Application and modeling of aniline sorption

Abstract

Passive and active vegetative systems, and building integrated systems, were studied as viable aniline treatment options. The research of aqueous aniline sorption was executed to understand the best way to treat aniline, and possibly other volatile organic compounds (VOCs), with a building integrated system using growing media.

The sorption of aniline to four different growing media (e.g., expanded clay, growstone, activated carbon (AC) sheets, and granular activated carbon (GAC)) was studied after 1- and 7-day equilibration. The GAC was found to have the greatest sorption capacity for aniline with an average 7-d sorption value of 196.0 mg/g. Expanded clay and growstone did not adsorb much aniline with average 7-d sorption values of 0.16 and 0.01 mg/g, respectively. The AC sheets were tested with the idea that this material would provide even air treatment in a building integrated active phytoremediation system, but did not perform as well as GAC with a 7-d average sorption value of 5.1 mg/g.

A mathematical model that estimates the throughput parameter and subsequent time for a C/Co aniline concentration ratio, was developed. This model predicted a breakthrough curve of aniline through a GAC packed bed system. A laboratory study of a GAC packed column was studied to compare experimental results to the model output. The model was used in three different ways: [1] at equilibrium (7-d Freundlich coefficients of 16.6 (KF) and 0.37 (N)), [2] at non-equilibrium (1-d Freundlich coefficients of 24.5 (KF) and 0.45 (N)), and [3] in expected gas phase. The equilibrium model matched the laboratory breakthrough curve well with both curves having C/Co values of 0.5 occurring at about 9 days.