Research article Kinetics of biogas production and chemical oxygen demand removal from compost leachate in an anaerobic migrating blanket reactor Aliasghar Ebrahimi a , Hassan Hashemi b , Hadi Eslami c , Reza Ali Fallahzadeh a , Rasoul Khosravi d, * , Roohollah Askari e , Esmail Ghahramani f a Environmental Science and Technology Research Center, Department of Environmental Health Engineering, Shahid Sadoughi University of Medical Sciences, Yazd, Iran b Research Center for Health Sciences, Shiraz University of Medical Sciences, Shiraz, Iran c Department of Environmental Health Engineering, School of Health, Rafsanjan University of Medical Sciences, Rafsanjan, Iran d Social Determinants of Health Research Center, Department of Environmental Health Engineering, School of Health, Birjand University of Medical Sciences, Birjand, Iran e Department of Healthcare Management, School of Health, Shahid Sadoughi University of Medical Sciences, Yazd, Iran f Kurdistan Environmental Health Research Center, Kurdistan University of Medical Sciences, Sanandaj, Iran article info Article history: Received 19 May 2017 Received in revised form 24 September 2017 Accepted 19 October 2017 Keywords: Leachate Modeling Biological treatment Biogas Solid waste Composting abstract In this study, laboratory anaerobic migrating blanket reactor (AMBR) with four units was used to reduce and remove COD leachate of composting process; it was also used to determine the kinetic coefficients of COD removal and biogas and methane gas production in several different OLRs. The maximum con- centration of organic matter entering the reactor was 100,000 mg/L and the reactor was under operation for 319 days. The results showed that the COD removal efficiency of AMBR in all concentrations of substrate entering the reactor was above 80%. First-order model and Stover-Kincannon were used to investigate the kinetics of COD removal via AMBR biological process; in addition, the two models of Modified Stover-Kincannon and Van der Meer and Heertjes were used to check the kinetic constants of biogas and methane gas production. The results obtained from the models showed that the experimental data on COD removal were more consistent with the results obtained from Stover-Kincannon model (R 2 ¼ 0.999) rather than with the First-order model (R 2 ¼ 0.926). Kinetic constants calculated via Stover- Kincannon model were as follows: saturation value constant (KB) and maximum utilization rate con- stants (U max ), respectively, were 208,600 mg/L d and 172,400 mg/L d. We investigated the linear rela- tionship between the experimental data and the values predicted by the models; as compared with the values predicted by the First-order model, the values predicted by Stover-Kincannon model were closer to the values measured via experiments. Based on the results of the evaluation of kinetic coefficients of Stover-Kincannon model, with the migration of the leachate flow from unit 1 to unit 4, U max value has fallen significantly. The values of maximum specific biogas production rate (G max ) and proportionality constant (GB) obtained from the Stover-Kincannon model, respectively, were 35,714 ml/L d and 42.85 (dimensionless) and value of kinetic constant of Van der Meer and Heertjes (ksg) was 0.0473 ml CH 4 /mg COD. © 2017 Elsevier Ltd. All rights reserved. 1. Introduction The amount of waste produced globally has increased in the past decade, as the amount of waste a decade earlier was 0.68 billion tons and it already has reached about 1.3 billion tons. In addition, it is estimated that the amount of waste will have reached 2.2 billion tons by 2025 (Pellera et al., 2016). Apart from the increase in population, there are some other reasons for the increased production of waste, such as changes in lifestyle, rapid * Corresponding author. E-mail addresses: ebrahimi20007@gmail.com, ebrahimi20007@ssu.ac.ir (A. Ebrahimi), hashemi@sums.ac.ir (H. Hashemi), hadieslami1986@yahoo.com (H. Eslami), fallahzadeh4@yahoo.com (R.A. Fallahzadeh), khosravi.r89@gmail.com (R. Khosravi), r.asqari@gmail.com (R. Askari), ghahramani64@gmail.com (E. Ghahramani). Contents lists available at ScienceDirect Journal of Environmental Management journal homepage: www.elsevier.com/locate/jenvman https://doi.org/10.1016/j.jenvman.2017.10.038 0301-4797/© 2017 Elsevier Ltd. All rights reserved. Journal of Environmental Management 206 (2018) 707e714