初始pH值对提油后藻渣发酵制氢的影响

Influence of initial pH on hydrogen production from lipid-extracted microalgal biomass residues

提油后藻渣的利用和处理对于微藻生物柴油产业的发展具有重要意义。采用批次实验研究了初始pH值（pH值范围为5~9）对提油后藻渣发酵产氢的影响。研究结果表明,提高初始pH值引起累积产氢量和氢气产量逐渐下降。初始pH值从5增加到6.5引起氢气产生速率逐渐增加,而初始pH值从6.5增加到9时,氢气产生速率则逐渐下降。在pH 5时虽然氢气产量最高,为50 mL/g-挥发性固体,但是产氢延迟时间则长达20 h。在pH 6.5时发酵产氢启动较快（1.7 h）,并且氢气产生速率最大,为3.79 mL/h。因此,藻渣发酵产氢的最适初始pH值为6.5。

It is significant for development of microalgal biodiesel industry to utilize lipid-extracted microalgal biomass residues.Hydrogen production from lipid-extracted microalgal biomass residues was performed via batch tests by using heat treated anaerobic digested sludge,and the effect of initial pH 5~9 on the biohydrogen production was firstly investigated.The results showed that increasing the initial pH led to decreases in hydrogen yield and cumulative hydrogen production.The hydrogen production rate increased with initial pH from 5 to 6.5,and then decreased as the pH further increased to 9.The lowest initial pH 5 offered the highest hydrogen yield of 50 mL H2/g VS（volatile solid）,a lower hydrogen production rate of 2.69 mL H2/h,and a longer lag-phase of 20 h,whereas the highest hydrogen production rate of 3.79 mL H2/h and a lower lag-phase time of 1.7 h occurred at optimal initial pH 6.5.