Application of Biosorption for Removal of Heavy Metals from Wastewater

Fresh water accounts for 3% of water resources on the Earth. Human and industrial activities produce and discharge wastes containing heavy metals into the water resources making them unavailable and threatening human health and the ecosystem. Conventional methods for the removal of metal ions such as chemical precipitation and membrane filtration are extremely expensive when treating large amounts of water, inefficient at low concentrations of metal (incomplete metal removal) and generate large quantities of sludge and other toxic products that require careful disposal. Biosorption and bioaccumulation are ecofriendly alternatives. These alternative methods have advantages over conventional methods. Abundant natural materials like microbial biomass, agro-wastes, and industrial byproducts have been suggested as potential biosorbents for heavy metal removal due to the presence of metal-binding functional groups. Biosorption is influenced by various process parameters such as pH, temperature, initial concentration of the metal ions, biosorbent dose, and speed of agitation. Also, the biomass can be modified by physical and chemical treatment before use. The process can be made economical by regenerating and reusing the biosorbent after removing the heavy metals. Various bioreactors can be used in biosorption for the removal of metal ions from large volumes of water or effluents. The recent developments and the future scope for biosorption as a wastewater treatment option are discussed

Amelioration of Abnormalities Associated with the Metabolic Syndrome by Spinacia oleracea

The present study evaluates the protective effects of an antioxidant-rich extract of Spinacea oleracea (NAOE) in abnormalities associated with the metabolic syndrome (MetS) in rats. HPTLC of NAOE revealed the presence of 13 total antioxidants, 14 flavonoids, and 10 phenolic acids. Rats administered with fructose (20% w/v) in drinking water for 45 days to induce abnormalities of MetS received NAOE (200 and 400 mg/kg, po), the standard drug gemfibrozil (60 mg/kg, po), aerobic exercise (AE), and a combination of NAOE 400 mg/kg and AE (NAOEAE) daily for 45 days. All treatments significantly altered the lipid profile and attenuated the fructose-elevated levels of uric acid, C-reactive protein, homocysteine, and marker enzymes (AST, LDH, and CK-MB) in serum and malondialdehyde in the heart and restored the fructose-depleted levels of glutathione and antioxidant enzymes (superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase). A significant decrease in blood glucose and insulin levels decreased insulin resistance, and improved glucose tolerance was observed in the treatment animals when compared with the fructose-fed animals. The best mitigation of MetS was shown by the NAOEAE treatment indicating that regular exercise along with adequate consumption of antioxidant-rich foods such as spinach in diet can help control MetS

Virulence Factors of Clinical and Fecal Isolates of Enterococci Species

Enterococci species are known commensals of the gastrointestinal flora; however, in recent years, they have emerged as important nosocomial pathogens that possess many virulence factors that are attributed to the pathogenesis of diseases caused by them. The study evaluated and compared the virulence factors of Enterococci isolated from fecal and clinical samples. From the obtained isolates, the clinical enterococcal isolates produced 35%, 20%, and 50%, and fecal isolates produced 23%, 13%, and 13% gelatinase, hemolysin, and biofilm, respectively. Biofilm production determined by the Congo Red agar, tube, and microtiter plate methods was 23%, 39%, and 49%, respectively. The sensitivity of the Congo Red agar and tube method compared to the microtiter plate method was 27% and 46%, respectively, whereas the specificity of both tests was 79%. This study showed that biofilm production plays a significant role in the pathogenesis of diseases caused by Enterococci. Detection of biofilm production using the microtiter plate method is more sensitive and specific than the Congo Red agar and tube method

Synthesis of Functionalized Iron Oxide Nanoparticle with Amino Pyridine Moiety and Studies on Their Catalytic Behavior

