Acidic and alkaline shock pretreatment to enrich acidogenic biohydrogen producing mixed culture: long term synergetic evaluation of microbial inventory, dehydrogenase activity and bio-electro kinetics

Regulating biohydrogen production from wastewater by applying organic load-shock: Change in the microbial community structure and bio-electrochemical behavior over long-term operation

“…and facilitates the H þ availability in the cell through redox reactions to make H 2 [20]. LST biocatalyst showed higher DH activity over control operation and correlated with the H 2 production and substrate degradation ( Fig.…”

“…Later, a drop in H 2 production was observed till the 92nd cycle (0.9 mmol). The drop in H 2 production after a certain period of operation might be attributed to the longterm operation under uncontrolled conditions, which might have resulted in regaining methanogenic activity [20]. Loading unsterilized wastewater continuously for a number of cycles might also be responsible for the regaining of the i n t e r n a t i o n a l j o u r n a l o f h y d r o g e n e n e r g y 3 7 ( 2 0 1 2 ) 1 7 7 6 3 e1 7 7 7 7 methanogenic activity [3,9].…”

“…The resulting thick sludge (3.6 g VSS/l) after removing grit by nylon filter was used for the inoculum preparation. The inoculums were enriched with designed synthetic wastewater (DSW; with organic loading rate (OLR) of 2.14 kg COD/m 3 -day under anaerobic microenvironment for 3 days [20].…”

Toward bioenergy recovery from waste activated sludge: improving bio-hydrogen production and sludge reduction by pretreatment coupled with anaerobic digestion–microbial electrolysis cells

“…6,7 Recently, waste activated sludge (WAS) as the operation byproduct of wastewater treatment plants (WWTPs), its production has been increased signicantly with the rapid development of population and urbanization. 8,9 At present, although some approaches (landll, incineration, land-use, etc.) could effectively solve the WAS problems, the effects followed are not friendly to both environment and ecosystem.…”

“…[8][9][10][11][12][13][14][15] With the purpose to enhance the performance of AD process, a series of researches on WAS pretreatment have been done, aiming to improve WAS hydrolysis, such as biological, chemical, mechanical and codigestion, etc. 9,12,[16][17][18] In order to further improve WAS utilization, some previous studies have reported that it is possible to make the fermented liquid (mainly consisted of soluble protein, soluble carbohydrate, volatile fatty acids (VFAs), etc.) of WAS as the substrates for microbial electrolysis cells (MECs) to produce bio-hydrogen.…”