Comparative studies of adsorption of heavy metals from cement waste water using activated carbon from Palm Kernel Husk, coconut and groundnut shells

Cement waste water is a major source of heavy metal pollution which requires removal before disposal. This paper therefore evaluates the comparative adsorption of heavy metals from cement waste water using activated carbon from palm kernel husk, coconut and groundnut shells in line with standard methods. With 0.1M KOH as activating agent at 400 oC, PKH and GNS reduced zinc concentration in water from 0.06mg/l to 0.01mg/l while CCS reduced iron concentration by 50% for temperature range of 450 oC – 500 oC. However, when 0.1M ZnCl was used as activating agent, all three adsorbents reduced the concentration of Zn, Fe and Pb to 0.01mg/l within the temperature range of 400 oC – 450 oC while Nickel was substantially reduced to 0.01mg/l by all three adsorbents with 0.2M ZnCl as activating agent for temperature range of 400 oC to 500 oC. The result shows that all three materials could serve as adsorbents but their performance depends on temperature and activating agents. For palm kernel husk and coconut shell, their performance was inversely proportional to temperature, while groundnut shell shows a direct relationship. On the overall, the three precursors showed capacity as good adsorbent for treatment of cement waste- water.Keywords: Cement, waste- water, activated- carbon, heavy-metals adsorptio

Generation of empirical correlation for predicting drag reduction of oil-water flows with natural polymers

There is an increasing need to accurately predict the behaviour of fluid in the different flow geometry as applicable in the industries. The prediction of drag reduction phenomenon observed during the two-phase oil-water flow with drag reducing polymers in horizontal pipes was investigated. The Power law model was adopted inthis study to empirically correlate the data acquired from our earlier experimental works in a 12-mm ID and 20-mm ID pipes. The model accurately predicts the drag reduction across the horizontal pipes. The agreement between the predicted and experimental drag reductions was better in the 12-mm ID pipe than in the 20-mm ID pipe. More work and data is needed to enhance the predictive accuracy of applicable models.Keywords: Drag reduction; polymers; horizontal pipes, oil-water flow, modellin

Kinetic evaluation of petroleum refinery wastewater biodegradation in an activated sludge process

Experimental assessment of process kinetic is essential for process modelling and can serve as a useful tool to improve process performance. In this study, kinetic evaluation of petroleum refinery wastewater (PRWW) biodegradation in an activated sludge process (ASP) was carried out in a 25 L ASP reactor which was operated within the conventional aeration mode of 2-10 hours, hydraulic retention time (HRT), effluents from the secondary sedimentation tank were analyzed at various HRT for biochemical oxygen demand (BOD) and biomass growth. The data obtained were analyzed and fitted to different related kinetic models which show that the biodegradation of PRWW in ASP follows the Modified Monod Kinetic Model, amongst the related models evaluated, with 0.9745 correlations with the experimental data. Physicochemical characterization of the PRWW used for the study was carried out using the Standard Methods for the Examination of Water and Wastewater; which gave a biodegradability index of 0.3333