Distribution of Potentially toxic elements in Water, Sediment and Soils in the Riparian Zones around a Kraft Pulp and Paper Mill in Western Kenya

This chapter discusses the impact of effluent discharge on the distribution of potentially toxic elements (Pb, Cd, Cu and Zn) in water, sediments and soils near a Kraft mill in Western Kenya. Potentially Toxic Elements (PTEs) concentrations were determined at three sites: Water Intake Point, Effluent Discharge Point and Downstream Point. The mill liquid effluent parameters and gaseous emissions were also characterized. One-way ANOVA was used to analyze the spatial differences in PTEs concentrations. Principal component analysis determined the correlations between the proximity to the Kraft mill and the PTEs in soils, water and sediments. In riverine soils, Cd was 0.78 ± 0.01 mg/kg, while Pb was 94.38 ± 9.65 mg/kg. In sediments, the concentration was 16.81 ± 2.46 mg/kg for Zn, 6.16 ± 0.72 mg/kg for Cd and 75.28 ± 5.97 mg/kg for Pb. In water, Zn was 0.26 ± 0.038 mg/L, Cu was 0.75 ± 0.11 mg/L, Cd was 0.05 ± 0.004 mg/L and Pb was 1.26 ± 9.65 mg/L. The spatial distributions of PTEs in soils near the factory and across the river may have resulted from the factory’s effluent discharge and gaseous emissions. These findings should help formulate more stringent industrial effluent management programs in Western Kenya

Effect of Black Soldier Fly (Hermetia illucens) Larvae Feed Supplement on Length-Weight Relationship of Nile Tilapia (Oreochromis niloticus)

One of the main challenges in the aquaculture sector is the high cost of fishmeal, which accounts for about 70 percent of production costs. The black soldier fly (BSF) larvae meal could be an alternative because of its high protein and essential fatty acids contents that are important for fish to grow and develop normally.An analysis was carried out to examine the effect of various feeding strategies on the growth and performance of Nile tilapia (Oreochromis niloticus). Five diets with equal nitrogen content were enriched with BSF larvae meal at different proportions (0%, 25%, 50%, 75%, and 100%). The meal with 0% BSF was used as a control. The length and weight of the fish were collected biweekly, while mortality data were collected daily. The study assessed the length and weight relationship of the fish using the parameter 'b'(regression coefficient). From this research, 'b' was found to range from 3.230 to 3.635, indicating isometric growth patterns. The well-being of the experimental fish was also evaluated through the condition factor 'K,' which ranged from 0.907 to 1.002, suggesting that all the fish were in good health. We, therefore, conclude that substituting the conventional fish means with black soldier fly larvae appears to be possible and impacts fish growth normally

Effect of Black Soldier Fly (Hermetia illucens) Larvae Feed Supplement on Length-Weight Relationship of Nile Tilapia (Oreochromis niloticus)

One of the main challenges in the aquaculture sector is the high cost of fishmeal, which accounts for about 70 percent of production costs. The black soldier fly (BSF) larvae meal could be an alternative because of its high protein and essential fatty acids contents that are important for fish to grow and develop normally.An analysis was carried out to examine the effect of various feeding strategies on the growth and performance of Nile tilapia (Oreochromis niloticus). Five diets with equal nitrogen content were enriched with BSF larvae meal at different proportions (0%, 25%, 50%, 75%, and 100%). The meal with 0% BSF was used as a control. The length and weight of the fish were collected biweekly, while mortality data were collected daily. The study assessed the length and weight relationship of the fish using the parameter 'b'(regression coefficient). From this research, 'b' was found to range from 3.230 to 3.635, indicating isometric growth patterns. The well-being of the experimental fish was also evaluated through the condition factor 'K,' which ranged from 0.907 to 1.002, suggesting that all the fish were in good health. We, therefore, conclude that substituting the conventional fish means with black soldier fly larvae appears to be possible and impacts fish growth normally