1. Determine the partition coefficients of carbofuran and 2,3,4,4’-PCB (PCB 47) by a soil with a foc of 1.2% using its octanol/water partition coefficient and an appropriate sp-LFER (your choice). Repeat using the pp-LFER and one of the “standard” (not low or high) Pahokee Peat parameters given in Table 13.3 and the solutes in the UFZ database (use PCB 47). Provide possible explanations for any significant differences between the two methods for measuring Kp.
2. You found dissolved organic matter at a groundwater site at a concentration of 100mg/L dissolved organic carbon (from a nearby landfill leachate containing coal-tar). If one of the contaminants of concern is benz[a]anthracene (Kow = 105.91), how much more of this compound (on a percent scale) will be mobilized (i.e., an increase in the porewater concentration) by the presence of DOM Please determine DOM based on Suwannee River fulvic acid and its system parameters in Table 13.3 while that for BA is in the UFZ database (you must type the analyte in exactly for it to show up).
3. The sorption of a dissolved organic carbon (DOC) from McDonald’s Branch (a blackwater stream in New Jersey) by goethite from Meier et al., 2004 (Biogeochemistry) is given below:
Cw (mg/L) Cs (mg/Kg)
0.4 0.09
1.0 0.175
1.9 0.27
3.5 0.33
5.5 0.36
8.5 0.38
• Fit the data to the Freundlich and Langmuir models and show the model results as a plot of Cw vs. Cs with the data.
• Which model provides the better fit and speculate on the sorption mechanism.