The presence of multicomponent nonaqueous-phase liquids (NAPLs) on contaminated sites critically alters the biodegradation susceptibility of many target pollutants, including polycyclic aromatic hydrocarbons. This study investigated the effects of petroleum-derived multicomponent NAPLs on biodegradation of benzo[a]pyrene by a bacterial consortium in liquid culture. When high-boiling point diese...

Dissolution of nonaqueous-phase liquids (NAPLs) from variable-aperture fractures couples fluid flow, transport of the dissolved NAPL, interphase mass transfer, and the corresponding NAPL-water-interface movement. Each of these fundamental processes is controlled by fracture-aperture variability and entrapped-NAPL geometry. We develop a depth-averaged computational model of dissolution that inco...

Bioremediation is a potentially cost-effective, in situ method for cleaning up NAPL-contaminated sites. The ability of microorganisms to access and degrade NAPL constituents is highly dependent on the heterogeneity of the soil and the morphology of the NAPL source. Soil heterogeneities can result in preferential pathways of air and water flow through the subsurface. Intermediate-scale studies w...

A non-equilibrium, two-phase, three-component compositional model for the simulation of alcohol flooding has been developed and tested. Inter-phase mass transfer algorithms allow for transfer of all three components at high concentrations and high mass flux rates using a two-film model. The model has been used to simulate alcohol floods where the alcohol has an affinity for either the water-ric...

Presented here is a reanalysis of results previously presented by [Davis, B.M., Istok, J.D., Semprini, L., 2002. Push-pull partitioning tracer tests using radon-222 to quantify non-aqueous phase liquid contamination. J. Contam. Hydrol. 58, 129-146] of push-pull tests using radon as a naturally occurring partitioning tracer for evaluating NAPL contamination. In a push-pull test where radon-free ...

3D point cloud semantic segmentation is one of the fundamental tasks for scene understanding and has been widely used in metaverse applications. Many recent methods learn a single prototype (classifier weights) each class, classify points according to their nearest prototype. However, learning only class limits model’s ability describe high variance patterns within class. Instead this paper, we...

Fracture apertures play a significant role in groundwater systems. For proper groundwater quantity and contamination management, fractures have to be properly characterised. However, due to their complexity, fracture characterisation is one of the main challenges for hydrogeologists all over the world. This is particularly important in South Africa, where aquifers are predominantly fractured. T...

A model is presented for the description of the pump and treat (or flushing) remediation of the saturated zone with non-aqueous phase liquid (NAPL) present as droplets. Sensitivity analysis shows that the most important variables are the NAPL droplet size and the distance through which the dissolved organic compound must diffuse to reach the advecting aqueous phase. The time needed to achieve c...

Reactive zero valent iron nanoparticles can degrade toxic nonaqueous phase liquids (NAPL) rapidly in contaminated groundwater to nontoxic products in situ, provided they can be delivered preferentially to the NAPL/water (oil/water) interface. This study demonstrates the ability of novel triblock copolymers to modify the nanoiron surface chemistry in a way that both promotes their colloidal stab...