Environment Research Center, Research Institute for Primordial Prevention of Non-communicable Disease, Isfahan University of Medical Sciences, Isfahan, Iran; Department of Environmental Health Engineering, School of Health, Isfahan University of Medical Sciences, Isfahan, Iran.
Environment Research Center, Research Institute for Primordial Prevention of Non-communicable Disease, Isfahan University of Medical Sciences, Isfahan, Iran; Department of Environmental Health Engineering, School of Health, Isfahan University of Medical Sciences, Isfahan, Iran; Student Research Committee, School of Health, Isfahan University of Medical Sciences, Isfahan, Iran, Isfahan, Iran.
J Environ Manage. 2019 Nov 15;250:109461. doi: 10.1016/j.jenvman.2019.109461. Epub 2019 Sep 6.
Mixed culture sludge has been widely used as a microbial consortium for biohydrogen production. Simple thermal treatment of sludge is usually required in order to eliminate any H-consuming bacteria that would reduce H production. In this study, thermal treatment of sludge was carried out at various temperatures. Electron flow model was then applied in order to assess community structure in the sludge upon thermal treatment for biohydrogen production. Results show that the dominant electron sink was acetate (150-217 e- meq/mol glucose). The electron equivalent (e- eq) balances were within 0.8-18% for all experiments. Treatment at 100 °C attained the highest H yield of 3.44 mol H/mol glucose from the stoichiometric reaction. As the treatment temperature increased from 80 to 100 °C, the computed acetyl-CoA and reduced form of ferredoxin (Fd) concentrations increased from 13.01 to 17.34 e- eq (1.63-2.17 mol) and 1.34 to 4.18 e- eq (0.67-2.09 mol), respectively. The NADH balance error varied from 3 to 10% and the term e-(Fd↔NADH) (m) in the NADH balance was NADH consumption (m = -1). The H production was mainly via the Fd:hydrogenase system and this is supported with a good NADH balance. Using the modified Gompertz model, the highest maximum H production potential was 1194 mL whereas the maximum rate of H production was 357 mL/h recorded at 100 °C of treatment.
混合培养污泥已被广泛用作生物制氢的微生物联合体。为了消除任何会降低氢气产量的消耗氢气的细菌，通常需要对污泥进行简单的热处理。在本研究中，对污泥进行了不同温度的热处理。然后应用电子流模型来评估污泥在用于生物制氢的热处理过程中的群落结构。结果表明，主要的电子汇是乙酸盐（150-217 e- meq/mol 葡萄糖）。所有实验的电子当量（e- eq）平衡都在 0.8-18%之间。在 100°C 的处理条件下，从化学计量反应中获得了 3.44 mol H/mol 葡萄糖的最高氢气产率。随着处理温度从 80°C 升高到 100°C，计算得出的乙酰辅酶 A 和还原型铁氧还蛋白（Fd）浓度分别从 13.01 e- eq（1.63-2.17 mol）和 1.34 e- eq（0.67-2.09 mol）增加到 17.34 e- eq（2.17-2.75 mol）和 4.18 e- eq（2.09-4.37 mol）。NADH 平衡误差在 3-10%之间，NADH 平衡中的项 e-(Fd↔NADH)（m）为 NADH 消耗（m =-1）。氢气的产生主要通过 Fd：氢化酶系统进行，这得到了良好的 NADH 平衡的支持。使用修正的 Gompertz 模型，在 100°C 处理时，最大氢气产生潜力为 1194 mL，最大氢气产生速率为 357 mL/h。
