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Degradation of metals associated with hydrocarbon production, combustion processes, and carbon capture is a pernicious problem in the energy sector. Consequently, laboratory simulation of CO2-containing aqueous environments is of vital importance for the study of steel corrosion. However, discrepancies between predicted, experimental, and field corrosion rate data in a midrange of operating parameters have been reported. These discoveries necessitate improving the accuracy of corrosion prediction models. Based upon preliminary experiments, iron carbonate formation near its saturation condition was identified as a major factor observed corrosion rate discrepancies. Therefore, it is imperative to conduct a systematic study to gain more understanding of corrosion product layer formation mechanisms in controlled water chemistry conditions. Small scale CO2 corrosion experiments have lacked control of pH and ferrous ion concentration, potentially creating misleading conditions related to the growth of protective iron carbonate (FeCO3). An improved experimental apparatus to study steel corrosion and associated formation of FeCO3 was developed. The design incorporates a flow-through system, enabling control of water chemistry, and newly developed sample holders that eliminate non-uniformity of flow associated with hanging samples as well as centrifugal effects associated with rotating cylinder electrodes. Corrosion experiments were conducted in a conventional glass cell and the newly developed flow-through system. Significantly different corrosion product morphologies were observed in these different systems. In controlled water chemistry conditions, iron carbide (Fe3C) was found to play a crucial role in the development of the corrosion product as it provided a favorable environment for the formation of a FeCO3 layer at the steel surface.Three different kinds of material (X65 with tempered-martensitic microstructure, C1018 with ferritic-pearlitic microstructure, and 99.8% pure iron) were used to confirm the influence of iron carbide on the formation of corrosion products near saturation conditions. It was found that in the absence of iron carbide (Fe3C), pure iron produced no significant FeCO3 formation under the same operating conditions as the tests conducted on mild steels.Environmental parameters relating to the effect of FeCO3 saturation value, solution pH, and temperature on the formation of corrosion product layers were also investigated. Saturation value conferred the strongest effect on FeCO3 layer formation near saturation conditions among the three environmental parameters explored.

Coastal resource management in New Zealand is accompanied by complex legislation, a multiplicity of authorities who have jurisdiction over the coastal zone, competing resource uses and a unique yet finite, natural resource. This thesis examines the Whakatane District Coastal Zone in terms of the public agencies involved in resource administration, the inherent nature of the coastal resource and the current uses applied to the resource in pursuit of the following 'aims: (i) Identifying both resource based problems, such as conflicts among competing uses and organisational problems such as insufficient data and a general lack of adequate information on which to base sound decisions. (ii) Recommending appropriate solutions to the problems in the context of current and anticipated impacts of particular resource uses on the environment. The recommendations are contained in the form of policies derived for particular resource uses and for the maintenance of important environmental parameters such as water quality. The section on regional planning deals with appropriate levels of coastal resource planning within existing legislation and with an adequate background of data and tools for implementation. Appropriate legislation and agencies currently exist for comprehensive coastal zone management and planning at the district level. All that is needed now is commitment and innovation by the Whakatane District Council and a high degree of public involvement in managing what is essentially a public resource.