Adsorption Curve Fits For Landfill Vocs On Bituminous Coal Based And Coconut Shell Based Activated Carbon

This study explores adsorption as a method of controlling hazardous gas emissions from Municipal Solid Waste Landfills (MSWL). In particular, the hazardous air pollutants (HAPs) para, meta, and ortho-xylene, ethylbenzene and methyl ethyl ketone are selected for experimental study. Activated carbon is a good adsorbent and well known for its high surface area. Among the many varieties of activated carbon, bituminous coal based activated carbon (BPL) and coconut shell based activated carbon (OVC) are compared in this study. Each experiment was conducted in a vial with a known amount of carbon in it. The pollutant concentration remaining in the vial headspace at equilibrium was measured using gas chromatography (GC), model SRIGC8610. PeakSimple software associated with the GC was used for plotting chromatograms of concentration vs time. Adsorption curve fits of Langmuir and Freundlich isotherms were determined for each compound and each type of activated carbon and compared with the measured adsorbed values to find the best isotherm curve fits for these compounds. Linear and non-linear approaches were used for finding isotherm constants.This study found that bituminous coal based activated carbon is more effective than coconut shell based activated carbon for the compounds tested, which is likely due to its different physical structure and the properties of the compounds. The non-linear approach of finding the constants is found to be better than linear analysis.For OVC, MEK, ethylbenzene and para xylene fit Freundlich isotherm (FI) better, whereas ortho- xylene fit Langmuir isotherm (LI) better. For BPL, MEK, and ethylbenzene follow FI and para and ortho-xylene isomers follow LI.. For BPL and OVC, meta-xylene fits for both LI and FI.