生态环境学报
生態環境學報
생태배경학보
ECOLOGY AND ENVIRONMENT
2013年
1期
123-128
,共6页
张伟%刘同旭%李芳柏*%李晓敏
張偉%劉同旭%李芳柏*%李曉敏
장위%류동욱%리방백*%리효민
竞争效应%硝酸盐还原%铁还原%交互反应体系
競爭效應%硝痠鹽還原%鐵還原%交互反應體繫
경쟁효응%초산염환원%철환원%교호반응체계
competition effect%nitrate reduction%ferric reduction%interactive response system
中性厌氧条件下,脱色希瓦氏菌 Shewanella decolorationis(S12)能够使用多种电子受体进行厌氧呼吸,包括溶解态的硝酸盐以及难溶态的氧化铁基质.因此,本文通过构建“脱色希瓦氏菌/铁氧化物/硝态氮”的交互反应体系,研究这一体系中铁还原与硝态氮还原的相互作用过程,并对相互作用机制进行初步探讨.结果表明,交互反应体系中氧化铁还原与硝酸盐还原存在明显的竞争关系;随着氧化铁比表面积、可利用态铁含量的增大,硝酸受抑制作用逐渐增强;通过不同温度煅烧而得到的不同结晶度的赤铁矿对硝态氮的抑制作用也被研究.结果还表明,氧化铁结晶度越高,S12对硝态氮的还原抑制作用越小.循环伏安电化学测试结果发现,加入硝酸条件下,铁氧化峰几乎完全消失,表明硝态氮存在条件下,铁还原受到明显抑制.针对以上结果,初步探讨了铁还原与硝态氮还原竞争的原因,即:(1) Fe(Ⅲ)与NO3–同时作为电子受体,因竞争电子而受到抑制;(2)吸附态Fe(Ⅱ)物种还原NO3–,导致Fe(Ⅱ)累积减少,NO3–还原因产生的Fe(Ⅱ)的低速率而被抑制.
中性厭氧條件下,脫色希瓦氏菌 Shewanella decolorationis(S12)能夠使用多種電子受體進行厭氧呼吸,包括溶解態的硝痠鹽以及難溶態的氧化鐵基質.因此,本文通過構建“脫色希瓦氏菌/鐵氧化物/硝態氮”的交互反應體繫,研究這一體繫中鐵還原與硝態氮還原的相互作用過程,併對相互作用機製進行初步探討.結果錶明,交互反應體繫中氧化鐵還原與硝痠鹽還原存在明顯的競爭關繫;隨著氧化鐵比錶麵積、可利用態鐵含量的增大,硝痠受抑製作用逐漸增彊;通過不同溫度煅燒而得到的不同結晶度的赤鐵礦對硝態氮的抑製作用也被研究.結果還錶明,氧化鐵結晶度越高,S12對硝態氮的還原抑製作用越小.循環伏安電化學測試結果髮現,加入硝痠條件下,鐵氧化峰幾乎完全消失,錶明硝態氮存在條件下,鐵還原受到明顯抑製.針對以上結果,初步探討瞭鐵還原與硝態氮還原競爭的原因,即:(1) Fe(Ⅲ)與NO3–同時作為電子受體,因競爭電子而受到抑製;(2)吸附態Fe(Ⅱ)物種還原NO3–,導緻Fe(Ⅱ)纍積減少,NO3–還原因產生的Fe(Ⅱ)的低速率而被抑製.
중성염양조건하,탈색희와씨균 Shewanella decolorationis(S12)능구사용다충전자수체진행염양호흡,포괄용해태적초산염이급난용태적양화철기질.인차,본문통과구건“탈색희와씨균/철양화물/초태담”적교호반응체계,연구저일체계중철환원여초태담환원적상호작용과정,병대상호작용궤제진행초보탐토.결과표명,교호반응체계중양화철환원여초산염환원존재명현적경쟁관계;수착양화철비표면적、가이용태철함량적증대,초산수억제작용축점증강;통과불동온도단소이득도적불동결정도적적철광대초태담적억제작용야피연구.결과환표명,양화철결정도월고,S12대초태담적환원억제작용월소.순배복안전화학측시결과발현,가입초산조건하,철양화봉궤호완전소실,표명초태담존재조건하,철환원수도명현억제.침대이상결과,초보탐토료철환원여초태담환원경쟁적원인,즉:(1) Fe(Ⅲ)여NO3–동시작위전자수체,인경쟁전자이수도억제;(2)흡부태Fe(Ⅱ)물충환원NO3–,도치Fe(Ⅱ)루적감소,NO3–환원인산생적Fe(Ⅱ)적저속솔이피억제.
Decolorizing Shewanella (Shewanella decolorationis, S12) can be used as a variety of electron acceptor for anaerobic respiration under anoxic condition, including dissolved nitrates and insoluble iron oxide matrix. Therefore, the aim is to study the interaction mechanism of this interactive response system in iron reduction and nitrate reduction by constructing“S12/iron oxide/nitrate”interactive response system. The results show that there is a significant competitive relationship with the nitrate reduction and ferric reduction in the reaction system. The iron oxides with higher surface area and Fe(Ⅲ) availability take up stronger inhibition of nitrate reduction. The effect of crystalline degree of hematite on the inhibition of nitrate reduction was studied with hematite sintered at different temperature. Results showed that the extent of nitrate reduction inhibition decreased gradually in presence of increasing crystalline degree of hematite. Electrochemical methods were used to investigate the ferrous peak in the presence and absence of nitrate. Results showed that sharp peaks of Fe(Ⅱ) was found in the CV curves, indicating the formation of reactive Fe(Ⅱ), while the presence of nitrate can obviously decrease the reactive Fe(Ⅱ) peaks, indicating the iron reduction was significantly inhibited by the addition of nitrate. In response to the above results, the mainly reasons leading to competition between nitrate reduction and ferric reduction are as follows: (1) Fe (Ⅲ) and NO3– act as the competitive electron acceptor; (b) NO3– reduction by adsorbed Fe(Ⅱ) specials.
