铁盐投加对模拟污水管道系统H_2S控制

Effect of Ferric Dosage on Hydrogen Sulfide Control in Lab-Scale Sewer

以人工配制生活污水为进水,室温条件下采用重力流排水管道反应器,研究投加铁盐对模拟污水管道中H2S的控制及其可能机理。试验首先测定了控制反应器和铁盐投加反应器内液相S2-浓度的历时和沿程变化以及H2S气体的沿程差异,在此基础上通过静态试验提出铁盐投加后污水管道系统的生化反应机理并据此进行了铁硫物料衡算。结果表明:在Fe3+投加浓度为30mg/L时,管道反应器出水S2-浓度平均低于1mg/L,各反应槽中H2S气体浓度平均未超过40ppm,远低于控制反应器;此时,约有44%的铁转化为磷酸铁,且该浓度足以抑制硫酸盐还原菌的活性。

The investigation was carried out in lab-scale sewer system focusing on hydrogen sulfide control when ferric iron [Fe （III）] was added. Two lab-scale gravitational sewer systems fed with synthetic domestic wastewater were operated at room temperature. Concentration of S2 and H2S in two sewer systems was measured firstly. Then the possible reactive mechanism of ferric dosage was proposed and mass balance of those was calculated. The results showed that S2- concentration in effluent appeared no more than 1 mg/L and hydrogen sulfide in each slot was below 40 ppm averagely in ferric addition reactor, which were lower obviously than that in the control reactor. On the other side, batch tests exhibited about 44% ferric was converted into ironic phosphate, which had no effect on restraining the activity of sulfate- reducing bacteria. In a word, Fe3＋ dosage could inhibit producing S2 and releasing H2S effectively although most of the Fe3＋ was converted into ironic phosphate.