Aim: The main objective of this paper is to study the synthesis of functionalized iron oxide nanoparticle and its reactivity towards chromene synthesis Study design: Functionalized iron oxide nanoparticle study. Place and duration of study: Department of Studies and Research in Industrial Chemistry, School of Chemical Sciences, Kuvempu University, Shankaraghatta, between December 2009 and July 2010. Methodology: This paper describes synthesis of stable functionalized iron oxide nanoparticles through surface modification of magnetic iron oxide nanoparticles by amino pyridine. Iron oxide nanoparticles were synthesized by co-precipitation method and the surface modification process was achieved by treating the nanoparticles with (chloro propyl trimethoxy silane) CPTS and aminopyridine. The developed functionalized iron oxide nanoparticle was evaluated as the catalyst for synthesis of chromones under MW irradiation conditions. Results: The catalysts were magnetically recovered and reusable without significant loss of their catalytic efficiency. To receive morphological and structural information on the obtained functionalized nanoparticle, the samples were analyzed by X-ray diffraction (XRD) measurements, FTIR and scanning electron microscopy (SEM) imaging. All synthesized chromene derivatives were characterized using analytical techniques such as IR, 1H NMR, and mass spectroscopy. Also the identity of these compounds was easily established by comparison of their melting point with those of reported samples. Conclusion: In summary, we have developed a new magnetically recyclable and efficient functionalized magnetic nano catalyst for the chromene synthesis. Magnetic nanoparticle catalyst achieves a simple separation of catalyst without filtration including high yield in product

Effect of pretreatment of Bacillus subtilis biomass on biosorption and its real time application

The research study investigated the biosorption behavior of Pb(II) ions by treated and untreated biomass of B. subtilis. At initial biosorption conditions, the biosorption efficiency was found to be 36.75%. At the optimized experimental conditions, control biomass showed maximum biosorption efficiency of 58.04% where the biomass was treated with different chemicals. The biomass treated with formaldehyde showed the highest efficiency of 80.9% which was further optimized and attained maximum efficiency of 89.8% for Pb(II) ions. SEM (Scanning Electron Microscope) and EDX (Energy dispersive X- ray) analysis evaluates the structural and elemental changes that occurred as a result of biosorption. Functional groups that are involved in biosorption were revealed by FTIR (Fourier Transform Infrared spectroscopy). Kinetic data showed the best fit with the pseudo second-order model. Effective removal of lead ions from industrial contaminated water sources by pretreatment biomass of B. subtilis elucidates its potential use as biosorbent for metal remediation

Fe3O4 nanoparticle supported Ni(II) complexes: A magnetically recoverable catalyst for Biginelli reaction

A novel magnetically recoverable functionalized magnetic(Fe3O4) nanoparticle supported-nickel(II) complex with a high surface area has been synthesized by chemical conjugation of magnetite nanoparticles with highly reactive silanols on the surface of magnetic Fe3O4 to improve the affinity of Fe3O4 nanoparticles for the target species. Functionalized Ni(II) complex containing surface of pyridine, methoxysilanyl and amino groups. Studies revealed that Fe3O4@[Ni(bpy)2(py-tmos)] is a new and highly efficient green catalyst for the synthesis of a diverse range of 3,4-dihydropyrimidin-2(1H)-ones under solvent free conditions, and in addition Fe3O4@[Ni(bpy)2(py-tmos)] could be easily recovered by a simple magnetic separation and recycled at least 5 times without deterioration in catalytic activity. Keywords: Fe3O4-bpy-Ni(II) complex, Nano catalyst, Biginelli condensatio

Synthesis, antimicrobial, DNA-binding and photonuclease studies of Cobalt(III) and Nickel(II) Schiff base complexes

New metal complexes of the type M(nih)(L)](PF6)(n)center dot xAH(2)O and M(nih)(2)](PF6)center dot xH(2)O (where M = Co(III) or Ni(II), L = 1,10-phenanthroline (phen)/or 2,2' bipyridine (bpy), nih = 2-hydroxy-1-naphthaldehyde isonicotinoyl hydrazone, n = 2 or 1 and x = 3 or 2) have been synthesized and characterized by elemental analysis, magnetic, IR and H-1 NMR spectral data. The electronic and magnetic moment 2.97-3.07 B.M. data infers octahedral geometry for all the complexes. The IR data reveals that Schiff base (nih) form coordination bond with the metal ion through azomethine-nitrogen, phenolic-oxygen and carbonyl-oxygen in a tridentate fashion. In addition, DNA-binding properties of these six metal complexes were investigated using absorption spectroscopy, viscosity measurements and thermal denaturation methods. The results indicated that the nickel(II) complex strongly bind with calf-thymus DNA with intrinsic DNA binding constant K-b value of 4.9 x 10(4) M-1 for (3), 4.2 x 10(4) M-1 for (4), presumably via an intercalation mechanism compared to cobalt(III) complex with K-b value of 4.6 x 10(4) M-1 (1) and 4.1 x 10(4) M-1 (2). The DNA Photoclevage experiment shows that, the complexes act as effective DNA cleavage agent. (C) 2012 Elsevier B.V. All rights reserved