Recovery of Valuable Metals from Marine Mineral Resources by Autotrophic Bacteria

本文介绍了锰结核微生物处理的3个阶段的生物工艺，即结核的生物浸出，浸出金属的生物硫化氢的沉淀和回收，以及废物硫化氢的微生物处理。以单质硫为能量源的嗜酸硫氧化菌在生长过程中溶解锰结核。嗜热菌brierleacidianus brierlei对结核的浸出效果优于嗜热菌氧化亚铁硫杆菌和氧化硫硫杆菌。利用布氏芽孢杆菌浸出试验数据，对培养基pH、初始池浓度、初始硫液负载比、初始结核液负载比等工艺参数进行优化。为了利用生物源H_2S回收浸出金属作为不溶性硫化物，我们在h_2 - spar_more - ed和搅拌反应器中测量了脱硫弧菌在硫酸盐上的批量生长速率和随后的H_2S脱附速率。对实验数据进行分析，确定微生物形成H_2S的动力学和化学计量学参数。基于反应传质理论的预测表明，生物源H_2S的脱附是一个传质过程，膜反应可以忽略不计。观察到的解吸速率通过细菌生长和随后的H_2S形成动力学、溶解H_2S的解离平衡以及生物反应器中的传质特性进行了定量解释。为处理废硫化氢，在连续培养条件下研究了硫代氧化t菌对硫化氢的液相氧化作用。对观察到的数据进行了分析，评价了莫诺方程的生长率和动力学参数。从以上结果可以看出，结核的生物浸出是3阶段生物过程中的一个限速步骤。因此，我们可以得出结论，在确定的最佳条件下，所提出的微生物处理在3天内从结核中获得100%的铜和锌，并在10天内获得较高的镍（85%）和钴（70%）的回收率。少

This report describes results on the microbial treatment of manganese nodules using a 3-stage bioprocess which consists of the bioleaching of nodule, the precipitation and recovery of leached metals by biogenic H_2S,and the microbial treatment of waste H_2S.1. Manganese nodules were solubilized during the growth of acidophilic sulfur-oxidizing bacteria using elemental sulfur as their energy sources. The thermophile Acidianus brierleyi was more effective for the nodule leaching than the mesophiles Thiobacillus ferrooxidans and Thiobacillus thiooxidans. The experimental data for the leaching with A.brierleyi were used to optimize various process parameters, such as medium pH,initial cell concentration, initial sulfur-liquid loading ratio and initial nodule-liquid loading ratio.2. For the utilization of biogenic H_2S to recover leached metals as insoluble sulfides, we measured the rates of batch growth of Desulfovibrio desulfuricans on sulfate and subsequent H_2S desorption in a H_2-sparg … More ed and stirred reactor. The experimental data were analyzed to determine kinetic and stoichiometric parameters for the microbial H_2S formation. Predictions based on the theory of mass transfer with reaction indicated that the desorption of biogenic H_2S is a mass transfer process with negligible film reaction. The observed desorption rates were interpreted quantitatively by using the developed kinetics of bacterial growth and subsequent H_2S formation, the dissociation equilibria of dissolved H_2S,and the mass transfer characteristics in the bioreactor.3. To treat waste H_2S,the liquid-phase oxidation of H_2S by T.thiooxidans was studied in continuous culture. The observed data were analyzed to evaluate the growth yield and the kinetic parameters in the Monod equation.4. From the above results it was found that the bioleaching of nodules is a rate-limiting step in the 3-stage bioprocess. Thus we can conclude that under the conditions determined as optimum, the proposed microbial processing yields the 100% recovery of copper and zinc from nodules within 3 days, and high recoveries of nickel (85%) and cobalt (70%) for 10 days. Less