Saeed ur Rehman

In-vitro antibacterial, antifungal and cytotoxic activities of some coumarins and their metal complexes

A series of new antibacterial and antifungal coumarin-derived compounds and their transition metal complexes [cobalt (II), copper (II), nickel (II) and zinc (II)] have been synthesized, characterized and screened for their in vitro antibacterial activity against Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Pseudomonas aeruginosa, Salmonella typhi, Shigella dysenteriae, Bacillus cereus, Corynebacterium diphtheriae, Staphylococcus aureus and Streptococcus pyogenes bacterial strains and for in vitro antifungal activity against Trichophyton longifusus, Candida albicans, Aspergillus flavus, Microsporum canis, Fusarium solani, Candida glaberata. The results of these studies show the metal complexes to be more antibacterial and antifungal as compared to the uncomplexed coumarins. The brine shrimp bioassay was also carried out to study their in vitro cytotoxic properties.

Study of thallium (III) adsorption onto multiwall carbon nanotubes

Multiwall carbon nanotubes (MWCNTs) oxidized by H2SO4, KMnO4, and HNO3 were used as sorbents and their sorption abilities for Tl(III) were compared with raw MWCNTs. The Langmuir model was used for the calculation of the amount of Tl(III) sorbed on the surface of MWCNTs. The acidic oxidation treatment of MWCNTs yielded a large number of functional groups, leading to a sharp increase in Tl(III) adsorption. Maximum adsorption of Tl(III) was recorded at a pH value of 7. The maximum amounts of Tl(III) sorbed on raw MWCNTs, H2SO4-oxidized, KMnO4-oxidized and HNO3-oxidized MWCNTs calculated by the Langmuir model were 3.0, 11.7, 21.6 and 31.5 mg/g, respectively. The MWCNTs oxidized by HNO3 showed the best sorption performance for Tl (III) ions.

Transport of Zn (II) by TDDA-Polypropylene Supported Liquid Membranes and Recovery from Waste Discharge Liquor of Galvanizing Plant of Zn (II)

The facilitated passage of Zn (II) across flat sheet supported liquid membrane saturated with TDDA (tri-n-dodecylamine) in xylene membrane phase has been investigated. The effect of acid and metal ion concentration in the feed solution, the carrier concentration in membrane phase, stripping agent concentration in stripping phase, and coions on the extraction of Zn (II) was investigated. The stoichiometry of the extracted species, that is, complex, was investigated on slope analysis method and it was found that the complex (LH)2·Zn(Cl2) is responsible for transport of Zn (II). A mathematical model was developed for transport of Zn (II), and the predicted results strongly agree with experimental ones. The mechanism of transport was determined by coupled coion transport mechanism with H+ and Cl− coupled ions. The optimized SLM was effectively used for elimination of Zn (II) from waste discharge liquor of galvanizing plant of Zn (II).