evaluated in column experiments. Breakthrough curves were obtained for GAC and Macronet resins. In case of hyper-cross-linked polymers saturation was not totally achieved after more than 1200 bed volumes (BV), while GAC was saturated after 200 BV. The regeneration process by elution test confirmed hyper-cross-linked polymers as a competitive sorbents, since after 3 BV almost 100 % of dye was eluted for MN200 and close to 80% for MN300.
