[Start-up of EGSB for biohydrogen production from compost leachate]

An expanded granular sludge bed reactor (EGSB) was employed to evaluate the start-up process of fermentative biohydrogen production from compost leachate. The removal performance of COD, total nitrogen, total phosphorus in leachate as well as the hydrogen production ability of EGSB was investigated. The results showed that at 35 degrees C +/- 1 degrees C, organic loading rate of 1.4-16.7 g/(L x d), the main pH of 5.0 to 5.5, the continuous hydrogen production by EGSB reactor using the compost leachate as substrate could be achieved after 20d's acclimatization. Under conditions of HRT of 30 h and liquid flow rate of 3.0 m/h, the COD removal rate of between 50% to 70%, the content of hydrogen in the biogas of between 19%-33%, the maximal hydrogen production rate of 1 460 mL/(L x d), total phosphorus and total nitrogen removal rate of between 40%-70% and 32%-65% respectively, were achieved.The total ethanol and acetic acid content was more than 80% in liquid end products (VFAs), suggesting the main fermentation is ethanol fermentation type.