The microbial remediation of former gasworks sites: A review

Abstract

This review has considered the feasibility of applying current microbial treatment techniques to the remediation of former gasworks. Success would appear dependent upon the contaminants of interest being biodegradable and an effective means of implementation. Contaminants of concern at gasworks include PAH, phenols and cyanides. Laboratory and field studies suggest that these contaminants are biodegradable although little data exists with respect to mixtures in the form present at gasworks. Further research is recommended in this respect. Subsurface investigations of gasworks have revealed an extremely heterogeneous environment which suggests that current in situ remedial techniques may be unsuitable. Techniques that excavate and homogenise the contamination prior to treatment may improve the chances of successful remediation. Pilot studies appear successful but future research should emphasise a mass balance approach where the significance of non biological degradative mechanisms can be assessed. Contaminated groundwaters appear amenable to treatment in surface reactors. The success of overall remediation will however be dependent on the efficiency of the hydraulic withdrawal system used. The implementation of such a scheme should only be undertaken with a clear understanding of the limitations of this technology.

The Gulf Oil Spill

“…Approximately two-thirds of the PAHs in surface waters are particle-bound and can be removed by sedimentation, flocculation, and filtration processes. The remaining one-third of the dissolved PAHs usually require oxidation for partial removal/transformation (EPA 1980 Bioremediation is emerging as a practical alternative to traditional disposal techniques (Cemiglia 1993;Thomas and Lester 1993;Wilson and Jones 1993). It has only recently been considered as a viable treatment method for contaminated soils but is now being used or is under consideration by the EPA for clean-up in over 135 Super-fund and underground storage tank sites (Carraway and Doyle 1991;Sims 1990;EPA 1989d).…”

Fluoranthene metabolism in Mycobacterium sp. strain KR20: identity of pathway intermediates during degradation and growth

“…Soil areas heavily contaminated by these compounds, such as former carbonizing plant or gasworks sites, need a proper clean-up prior to future human use and thus are major targets for the application of microbiological remediation techniques (Thomas & Lester, 1993, 1994. During the last 15 years it has become evident that PAHs with more than three rings, despite their low water solubility, may serve as growth substrates for a number of soil bacteria.…”

Phytotoxicity of ancient gaswork soils. Effect of polycyclic aromatic hydrocarbons (PAHs) on plant germination

“…Industrial soils from oil refineries and ancient gasworks worldwide are potentially contaminated by PAHs. So far, the main remediation strategies include thermal and biological treatments (Wilson and Jones, 1993, Thomas and Lester, 1993, Oudot, 1994. Incineration is rapid but suffers from its cost, its energy demand and its production of hazardous waste.…”