Contaminant transport in a fractured chalk aquifer

ISBN-13: 9783639287455 / Angielski / Miękka / 2010 / 112 str.

Fathy Ahmed Abdalla Ahmed

Opis

Transport processes in fractured aquifer are characterised by a couple of transport mechanisms within the fracture and the neighbouring matrix. To understand the possible transport mechanisms of tracers in a fractured chalk block, laboratory single- and multi-tracer tests were carried out in two blocks under defined boundary conditions. The breakthrough curves (BTCs) of the tracers are governed by sharp peaks due to advective transport and dispersive respectively diffusive transport processes in the tailing part of the BTCs. The simulation of the BTCs with the single fissure dispersion model could not reasonably fit the BTCs. A multichannel SFDM with the superposition of BTCs of at least two different flow paths, resulted in an acceptable fit (by calculating the cumulative tracer breakthrough and recovery curves). Those simulations indicate the existence of flow channelling effects within the fracture. The results showed that matrix diffusion process plays only a minor role in the determination of the fate of nitrate in the groundwater aquifers. The key factor controlling the fate of nitrate in the groundwater is the redox process.

O autorze

Name: Fathy Ahmed Abdalla Academic grade: Ph.D, Bonn University, Germany Position: Lecturer and consultant of Hydrogeology & Environmental geology Working address: Geology Dept., Faculty of Science, South Valley University, Qena, Egypt Mobil: 002-0107060715 E.mail: fathyhyd@yahoo.com