硫自养填充床生物反应器去除水中的高氯酸盐

建立了硫自养填充床生物反应器用于水中ClO4-的去除,考察水力停留时间(HRT)、水温的影响及副产物产生规律。结果表明,当进水ClO4-浓度为22.40~21.07 mg/L时,逐步缩短HRT为12、8、4、2、1.5和1 h,经4~6 d的适应期,反应器对其去除率可达99%以上;低浓度的NO3--N(2.17 mg/L)的存在对ClO4-的降解不产生抑制,两者可同步去除;3℃以内的水温波动对其去除影响较小,较大的温度波动(-8℃)会造成去除率下降;Cl-作为惟一还原产物,其浓度增多符合化学计量比。同时,研究证实了硫歧化反应的发生,出水SO42-浓度的增加量大于理论值,S2-离子浓度较低(4-完全去除时,出水pH值比进水降低约1.1个单位。

Sulfur-autotrophic reduction of perchlorate from aqueous solution using a packed bed reactor

Sulfur-autotrophic reduction of perchlorate from aqueous solution by packed bed reactor was investigated to explore the effect of hydraulic retention time(HRT), temperature and the rule of by-products generation. For 22.40-21.07 mg/L ClO4- in influent, through shortening HRT to 12, 8, 4, 2, 1, 5 and 1 h gradually, the removal efficiency could reach more than 99% after 4-6 days adaptation. Besides, nitrate with low concentration(2.17 mg N/L) could be removed simultaneously without inhibition. Low fluctuation of water temperature(3℃) had little effect on removal, while high temperature fluctuation(-8℃) decreased the removal efficiency. Cl- was the only observed reduction product, and the average yield of Cl- was close to the stoichiometric value. Furthermore, sulfur disproportionation was verified in this study, the yield of SO42- was greater than the stoichiometric yield of sulfur autotrophic reduction, and the S2- concentration in effluent was lower than 0.40 mg/L. The disproportionation could be inhibited with shorter HRT or lower temperature. The sulfur-autotrophic reduction process consumes solution alkalinity, pH of effluent is about 1.1 units lower than influent when removal efficiency of perchlorate >99%.