硫和石英砂比对自养填充床反应器去除高浓度高氯酸盐的影响

运行不同硫和石英砂体积比的3个自养填充床反应器R1(2∶1)、R2(1∶1)、R3(1∶2)去除模拟高浓度高氯酸盐(ClO_4~-)污染水,在不同进水ClO_4~-浓度和水力停留时间(HRT)下研究反应器的ClO_4~-去除效果、动力学及生物膜生长规律.结果表明,ClO_4~-去除率随着ClO_4~-浓度的提高和HRT的减小而下降,且R1R2R3;当HRT为3.2 h,进水ClO_4~-浓度为300mg·L-1时,R1达到最大去除负荷2.18 kg·(m3·d)-1;3个反应器ClO_4~-去除均符合半级动力学,反应速率常数1/2K1/2v分别为8.036、6.596、4.212 mg1/2·(L1/2·h)-1;硫歧化反应使出水SO_4~(2-)浓度高于理论值,硫歧化反应随着ClO_4~-浓度的提升和HRT的下降受到抑制,R3出水SO_4~(2-)浓度最低,歧化反应最弱;出水p H和碱度随着进水ClO_4~-浓度和HRT的增大而减小,且R3一直较高;R2、R3挂膜效果好于R1,胞外聚合物(EPS)的分泌可以促进生物膜生长,且分泌量随着HRT的减小而减少.

Effect of Sulfur to Quartz Sand Ratios on the Removal of High-Concentration Perchlorate in Packed-Bed Reactors

Three autotrophic packed-bed reactors, each with a different sulfur/quartz sand ratio(R1, 2:1; R2, 1:1; R3, 1:2,)were used to remove high-concentration perchlorate from contaminated water. The perchlorate removal efficiency, kinetics, and biofilm of the reactors were studied using different perchlorate concentrations and hydraulic retention times (HRTs). The perchlorate removal efficiency decreased with higher perchlorate concentration and shorter HRT, and the removal efficiency of R1 was higher than of R2 and R3. The maximum removal loading of R1 was 2.18 kg·(m³·d)^-1at an HRT of 3.2 h and perchlorate concentration of 300 mg·L^-1. The half-order kinetics model fit the reactors'' experimental data well; the reaction rate constants of R1, R2, and R3 were 8.036, 6.596, and 4.212 mg^1/2·(L^1/2·h)^-1. The yield of SO₄^2- was greater than the stoichiometric yield of sulfur autotrophic reduction owing to sulfur disproportionation. The disproportionation was inhibited with a higher perchlorate concentration or shorter HRT. Moreover, disproportionation of R3 was the weakest because the SO₄^2- yield of R3 was lower than of R1 and R2. The pH and alkalinity of the effluent increased with lower perchlorate concentration and shorter HRT. The development of biofilm in R2 and R3 was better than in R1. The secretion of extracellular polymeric substances can promote the formation of biofilm.