微生物接种密度和矿物收集时间对生物沥浸中次生铁矿物形成的影响

Effects of Acidithiobacillus ferrooxidans inoculation density and minerals collection time on the formation of biogenic secondary iron minerals in bioleaching system

摘要:

在嗜酸性氧化亚铁硫杆菌Acidithiobacillus ferrooxidans作用下, 污泥生物沥浸体系中常会有次生铁矿物形成, 这些矿物对污泥脱水和重金属溶出有重要影响。在FeSO4-K2SO4-H2O生物成矾临界点模拟生物沥浸过程, 考察了Acidithiobacillus ferrooxidans菌接种密度和矿物收集时间对次生铁矿物的影响。结果表明, 微生物接种密度和矿物收集时间对生物沥浸过程中次生铁矿物的重量及其类型均有一定影响, 随矿物收集时间的推迟, 溶液中含有的一价阳离子(如K+等)可导致施氏矿物向黄铁矾发生转变, 并成为影响铁矿物类型的主导因素。

Abstract:

The formation of secondary iron minerals often is observed in sludge bioleaching system facilitated by Acidithiobacillus ferrooxidans, which affected the sludge dewaterability and heavy metals leaching. At the critical point of jarosite formation in FeSO4-K2SO4-H2O system inoculated by Acidithiobacillus ferrooxidans, a simulative experiment were carried out to study the effects of bacteria density and the resulting minerals collection time on the iron precipitation formation. The results indicated that the amount and type of precipitates formed in the bioleaching system depended, to a certain extent, on the Acidithiobacillus ferrooxidans density and mineral collection time. If the resulting iron mineral wasn’t removed through manual collection in time, monovalent cation (such as K+) existed in reaction solution would facilitate easily the resulting schwertmannite to transform into jarosite.