连续流生物制氢反应器中有机负荷对产氢的影响

EFFECT OF ORGANIC LOADING ON HYDROGEN YIELD IN CONTINUOUS BIO-HYDROGEN PRODUCTION REACTOR

采用连续流搅拌槽式反应系统(CSTR)作为反应装置,以红糖水为发酵底物,污水处理厂剩余污泥为反应的启动污泥,在进水p H值为7.0±0.1、氧化还原电位(ORP)为-420 m V、温度(35±1)℃、水力停留时间(HRT)为6 h等影响因子调控下,达到稳定产氢(主要为乙醇型发酵)。在其他参数不变的条件下,通过改变有机负荷,着重研究其对产氢能力的影响,同时调节p H值使微生物保持较高活性。结果表明,当有机负荷从12 kg/(m3·d)上升为32 kg/(m3·d)时,产气和产氢速率均有持续增大的趋势。当有机负荷为32 kg/(m3·d)时,达最大产气速率(18.6 L/d),产氢速率为6.4 L/d,较初始有机负荷12 kg/(m3·d)时分别提高89%和87%。在系统运行过程中,进水p H值降低至5.85时,厌氧发酵微生物活性受到抑制,产氢速率有所下降,ORP上升至-328 m V。此时,向反应器内投加一定量的Na OH调节p H值,使反应器保持较高产氢速率的乙醇型发酵类型。

The experiment used continuous stirred tank reactor （CSTR） with brown sugar water as fermentation substrate, sewage sludge as the initiation of reaction. Under the influencing factors＇ regulation of intake pH value 7.0 e 0.1, oxidation-reduction potential （ORP）-420 mV, temperature （35±1）℃ and hydraulic retention time （HRT） 6 hours, the hydrogen production reached stable （Mainly for the ethanol-type fermentation）. When other parameters were equal, the impact of changing organic load on hydrogen production capacity was focused. At the same time, the microorganisms were allowed to maintain high activity by regulating pH value. The results show that when the organic load increased from 12 kg/（m^3·d） to 32 kg/（m^3·d）, both biogas and hydrogen production rates have continuously increasing trend. When the organic load is 32 kg/（m^3·d）, the maximum biogas production rate and hydrogen production rate reached 18.6 L/d and 6.4 L/d, respectively. Compared with the initial 12 kg/（m^3·d）, 89% and 87% are improved, respectively. During the system operation, while lowering the intake pH value to 5.85, microbial activity of anaerobic fermentation is inhibited, hydrogen production rates decline and ORP is up to -328 mV. At this time, the reactor can maintain a high hydrogen production rate of ethanol-type fermentation by adding a certain amount of NaOH in the reactor to regulate pH value.