Comparative study on the performance of iron-amended cassava pulp feed bio-methanation in CSTRs

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Htay Aung Pyae Win Win Aye Chatpet Yossapol Somchai Dararatana


In recent years, the advances in the biogas related technology and plant design open new possibilities in biogas production from various biomasses other than activated waste sludge from a waste water treatment plant. Although, the anaerobic digestion (AD) process offers sustainable and environmental friendly energy to curb heavy reliance on fossil fuels to a certain extent, the low methane (CH4) content of biogas remains as a challenge. Using selected pieces of scrap iron with the properties of zero valent iron (ZVI), this paper attempts to enhance the biomethane content of biogas in terms of quality and quantity. The characteristics of scrap iron were verified using XPS and SEM. The optimum iron level was observed at 20 g/L where COD removal reached 95%. This represents a 20% enhancement over than that a of control reactor with 75% removal.  Bio‑methane production could further be improved using iron with superior characteristics (particularly zero valent iron, ZVI). Nevertheless, by means of the current iron amendments in cassava pulp feed CSTRs with an optimum organic loading rate (OLR) of 3.25 g VSS L‑1 day-1, methane was enriched from 50% to 75% with 10% to 35% additional gas yield over that of the control reactor. VFA/TA levels are a critical control factor. Inhibition starts when iron addition exceeds 20 g/L. The outcome of iron addition is seen immediately, making the process easier to control with better stability during digestion. The presence of iron cut the frequency of re-buffering and thus reduced chemical consumption for pH control and provided for a longer buffer resistance period. Iron amendment during anaerobic digestion of cassava pulp was shown to promote higher levels of bio-methane production.


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Pyae, H., Aye, W., Yossapol, C., & Dararatana, S. (2019). Comparative study on the performance of iron-amended cassava pulp feed bio-methanation in CSTRs. Engineering and Applied Science Research, 46(3), 219-226. Retrieved from


[1] González-García S, Dias AC, Clermidy S, Benoist A, Maurel VB, Gasol CM, et al. Comparative environmental and energy profiles of potential bioenergy production chains in Southern Europe. J Clean Prod. 2014;76:42-54.

[2] Forsell N, Selosse S. Importance of bioenergy markets for the development of the global energy system. International Energy Workshop (IEW); 2012 Jun; Cap Town, South Africa; 2012. No. hal-00868633f.

[3] IRENA [Internet]. Renewable energy outlook: International Renewable Energy Agency, Thailand; 2017 [cited 2018 Nov 5]. Available from: Thailand_2017.pdf.

[4] Achawangkul Y. Thailand’s Alternative Energy Development Plan (AEDP). National Dialogue on the Urban Nexus in Thailand; 2017 Mar 2; Bangkok, Thailand.

[5] Hobson PN, Bousfield S, Summers R. Methane production from agricultural and domestic wastes. England: Applied Science Publishers Ltd; 1981.

[6] Ostrem K. Greening waste: anaerobic digestion for treating the organic reaction of municipal solid wastes [thesis]. New York: Columbia University; 2004.

[7] Weiland P. Biogas production: current state and perspectives. Appl Microbiol Biotechnol. 2010;85(4):849-60.

[8] Mata-Alvarez J. Fundamentals of the anaerobic digestion process. In: Mata-Alvarez J, editor. Biomethanization of the organic fraction of municipal solid wastes. London: IWA Publishing; 2003. p. 1-20.

[9] Verma S. Anaerobic digestion of biodegradable organics in municipal solid wastes. New York: Columbia University; 2002.

[10] Sun Q, Li H, Yan J, Liu L, Yu Z, Yu X. Selection of appropriate biogas upgrading technology-a review of biogas cleaning, upgrading and utilisation. Renew Sustain Energy Rev. 2015;51:521-32.

[11] Vintila T, Neo S, Vintilă C. Biogas production potential from waste in timis county. Anim Sci Biotechnol. 2012;45(1):366-73.

[12] Karki AB. Biogas: as renewable source of energy in nepal; theory and development. Nepal: BSP-Nepal; 2005.

[13] Salomon KR, Lora EES. Estimate of the electric energy generating potential for different sources of biogas in Brazil. Biomass Bioenerg; 2009;33(9):1101-7.

[14] Angelidaki I, Ellegaard L, Ahring BK. A comprehensive model of anaerobic bioconversion of complex substrates to biogas. Biotechnol Bioeng, 1999;63(3):363-72.

[15] Yu D, Kurola JM, Lähde K, Kymäläinen M, Sinkkonen A, Romantschuk M. Biogas production and methanogenic archaeal community in mesophilic and thermophilic anaerobic co-digestion processes. J Environ Manag. 2014;143:54-60.

[16] Wilkie AC. Anaerobic digestion: biology and benefits. Dairy manure management conference: treatment, handling, and community relations; 2005 Mar 15-17; New York: Cornell University. p. 63-72.

[17] Hinken L, Urban I, Haun E, Weichgrebe D, Rosenwinkel KH. The valuation of malnutrition in the mono-digestion of maize silage by anaerobic batch tests. Water Sci Tech. 2008;58(7):1453-9.

[18] Möller K, Müller T. Effects of anaerobic digestion on digestate nutrient availability and crop growth: a review. Eng Life Sci. 2012;12(3):242-57.

[19] Choong YY, Norli I, Abdullah AZ, Yhaya MF. Impacts of trace element supplementation on the performance of anaerobic digestion process: A critical review. Bioresource Technol. 2016;209:369-79.

[20] Romero-Güiza MS, Vila J, Mata-Alvarez J, Chimenos JM, Astals S. The role of additives on anaerobic digestion: a review. Renew Sustain Energ Rev. 2016;58:1486-99.

