Song Yongwei, Zhang Jianyu, Wang Heru
Department of Environmental Engineering, School of Information and Safety Engineering, Zhongnan University of Economics and Law, Wuhan 430073, China E-mail:
School of Environmental Studies, China University of Geosciences, Wuhan 430074, China.
Water Sci Technol. 2018 Dec;78(10):2183-2192. doi: 10.2166/wst.2018.499.
It is of practical significance to promote the transformation of Fe in acid mine drainage (AMD) into ferric hydroxysulfate minerals with strong ability to remove heavy metals or metalloids. To investigate the types of biogenic ferric hydroxysulfate minerals generated in AMD by Acidithiobacillus ferrooxidans (A. ferrooxidans), different pH and K concentrations are tested for the formation of precipitates in media containing 160 mmol/L Fe. The Cr(VI) removal efficiencies of ferric hydroxysulfate minerals in AMD with different acidities are also compared. Results indicate that the mineralizing abilities of the initial pH levels (pH 3.0 > pH 2.5 > pH 2.0) and K concentrations (53.3 mmol/L > 3.2 mmol/L ≈ 0.8 mmol/L) differ, with cumulative Fe precipitation efficiencies of 58.7%, 58.0%, and 44.2% (K = 53.3 mmol/L), and 58.7%, 29.9%, and 29.6% (pH 3.0) after 96 h of A. ferrooxidans incubation, respectively. X-ray diffraction indicates that K-jarosites are formed in the treatments n(Fe)/n(K) = 0.1 and 3 at pH 2.0-3.0, while only schwertmannite is generated in a system of pH 3.0 and n(Fe)/n(K) = 200. X-ray photoelectron spectroscopy reveals that HCrO may be adsorbed as an inner-sphere complex on schwertmannite when the AMD pH is 3.0.
促进酸性矿山排水（AMD）中的铁转化为具有强大重金属或类金属去除能力的羟基硫酸铁矿物具有实际意义。为了研究氧化亚铁硫杆菌（A. ferrooxidans）在AMD中产生的生物成因羟基硫酸铁矿物的类型，在含有160 mmol/L铁的培养基中测试了不同的pH值和钾浓度对沉淀物形成的影响。还比较了不同酸度的AMD中羟基硫酸铁矿物对Cr(VI)的去除效率。结果表明，初始pH值水平（pH 3.0 > pH 2.5 > pH 2.0）和钾浓度（53.3 mmol/L > 3.2 mmol/L ≈ 0.8 mmol/L）的矿化能力不同，在氧化亚铁硫杆菌培养96小时后，累积铁沉淀效率分别为58.7%、58.0%和44.2%（K = 53.3 mmol/L），以及58.7%、29.9%和29.6%（pH 3.0）。X射线衍射表明，在pH 2.0 - 3.0、n(Fe)/n(K) = 0.1和3的处理中形成了钾铁矾，而在pH 3.0、n(Fe)/n(K) = 200的体系中仅生成了施氏矿物。X射线光电子能谱显示，当AMD的pH值为3.0时，HCrO 可能以内层配合物的形式吸附在施氏矿物上。
