Effects of hydraulic retention time and sulfide toxicity on ethanol and acetate oxidation in sulfate-reducing metal-precipitating fluidized-bed reactor
Effects of hydraulic retention time and sulfide toxicity on ethanol and acetate oxidation in sulfate-reducing metal-precipitating fluidized-bed reactor
复制标题
DOI：
10.1002/bit.20061
复制
发表时间：
2004-05-05
影响因子：
3.8
通讯作者：
Puhakka, JA
中科院分区：
文献类型：
--
作者：
Kaksonen, AH;Franzmann, PD;Puhakka, JA
采用硫酸盐还原流化床反应器（FBR）处理酸性含金属废水，研究了水力停留时间（HRT）和硫化物毒性对乙醇和乙酸盐利用率的影响。水力停留时间的影响，确定与连续流FBR实验。在HRT为6.5 h（负载量为2.6 g乙醇L-1 d（-1））时，乙醇的氧化率为99.9%，而在HRT低于12 h（负载量为1.4 g乙醇L-1 d（-1））时，乙酸在FBR中积累。部分乙酸盐的利用伴随着溶解的硫化物（DS）和碱度的浓度降低的流出物，并最终导致过程失败时，HRT降低到6.1小时（负载2.7 g乙醇L-1 d（-1））。随着水力停留时间的降低，锌和铁的沉淀速率分别增加到600 mg L-1 d（-1）和300 mg L-1 d（-1）以上。在水力停留时间为6.5小时，百分之金属沉淀超过99.9%，和流出物金属浓度保持低于0.08毫克L-1。在这些条件下，由底物利用产生的碱度将废水pH从3提高到7.9-8.0。从乙醇到硫酸盐还原的电子流的百分比平均为76 +/-10%，并且不受HRT的影响。最低的HRT没有导致从FBR的显着的生物量冲洗。采用间歇式动力学实验研究了硫毒性对FBR中硫酸盐还原菌的影响。非竞争性抑制模型较好地描述了硫酸盐还原菌对硫化物的抑制作用。(DS)乙醇和乙酸盐氧化的抑制常数（Ki）分别为248 mg S L-1和356 mg S L-1，并且H2S的相应Ki值为84 mg S L-1和124 mg S L-1。总之，乙醇氧化抑制硫化物毒性比乙酸氧化。(C)2004 Wiley Periodicals，Inc.
The effects of hydraulic retention time (HRT) and sulfide toxicity on ethanol and acetate utilization were studied in a sulfate-reducing fluidized-bed reactor (FBR) treating acidic metal-containing wastewater. The effects of HRT were determined with continuous flow FBR experiments. The percentage of ethanol oxidation was 99.9% even at a HRT of 6.5 h (loading of 2.6 g ethanol L-1 d(-1)), while acetate accumulated in the FBR with HRTs below 12 h (loading of 1.4 g ethanol L-1 d(-1)). Partial acetate utilization was accompanied by decreased concentrations of dissolved sulfide (DS) and alkalinity in the effluent, and eventually resulted in process failure when HRT was decreased to 6.1 h (loading of 2.7 g ethanol L-1 d(-1)). Zinc and iron precipitation rates increased to over 600 mg L-1 d(-1) and 300 mg L-1 d(-1), respectively, with decreasing HRT. At HRT of 6.5 h, percent metal precipitation was over 99.9%, and effluent metal concentrations remained below 0.08 mg L-1. Under these conditions, the alkalinity produced by substrate utilization increased the wastewater pH from 3 to 7.9-8.0. The percentage of electron flow from ethanol to sulfate reduction averaged 76 +/- 10% and was not affected by the HRT. The lowest HRT did not result in significant biomass washout from the FBR. The effect of sulfide toxicity on the sulfate-reducing culture was studied with batch kinetic experiments in the FBR. Noncompetitive inhibition model described well the sulfide inhibition of the sulfate-reducing culture. (DS) inhibition constants (K-i) for ethanol and acetate oxidation were 248 mg S L-1 and 356 mg S L-1, respectively, and the corresponding Ki values for H2S were 84 mg S L-1 and 124 mg S L-1. In conclusion, ethanol oxidation was more inhibited by sulfide toxicity than the acetate oxidation. (C) 2004 Wiley Periodicals, Inc.