摘要
氧化亚铁硫杆菌(A.ferrooxidans)生物氧化Fe2+与石灰中和相耦合是一种具有发展潜力的酸性矿山废水处理工艺.在Fe2+生物氧化段提高Fe2+氧化与总Fe沉淀效率是调控此类废水高效处理的关键步骤,且该阶段常伴有黄铁矾等次生铁矿物的合成.本研究通过摇瓶实验,在p H约2.50的K2SO4(8 mmol·L-1)-Fe SO4(160 mmol·L-1)-H2O酸性硫酸盐体系中按约3×105cells·m L-1的浓度接入A.ferrooxidans,在15℃和30℃两个温度水平下,探究附着微生物的黄钾铁矾回流对体系Fe2+生物氧化与总Fe沉淀行为的影响.结果表明,15℃条件下培养至144h,体系p H变化至2.40,Fe2+氧化率和总Fe沉淀率分别仅为46.7%和12.2%.当体系接入附着微生物黄钾铁矾10 g·L-1时,体系Fe2+在132h即可完全氧化.144 h时,体系p H降低至2.24,总铁沉淀率为25.3%.30℃条件下体系Fe2+在72 h完全氧化,p H变化至1.89,总Fe沉淀率为34.3%.当体系接入回流的黄钾铁矾10 g·L-1时,体系Fe2+完全氧化时间缩短至60 h,p H降低至1.85,总Fe沉淀率为37.3%.本研究不同处理体系所得次生铁矿物均为黄钾铁矾,附着微生物黄铁矾回流对15℃环境所得黄钾铁矾形貌影响不大,均为粘附紧密、表面光滑的晶体形貌.而30℃环境中,附着微生物黄铁矾回流却使得原本较为分散、晶型棱角明显的黄铁矾晶体结构变得紧密而光滑.本研究结果可为酸性矿山废水处理提供一定的参数支撑.
The combination of Fe2 ＋oxidation by A. ferrooxidans and lime neutralization technology shows a wide application prospect in the acidic mine drainage（ AMD） treatment. Improving Fe2 ＋bio-oxidation efficiency and total Fe precipitation are the key steps for AMD treatment. Jarosite,a secondary iron mineral,can be synthesized during Fe2 ＋bio-oxidation process. Enhancement of returned jarosite carring A. ferrooxidans for Fe2 ＋bio-oxidation and total Fe precipitation was investigated at 15 ℃ and 30 ℃,under the conditions of K2SO4（ 8 mmol·L- 1）-Fe SO4（ 160 mmol·L- 1）-H2 O,initial p H ~ 2.50,A. ferrooxidans inoculation density ~ 3 × 105cells·m L- 1. Results showed that system p H changed from 2. 50 to 2. 40 in 144 h under 15 ℃condition,with a Fe2 ＋bio-oxidation efficiency and a total Fe precipitation efficiency of 46. 7% and 12. 2%. However,when a 10 g·L- 1ofA. ferrooxidans-absorbed potassium jarosite was added,complete oxidation of Fe2 ＋was achieved at 132 h,with a decreasing p H of 2. 24 and a total Fe precipitation efficiency of 25. 3% after 144 h. When temperature was elevated to 30 ℃,a final p H of 1. 89,complete oxidation of Fe2 ＋and total Fe precipitation efficiency of 34. 3% can be obtained after 72 h of incubation. Similarly,when inoculated with A. ferrooxidans-absorbed potassium jarosite,complete Fe2 ＋oxidation,an even lower p H of 1. 85 and higher Fe precipitation efficiency at 37. 3% was achieved after 60 h. Potassium jarosite was identified as the main secondary iron mineral phase in all treatments. Under 15 ℃,bio-synthesized jarosite crystals closely adhered together with smooth surface,and the morphology of jarosite has no obvious change when A. ferrooxidans-adsorbed jarosite was added into systems. However,under 30 ℃,potassium jarosite crystals dispersed greatly with edge and corners appeared,and the morphology changed to close and smooth when A. ferrooxidansadsorbed jarosite was added into systems. The outcomes of this study were helpful in the iron- and sulfate-rich acidic water（ such as AMD） engineering treatment.
出处
《环境科学学报》
CAS
CSCD
北大核心
2016年第2期513-520,共8页
Acta Scientiae Circumstantiae
基金
国家自然科学基金(No.21407102
41371476)
山西省自然科学基金(No.2015011022)
山西农业大学青年拔尖创新人才项目(No.TYIT 201405)~~
关键词
黄钾铁矾
酸性矿山废水
Fe2+氧化率
总Fe沉淀率
矿物形貌
potassium jarosite
acidic mine drainage
Fe2 ＋bio-oxidation efficiency
total Fe precipitation efficiency
mineral morphology
