废弃活性污泥加碱预处理后厌氧消化的试验研究

ANAEROBIC DIGESTION BY BASIC PRETREATED WASTE ACTIVATED SLUDGE

以废弃活性污泥（wasteactivatedsludge，WAS）作为基质来进行厌氧消化反应，在过去已有许多研究；若是将废弃活性污泥以碱剂预处理，则化学水解基质的作用会对厌氧消化处理有何影响，是本研究所欲了解的结果。本试验是在35℃的恒温中培养四组厌氧反应槽，一组为控制组（无碱预处理，1％TS），其余三组为将不同固体物浓度（1％或2％TS）的废弃活性污泥，以不同的碱剂量预处理（20或40meq／LNaOH），再饲入半连续式厌氧消化槽，培养期间共经历五个污泥停留时间（20，13．3，10，7．5及5d）；与无碱预处理的情况相较而言，发现基质的去除率、产气率、单位基质去除所产生的甲烷量，以及产气组成中甲烷所占比例，均有增加。试验进行至污泥停留时间为7.5d时，四组反应槽仍呈现正常的厌氧消化状态，而污泥停留时间在缩短为5d时，则有不稳定的情形发生。在试验过程中所经历的污泥停留时间范围内，结果显示以碱预处理的废弃活性污泥，在厌氧消化时基质去除率及反应速率均有较佳的结果。

Some studies were conducted to take the waste activated sludge (WAS) as substrate for anaerobic digestion in the past. The aim of the present study is to know the effect of chemically hydrolysis substrate from basic pretreated WAS on the anaerobic digestion. Four sets of seTni-continuous anaerobic reactors were prepared under thermostatic condition of 35 degree Ce1sius, three of thern were fed with WAS of different solid contents (TS of 1% %and 2%) and pretreated with different basic levels (20 or 40meq/l NaOH) and another one was remained as blank control (1 % of TS, no basic pretreatment). Incubations were carried out at five time intervais of sludge retention time (SRT = 20, 13. 3, 10, 7. 5and 5 days). In all cases the main parameters of anaerobic digestion including the removal ratio of substrate, the gas production ratio, the specific methane production of substrate removal and the methane proportion in produced gas for the basic treated rnedia were higher than that of untreated one. For experiments at 7.5days of SRT the norma1 anaerobic digestion condition remained and if the SRT was reduced to 5 days unsteady state was observed. In the range of tested SRT the experiment results show that for the anaerobic digestion the substrate removal ratio and the reaction rate of the basicwtreated WAS will be better than that of the untreated.