Cassava waste: treatment options and value addition alternatives

Value addition of cassava and cassava wastes is necessitated by rapid post-harvest spoilage, deterioration, low protein content and environmental pollution caused by the effluent and the other associated wastes that poses aesthetic nuisance. Biogas plants of all sizes and varying levels of technical sophistication not only recover the energy contained in cassava wastes but also eliminate most of the animal and human health problems associated with contamination. Studies have shown the technical feasibility and nutritional desirability of converting carbohydrates and their residues into products containing a large amount of protein by means of microorganisms. Wastes transformation offers the possibility of creating marketable value-added products. There exists a great potential in the use of microorganisms such as fungi for the production of high quality feedstuffs from the abundantly available agro-industrial wastes, particularly carbohydrate residues. Cassava wastes can be processed and converted into value-added components such as methane (biogas), pig meat, ethanol, surfactant and fertilizer etc. Attention is now focused on the by-products of the anaerobic decomposition of the waste that takes place in a biodigester, which are the liquid fraction called biol and the solid fraction or biosol, which are excellent fertilizers for a variety of crops. The present review addresses the progress that has been made in each of these aspects with emphasis on the advantages of biol and biosol fertilizers

Studies on the effect of abattior and microbial quality of Aba river in Nigeria

Levels of lead, iron, zinc, copper, arsenic, cobalt, chromium, manganese, mercury and cadmium, as well as the microbial profile were determined in water samples from Aba River. Physico-chemical examinations revealed that manganese (0.03 mg/l), zinc (4.81 mg/l) and copper (0.19 mg/l) were below the maximum allowable levels set by the United States Environment Protection Agency (USEPA), while lead (0.064 mg/l), iron (0.81 mg/l), arsenic (0.1 mg/l) chromium (0.006 mg/l) and mercury (0.009 mg/l) were high but not significantly. The implication is that waste assimilation capacity of the river is high, a phenomenon attributable to dilution, sedimentation and depuration. Quantitative examinations of the microorganisms present revealed that as many as 2.05 x 108 viable bacterial (cfu/ml) were present. The predominant bacterial forms include Staphylococcus species, Streptococcus faecalis, Escherichia coli, Salmonella species, Bacillus and Clostridium species implying that the abattoir wastes discharged into the river may have had a significant impact on the river ecosystem.African Journal of Biotechnology Vol. 4 (3), pp. 266-272, 200

Full Length Research Paper - Studies on the effect of abattior and industrial effluents on the heavy metals and microbial quality of Aba river in Nigeria

Levels of lead, iron, zinc, copper, arsenic, cobalt, chromium, manganese, mercury and cadmium, as well as the microbial profile were determined in water samples from Aba River. Physico-chemical examinations revealed that manganese (0.03 mg/l), zinc (4.81 mg/l) and copper (0.19 mg/l) were below the maximum allowable levels set by the United States Environment Protection Agency (USEPA), while lead (0.064 mg/l), iron (0.81 mg/l), arsenic (0.1 mg/l) chromium (0.006 mg/l) and mercury (0.009 mg/l) were high but not significantly. The implication is that waste assimilation capacity of the river is high, a phenomenon attributable to dilution, sedimentation and depuration. Quantitative examinations of the microorganisms present revealed that as many as 2.05 x 108 viable bacterial (cfu/ml) were present. The predominant bacterial forms include Staphylococcus species, Streptococcus faecalis , Escherichia coli , Salmonella species, Bacillus and Clostridium species implying that the abattoir wastes discharged into the river may have had a significant impact on the river ecosystem