Emmanuel Sone Njumbe
Course: PhD Environmental Sciences
"Today, I see myself as a trained, versatile scientist with an aptitude and skills that underpin the ability to absorb and apply new concepts quickly as well as the ability to think laterally and solve problems practically."
"The idea to undertake research study in environmental science was fuelled by my interest in contemporary issues of 'sustainability' and 'sustainable development'. Most important was the realisation that the rate of industrialization and urbanization in the developing world was typically outpacing investments in water supply, waste treatment and disposal facilities. The overall objective of the PhD programme was therefore to assess the impact of industrialization and urbanization on aquatic and terrestrial systems. This would entail field studies as well as laboratory analysis.
"The key technical approach of the study involved batch and column experiments modelled and designed to study sorption characteristics (within characteristic geomedia) of important contaminants identified through a non-target screening of sediment and water samples from the Douala drainage basin in the SW of Cameroon. An understanding of the dynamics of sorption is crucial in predicting the fate of contaminants from accidental spills or waste disposal sites, and in producing risk assessment models. All these underpin the design of clean-up and remediation technologies.
"I employed an automated sediment column to simulate a typical tropical aquifer system and carried out flow-through column experiments to investigate the sorption kinetics and maximum uptake levels of dissolved contaminants (PAHs and Pesticides) onto characteristic solid phases present within the system. Various sorption models were applied to the data in an attempt to understand how natural physico-chemical processes would influence the subsurface migration of the model contaminant. In practical terms, these processes will determine the point at which a model contaminant flux injected into the system would appear at a monitoring point, as well as the spreading pattern of a contaminant plume.
"Batch experiments were employed to evaluate the potential of locally available geosorbents (clay) in the design of low-cost landfills and waste disposal facilities. The key was to determine the relative distribution of the model solute between aqueous and sorbed phases (with varying clay content) as a function of time and equilibrium.
"The findings from the study have provided the first ever comprehensive set of baseline data on the extent and character of environmental degradation within and around the city of Douala. The Results from the sorption experiments provide the first scientific tool of its kind in elucidating the level of pollution risk for water resources arising from indiscriminate waste disposal as well as pesticide application.
"It is my anticipation that results and conclusions from the study should provide decision makers in the country with a tool to reassess pre-existing regulatory instruments on environmental management within the framework of sustainable development.
"Through this programme I have developed a broad range of skills that I consider invaluable to my career. Prior to commencing the programme, I regarded myself as a geologist locked within the academic world of rocks. Today, I see myself as a trained, versatile scientist with an aptitude and skills that underpin the ability to absorb and apply new concepts quickly as well as the ability to think laterally and solve problems practically utilising the tools and facilities available. I owe all of these to the great team of individuals at The University of Manchester, with whom I have worked."