Metal contamination in the environment is a persisting global issue. The metal reservoirs in the earth have declined due to society’s needs and due to uncontrolled mining activities. Therefore, the idea to recover metals from waste streams has emerged.
In this thesis, cost competitive technologies such as adsorption using agro-wastes and precipitation using an inverse fluidized bed (IFB) reactor were investigated, with special emphasis on the recovery of base metals. Groundnut shell showed good potential for metal (Cu, Pb and Zn) removal. From artificial neural network modeling, the performance of the sulfate reducing bacteria (SRB) was found to be strongly pH dependent; the removal efficiency of Cu and Zn in the IFB at pH 5.0 was >97%. Electronic waste is a good candidate as secondary metal resource. The recovery of Cu from computer printed circuited boards (PCBs) using biogenic sulfide precipitation was investigated as well. Using this technology, Cu could be recovered at ~0.48 g Cu/g PCBs.
1. General Introduction
2. Metal Rich Waste Stream and Feasibility of Recovery
3. Adsorption Technology for Metal Contaminated Wastewater Treatment
4. The Performance of Sulfate Reducing Bacteria Biotechnology in an Inverse Fluidized Bed SRB Bioreactor
5. Inversed Fluidized Bed SRB Bioreactor for Metal Contaminated Wastewater Treatment
6. Effects of Process Parameter on Metal Yield in E-waste Leachate
7. General Discussion
IHE Delft PhD programme leads to a deepening of a field of specialisation. PhD fellows do scientific research, often with conclusions that directly influence their region. At IHE Delft, PhD researchers from around the world participate in problem-focused and solution-oriented research on development issues, resulting in an inspiring research environment. PhD fellows work together with other researchers from many countries dealing with topics related to water and the environment.
PhD research is often carried out in the ‘sandwich’ model. Preparation and final reporting – the first and last portion of the programme – are carried out in Delft, while actual research is done in the fellow’s home country, under co-supervision of a local institute. Regular contacts with the promotor are maintained through visits and long-distance communication. This enables researchers to employ solutions directly to problems in their geographical region.
IHE Delft PhD degrees are awarded jointly with a university. The degrees are highly valued and fully recognised in all parts of the world.