Characteristics of contaminant transport in bank filtration through dunes

Abstract

A column experiment simulating bank filtration was conducted to evaluate characteristics of contaminant sorption and migration through saturated porous media. Also a mathematical model describing contaminant transport was developed to delineate results of column tests. Temporal and spatial distributions of ammonia, lead, phenol and trichloroethylene (TCE) were plotted as breakthrough curves (BTCs). BTCs of TCE and lead revealed more retardation in the transport up to 3 pore volumes compared to the other contaminants tested. It was attributed to the higher affinity of the TCE and lead to the solid surface. The mathematical model developed in the reported research, coupled with a linear sorption isotherm model, was based on the mass balance principle in two phases, i.e., solid phase and aqueous phase. The governing equation was generalized in the form of nondimensionalization and was solved by numerical analysis. The proposed model showed an excellent match with experimental results except in the case of TCE BTC. The proposed model was employed to simulate the behavior of ammonia under the environment of ongoing nitrification. Almost 60 times more biomass than ammonia mass was required to produce the reported water quality in the reported literature (KOWACO, 1994). The analysis of numerical experiments showed that the ammonia concentration in the bank filtrate will vary significantly as the bioactivity changes due to environmental factors such as temperature and pH in the system domain. (C) 1998 published by Elsevier Science Ltd. All rights reserved.