Effect of hydraulic retention time on hydrogen production from sewage sludge and wine vinasse in a thermophilic acidogenic CSTR: a promising approach for hydrogen production within the biorefinery concept

Abstract

The aim of the present study was to investigate the effect of hydraulic retention time (HRT) on hydrogen production from sewage sludge:wine vinasse (50:50 v/v) in a laboratory-scale continuously stirred tank reactor under thermophilic conditions. For this purpose, nine HRT ranging from 5.0 to 0.25 days were tested. Maximum hydrogen production and specific hydrogen production of 0.90 LH2/Lreactor/d and 35.19 mLH2/g VSadded were respectively obtained at a HRT of 0.5 days. Eubacteria was the main group (65–79%) for all the tested HRT. Decreasing HRT was inversely correlated with hydrogen production and microbial population. HRT of 0.5 days is optimal for the growth of the acidogenic population and therefore this population is more active and maximum microbial activity (15.28·10−10 LH2/cells) was also achieved at this HRT.