title: Synthesis of CdS nanoparticles from cadmium sulfate solutions using the extracellular polymeric substances of B. licheniformis as stabilizing agent.
abstract: Mining and hydrometallurgical industries produce large amounts of hazardous metal sulfate solutions as a by-product which can be recycled and exploited to produce valuable and advanced materials. Here, for the first time, extracellular polymeric substances of Bacillus licheniformis were applied as biosurfactants to synthesize quantum dots of cadmium sulfide from pure artificial and impure industrial cadmium sulfate solutions. The bacterial biopolymers stabilized the generated crystalline nuclei as colloidal dots and prevented their further growth or agglomeration. In order to discover the composition and size distribution of the produced particles, characterization was performed by X-ray diffraction (XRD), and transmission electron microscopy (TEM). Results showed that the particles biosynthesized from the pure solution were nano-sized cubic crystals of CdS with the dimensions of 2-10nm. The same product was also derived from the impure industrial solution. The outcomes of this study indicate the feasibility of cadmium or probably other metal recovery from industrial solutions and wastewaters in the form of valuable metal sulfide nanoparticles.
authors.affiliation: Department of Mining Engineering, Isfahan University of Technology, Isfahan 84156-83111, Iran.
authors.forename: Mehran
authors.initials: M
authors.lastname: Bakhshi
authors.affiliation: Department of Mining Engineering, Isfahan University of Technology, Isfahan 84156-83111, Iran. Electronic address: raoofsmh@yahoo.com.
authors.forename: Mohammad Raouf
authors.initials: MR
authors.lastname: Hosseini
mesh_terms: D000069976:Bacillus licheniformis / Q000378:metabolism*; D001704:Biopolymers / Q000378:metabolism; D001709:Biotechnology; D019187:Cadmium Compounds / Q000737:chemistry* / Q000378:metabolism; D005240:Feasibility Studies; D055772:Green Chemistry Technology; D007220:Industrial Waste / Q000032:analysis; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D036103:Nanotechnology; D045663:Quantum Dots / Q000737:chemistry / Q000648:ultrastructure; D012996:Solutions; D013431:Sulfates / Q000737:chemistry* / Q000378:metabolism; D013440:Sulfides / Q000737:chemistry* / Q000378:metabolism; D013501:Surface-Active Agents / Q000378:metabolism; D062065:Wastewater / Q000737:chemistry
chemical_list: D001704:Biopolymers; D019187:Cadmium Compounds; D007220:Industrial Waste; D012996:Solutions; D013431:Sulfates; D013440:Sulfides; D013501:Surface-Active Agents; D062065:Wastewater; C034939:cadmium sulfide; C037123:cadmium sulfate
keywords: Bacteria; Biosynthesis; Cadmium sulfide; Nanoparticle; Quantum dots