Impact of Nanoparticles and Natural Organic Matter on the Removal of Organic Pollutants by Activated Carbon Adsorption
Isotherm experiments evaluating trichloroethylene (TCE) adsorption onto powdered activated carbon (PAC) were conducted in the presence and absence of three commercially available nanomaterials—Iron oxide (Fe2O3), titanium dioxide (TiO2), and silicon dioxide (SiO2). Isotherm experiments were also conducted in the presence and absence of natural organic matter (NOM), in the form of humic acid, to more closely model natural water conditions. Nanoparticles at two concentration levels (0.5 and 1.0 mg/L for Fe2O3 and TiO2, and 5.0 and 10 mg/L for SiO2) were considered. Particle size distribution (PSD) of the nanoparticle solutions was analyzed with time in order to determine the nanoparticle size range of each solution. Aggregation of Fe2O3 and TiO2 was noticed, while none was observed for SiO2 solutions. Adsorption isotherm experiments were conducted at three initial TCE concentrations, two nanoparticle concentrations, and with varying amounts of powdered activated carbon (PAC). Isotherm data showed a higher degree of TCE adsorption in the presence of Fe2O3 and TiO2 nanoparticles, regardless of concentration. Fe2O3 and TiO2 nanoparticles alone were observed to act as adsorption sites for TCE by removing up to 60% of TCE from the aqueous phase. Silica appeared to have no impact on TCE adsorption at either concentration used, except in the presence of humic acid. GAC column experiments were also conducted to determine how the presence of silica nanoparticles impacted the breakthrough behavior of TCE in an adsorber bed.
School:University of Cincinnati
School Location:USA - Ohio
Source Type:Master's Thesis
Keywords:activated carbon adsorption aggregation nanoparticles particle size distribution trichloroethylene
Date of Publication:01/01/2008