[21] Demirel B, Scherer P. Trace element requirements of agricultural biogas digesters during biological conversion of renewable biomass to methane. Biomass Bioenerg. 2011;35(3):992-8.

[22] Joo SH, Delicio L, Muniz J, Baek S. Perspective: catalytic increase of biogas production in an anaerobic co-digestion system. Int J Nanoparticles Nanotech, 2018;4(1):1-6.

[23] Carpenter AW, Laughton SN, Wiesner MR. Enhanced biogas production from nanoscale zero valent iron-amended anaerobic bioreactors. Environ Eng Sci. 2015;32(8):647-55.

[24] Feng Y, Zhang Y, Quan X, Chen S. Enhanced anaerobic digestion of waste activated sludge digestion by the addition of zero valent iron. Water Res. 2014;52:242-50.

[25] Ibrahim SH, Abdulaziz M. The effect of different zero-valent iron sources on biogas production from waste sludge anaerobic digestion. J Biotechnol Res. 2016;2(8):59-67.

[26] Liu Y, Wang Q, Zhang Y, Ni BJ. Zero valent iron significantly enhances methane production from waste activated sludge by improving biochemical methane potential rather than hydrolysis rate. Scientific reports. 2015;5: Article no.: 8263.

[27] Zhang Y, Jing Y, Quan X, Liu Y, Onu P. A built-in zero valent iron anaerobic reactor to enhance treatment of azo dye wastewater. Water Sci Technol. 2011;63(4):741-6.

[28] Yang Y, Guo J, Hu Z. Impact of nano zero valent iron (NZVI) on methanogenic activity and population dynamics in anaerobic digestion. Water Res. 2013;47(17):6790-800.

[29] Feng Y, Zhang Y, Quan X, Chen S. Enhanced anaerobic digestion of waste activated sludge digestion by the addition of zero valent iron. Water Res. 2014;52:242-50.

[30] Ignace AC, Fidèle S, Dimon B, Franck Y, Lyde TA, Daouda M, et al. Biogas recovery from sewage sludge during anaerobic digestion process: effect of iron powder on methane yield. Int Res J Environment Sci. 2016;5(1):7-12.

[31] Rice EW, Baird RB, Eaton AD, Clesceri LS. Standard methods for the examination of water and wastewater. Washington: APHA, AWWA, WPCR; 2012.

[32] Scorpio R. Fundamentals of acids, bases, buffers and their application to biochemical systems. USA: Kendall Hunt Publishing; 2000.

[33] Manyi-Loh C, Mamphweli S, Meyer E, Okoh A, Makaka G, Simon M. Microbial anaerobic digestion (bio-digesters) as an approach to the decontamination of animal wastes in pollution control and the generation of renewable energy. Int J Environ Res Publ Health. 2013;10(9):4390-417.

[34] Cioabla AE, Ionel I, Dumitrel GA, Popescu F. Comparative study on factors affecting anaerobic digestion of agricultural vegetal residues. Biotechnol Biofuels. 2012;5(39):1-9.

[35] Smith JA, Carliell-Marquet CM. A novel laboratory method to determine the biogas potential of iron-dosed activated sludge. Bioresource Technol. 2009;100(5):1767-74.

[36] Adamson AW, Gast AP. Physical chemistry of surfaces. 6th ed. New York: John Wiley & Sons; 1967.

[37] Li Y, Zhang R, Chen C, Liu G, He Y, Liu X. Biogas production from co-digestion of corn stover and chicken manure under anaerobic wet, hemi-solid, and solid-state conditions. Bioresource Technol. 2013;149:406-12.

[38] Venkiteshwaran K, Bocher B, Maki J, Zitomer D. Relating anaerobic digestion microbial community and process function. Microbiol Insights. 2015;8(Suppl 2):37-44.

[39] Nguyen LN, Nguyen AQ, Nghiem LD. Microbial community in anaerobic digestion system: Progression in microbial ecology. In: Bui XT, Chiemchaisri C, Fujioka T, Varjani S, editors. Water and Wastewater Treatment Technologies: Energy, Environment, and Sustainability. Singapore: Springer; 2019. p. 331-55.

[40] Kuglarz M, Mrowiec B, Bohdziewicz J. Influence of kitchen biowaste addition on the effectiveness of animal manure digestion in continuous condition [Internet]. 2011[cited 2014 Mar 1]. Available online:

[41] Appels L, Baeyens J, Degreve J, Dewil R. Principles and potential of the anaerobic digestion of waste-activated sludge. Prog Energy Combust Sci. 2008;34:755-81.

[42] Kim JK, Oh BR, Chun YN, Kim SW. Effects of temperature and hydraulic retention time on anaerobic digestion of food waste. J Biosci Bioeng 2006;102:328-32.

[43] Grau P, Dohanyos M, Chudoba J. (1975). Kinetics of multicomponent substrate removal by activated sludge. Water Res. 1975;9(7):637-42.

[44] Jackson-Moss CA, Duncan JR. The effect of iron on anaerobic digestion. Biotechnology letters, 1990; 12(2):149-54.

[45] Agani IC, Suanon F, Dimon B, Ifon EB, Yovo F, Wotto VD, et al. Enhancement of fecal sludge conversion into biogas using iron powder during anaerobic digestion process. Am J Environ Protect. 2016;5(6):179-86.

[46] Zhang Y, Feng Y, Quan X. Zero-valent iron enhanced methanogenic activity in anaerobic digestion of waste activated sludge after heat and alkali pretreatment. Waste manag. 2015;38:297-302.

[47] Wei W, Cai Z, Fu J, Xie GJ, Li A, Zhou X, et al. Zero valent iron enhances methane production from primary sludge in anaerobic digestion. Chem Eng J. 2018;351:1159-65.