点击次数：

论文类型：期刊论文

发表时间：2015-05-15

发表刊物：WATER RESEARCH

收录刊物：SCIE、EI、PubMed、Scopus

卷号：75

页面范围：292-300

ISSN号：0043-1354

关键字：Zero valent iron; Methane production; Sulfate reduction; Mathematical modeling; Anaerobic granular sludge

摘要：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(+) = Fe2+ + H-2) 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/SO42- ratio (e.g., 2-4.5) rather than high COD/SO42- 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. (C) 2015 Elsevier Ltd. All rights reserved.