针对尾矿中重金属对矿区的污染,考虑尾矿中部分金属的回收利用,利用环境友好,反应温和,流程短,能耗低的细菌浸出的方法来处理尾矿,浸提重金属Cu和Zn。在浸矿前,用磁场磁化半小时的无铁培养基做浸矿基液,用嗜酸氧化亚铁硫杆菌浸出27 d。...针对尾矿中重金属对矿区的污染,考虑尾矿中部分金属的回收利用,利用环境友好,反应温和,流程短,能耗低的细菌浸出的方法来处理尾矿,浸提重金属Cu和Zn。在浸矿前,用磁场磁化半小时的无铁培养基做浸矿基液,用嗜酸氧化亚铁硫杆菌浸出27 d。实验结果显示,在浸矿浓度为5%,接种量为10%,温度为30℃,p H值为2的条件下,在磁场强度分别为2、5、8、11 m T的情况下,Cu的浸出率受磁场的影响较小,而对Zn的浸出率有较大影响,Zn的浸出率最大提高了13%左右。磁感应强度的大小对锌的浸出率也有影响,锌的最佳浸出磁感应强度是2 m T。展开更多
An acidophilic,chemolithotrophic and ferrous oxidizing bacterium strain GF was isolated from the acid mine drainage (AMD) of Gaofeng Mine,Guangxi Province,China using 9K enrichment medium,and then purified on solid fe...An acidophilic,chemolithotrophic and ferrous oxidizing bacterium strain GF was isolated from the acid mine drainage (AMD) of Gaofeng Mine,Guangxi Province,China using 9K enrichment medium,and then purified on solid ferrous-agarose medium.The physiological experiments show that it can use ferrous or sulfur as sole energy and a low level (0.1%,w/v) of peptone can accelerate the growth of the isolated strain.The optimum pH and temperature for growth are 2.0 and 30 ℃,respectively.The isolated strain shares 99.64% identities of 16S rRNA gene with the type strain Acidthiobacillus ferrooxidans ATCC 23270 and 100% identities of iro gene (CDS) with A.ferrooxidans strain Fe-1.These results show that the strain can be considered as Acidthiobacillus ferrooxidans.Because of the high activity of oxidizing ferrous and sulfide mineral,strain GF was used in bioleaching of marmatite.The Zn concentration is 0.273 g/L under the steriled control and 7.30 g/L with adapted GF strain incubated after 29 d in leaching marmatite.The isolated strain GF can be used to leach marmatite in industry application.展开更多
文摘以嗜酸氧化亚铁硫杆菌(Acidthiobacillus ferrooxidans,简称At.f菌,FN811931)为研究对象,探讨了Mg^(2+)对其氧化活性的影响规律,并采用Zeta电位及红外光谱分析,考察了其影响的内在机制.结果表明:在Mg^(2+)质量浓度小于5.0g/L的体系中,培养35h时,p H值从培养初期的2.00左右下降到1.70左右,氧化还原电位从培养初期的390 m V左右上升到600 m V以上,Fe^(2+)氧化率接近100%,细菌生长达到旺盛期;当Mg^(2+)质量浓度超过5.0 g/L时,体系p H值下降速率、氧化还原电位上升速率、Fe^(2+)氧化率、细菌生长速率均降低,且Mg^(2+)质量浓度越大,影响效果越显著.Zeta电位测试结果表明,20.0 g/L镁离子作用下细菌等电点为3.6,高于9K培养基中细菌的等电点2.7,这从宏观上解释了细菌细胞壁结构的变化;红外光谱测试结果显示,Mg^(2+)作用下,细菌细胞壁中的官能团发生了交联作用,导致吸收峰N—H的消失和—OH、—C‖O、—CH3、—CH2、—P‖O、—CN的偏移,致使细胞壁表面蛋白质结构发生变化,进而影响了细菌的氧化活性.
文摘针对尾矿中重金属对矿区的污染,考虑尾矿中部分金属的回收利用,利用环境友好,反应温和,流程短,能耗低的细菌浸出的方法来处理尾矿,浸提重金属Cu和Zn。在浸矿前,用磁场磁化半小时的无铁培养基做浸矿基液,用嗜酸氧化亚铁硫杆菌浸出27 d。实验结果显示,在浸矿浓度为5%,接种量为10%,温度为30℃,p H值为2的条件下,在磁场强度分别为2、5、8、11 m T的情况下,Cu的浸出率受磁场的影响较小,而对Zn的浸出率有较大影响,Zn的浸出率最大提高了13%左右。磁感应强度的大小对锌的浸出率也有影响,锌的最佳浸出磁感应强度是2 m T。
基金Project (50621063) supported by the National Natural Science Foundation of ChinaProject (2004CB619201) supported by the National Basic Research Program of China
文摘An acidophilic,chemolithotrophic and ferrous oxidizing bacterium strain GF was isolated from the acid mine drainage (AMD) of Gaofeng Mine,Guangxi Province,China using 9K enrichment medium,and then purified on solid ferrous-agarose medium.The physiological experiments show that it can use ferrous or sulfur as sole energy and a low level (0.1%,w/v) of peptone can accelerate the growth of the isolated strain.The optimum pH and temperature for growth are 2.0 and 30 ℃,respectively.The isolated strain shares 99.64% identities of 16S rRNA gene with the type strain Acidthiobacillus ferrooxidans ATCC 23270 and 100% identities of iro gene (CDS) with A.ferrooxidans strain Fe-1.These results show that the strain can be considered as Acidthiobacillus ferrooxidans.Because of the high activity of oxidizing ferrous and sulfide mineral,strain GF was used in bioleaching of marmatite.The Zn concentration is 0.273 g/L under the steriled control and 7.30 g/L with adapted GF strain incubated after 29 d in leaching marmatite.The isolated strain GF can be used to leach marmatite in industry application.
