Abstract

The main factors that affect the biohydrogen production from renewable resources are continually studied because their limitations are variable and depend largely on the substrate type, especially when using real wastewater. Inoculum pretreatment and pH are critical factors that govern the metabolic pathways driving the fermentative hydrogen production. In this work, the influence of inoculum pretreatment and initial pH on the fermentative production of hydrogen was investigated using cassava wastewater in anaerobic batch reactors at room temperature (29.0–34.5 °C). A mixed factorial design was performed to evaluate the effect of initial pH and inoculum pretreatment on hydrogen yield. Two pretreatment methods were evaluated (chemical and heat), and the initial pH was examined at three levels (5.7, 5.4, and 5.0). The pretreatments efficiently inhibited the activity of hydrogen-consuming bacteria for short periods. The highest biogas production, 91 ± 14 mL, was achieved with chemical pretreatment at pH 5.4, and 86 ± 12 mL of biogas was obtained with heat pretreatment at pH 5.0. Moreover, the results showed that the optimum pH interval for fermentative hydrogen production from cassava wastewater was between 5.0 and 5.4, and the highest yield of H₂ was 1.25 ± 0.01 mol H₂ mol⁻¹ carbohydrates with heat pretreatment.

摘要

影响可再生资源生产生物氢的主要因素不断被研究，因为它们的局限性是可变的，并且很大程度上取决于底物类型，尤其是在使用真实废水时。接种物预处理和 pH 值是控制驱动发酵产氢的代谢途径的关键因素。在这项工作中，在室温（29.0-34.5°C）下，在厌氧间歇反应器中使用木薯废水研究了接种物预处理和初始 pH 值对发酵产氢的影响。进行混合因子设计以评估初始 pH 值和接种物预处理对氢气产量的影响。评估了两种预处理方法（化学和加热），并在三个水平（5.7、5.4 和 5.0）下检查了初始 pH 值。预处理在短时间内有效地抑制了耗氢细菌的活性。通过 pH 5.4 的化学预处理获得最高的沼气产量，91 ± 14 mL，在 pH 5.0 的热处理下获得 86 ± 12 mL 的沼气。结果表明,木薯废水发酵制氢的最适pH区间为5.0~5.4,H₂是经过热预处理的 1.25 ± 0.01 mol H ₂ mol ^-1碳水化合物。