Enhancement of Escherichia coli bacterial biomass and hydrogen production by some heavy metal ions and their mixtures during glycerol vs glucose fermentation at a relatively wide range of pH

2017 ◽  
Vol 42 (10) ◽  
pp. 6590-6597 ◽  
Author(s):  
Karen Trchounian ◽  
Anna Poladyan ◽  
Armen Trchounian
Keyword(s):  
Escherichia Coli ◽  
Heavy Metal ◽  
Hydrogen Production ◽  
Metal Ions ◽  
Heavy Metal Ions ◽  
Bacterial Biomass ◽  
Glucose Fermentation ◽  
Wide Range

scholarly journals Electrochemical modification of platinum and glassy carbon surfaces with pyridine layers and their use as complexing agents for copper (II) ions

2019 ◽  
Vol 17 (1) ◽  
pp. 722-727 ◽  
Author(s):  
Veton Haziri ◽  
Avni Berisha ◽  
Fetah I. Podvorica
Keyword(s):  
Heavy Metal ◽  
Metal Ions ◽  
Glassy Carbon ◽  
Heavy Metal Ions ◽  
Square Wave Voltammetry ◽  
Square Wave ◽  
Electrode Surfaces ◽  
Wave Voltammetry ◽  
Wide Range ◽  
Carbon Surfaces

AbstractThe electrochemical grafting of the “in-situ” prepared diazopyridinium salt have permitted the attachment of pyridine moieties onto platinum and glassy carbon surfaces. The modification of the electrode surfaces is observed by a redox probe. The ability of the film for the complexation of copper (II) ions is demonstrated by square wave voltammetry. After 45 min accumulation of copper (II) ions onto the grafted electrode surfaces, the electrode signal obtained by square wave voltammetry measurement served to discriminate the adsorbed heavy metal ions. Such measurements showed that the grafted pyridine has the ability to display complexing behavior toward some heavy metal ions. DFT calculations support a strong binding of the pyridine moieties onto the Pt surface. The most favorable complexation mode of copper (II) ions as suggested from DFT is the bidentate complex. This strategy is vital in constructing a wide range of different electrochemical sensors.

scholarly journals Characterization and application of biosorbents modified with TiO2 for heavy metal ions removal

2016 ◽  
Vol 14 (2) ◽  
pp. 79-87 ◽  
Author(s):  
Nena Velinov ◽  
Miljana Radovic ◽  
Aleksandra Zarubica ◽  
Aleksandar Bojic
Keyword(s):  
Heavy Metal ◽  
Metal Ions ◽  
Heavy Metal Ions ◽  
Metal Removal ◽  
Heavy Metal Removal ◽  
Bacterial Biomass ◽  
Sorption Process ◽  
Promising Alternative ◽  
Maximum Sorption ◽  
Heavy Metal Ions Removal

Preparation, characterization and application of materials modified with TiO2 nanoparticle have been reviewed. Chitosan, bacterial biomass and dendrimers were the starting material for modification. Sorbents characterization was performed by scanning electron microscopy (SEM). In order to investigate the sorption capabilities of sorbents, we used them for removal of heavy metal ions from aqueous solution. The effect of contact time on heavy metal ions sorption and maximum sorption capacities of biosorbents are shown. As a very important parameter of the sorption process, the effect of initial pH values on heavy metal removal was examined. This paper indicates that sorption using the material modified with TiO2 is becoming a promising alternative to conventional adsorbents in removing heavy metal ions.

scholarly journals Influence of heavy metal ions on ecotoxicological indicators of planorbarius corneus (Mollusca, Gastropoda, Pulmonata, Bulinidae)

2021 ◽  
pp. 76-83
Author(s):  
Y. Babych ◽  
◽  
T. Pinkina ◽  
Keyword(s):  
Heavy Metal ◽  
Metal Ions ◽  
Heavy Metal Ions ◽  
Copper Ions ◽  
Toxic Metal ◽  
Pathological Process ◽  
Planorbarius Corneus ◽  
Wide Range ◽  
Lethal Time ◽  
Mean Time

The influence of different concentrations of ions of copper, zinc, nickel, manganese of the aquatic environment on the ecotoxicological indicators of the wide range and the most numerous species of malacofauna of Ukraine – Planorbarius corneus (Linnaeus, 1758) was studied. According to the level of toxic effect on the coils, the pollutants studied by us belong to the categories of low-toxic (Mn2+), moderately toxic (Ni2+), highly toxic (Zn2+) and highly toxic (Cu2+) substances. The values of subthreshold, sublethal, chronically lethal, and acute lethal concentrations for each of the used toxicants (mg/dm3) were determined according to the peculiarities of behavior and physiological condition of the experimental animals. As the concentrations of metal ions in the medium increase, the values of the latent period in P. corneus increase. The first signs of poisoning in animals are a weakening of motor activity and increased mucus secretion. At lethal concentrations (LC100) of these toxicants in experimental mollusks develops a rapid pathological process. By the end of the experiment, all individuals in this group die. With increasing concentrations of heavy metal ions, lethal time and lethal mean time decrease. The highest lethal time values were observed for manganese (II) ions, and the lowest for copper ions. The reversibility of mollusk poisoning by different concentrations of these metals was studied. Restoration of functions in the studied animals is carried out in reverse order. Under the action of the same concentrations of heavy metal ions, the duration of the lethal mean time is different. The value of the coefficient of endurance under the influence of heavy metals on the horn extract decreases from high to low concentrations. At subthreshold concentrations, this coefficient cannot be established due to the absence of 100 % death of individuals until the end of the acute experiment. The values of the adaptation coefficient are the highest for highly toxic metal (Cu2+) and the lowest for weakly toxic (Mn2+). Under the action of copper ions, the adaptation of animals to the effects of the toxicant is temporary, followed by depression.

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