John W Gichuki

Equilibrium and Kinetics studies for the biosorption of aqueous Cd (II) ions onto Eichhornia crasippes biomass

Batch experiments were carried out to determine the capacity of E. crasippes biomass to adsorb Cd (II) ions from aqueous solutions with respect to contact time and initial concentration of Cd (II) ions, adsorbent dosage, pH and temperature. The experimental data were modeled by Langmuir and Freundlich isotherm models. The data fitted well with the Freundlich model which implies that the adsorption was multilayer. The data was also subjected to Kinetic models and the pseudo-second-order model found to fit the data. The macrophyte biomass used in this study did not undergo any chemical modification or pretreatment, which when added to its abundance and its low cost make it a green alternative for the removal of Cd (II) ions from water and waste water.

Increase in Anoxia in Lake Victoria and Its Effects on the Fishery

Murithi Njiru1, Chrisphine Nyamweya2, John Gichuki2, Rose Mugidde3, Oliva Mkumbo4 and Frans Witte5 1Department of Fisheries and Aquatic Sciences, Moi University, Eldoret, 2Kenya Marine and Fisheries Research Institute, Kisumu, Kenya 3COWI, Uganda Ltd, Plot No. 3, Portal Avenue, Kampala, 4Lake Victoria Fisheries Organisation (LVFO), Jinja, 5Institute of Biology Leiden, Leiden University, Leiden, 1,2Kenya 3,4Uganda 5Netherlands