The Charles Edward Via, Jr. Department of Civil and Environmental Engineering, Virginia Polytechnic Institute and State University, 419 Durham Hall, Blacksburg, VA 24061, USA *Present address: Cheil Industries Inc., 332-2, Gocheon-dong, Uiwang-si, Gyeonggi-do 437-711, Republic of Korea E-mail:
Water Sci Technol. 2013;68(11):2391-6. doi: 10.2166/wst.2013.507.
The role of iron addition to sewage sludge prior to anaerobic digestion was evaluated to determine the effect of iron on digestion performance and generation of odor-causing compounds. Hydrogen sulfide (H2S) and volatile organic sulfur compounds (VOSCs) were the odorous gases evaluated in this study. Samples were obtained from seven municipal wastewater treatment plants (WWTPs), and batch anaerobic digestion tests were conducted using primary and secondary sludges at 30 day solids retention time (SRT) under mesophilic conditions. Volatile solid removal (VSR) was highly predictable with background iron concentrations measured in the combined sludge. They were likely to increase as influent iron content increased. 1.25% w/w ferric chloride (FeCl3) was added to the anaerobic digester feed in order to simulate iron addition for sulfide control in full-scale WWTPs. The results showed that it had a positive impact on digestion performance with higher VSR and odor control with reduced H2S and TVOSCs in the headspace gas of dewatered biosolids considered in the tests. Ferric chloride is considered a beneficial additive as a strategy for an odor mitigation, not to mention more efficient digestion under anaerobic conditions.
在进行厌氧消化之前，向污水污泥中添加铁的作用进行了评估，以确定铁对消化性能和产生气味化合物的影响。本研究评估了硫化氢（H2S）和挥发性有机硫化合物（VOSC）这两种有气味的气体。本研究从七个城市污水处理厂（WWTP）中采集了样品，并在中温条件下使用 30 天固体停留时间（SRT）的初级和次级污泥进行了批量厌氧消化测试。挥发性固体去除率（VSR）与组合污泥中测量的背景铁浓度高度相关。随着进水铁含量的增加，它们可能会增加。为了模拟在全规模 WWTP 中进行硫化物控制的铁添加，向厌氧消化器进料中添加了 1.25% w/w 的三氯化铁（FeCl3）。结果表明，它对消化性能有积极影响，在测试中考虑的脱水生物固体的顶部空间气体中，更高的 VSR 和气味控制降低了 H2S 和 TVOSC。三氯化铁被认为是一种有益的添加剂，不仅可以减轻气味，而且可以在厌氧条件下更有效地进行消化。
