Evaluating peats for their capacities to extract methyl tertiary butyl ether from contaminated water using solid-phase microextraction with gas chromatography.

Methyl tertiary butyl ether (MTBE), the most common fuel additive used to oxygenate gasoline, is being detected more frequently in drinking water supplies. This research investigates the capacities of 10 different types of highly characterized peats to extract MTBE from contaminated water. Peat samples were slurried for 24 hours under controlled conditions in aqueous solutions of MTBE. Liquid portions of the samples were analyzed for MTBE concentrations using a Solid-phase Microextraction GC/MS (SPME-GC/MS) method and were compared to samples of the MTBE solution (without peat addition) to determine the peats' MTBE sorption capacities. The SPME-GC/MS results indicate that all peats tested worked well at extracting MTBE from an aqueous solution. Although this was so, some peats tended to work better than others. The Loxahatchee Nymphaea and the Maine Sphagnum peats worked best, producing 92 and 88% MTBE reductions, respectively, while the Okefenokee Taxodium and the New York peats achieved the poorest results, producing only 50 and 47% MTBE reductions, respectively. In addition, the peats derived from herbaceous vegetation worked better than those derived from woody plants (except for the woody North Carolina peat). Overall, the peats that were the most effective at extracting MTBE from water tended to have higher hydraulic conductivities, microporosities, macroporosities, total porosities, and water holding capacities, but lower bulk densities, total ash contents, Ti contents, P contents, Si contents, K contents, Al contents, fulvic acid contents, total guaiacyl lignin contents, and total other ketones contents. Peats with higher MTBE extraction capacities also had humic acids contents that ranged between 4.6-7.1%. These results suggest that peats could be used as filtration, or sorption, media to remediate surface water or groundwater that is contaminated with MTBE. SPME-GC/MS analysis was found to be a reasonably inexpensive and efficient way to evaluate MTBE sorption capacities of peat samples.

Retention of nitrogen and phosphorous from liquid swine and poultry manures using highly characterized peats.

This paper reports on research designed to test the hypothesis that differences in peat composition will cause differences in amounts of N and P retained during contact with liquid swine manure (LSM) and liquid poultry manure (LPM). Peat types representing a wide range of properties were tested in order to establish which chemical and physical properties might be most indicative of their capacities to retain N and P from LSM and LPM. Eight-percent slurries (peat/LSM and peat/LPM) were measured for total nitrogen (TKN) and total phosphorous (TP) after 6, 24 and 96 hours. Tests were done to determine the TKN and TP contents of these peats, the LSM, and the LPM, both before and after they were mixed together. The N and P retention results revealed that most peats worked reasonably well at retaining N and P from either LSM or LPM. However, some peats were more effective than others. These peats also decreased the N and P levels in the liquid portion of the LSM. Peats with higher N retention capacities tended to have lower ash contents, but higher macroporosities and total cellulose contents. Peats with higher P retention capacities tended to have lower bulk densities, ash contents, total guaiacyl lignins contents, fulvic acids contents, but higher microporosities, macroporosities, H contents, and total cellulose contents. Peats with higher N and P retention capacities also had humic acid contents between 5-7%. The results of this study suggest that if these peats are used to reduce odors and N and P contamination, possible byproducts could be the production of odorless fertilizers.