维生素B12对厌氧污泥还原降解8:2FTOH的影响

Influence of vitamin B12 on the reductive degradation of 8:2FTOH by anaerobic activated sludge.

研究了投加生物催化剂维生素B12(VB12)对厌氧活性污泥还原降解8:2氟调聚醇(8:2FTOH)的影响.结果表明,投加VB12能够改变厌氧活性污泥还原降解8:2FTOH的动力学特性并增加其最终去除率,但投加量存在上下限:当VB12投加量≤1mg/L时,8:2FTOH最终去除量无显著增加;当VB12投加量≥5mg/L时,8:2FTOH最终去除量也不再持续增加.投加所有剂量的VB12均可显著增加8:2FTOH的最终脱氟率.投加VB12对厌氧活性污泥还原降解8:2FTOH去除率和脱氟率的影响并不一致.此外,投加较高浓度的VB12可以抑制厌氧污泥还原降解8:2FTOH过程中多氟代化合物等中间降解产物的积累,提高全氟代化合物等终态降解产物的产率,同时有利于增加8:2FTOH的矿化脱氟率,但却导致了更低的总物质的量回收率.

The influences of vitamin B12(VB12),a biocatalyst,on the reductive degradation of 8:2fluorotelomer alcohol(8:2FTOH)in anaerobic activated sludge were investigated.VB12 could change the dynamic characteristic of reductive degradation of 8:2FTOH by anaerobic activated sludge and enhance the final removal rates of 8:2FTOH,but there were the upper and the lower dosage limits for the VB12.The final removal rates of 8:2FTOH in anaerobic activated sludge could not be enhanced while the spiked dosage of VB12 was less than or equal to 1mg/L,but no further improvement was also observed when the VB12 concentration was increased to more than or equal to 5mg/L.The final defluorination rates of 8:2FTOH could be significantly inhenced with spiking all VB12 dosages in the present study.The influences of VB12 dosages on the removal rates and defluorination rates of 8:2FTOH in the anaerobic activated sludge were inconsistent.In addition,when the anaerobic activated sludge was amended with the higher concentrations of VB12,the accumulation of intermediate degradation products(i.e.polyfluorinated compounds)was generally inhibited and the lower total molar recoveries of 8:2FTOH were observed while the molar yields of final degradation products(i.e.perfluorocarboxylates),as well as the mineralization defluorination rates of 8:2FTOH,were enhanced.