硫酸盐还原菌和铁细菌对回灌堵塞影响的试验研究

Test on the influence of sulfate reducing bacteria and iron bacteria on the clogging of recirculation

针对铁锰含量较高地区,分析不同渗流时期由硫酸盐还原菌(SRB)及铁细菌(FB)导致的回灌堵塞成因。采用室内砂柱模拟间歇性回灌堵塞过程,通过测定水通量、砂柱中胞外聚合物(EPS)的含量、细菌含量及产生的气体体积变化,分析微生物回灌堵塞的特征,并在试验结束后通过XRD衍射判断生成物质。试验结果表明,回灌过程中渗流初期介质渗透性能的降低是由菌体本身引起的,渗流中后期介质渗透性能的降低是由菌体本身、EPS和生化作用生成的四氧化三铁及硫化亚铁等不溶性固体共同作用导致。发现有产气菌(即SRB)参与的回灌过程易发生气阻且气阻作用一直存在,从而导致回灌难以进行,且该现象在微生长期格外突出。在生物堵塞中,由细菌导致的化学衍生物也是导致含水介质的渗透性能降低的主要因素。该研究为微生物堵塞的研究机理提供进一步依据。

In view of the problem of clogging caused by sulfate-reducing bacteria and iron bacteria in areas with high contents of iron and manganese,the causes of clogging during different seepage periods are analyzed.The results can provided further evidence for the mechanism of microbial blockage.The clogging process of intermittent recharge is simulated using the indoor sand column.The characteristics of microbial recharge are analyzed by measuring the water flux,the EPS content in the sand column,the bacterial content and the gas volume change.After the experiment,diffraction is used to determine the generation of material.The results show that the decrease in permeability of the medium in the process of recharge is mainly caused by the bacteria itself.When the bacteria are in the decay stage,it is mainly caused by the increase in the EPS content,and then the bacteria and EPS and the biochemical iron and ferrous sulfide and other insoluble solids together.In the presence of sulfate-free bacteria and other gas-producing bacteria involved in the occurrence of air resistance,the recovery is difficult to carry out.