Contaminant interaction and remediation in soil microcosms and pilot-scale studies

The contamination of soil, groundwater and ultimately potable water sources, is a quantifiable
risk associated with the sub-surface release of cable oil into the environment. This research has
provided the National Grid Transco (NGT) with an evaluation of the feasibility of biological
systems as a means of re mediating soil and groundwater contaminated with cable oil.
This has been achieved through treatability studies undertaken at three levels of process
sophistication; laboratory-scales micro-cosms, a pilot-study to develop full-scale design criteria
and a full-scale pilot-study under semi-controlled field conditions. The full-scale pilot-scale
study was undertaken together with a simple temporal and spatial model of oil distribution
through two contrasting soil blocks.
Experimental data obtained in this thesis has shown, for the first time that anaerobic degradation
processes are able to offer an effective alternative to aerobic in situ bioremediation for cable oil.
Each level of process in this three-phase study has demonstrated anaerobic soil organisms
capable of survival on cable oil and mineral salts ~lone. Sulphate reducing micro-organisms are
also suggested as playing an important role in the degradation process. Biodegradation of the
cable oil of up to 41 % was achieved, in some cases reducing the concentration to below 50ppm
threshold required by the Dutch Intervention Values (1994).
The study of pollutant migration found that the temporal and spatial distribution of cable oil is
specific to soil type and is influenced by the soil structure, particle size distribution and water
suction potential. The extent of oil migration in both soils is a function of the volume of cable
oil present and is time dependent.
The significant outcome of this work is that prior to this study, there have been no reports of
higher alkylbenzenes being degraded anaerobically. Consequently, monitored natural
attenuation may now be considered by NGT as a feasible remediation option under certain
conditions, providing an acceptable, non-intrusive technique for sites contaminated with cable
oil.

Identiferoai:union.ndltd.org:CRANFIELD1/oai:dspace.lib.cranfield.ac.uk:1826/11061
Date04 1900
CreatorsHerbath, Y.
ContributorsWarner, P., Patel, D., Butcher, M.
PublisherCranfield University
Source SetsCRANFIELD1
LanguageEnglish
Detected LanguageEnglish
TypeThesis or dissertation, Doctoral, PhD
Rights© Cranfield University, 2003. All rights reserved. No part of this publication may be reproduced without the written permission of the copyright holder.

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