Environmentally Benign Recovery and Reactivation of Palladium from Industrial Waste by Using Gram-Negative Bacteria
Environmentally Benign Recovery and Reactivation of Palladium from Industrial Waste by Using Gram-Negative Bacteria
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DOI：
10.1002/cssc.201000091
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发表时间：
2010-01-01
期刊：
影响因子：
8.4
通讯作者：
Skrydstrup, Troels
中科院分区：
文献类型：
--
作者：
Gauthier, Delphine;Sobjerg, Lina S.;Skrydstrup, Troels
矿山、冶金、电子、电镀等行业排放的重金属是大量的水和土壤污染物。[1]去除它们至关重要，因为它们具有高度毒性并在食物链中积累。[2]近年来，生物吸附作为一种去除环境中重金属的方法受到了相当大的关注。[3-8]这种方法利用容易获得的生物量来隔离有毒的重金属，从而使受污染场地得到生物再生，并回收有价值的金属。例如，Diels等人使用固定在管式膜反应器中的钩虫贪铜菌（Cupriavidus necator）细菌，通过诱导金属盐结晶过程从废水中回收重金属（Cd、Cu、Zn、Co、Ni、Pb、Pd、Y、Ge）。[9]与石灰沉淀法、离子交换法、生物硫化物沉淀法等传统方法相比，生物吸附法具有操作成本低、效率高等优点。最近，Mabbet等人报道了使用大肠杆菌和脱硫脱硫弧菌的钯化细胞从酸性沥滤液中回收铂族金属。虽然铑和铂被有效地除去，但钯不能完全回收。[10]Pd 0是工业上重要的精细化学合成催化剂，也广泛用于汽车催化剂。[11由于Pd 0在地壳中的分布稀少，从废物源中回收Pd 0是一个非常有吸引力的前景。我们最近证明了某些革兰氏阴性细菌的能力，通过减少可溶性钯Ⅱ在缓冲模型系统中回收钯0纳米粒子。[13微生物介导的Pd 0生物回收是两步过程，涉及将PdII吸附到细菌表面上，然后通过使用例如甲酸盐作为电子供体还原成Pd 0纳米颗粒（方案1）。形成的纳米颗粒保持附着在细胞表面或周质空间内，提供新的Pd 0源（“生物Pd 0”）。[15我们证明了这些与细菌表面相关的生物回收的Pd纳米颗粒形成了有价值的有机反应的活性催化剂，例如Suzuki-Miyaura [方程（1）]和Mizoroki-Heck反应[方程（2）]，[13]提供了可持续有机金属化学的实用和简单的手段。同样的原理被应用于从含有几种重金属，主要是Ag、Au、Pt、Pd、Rh、Ir、Ru、Pb和Cu的酸性浸出液中回收催化活性Pd。我们证明了第一次，纯的，nonpalladized细菌生物质可以使用，连同电子供体，Pd回收未稀释的废物。在此过程中形成的生物负载的Pd 0直接用作催化剂的C13 C键形成，说明直接回收的活性催化剂从工业废物。根据其结合重金属的能力选择了两种微生物菌株：钩虫贪铜菌（DSM 428）和耐金属贪铜菌（DS M2839）。[17这些菌株还具有高活性的氢化酶[19]-假设通过H2氧化使PdII还原成核的酶。[20]生物回收过程使用三种条件形式的生物质：（1）纯细胞，（2）从1.25mg Na 2 PdCl 4/10 mL培养物获得的钯化细胞（“bio-Pd 0-I”），和（3）从2.5mg Na 2 PdCl 4/10 mL培养物获得的钯化细胞（“bio-Pd 0-II”）。[13]通过将10 mL细菌悬浮液（600 nm处的光密度OD 600 = 1）在厌氧3-（N-吗啉代）丙磺酸（MOPS）缓冲液中与...
Heavy metals discharged by mining, metallurgical, electronic, and electroplating industries are abundant water and soil contaminants.[1] Their removal is critically important because they are highly toxic and accumulate in the food chain.[2] Biosorption has in recent years received considerable attention as a method for removing heavy metals from the environment.[3–8] This approach uses readily available biomass to sequester toxic heavy metals, leading to bioregeneration of contaminated sites and to recovery of valuable metals. For example, Diels et al. used Cupriavidus necator bacteria immobilized in tubular membrane reactors for the recovery of heavy metals (Cd, Cu, Zn, Co, Ni, Pb, Pd, Y, Ge) from wastewater by the induction of metal salt crystallization processes.[9] Compared with conventional methods, such as precipitation with lime, ion exchange, and precipitation with biosulfide, the biosorption process offers the advantages of low operating cost and high efficiency. Recently, Mabbet et al. reported the use of palladized cells of Escherichia coli and Desulfovibrio desulfuricans, for the recovery of platinum group metals from acidic leachates. While rhodium and platinum were removed efficiently, palladium could not be recovered completely.[10] Pd0 is an industrially important catalyst for fine chemical synthesis, and is also widely used in automotive catalysts.[11, 12] Because of its scarce distribution in the Earth’s crust, the recovery of Pd0 from waste sources is a highly attractive prospect. We recently demonstrated the capacity of certain Gram-negative bacteria to recover Pd0 nanoparticles through the reduction of soluble PdII in a buffered model system.[13, 14] Microbially mediated Pd0 biorecovery is a two-step process, involving sorption of PdII onto the surface of bacteria followed by reduction to Pd0 nanoparticles by using, for example, formate as electron donor (Scheme 1). The formed nanoparticles remain attached to the cell surface or within the periplasmic space, supplying a new Pd0 source (“bio-Pd0”).[15, 16] We demonstrated that these biorecovered Pd nanoparticles associated with the bacterial surface form an active catalyst for valuable organic reactions, for example, Suzuki–Miyaura [Equation (1)] and Mizoroki–Heck reactions [Equation (2)],[13] furnishing a practical and simple means of sustainable organometallic chemistry.In the present study, the same principle is applied to recover catalytically active Pd from an acidic leachate containing several heavy metals, mainly Ag, Au, Pt, Pd, Rh, Ir, Ru, Pb, and Cu. We demonstrate for the first time that pure, nonpalladized bacterial biomass can be used, together with an electron donor, for Pd recovery from undiluted waste. The biosupported Pd0 formed in this process was used directly as a catalyst for CÀC bond formation, illustrating the direct recovery of an active catalyst from industrial waste. Two microbial strains were selected for their ability to bind heavy metals: Cupriavidus necator (DSM428) and Cupriavidus metallidurans (DS M2839).[17, 18] These strains also possess highly active hydrogenases [19]—the enzyme hypothesized to nucleate PdII reduction via H2 oxidation.[20] Three conditioned forms of biomass were used for the biorecovery process:(1) pure cells,(2) palladized cells obtained from 1.25 mg of Na2PdCl4 per 10 mL of culture (“bio-Pd0-I”), and (3) palladized cells obtained from 2.5 mg of Na2PdCl4 per 10 mL of culture (“bio-Pd0-II”).[13] The palladized biomass was obtained in a one-step procedure by mixing 10 mL of a bacterial suspension (optical density at 600 nm OD600= 1) in anaerobic 3-(N-morpholino) propane sulfonic acid (MOPS) buffer with an aqueous solution of …