The University of Queensland, Advanced Water Management Centre (AWMC), Research Rd, Gehrmann building (bld 60) St. Lucia, Brisbane, QLD 4072, Australia.
Water Res. 2012 Jun 1;46(9):3085-93. doi: 10.1016/j.watres.2012.03.013. Epub 2012 Mar 15.
Corrosion caused by hydrogen sulfide leads to significant costs for the rehabilitation or replacement of corroded sewer pipes. Conventional methods to prevent sewer corrosion normally involve the dosing of significant amounts of chemicals with the associated transport and storage costs as well as considerable maintenance and control requirement. Recently, a novel chemical free method for sulfide abatement based on electrochemical sulfide oxidation was shown to be highly effective for the removal of sulfide from synthetic and real sewage. Here, we report on the electrochemical removal of sulfide using Ta/Ir and Pt/Ir coated titanium electrodes under simulated sewer conditions during field trials. The results showed that sulfide can successfully be removed to levels below the normal target value at the end of a simulated rising main (i.e. <1mg/L). A coulombic efficiency for dissolved oxygen generation of ≈ 60% was obtained and was independent of the current density. Scaling of the electrode and the membrane was observed in the cathode compartment and as a result the cell potentials increased over time. The cathode potentials returned to their original potential after switching the polarity every two days, but a more frequent switching would be needed to reduce the energy requirements of the system. Accelerated lifetime experiments indicated that a lifetime of 6.0 ± 1.9 years can be expected under polarity switching conditions at a pH of 14 and significantly longer at lower pH values. As operating the system without switching simplifies construction as well as operation, the choice whether to switch or not will in practice depend on operational cost (higher/lower energy) versus capital cost (reactor and peripherals). Irrespective of the approach, our study demonstrates that electrochemical sulfide control in sewer systems may be an attractive new option.
硫化氢引起的腐蚀会导致修复或更换腐蚀污水管的巨大成本。防止污水腐蚀的传统方法通常涉及大量化学物质的投加，随之而来的是运输和储存成本以及相当大的维护和控制要求。最近，一种基于电化学硫化物氧化的新型无化学药剂的硫化物减排方法被证明对去除合成污水和实际污水中的硫化物非常有效。在这里，我们报告了在现场试验中模拟污水条件下使用 Ta/Ir 和 Pt/Ir 涂层钛电极进行硫化物电化学去除的情况。结果表明，在模拟上升总管的末端，可以成功地将硫化物去除到低于正常目标值的水平（即 <1mg/L）。获得了溶解氧生成的库仑效率约为 60%，且与电流密度无关。在阴极室观察到电极和膜的缩放，因此电池电势随时间增加。每隔两天切换极性后，阴极电势会恢复到原始电势，但需要更频繁的切换才能降低系统的能量需求。加速寿命试验表明，在 pH 值为 14 且极性切换条件下，预计寿命为 6.0±1.9 年，在较低 pH 值下寿命显著延长。由于在不切换的情况下操作系统简化了施工和操作，因此是否切换的选择将取决于运营成本（更高/更低的能量）与资本成本（反应器和外围设备）。无论采用哪种方法，我们的研究都表明，电化学硫化物控制在污水系统中可能是一种有吸引力的新选择。
