Phytoremediation of Cassava Wastewater by Water Hyacinth

Background and Objective: Wastewater produced from the cassava processing industry contains a high
level of a toxic chemical called cyanide, which when discharged without proper treatment creates serious
environmental risks. The study aimed to investigate the possibility of water hyacinth as sustainable means
of reducing the level of toxicity in cassava wastewater. Materials and Methods: Cassava wastewater was
collected from fermented cassava tubers. Water hyacinth was grown on the fermented wastewater and
decanted for 7, 14, 21 and 28 days. The treated samples were collected and analyzed for Cyanide (CN),
Dissolved Oxygen (DO), Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand (COD), Electrical
Conductivity (EC), Total Soluble Solids (TSS) and pH using standard methods. Results: The water hyacinth
used as phytoremediators had positive effects on the wastewaters by increasing the pH and dissolved
oxygen to an acceptable standard and decreasing the electrical conductivity, total dissolved solids, total
suspended solids, cyanide, biological oxygen demand and chemical oxygen demand when compared to
their initial concentrations, though, the values recorded for all the tested parameters were far higher than
that recommended for water but not up the recommended standards after 28 days. Conclusion: The
wastewater from cassava is more polluted. Water hyacinth as a phytoremediator performed importantly
physicochemical parameters of the cassava wastewater.