预处理对造纸污泥厌氧消化产甲烷性能的影响研究

Methane production in anaerobic digestion of paper mill sludge by alkali/biological pretreatment

采用碱(NaOH)和生物(蘑菇渣、绿色木霉)2种方法分别预处理造纸污泥,并将预处理后的造纸污泥与味精废液进行联合厌氧消化,研究不同预处理方式对造纸污泥的影响以及对后续联合厌氧消化甲烷产率的影响.结果表明,造纸污泥经过碱(NaOH)预处理和生物预处理(蘑菇渣、绿色木霉)后,污泥颗粒的结构变得紧实、平滑,颗粒间的孔隙度减少,污泥絮体中的纤维长度明显变短、污泥中的SCOD增加了35.5%～1130%、VSS降低了6%～19%、SVsludge增加了32%～192%,NH3-N浓度提高了36%～62.4%,表明预处理后污泥中的大分子物质被降解成小分子物质,且碱预处理对污泥产生的变化较生物处理大;经预处理后的造纸污泥与味精废液联合厌氧消化,甲烷得率分别为:NaOH预处理0.32m3CH4/kgVS、蘑菇渣预处理0.23m3CH4/kgVS,较CK分别提高了54%～88%和12%～34%,可见碱预处理提高甲烷产率效果更明显,由于蘑菇渣预处理具有成本低、解决二次污染、实现废物再利用等优点,因此两者在预处理提高造纸污泥厌氧消化甲烷产率方面都具有重要意义.

Methane production in anaerobic digestion （AD） of the paper mill sludge （PS） and monosodium glutamate waste liquor （MGWL） after PS was pretreated with alkaline （i.e.,NaOH） and biological methods （i.e.,mushroom compost and cellulase） was studied.Most of the macromolecules of PS were degraded into monomers （proteins and carbohydrates） which would be easier to be decomposed by microorganism to increase the methane yield in the stage of AD.The details of the change were shown as follows：after pretreatment,PS particles in structure became more compact;the porosity of particle reduced;the crude fiber was obviously degraded into small units;the increase of soluble chemical oxygen demand （SCOD） in PS from 35.5% to 1130% was noticed;volatile suspended solids （VSS） decreased slightly （6%～19%）;sludge setting ration （SV） and NH3-N concentrations increased by 32%～192% and 36%～62.4%,respectively.Moreover,the changes of PS pretreated with alkaline were greater than those with biological methods.Additionally,the methane production in AD was 0.32m3 CH4/kg VS and 0.23 m3 CH4/kg VS after NaOH and biological pretreatment,respectively,which was enhanced by 54%～88% and 12%～34% compared with control.These two pretreatments showed promising results,and more research would be carried out.