Advanced Water Management Centre, The University of Queensland, St Lucia, Brisbane, QLD 4072, Australia.
Key Laboratory of Industrial Ecology and Environmental Engineering, Ministry of Education, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China.
Water Res. 2015 May 15;75:292-300. doi: 10.1016/j.watres.2015.02.056. Epub 2015 Mar 6.
Zero valent iron (ZVI) packed anaerobic granular sludge reactors have been developed for improved anaerobic wastewater treatment. In this work, a mathematical model is developed to describe the enhanced methane production and sulfate reduction in anaerobic granular sludge reactors with the addition of ZVI. The model is successfully calibrated and validated using long-term experimental data sets from two independent ZVI-enhanced anaerobic granular sludge reactors with different operational conditions. The model satisfactorily describes the chemical oxygen demand (COD) removal, sulfate reduction and methane production data from both systems. Results show ZVI directly promotes propionate degradation and methanogenesis to enhance methane production. Simultaneously, ZVI alleviates the inhibition of un-dissociated H2S on acetogens, methanogens and sulfate reducing bacteria (SRB) through buffering pH (Fe(0) + 2H(+) = Fe(2+) + H2) and iron sulfide precipitation, which improve the sulfate reduction capacity, especially under deterioration conditions. In addition, the enhancement of ZVI on methane production and sulfate reduction occurs mainly at relatively low COD/ [Formula: see text] ratio (e.g., 2-4.5) rather than high COD/ [Formula: see text] ratio (e.g., 16.7) compared to the reactor without ZVI addition. The model proposed in this work is expected to provide support for further development of a more efficient ZVI-based anaerobic granular system.
零价铁（ZVI）填充厌氧颗粒污泥反应器已被开发用于改善厌氧废水处理。在这项工作中，开发了一个数学模型来描述在添加 ZVI 的情况下，厌氧颗粒污泥反应器中甲烷生成和硫酸盐还原的增强。该模型使用来自两个具有不同操作条件的独立 ZVI 增强厌氧颗粒污泥反应器的长期实验数据集进行了成功的校准和验证。该模型令人满意地描述了来自两个系统的化学需氧量（COD）去除、硫酸盐还原和甲烷生成数据。结果表明，ZVI 直接促进丙酸降解和产甲烷作用，以增强甲烷生成。同时，ZVI 通过缓冲 pH 值（Fe(0) + 2H(+) = Fe(2+) + H2）和铁硫化物沉淀来缓解未解离 H2S 对产酸菌、产甲烷菌和硫酸盐还原菌（SRB）的抑制作用，从而提高硫酸盐还原能力，尤其是在恶化条件下。此外，与不添加 ZVI 的反应器相比，ZVI 对甲烷生成和硫酸盐还原的增强主要发生在相对较低的 COD/[Formula: see text]比（例如，2-4.5），而不是高 COD/[Formula: see text]比（例如，16.7）。本工作提出的模型有望为进一步开发更有效的基于 ZVI 的厌氧颗粒系统提供支持。
