## 2 Materials and Methods
### Experimental Methods

Table 1: Constant factors used in oil droplet size (Sauter diameter) prediction. Figure 1: Glassware and mixers used for laboratory dispersant effectiveness and biodegradation testing: (**a**) 250-mL Erlenmeyer flask used with mixing by orbital shaking; (**b**) 1000-mL baffled flask used with shaft-driven mixer; (**c**) paddle mixer; (**d**) helical ribbon mixer. The energy dissipation and applied energy were calculated utilizing Equations (2) and (3), based upon the rotational speed and impeller diameter. \[P=N_{p}\cdot\rho_{c}\cdot N^{3}\cdot d^{5} \tag{2}\]  
\[\varepsilon=\frac{P}{V} \tag{3}\]  
where \(P\) = power applied (watts), \(N_{p}\) = power number, \(\rho_{c}\) = density of water (kg/m\({}^{3}\)), \(N\) = impeller rotational speed (rpm), \(d\) = diameter of the impeller (m), and \(V\) = mass of the continuous phase (kg). Depending upon the type of impeller and the presence or absence of baffles, the appropriate power number correlations were used and calculated. Specifically, for the unbaffled container and paddle impeller, the power number was calculated using the unbaffled condition equations of [PERSON] et al. [13; 14], while for the baffled flask and paddle impeller, the baffled equations presented by [PERSON] et al. were used. For the unbaffled container and the helical ribbon impeller, the power number was calculated using the helical ribbon equations given in the reference of [PERSON] et al. [15]. The amount of power actually applied was not measured in these experiments, but only estimated by the calculation of the power number and use of Equation (2). Biodegradation testing was conducted using the addition of an oil and dispersant NAPL phase, mixing to disperse the NAPL in the same or similar manner as for the dispersant effectiveness test, then inoculating with Oppenheimer formula, which consists of microbial strains of _Actinobacteria_, _Gammaproteobacteria_, _Bacteroidia_, _Flavobacteria_ and _Bacil_ (Oppenheimer Biotechnology, Austin, TX, USA, relative amounts of the different bacterial species not provided nor measured), and subsequently incubating with passive aeration and mixing via orbital shaking at room temperature. The M9 minimal salts medium used as the nutrient broth for the biodegradation testing consisted of (per liter of distilled water) 6.0 g/L potassium phosphate (KH\({}_{2}\)PO\({}_{4}\)), 3.0 g/L ammonium chloride (NH\({}_{4}\)Cl), 9.0 g/L sodium phosphate dibasic (Na\({}_{2}\)HPO\({}_{4}\)), 2.1 g/L potassium chloride (KCI), 3.0 g/L bio-nutrients from Oppenheimer, and 1 mL of micronutrients solution containing 12.0 g/L magnesium sulfate (MgSO\({}_{4}\)), 1.098 g/L sulfate heptahydrate (FeSO\({}_{4}\).7H\({}_{2}\)O), 0.942 g/L manganese chloride tetrahydrate (MnCl\({}_{2}\).4H\({}_{2}\)O), and 0.792 g/L calcium chloride dihydrate (CaCl\({}_{2}\).2H\({}_{2}\)O). The chemicals used in this work are of analytical grade and obtained from Fisher Scientific International, Inc., Sigma-Aldrich, and VWR International Inc. The extent of biodegradation was determined periodically via the difference from the initial level by using the DCM extraction technique described above to determine the amount of residual oil present in the aqueous phase. For the biodegradation tests, controls were also conducted alongside the test conditions, and consisted of the same materials as the test conditions, except that no petroleum-degrading microbial consortia were added.