苹果渣与剩余污泥混合消化产氢性能研究

摘要

A batch experiment for hydrogen generation from apple waste and excess sludge by anaerobic digestion was conducted at the mesophilic temperature of 37 ℃ and with the initial pH of 8.0.Results showed that hydrogen yield was 11.5 mL/gVS and 8.6 mL/gVS with single-digestion of apple waste and excess sludge,respectively.The hydrogen yield of co-digestion group reached 16.9 mL/gVS,which was increased by 68.16％ as compared with the calculated value of co-digestion group.The pH value of excess sludge group was the highest,while the SCOD of apple waste group was the highest.Values of pH and SCOD of co-digestion group were between those for two single-digestion groups due to the well-balanced nutrients of two organic wastes,and the strong buffer capacity of the reactor system.These indicated that co-digestion was not just the simple sum of the two organic matters,and there was a certain synergic effect in the co-digestion process,which made the hydrogen production efficiency of co-digestion group enhanced.In addition,the dehydrogenase activity of co-digestion group was significantly higher than that of apple waste group during the whole process.The dehydrogenase activity of co-digestion group maintained around 340 TFμg/(mL· h),with a maximum value of 384 TFμg/(mL.h).%以苹果渣和剩余污泥为消化底物,在温度为37℃,初始pH值为8.0的条件下进行批式厌氧消化产氢试验,比较单独消化和混合消化的产气性能.结果表明,苹果渣组和剩余污泥组单独厌氧消化时,H2产量分别是11.5 mL/gVS和8.6 mL/gVS,混合厌氧消化时,混合组的H2产量达到16.9 mL/gVS,比计算值提高了68.16％.剩余污泥组的pH值最高,苹果渣组中SCOD浓度最高,混合组的pH值和SCOD浓度均介于两个单独消化组之间,这是由于混合组能均衡两种有机底物的营养成分,提高系统的缓冲能力.这说明混合消化不单单是两种有机物的简单叠加,两者之间相互促进,存在一定的协同作用,混合消化能够提高产氢效率.另外在整个反应过程中,苹果渣组脱氢酶的活性很低,混合组高于苹果渣组,混合组脱氢酶活性最大为384 TFμg/(mL·h),且基本维持在340 TFμ g/(mL· h)左右.