作　　者： ; ; ;

机构地区： 南京农业大学资源与环境科学学院

出　　处： 《环境科学学报》 2010年第8期1601-1607,共7页

摘　　要： 在FeSO4-K2SO4-H2O的嗜酸性氧化亚铁硫杆菌催化氧化体系中,当起始Fe2＋浓度分别为20、40、80和160mmol.L^-1时,通过设定系列Fe/K摩尔比（3-200）来调控溶液的K＋含量,合成得到次生羟基硫酸铁矿物,主要包括施威特曼石、黄钾铁矾以及两者的混合物.结果表明,当起始Fe^2＋浓度较低,如20mmol.L-1和40mmol.L^-1时,72h反应后,不同Fe/K摩尔比处理所得矿物质量很少,最大只有0.38g.而随着Fe^2＋浓度增大,Fe/K摩尔比例的减小,矿物质量明显增加,例如在Fe2＋=160mmo.lL^-1、Fe/K=3时,250mL体系中矿物质量达到了4.48g,同时矿物相由结晶度差的施威特曼石逐渐过渡到结晶度好的黄钾铁矾.笔者发现矿物质量与矿物相有非常密切的关系,当产物为晶型黄钾铁矾时,其对应的矿物质量也更多.因此,微生物成因羟基硫酸铁矿物质量在很大程度上取决于起始Fe2＋浓度和Fe/K摩尔比,该现象对去除酸性矿山废水中可溶性Fe和SO24-有潜在意义. In the FeSO4-K2SO4-H2O biological oxidation system facilitated by Acidithiobacillus ferrooxidans,secondary ferric hydroxysulfate minerals are able to be synthesized including schwertmannite,potassium jarosite,and their mixture.In our system,the initial concentrations of ferrous iron were designed as 20,40,80 and 160 mmol·L-1 and the Fe/K molar ratios for each ferrous iron concentration treatment were designed as 3 to 200.The results show that treatment with lower initial Fe2＋ levels such as 20 mmol·L-1 or 40 mmol·L-1 only produces a small amount of the precipitate with no more than 0.38 g produced after 72 h of reaction.With the increase of initial Fe2＋ and the decrease of Fe/K molar ratios in the solution,the total amount of the precipitate formed by Acidithiobacillus ferrooxidans is greatly increased.For example,4.48 g of jarosite are precipitated from 250mL of solution when the initial Fe2＋ is 160 mmol·L^-1and Fe/K is 3.The XRD pattern indicated that the precipitate is gradually transformed to crystallized jarosite from poorly-crystallized schwertmannite,exhibiting a close relationship between the mass produced and the mineral phase.For example,the amount of the precipitates formed as crystalline jarosite is much higher than that as poorly-crystallized schwertmannite.Therefore,the amount of biogenic minerals formed in the biological oxidation system depends,to a great extent,on the initial Fe2＋ concentration and Fe/K molar ratio.This phenomenon is of potential significance in the removal of soluble Fe and SO2-4 from acid mine drainage.

关 键 词： 嗜酸性氧化亚铁硫杆菌 次生铁矿物 环境意义

领　　域： [环境科学与工程]