水力停留时间对硫自养还原高氯酸盐和硝酸盐性能的影响

Effect of Hydraulic Retention Time on Sulfur Autotrophic Reduction of Perchlorate and Nitrate

以填充单质硫颗粒（S0）的生物膜反应器作为研究对象,研究了水力停留时间（HRT）变化对硫自养还原高氯酸盐（ClO4^-）和硝酸盐（NO3）性能的影响.研究结果表明,在进水NO3^--N和ClO4^-分别为20 mg/L和100μg/L时,在HRT从16 h逐渐缩短到0.5h过程中,NO3^--N去除率能在较短时间内达到99％以上.与硫自养还原NO3^--N相比,HRT的缩短导致ClO4^-去除率趋于稳定所需时间增加,说明硫自养还原NO3^--N过程先于硫自养还原ClO4^-的过程.在不同HRT下未发现中间产物ClO3^-和ClO2^-的积累,ClO4^-摩尔数减少量与Cl-摩尔数增加量比约为1∶1,出水中SO4^2-的实际产生量远大于理论产生量,出水pH值范围为6.8～7.1.通过PCR-DGGE图谱和测序结果分析可知,属于α-proteobacteria菌群在反应器中占优势地位,β-proteobacteria菌群次之.其中,具有NOr和ClO4^-还原能力的Denitromonas sp.和Azospirillum sp.存在于反应器的底部、中部和上部的生物膜,能还原ClO4^-的Dechloromonas sp.MissR被发现存在于反应器中部和上部的生物膜.

The effect of Hydraulic retention time （HRT） on sulfur autotrophic reduction of perchlorate and nitrate was investigated in a biofilm reactor filled with S0 particle.When the influent NO3^-N and ClO4^-concentration was 20 mg/L and 100μg/L,respectively,the removal efficiency of NO3^--N was obtain over 99% in a shorter period with the decrease of HRT from 16 h to 0.5 h.Compared with sulfur autotrophic reduction of nitrate,the steady time of ClO4^-removal efficiency required more longer with the decrease of HRT,suggesting sulfur autotrophic nitrate reduction had precedence over sulfur autotrophic perchlorate reduction in the biofilm reactor.No accumulation of ClO3^-and ClO2^-was found at different HRT,and the reduced mole of ClO4^-was almost equal to the increased mole of Cl.The actual production of SO4^2-in the effluent was more than the theory production of SO4^2-,and the effluent pH was in the range of 6.8 and 7.1.By analyzing the PCR-DGGE profile and sequencing results,α-proteobacteria was preponderant in the biofilm reactor,and β-proteobacteria followed.Denitromonas sp.and Azospirillum sp.were present in the biofilm of bottom,middle and upper in the reactor,which have the ability to reduce NO3^-and ClO4^-.Dechloromonas sp.MissR could reduce ClO4^-and was found in the biofilm of middle and upper in the reactor.