邵寨矿区解磷细菌的分离及其对煤矸石中有效磷和有效硅的增溶

Isolation of phosphorus-dissolving bacteria from Shaozhai mine and their solubilization of available phosphorus and available silica in coal gangue

  • 摘要: 针对煤炭开采洗选过程中产生的固体废弃物煤矸石,提出了一种基于微生物技术的资源化利用新途径。选取甘肃邵寨矿区煤矸石作为研究对象,首先从煤矸石中筛选出一株具有高效解磷能力的细菌,经鉴定为贝莱斯孢杆菌(简称为XK2细菌),再利用XK2细菌处理煤矸石,探讨了煤矸石中有效磷和有效硅的增溶效果。通过单因素实验和正交实验探究了培养基pH、菌液接种量、煤矸石粒径、XK2细菌对煤矸石处理时间等因素对XK2细菌增溶煤矸石中有效磷和有效硅的影响,确定了XK2细菌增溶煤矸石中有效磷的最佳条件:pH为8,菌液接种量为10.0 mL/50 mL培养基,煤矸石粒径0.25~0.50 mm,处理时间4 d。在此条件下,煤矸石中有效磷质量分数达到343.56 mg/kg,是原煤矸石的41.49倍。采用傅里叶变换红外光谱(FTIR)、X射线衍射(XRD)、扫描电子显微镜(SEM)和高效液相色谱(HPLC)对XK2细菌处理后的固液相产物进行分析,FTIR分析显示经XK2细菌处理后的煤矸石中Si—O—Si(473 cm−1)、Si—O—Al(537 cm−1)、Al—OH(908 cm−1)和Si—O(1 030 cm−1)吸收峰减弱,表明难溶性硅铝酸盐被分解;XRD分析显示经XK2细菌处理后煤矸石中含磷矿物三斜磷钙石(CaHPO4)及含硅矿物白云母(KAl2(AlSi3O10)(OH)2)的衍射峰减弱,表明XK2细菌通过溶解上述矿物以促进煤矸石中有效磷、硅元素增溶;此外,HPLC分析显示XK2菌株通过分泌丙酸、琥珀酸等有机酸破坏煤矸石中的硅铝酸盐结构,促进磷元素和硅元素的增溶。

     

    Abstract: A new way of resource utilization based on microbial technology is proposed for coal gangue, a solid waste in the process of coal mining. In this study, the coal gangue in Shaozhai mining area was selected as the research object, and firstly, a bacterial strain with available phosphorus solubilizing ability, Bacillus velezensis (referred to as Bacillus sp. XK2), was screened out from the gangue, and then experiments were carried out on solubilizing available phosphorus and available silicon in the gangue by using the Bacillus sp. XK2. Through one-way and orthogonal experiments, we explored the effects of factors such as medium pH, inoculum amount of bacterial solution, particle size of gangue, treatment time of gangue with Bacillus sp. XK2 on the solubilization of available phosphorus and available silicon in coal gangue by Bacillus sp. XK2, and determined the optimal conditions for the solubilization of effective phosphorus in the gangue by Bacillus sp. XK2: pH=8, inoculum amount of bacterial solution of 10.0 mL/50 mL of medium, gangue particle size of 0.25 – 0.50 mm, treatment time of 4 days. Under these conditions, the effective phosphorus content in the gangue reached 343.56 mg/kg, which was 41.49 times of the original gangue. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and high-performance liquid chromatography (HPLC) were used to analyze the solid-liquid phase products of the Bacillus sp. XK2 treatment, and the FTIR analysis showed that the gangue treated by the Bacillus sp. XK2 treatment contained Si—O—Si (473 cm−1), Si—O—Al (537 cm−1), Al—OH (908 cm−1) and Si—O (1030 cm−1) absorption peaks were weakened, indicating that the insoluble silica-aluminate was decomposed; XRD analysis showed that the diffraction peaks of phosphorus-containing minerals trilobaltic calcium phosphorite (CaHPO4) and silica-containing minerals dol omite (KAl2(AlSi3O10)(OH)2) were weakened in gangue treated with Bacillus sp. XK2, indicating that Bacillus sp. XK2 promoted the decomposition of the above minerals to promote the development of coal gangue by dissolving them. In addition, HPLC analysis showed that the Bacillus sp.XK2 destroyed the silica-aluminate structure in the gangue by secreting organic acids such as propionic acid and succinic acid, which promoted the solubilization of phosphorus and silicon.

     

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