Remediation of Groundwater Polluted by Aromatic Compounds by Means of Adsorption

Abstract

Abstract:In this work, an experimental and modeling analysis of the adsorption of four aromatic compounds (i.e., toluene, naphthalene, o-xylene and ethylbenzene) onto a commercial activated carbon is carried out. The aim is to assess the suitability of the adsorption process for the treatment of polluted groundwater, also when a multiple contamination is detected. Batch adsorption tests from simulated polluted groundwater are performed in single-compound systems and in two binary systems (i.e., toluene + naphthalene and o-xylene + ethylbenzene), at constant temperature (20 °C) and pH (7). Experimental results in single-compound systems reveal that all of the analytes are significantly adsorbed on the tested activated carbon. In particular, toluene and naphthalene adsorption capacities are the highest and of similar value, while for o-xylene and ethylbenzene, the performances are lower. The adsorption of these compounds seems to be influenced by a combined effect of several parameters, such as hydrophobicity, molecule size, structure of the molecule, etc. Experimental results in binary systems show a different behavior of the two systems, which confirms their complexity and explains the interest in these complex adsorption systems. In particular, toluene and naphthalene are mutually competitive, while in the case of OPEN ACCESSSustainability 2014, 6 4808 o-xylene + ethylbenzene, only the former undergoes competitive effects. The analysis of the entire experimental data set is integrated with a dedicated modeling analysis using the extended Langmuir model. For both single-compound and binary systems, this model provides acceptable results, in particular for low equilibrium concentrations, like those more commonly found in groundwater, and for the compounds involved in adsorptive competitive effects.

Macromolecular Structure of a Commercial Humic Acid Sample

“…Because of these properties, HA have been proposed as an adsorbent in wastewater purification plants [5][6][7]. On the other hand, HA cannot be removed from water by using conventional oxidation processes; however, several approaches are effective for treating recalcitrant compounds, such as adsorption [8,9] and advanced oxidation processes [10,11].…”

An optimized configuration of adsorptive wells for the remediation of an aquifer contaminated by multiple aromatic hydrocarbon pollutants

“…Several technologies, both ex-situ and in-situ, have been investigated and have evolved over the years to clean up contamination from such compounds (Canzano et al, 2014). Ex-situ technologies generally embrace pump and treat methods (P&T), which can be combined with a physical containment of the polluted water by installing slurry walls or some other permanent structure (Brauner and Killingstad, 1996).…”

Recycling of End-of-Life Vehicles in Small Islands: The Case of Kinmen, Taiwan

“…The improper management of ELVs may cause severe environmental problems by lead batteries, refrigerant gases, mercury, and mechanical oils [3]. The poor treatment of ELVs may also cause heavy metal soil pollution [4] and groundwater pollution [5]. The legislation on ELV recycling exists in the EU, Japan, Korea, China and Taiwan, but in many countries and regions where automobile ownership is rapidly increasing, the recycling systems and policies are not yet established [3].…”