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The thesis established the value of empirical data (biological, chemical and physical) in enabling an effective prediction of the potential for biological remediation to take place. While this was calibrated with over forty genuine environmental scenarios, its application to genuine fieldscale operations was more limited. Empirical data also underpinned the assessment of a set of low cost ameliorants in complexing heavy metals enabling the protection of controlled waters. In this case the ameliorant calcium polysulphide out-performed the other solid matrices investigated. The commercial sponsor of the project was Remedios Limited who have pioneered the development and environmental applications of microbial biosensors. This project served to audit the current performance of biosensors and consider their future potential. All of the empirical data and the statistically evaluated results were integrated into a tiered decision support tool. This tool: Remediation DST was developed through a series of options that were weighted to reflect the parameters that assist users in reaching and justifying decisions regarding contaminated land remediation. Tier 1 considers generic risk assessment in the context of remediation. Tier 2 is a multi-component correlation matrix that matches soils or water to the available technologies. A weighted scoring system differentiates the relative merit of the selected option. Tier 3 is a manual interface that links the bespoke needs of users to generic strategies for effective remediation. Once test driven, the tiered approach was effective at clearly justifying the best remedial option available. The output from this project makes full use of empirical data to enable end-users to reach clear and well justified decisions.

In this study, three biosorbents, crab carapace, the macroalgae <i>Fucus vesiculosus </i>and peat were compared with an activated-carbon and an ion-exchange resin for the removal of Cu²⁺ from synthetic solutions and distillery wastewater. Sorption of Cu²⁺ was evaluated and best represented by the pseudo-second order rate model for all materials. Langmuir and Freudlich isotherms were used to describe the sorption equilibrium data with maximum uptake values of 79.4, 114.9 and 71.4 mg g^-1 obtained for crab carapace, <i>Fucus vesiculosus </i> and ion-exchange resin respectively. The removal efficiencies of crab carapace and <i>Fucus vesiculosus</i> were &gt;95 % i.e. comparable with those achieved using ion-exchange resin. Metal uptake was found to proceed via a number of mechanisms including absorption on the material surface, ion-exchange and micro-precipitation. It was observed by GG-ATR FTIR that a number of different functional groups present in the materials were also involved in metal uptake and removal. Plant trials set up to provide a preliminary investigation into the application of Cu²⁺ enriched crab carapace to a Cu²⁺ deficient soil showed that although the addition of crab carapace enriched with Cu²⁺ does not immediately help deficiency problems, it is possible that there is scope for such an application as a route for disposal. Crab carapace is an effective and efficient biosorbent for the removal of Cu²⁺ from aqueous solutions and may be considered a viable alternative to activated-carbon and ion-exchange resin. As a waste material from the fishing industry it also presents the most economically and environmentally sound material for biosorption.

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LTA (4A) and NaX (13X) zeolite have been grown in the macrostructure of four 'unmodified' carbons (MAST™, willow, pine and rattan) without blocking the meso/micropores of the substrate. A lack of modification reduces environmenta1/production costs, avoids weakening the substrate and prevents side reactions. The :MAST ™/NaX composites can be rapidly regenerated in-situ by electrical heating using the resistivity of the carbon substrate. Calcination of the composites to remove the carbon produces a zeolite-only replica of the carbon substrate and (though fragile) the zeolite structures may be of use jn their own right. Zeolite loading could be increased almost 200% (from 3.3% to 9.6% mass) by extending substrate time in the precursor solution, or further increased (to 28-44% MASTTM) by gravity deposition of the zeolite on the substrate. Extending the synthesis time may have produced a different zeolite inside the pores to that produced externally. SEM on a 5-week synthesised LTA sample suggests that the zeolite hydroxy sodalite (H-SOD) has formed inside the pores while LTA developed externally. Hence, growth rates were found to be different inside the carbon pores as crystal growth continued after it was attested in the external solution. However, XRD and 29Si MAS-NMR analysis indicated that, in the first 14 h, NaX zeolite synthesis was slower inside the carbon pores than the external liquor. Acidity was expected to be important in the ability of a material to adsorb the basic molecule ammonia, so, to assess if this is indeed the case, LTA, carbon and composites were H+ exchanged using Hel before ammonia adsorption. Ammonia adsorption was not found here to be significantly increased by acid exchange. Indeed, Na~ LTA was found to adsorb NHJ just as extensively (6.6mmol/g) as H~LTA (6.8mmol/g) and adsorption in ~ LTA zeolite exchanged using the N H./ LTA method (then heated to remove NHJ was decreased by 50%, and only 3.3nunol/ g was adsorbed (on the 6.6rrunol/g adsorbing LTA) after NH/ exchange. The carbon substrate, however, performed much better when acid treated. Boehm titration results indicated that acidity ranges from 0.14nunol/g to 1.36nunol/g, even in non-acidified synthetic carbons, depended on the activation method performed (steam, CO2, etc.) and when add treated the carbon NH, adsorption increased 10 fold (from O.3mmol/g to 3.3mmol/g). NaX was found to be the best zeolite for NH J adsorption (5. l mmol/g for a 2 h outgas, 9.7mmol/g for a 4 h outgas and 18.6mmol/g for a 10 h+ outgas), if properly pre-conditioned

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