Starting Up And Operating Biohydrogen Production Reactor And Influencing Factors Of Hydrogen Production From Sluge

Energy from hydrogen is widely appreciated because of its prominentadvantage of cleanness and high efficiency etc. The technology of biohydrogenproduction has many advantages such as not consuming fossil resource, low costand so on. It is a new technology which accords with continuous development.Among the methods of biohydrogen production, biohydrogen productionfrom fermentation is more prominent than biohydrogen production fromphotosynthesis because of its better stability and ability of hydrogen production.Continuous stirred tank reactor （CSTR） was used as biohydrogen productionreactor in this study, and the iron was added to investigate the effect of hydrogenproduction in the start-up stage of reactor. Molasses was used as substract andactived sludge was added to CSTR after pretreatment of aeration. The resultsshowed that biogas was decreasing within7days when the reactor was runned atthe volume loading of7.992kgCOD/m³·d^-1, hydraulic retention time at9h.Reactor was started to hydrogen production from4thday.The H₂yield keptsteadily after26thday. The maximal biogas reach at9.24L/d in26thday while themaximal H2yield at3.42L/d. The COD removal rate was higher in the first2days, which was74.23%,73.41%respectively. The COD removal rate kept about17%between26-30thdays. The effluent pH was falling rapidly within1-10thdays. The final pH dropped to4.8. The effluent pH was kept about5.0at the stageof hydrogen production in stable condition. The glucose conversion rate keptabout75%within1-7thdays. And then, it kept at a higher conversion rate of93%,at the end of30days operation, The settlement performance of mature activesludge that isolated H2-producing strains and obtained from CSTR was good. Themax sedimentation velocity and sedimentation ratio was7mm/min,42%respectively. On the contrast, it was only1.6mm/min and65%in the period ofdecreasing of VSS.The resulsts of batch experiments showed that the maximal production yieldof hydrogen were211.7mL,221.0mL,208.8mL obtained at the ironconcentration of800mg/L,200mg/L,25mg/L FeSO4respectively. Theinhibitory effect of ethanol, propionic acid and butyric acid was growing whenthe added concentration was increasing from0-300mmol/L. The inhibitory effect of added ethanol on fermentative hydrogen production was smaller than those ofadded acetic acid, propionic acid and butyric acid. The effect of various methodsof pretreating sluge on hydrogen yield was aerate, heat, base, acid, ultrasonic,ultraviolet. Pretreatment of activated sludge by aerate method was optimalchoice.