H2 oxidation in Azotobacter vinelandii is catalyzed by a membrane-bound, alpha beta dimeric [NiFe] hydrogenase. Maturation of the enzyme involves cleavage of a putative N-terminal signal sequence in the beta subunit and removal of 15 amino acids from the C terminus of the alpha subunit. Cells limited for nickel exhibited low hydrogenase activities and contained an apparently large form of the a...

This work aims to investigate the competitive time-dependent desorption rate of heavy metals (lead, zinc, nickel) coexisting with phenanthrene from natural high buffering soil. Two non-ionic surfactants (Tween 80 and Brij 35) combined with disodium ethylene diamine tetraacetate salt (Na2-EDTA) were utilized as the reagents. The contaminants’ time-dependent desorption data was fitted with five k...

Introduction: Sequential batch reactor (SBR) is one of the modified biological treatment systems which is able to remove BOD5, Nitrogen, and phosphorus from wastewater. The object of this study is to determine the removal efficiency of nitrogen, phosphorus, and heavy metals from municipal wastewater by the advanced SBR system. Materials and Methods: This descriptive-analytical and cross-sectio...

INTRODUCTION The fitness of water supplies for public consumption may be assured by minimal treatment where high purity sources are available. Aluminium sulphate is used in the coagulation process forming a floc which acts as a filter for the removal of finer particles. The presence of a high concentration of aluminium sulphate in the water supply lowers the pH of the water and may result in th...

BACKGROUND Complete removal of old filling material during root canal retreatment is fundamental for predictable cleaning and shaping of canal anatomy. Most of the retreatment methods tested in earlier studies have shown inability to achieve complete removal of root canal filling. Therefore the aim of this investigation was to assess the efficacy of three different rotary nickel titanium retrea...

Mixed iron-manganese oxide nanoparticles, synthesized by a simple procedure, were used to remove nickel ion from aqueous solutions. Nanostructures, prepared by using different weight percents of manganese, were characterized by transmission electron microscopy, selected area diffraction, X-ray diffraction, Raman spectroscopy, and vibrating sample magnetometry. Adsorption/desorption isotherm cur...

The Sinos river Basin is an industrial region with many tanneries and electroplating plants in southern Brazil. The wastewater generated by electroplating contains high loads of salts and metals that have to be treated before discharge. After conventional treatment, this study applied an advanced oxidative process to degrade organic additives in the electroplating bright nickel baths effluent. ...

Heavy metal’s release without treatment poses a significant threat to the environment. Heavy metals are non-biodegradable and persistent. In the present study the ash of water hyacinth (Eichhornia crassipes), was used to remove six metals from aqueous solutions through biosorption. Results of batch and column experiments showed excellent adsorption capacity. Removal of lead, chromium, zinc, cad...

to cobalt with negative results for chromium, nickel and cement. Both prostheses were removed and the joints were sterile but contained grey pultaceous material with a relatively high cobalt and chromium content; there were multiple acetabular fractures on each side and the acetabular wall was paper-thin. Following the removal of the second prosthesis she became cobalt-negative and her urinary ...

Heavy metals are categorized based on their high density, atomic weight, atomic number and molecular weight. Lewis acids property of metal ions results in covalent complex formation with different ligands in humans and other living forms which make metals nondegradable and cause toxicity (Duffus, 2002). Pulp and paper mill are categorized as one of the 12 most polluting industries in India whic...