Optimization and Modeling of Cyanide Removal from Cassava Waste Water Using Calcined and Activated Adsorbent Mixtures of Oyster Shell and Periwinkle Shell Ash

Chukwunonso O. Njoku *

Department of Chemical and Petroleum Engineering, University of Uyo, Uyo, Nigeria.

B. R. Etuk

Department of Chemical and Petroleum Engineering, University of Uyo, Uyo, Nigeria.

*Author to whom correspondence should be addressed.


Cyanide, a toxic compound found in cassava wastewater which on frequent basis is discharged to the environment poses danger to the ecosystem; this research work aims to curb this menace. Temperature, pH, dosage, contact time, adsorbent mixture ratio and initial concentration were optimized using CCD on periwinkle-oyster shells composite mixtures for activated and also, calcined adsorbents on the cyanide adsorption from cassava wastewater. Three RSM models (linear, 2FI and quadratic) were applied to study, optimize and predict this adsorption process. ANOVA showed that quadratic model best predicted the processes for both the activated and calcined adsorbents having R2 values of 0.9678, CV% of 15.51% for the activated and R2 values of 0.9550, CV% of 18.54% for the calcined composite adsorbent. Surface and contour plots were generated to study the interaction between the adsorption parameters and cyanide adsorption. Results from this study also show that pH and initial cyanide concentration were the most determining factors of the adsorption process for both adsorbent samples with the highest adsorption capacity of 96.648% and 96.112% obtained for the activated and calcined composite adsorbent respectively. Numerical optimization was carried out and the confirmation test on the analyzed best-fit quadratic models yielded actual adsorption efficiency of 90.174% as against the predicted adsorption efficiency of 89.83% for the activated and actual adsorption efficiency of 82.274% as against the predicted adsorption efficiency of 83.475% for the calcined composite adsorbent hence, confirms that both activated and calcined adsorbents of oyster-periwinkle shells composite mixture is effective for cyanide adsorption from cassava wastewater and the RSM models were effective to optimize and predict the process.

Keywords: Cyanide, periwinkle-oyster shell composite adsorbent, cassava wastewater, adsorption

How to Cite

Njoku , C. O., & Etuk, B. R. (2023). Optimization and Modeling of Cyanide Removal from Cassava Waste Water Using Calcined and Activated Adsorbent Mixtures of Oyster Shell and Periwinkle Shell Ash. Journal of Engineering Research and Reports, 24(8), 20–35. https://doi.org/10.9734/jerr/2023/v24i8835


Download data is not yet available.


Eze S, Azubuike A. Assessment of the physicochemical properties and applications of some cassava varieties. Research Journal of Applied Sciences. 2010;5:309-314.

Cumbana A, Mirione E, Cliff J, Bradbury J. Reduction of cyanide content of cassava flour in Mozambique by the wetting method. Food Chemistry. 2007;101:894-897.

Oghenejoboh KM Effects of cassava wastewater on the quality of receiving water body intended for fish farming. British Journal of Applied Science & Technology. 2015;6:164-171.

Agency for Toxic Substances and Disease Registry-ATSDR. Toxicological profile for cyanide. US department of health and human services. Public health service. Encyclopedia of global health, 4th ed. 2006;57-71.

ASTM D2866. Standard test method for total ash content of activated carbon. ASTM International, West Conshohocken. 2004;105.

ASTM D2867. Standard test methods for moisture in activated carbon. ASTM International, West Conshohocken. 2009;47.

White WLB, McMahon JM, Sayre RT. Regulation of cyanogenesis in cassava. Acta Horticulturae. 1994;375:69-77

Cardoso AP, Mirion E, Ernesto M, Massaza F, Cliff J, Haque MR, Bradbury JH. Processing of cassava roots to remove cyanogens. Journal of Food Composition and Analysis. 2005;18:451-460.

Al-Qodah Z, Shawabkah R. Production and characterization of granular activated carbon from activated sludge. Brazilian Journal of Chemical Engineering. 2009; 26(1):127-136.

ASTM D3838-80. Standard test method for pH of activated carbon. ASTM International, West Conshohocken. 1999; 140.

Tang P, Hseu YC, Chou HH, Huang KY, Chen SC. Proteomic analysis of the effect of cyanide on Klebsiella oxytoca. Current Microbiology. 2010;60(3):224-228.

Attah IC, Etim RK, Sani JE. Response of oyster shell ash blended cement concrete in sulphuric acid environment. Civil and environmental research. 2019;11:4-7.

Nworie CE, et al. Preparation and characterization of periwinkle shell activated carbon. Nigerian Research Journal of Chemical Sciences. 2020;(8)1:709-711.

Mhemeed AH. A general overview on the adsorption. College of Pharmacy, University of Misan, Iraq. 2018;22-27.

