THE EFFICIENCY OF CYANIDE (CN-) REMOVAL FROM CASSAVA STARCH FACTORY WASTEWATER USING AN UPFLOW ANAEROBIC SLUDGE BLANKET (UASB) REACTOR
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Abstract
This study evaluates the efficiency of cyanide (CN-) removal from cassava starch processing wastewater using a laboratory-scale Upflow Anaerobic Sludge Blanket (UASB) reactor. The experimental model, with a working volume of 10 liters, was operated in three phases, each corresponding to increasing initial COD concentrations of 1,000, 2,000, and 4,200 mgO₂/L, and CN- concentrations of 8.7, 17.4, and 36.6 mg/L, respectively, under a constant pH of 6.91. Across all phases, the results demonstrated high CN-removal efficiencies ranging from 97.5% to 99% . However, the effluent CN- concentrations remained above the permissible limit of Column B under QCVN 63:2017/BTNMT. COD removal efficiency remained stable between 60% and 70% after the acclimation period, though the effluent COD values also surpassed the regulatory standards. Biogas production averaged 4.71 L/day during Phase 2 and with a slight decline in Phase 3 due to organic loading exceeding the optimal threshold.
Keywords
biogas, cassava starch, cyanide, UASB, wastewater treatment
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References
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