Anaerobic digestion of lignocellulosic waste is considered to be an efficient way to answer present-day energy crisis and environmental challenges. However, the recalcitrance of lignocellulosic material forms a major obstacle for obtaining maximum biogas production. The use of biological pretreatment and bioaugmentation for enhancing the performance of anaerobic digestion is quite recent and still needs to be investigated. This paper reviews the status and perspectives of recent studies on biotechnology concept and investigates its possible use for enhancing biogas production from lignocellulosic waste with main emphases on biological pretreatment and bioaugmentation techniques.

No abstract

Due to the presence of various types of hydrogen-producing bacteria and numerous organics such as protein and carbohydrate, sewage sludge is a potential material for biological hydrogen production. In this study, two batch tests were carried out to investigate the impact of alkali and heat pretreatment on the pathway of hydrogen production from sewage sludge. The results showed that the heat treatment had a stronger lethal effect on bacteria than the alkali treatment, and could effectively kill hydrogen-consuming bacteria. The heat treatment was more suitable for enriching acidophilic hydrogen-producing bacteria, while the alkali treatment was more suitable for enriching basophilic hydrogen-producing bacteria. A maximum hydrogen production of 10.32 mL/g-COD from alkali pretreated sludge was obtained at an initial pH of 11; while a maximum hydrogen production of 8.94 mL/g-COD from heat pretreated sludge was obtained at an initial pH of 5. Hydrogen production in alkali conditions (pH>9) from alkali pretreated sludge mainly depended on the fermentation of protein by protein-utilizing bacteria; whereas hydrogen production in acidic conditions (pH<6) from heat pretreated sludge mainly depended on the fermentation of carbohydrate by glucose-utilizing bacteria. sewage sludge, alkali pretreatment, heat pretreatment, hydrogen production Citation:Wei S Z, Xiao B Y, Liu J X. Impact of alkali and heat pretreatment on the pathway of hydrogen production from sewage sludge.

No abstract