Stumm W. Chemistry of the solid water interface. John willey and sons, New York. 1992;31.

Akpan OP, Etuk BR. Adsorption of cyanide from cassava wastewater using calcined and activated oyster shell ash. Journal of Engineering Research and Reports. 2019;6(1):1-9.

Xu X, Lin X, Oh M, Park J. Oyster shell as a low-cost adsorbent for removing heavy metal ions from wastewater. Polish Journal of Environmental Studies. 2019;28(4): 2949-2959.

Odoemelam SA, Eddy NO. Studies on the use of oyster, snail and periwinkle shells as adsorbents for the removal of Pb2+ from aqueous solution. European Journal of Chemistry. 2008;6(1):213-222.

Chayapat T, Sinsupha J. Adsorption of lead ions from synthetic wastewater using oyster shell. International Journal of Environmental Research. 2009;31(1):45-53.

Gumus RH, Okpeku I. Production of activated carbon and characterization from snail shell waste (Helix pomatia). Advances in chemical engineering and science. 2015;5:51-61.

Eke-emezie NC, Etuk BR, Akpan OP, Chinweoke OC. Cyanide removal from cassava wastewater onto H3PO4 activated periwinkle shell carbon. Journal of applied water science. 2022;12:157.

Eke-emezie NC, Etuk BR. Cyanide adsorption from cassava wastewater onto calcined periwinkle shell. Journal of degraded and mining lands management. 2019;7:2502-2458.

Akanbi O, Babayemi, AK. Comparative analysis of heavy metal removal using activated bamboo and periwinkle shell, a case study of Cr (III) ion. Global Journal of Researches in Engineering: Chemical Engineering. 2019;19(2):11-17.

Awokoya KN, Sanusi RO, Oninla V, Ajibade O. Activated periwinkle shells for the binding and recognition of heavy metal ions from aqueous media. International Research Journal of Pure and Applied Chemistry. 2016;13(4):1-10.

Badmus MAO, Audu TOK, Anyata BU. Removal of lead ion from industrial wastewater by activated carbon prepared from periwinkle shells (Typononus fuscatus). Turkish Journal of Engineering and Environmental Science. 2007;31:251-268.

Okuo JM, Okolo PO. Removal of heavy metal ions by blended periwinkle shells. Journal of Applied Sciences. 2006;6(3):567-571.

Ekpete OA, Horsfall M. Preparation and characterization of activated carbon derived from fluted pumpkin stem waste. Research Journal of Chemical Sciences. 2011;1(3):10-17.

Njoku VO, Hameed BH. Preparation and characterization of activated carbon from corncob by chemical activation with H3PO4 for 2,4-dichlorophenoxyacetic acid adsorption. Chemical Engineering Journal. 2001;173(2):391-399.

Verla AW, Horsefall M (Jnr), Verla EN, Spiff AI, Ekpete OA. Preparation and characterization of activated carbon from fluted pumpkin (Telfairia occidentalis) seed shell. Asian Journal of Natural and Applied Sciences. 2012;1(3):39-46.

Kannan N, Veemaraj T. Removal of Lead (II) ions by adsorption onto bamboo dust and commercial activated carbons - a comparative study, e-Journal of Chemistry. 2009;6(2):247-256.

Nwoko CIA, Mbonu PI, Okoji JN. A comparative study of adsorption of cyanide onto dried peels of plantain and banana. International Journal on Recent and Innovation Trends in Computing and Communication. 2016;4(7):190-196.

Kaewkannetra P, Imai T, Garcia-Garcia FJ, Chiu TY. Cyanide removal from cassava mill wastewater using Azotobactor vinelandii TISTR 1094 with mixed microorganisms in activated sludge treatment system. Journal of Hazard Materials. 2009;172:224-228.

Evbuomwan BO, Agbede AM, Atuka MM. A comparative study of the physicochemical properties of activated carbon from oil palm waste (kernel shell and fibre). International Journal of Science and Engineering Investigations. 2013;2:75-79.

Agarwal B, Balomajumder C., Thakur PK. Simultaneous co-adsorptive removal of phenol and cyanide from binary solution using granular activated carbon. Chemical Engineering Journal. 2013;228:655-664.

Asgari G, Bahman R, Abdol MSM, Jamal MAP. The investigation of kinetic and isotherm of cyanide adsorption onto bone charcoal. International proceedings on Chemical, Biological and Environmental Engineering. 2012;43(25):119-122.

Eletta OAA, Ajayi OA, Ogunleye OO, Akpan IC. Adsorption of cyanide from aqueous solution using calcinated eggshells: equilibrium and optimization studies. Journal of Environmental Chemical Engineering. 2016;4:1367-1375.