不同Fe(Ⅲ)对活性污泥异化铁还原耦合脱氮的影响及机理初探  

Effect and mechanism of nitrogen removal by dissimilatory reduction of different Fe( Ⅲ) in activated sludge

作　　者：王亚娥[1] 冯娟娟[1] 李杰[1] 翟思媛[1] 

机构地区：[1]兰州交通大学环境与市政工程学院,兰州730070

出　　处：《环境科学学报》2014年第2期377-384,共8页Acta Scientiae Circumstantiae

基　　金：国家自然科学基金项目(No.51068015)~~

摘　　要：以投放海绵铁-AT-PVF复合填料的SBBR反应器活性污泥作为铁还原菌菌种来源,采用厌氧恒温培养试验,考察了不同Fe(Ⅲ)(氧化铁皮、青矿和红矿)对活性污泥异化铁还原能力及脱氮效果的影响,并对其作用机制进行了初步分析.结果表明:初始基质无NO-2的前提下,各体系Fe(Ⅲ)还原能力与脱氮效果表现出较好的关联性,同时发生NO-2-N和NO-3-N的积累现象.其中,氧化铁皮体系的脱氮效果最好,对NH+4-N、TN的累计去除量分别为75.04和80.99 mg·L-1,容积TN去除率为3.88 mg·L-1·d-1(以N计).更进一步的研究发现,不同培养时间内NH+4氧化量与Fe(Ⅱ)产生量之间符合幂指数关系,R2为0.9521.结合标准吉布斯自由能变化,厌氧环境下IRB参与活性污泥中N素循环的交互作用机制可分为3个子过程,即Fe(Ⅲ)的微生物还原解离耦合NH+4的氧化过程、厌氧氨氧化过程和NO-3-依赖型Fe(Ⅱ)氧化过程,其中,以IRB为主的微生物氧化还原过程对活性污泥中N循环起到了至关重要的作用.An activated sludge from a SBBR reactor, which was filled with sponge iron-AT-PVF, had been acclimated to Fe （ Ⅲ ）-rich environment for the purpose of securing an enrichment culture of iron-reducing bacteria. The dissimilatory Fe（ Ⅲ ） reduction ability and efficiency of nitrogen removal by dosing different Fe（Ⅲ ） under anaerobic condition were investigated and the mechanism was also explored. The results showed that there is a close link between the ability of Fe（Ⅱ） reduction and its effects on nitrogen removal with the condition of non-initial NO2- , while NO2- -N and NO3- -N accumulation was observed. The results have demonstrated that the oxide iron system showed better N removal performance. The accumulated NH4＋ -N and TN removal in the oxide iron system was up to 75.04 mg · L^ -1 and 80. 99 mg · L^ -1, respectively, making maximum nitrogen removal rate of 3.88 mg · L^ -1· d ^- 1. Furthermore, the experimental data of the oxidized NH4＋ and the reduced Fe（Ⅱ ） exhibited power relationship with R-Square coefficient of 0. 9521. By examining AGo during nitrogen removal using dissimilatory Fe（Ⅲ） reduction, it seems that the entire biodegradation course could be divided into three processes, i.e. Feammox, ANAMMOX and nitrate-dependent Fe（ Ⅱ） oxidation. More significantly, the biodegradation redox process driven by IRB and coupled with Fe（ Ⅲ） reduction under anaerobic condition is potentially a critical component of N cycle in activated sludge.

关 键 词：异化铁还原 活性污泥 铁氨氧化 脱氮 机制 

分 类 号：X703.1[环境科学与工程—环境工程]