Journal of Chemical Health Risks
Volume:1 Issue: 2, Winter 2011

In this work, efficiency and performance of Hazelnut shells (HS) adsorbent was examined for the removal and recovery of Direct Red 12B (DR12B) from wastewater. The absorbance of DR12B was measured spectrophotometrically at λmax=523 nm before and after adsorption of DR12B. The maximum removal was 99.8% for 30 mg L–1 of DR12B concentration on 0.3 gr HS adsorbent. Acidic pH was favourable for the adsorption of DR12B. The influence of variables including pH, concentration dye, particle size, amount of adsorbent, temperature, in column method and kinetics, isotherm, contact time on the dye removal has been investigated in batch method by one at a time optimization method. The effect of foreign cations, anions and other dyes was investigated on removal efficiency. In order to investigate the efficiency of DR12B adsorption on the HS, pseudo-first-order, pseudo-second-order, Elovich and intra-particle diffusion kinetic models were studied. The graphical correlation of various adsorption isotherm models like, Langmuir, Freundlich and Tempkin have been carried out for this adsorbent.

The interaction between Holo-Transferin (HTF) and Colchicine (COL) was investigated in the present of Pb+2 ions under physiological conditions by using synchronous fluorescence spectra. The synchronous fluorescence spectra show a slight change of tryptophan residue micro-environment. Synchronous fluorescence spectra show that the structure of the tyrosine residue environment was altered by interaction of the COL and Pb+2 ions with HTF. The fluorescence intensity of HTF decreased regularly beside a small blue shift with increasing concentrations of COL and Pb+2 ions. The intrinsic fluorescence of HTF was quenched in the presence of drug and ion. Interaction of drugs with HTF and HTF-Pb+2 can elucidate the properties of drug-protein and ion- protein complex, as it may provide useful information about the structural feature that determines the therapeutic effectiveness of ion and drugs. Therefore, it has become a significant research field in life science, chemistry, biotechnology and clinical medicine.

Nanotechnology is the study of manipulating matter on an atomic and molecular scale. Generally, nanotechnology deals with developing materials, devices, or other structures possessing at least one dimension size from 1 to 100 nanometers. Carbon nanotubes have great potentials for novel applications in industry, drug delivery system and many other uses. In this work after purification, multiwall carbon nanotube was functionalized in acids by liquid phase oxidation method for drug delivery system. The structural and chemical changes after carboxylation of MWNTs improved the solubility and dispersibility of the carboxylated MWNTs in water. Fourier transformed infrared spectroscopy, and transmission electron microscopies were carried out for characterization of these methods of MWCNTs functionalization.

Aqueous polyurethane dispersions (PUDs) have recently emerged as important alternatives to their solvent-based counterparts for various applications due to increasing health and environmental awareness (green chemistry). Anionic polyester-polyurethane dispersions were synthesized by three steps. In the first step, macromonomer diisocyanate having carboxylic acid was prepared by isophorone diisocyanate (IPDI), dimethylol propionic acid (DMPA) in percent of acetone as solvent and dibutyldtin dilaurate (DBTDL) as catalyst. Then, carboxylic polyurethane was prepared by reaction macromonomer diisocyanate having carboxylic acid with linear aliphatic polyester (Mw=2000), trifunctional polyester (Mw=2800) and butanediol (BDO) as chain extender. The next step involved neutralization and dispersion in water, where acidic polyurethane was neutralized by the addition of triethylamine (TEA). Factors influencing the synthesis of polyurethane dispersion mainly involve reaction temperature, reaction time, the concentration of catalyst, DMPA content and BDO content, were studied. The polymers have been characterized with DSC and FTIR.

Activated Charcol phase loaded with 2-propylpiperidine-1-carbodithioate (PPCD) were synthesized based on chemical binding and physical adsorption approaches. The stability of a chemically modified PPCD especially in concentrated hydrochloric acid which was then used as a recycling and pre-concentration reagent for further uses of activated Charcol immobilized PPCD. The application of this activated Charcol for sorption of a series of metal ions was performed by using different controlling factors such as the pH of metal ion solution and the equilibration shaking time by the static technique. This difference was interpreted on the basis of selectivity incorporated in these sulfur containing activated Charcol phases. Hg (II) was found to exhibit the highest affinity towards extraction by these activated Charcol phases. The pronounced selectivity was also confirmed from the determined distribution coefficient (Kd) of all the metal ions, showing the highest value reported for mercury (II) to occur by activated Charcol immobilized PPCD phase. The potential applications of activated Charcol immobilized PPCD phase for selective extraction of mercury(II) to occur from aqueous solution were successfully accomplished as well as pre- concentration of low concentration of Hg(II) (40 pg ml-1) from natural tap water with a pre-concentration factor of 200 for Hg(II) off-line analysis by cold vapor atomic absorption analysis.

A simple method has been developed for the preconcentration of Lead (II) based on the adsorption of its 1-(2-Pyridyl Azo)2-Naphtol (PAN) complex on aOctadecyl bonded silica cartridges. The influence of acidity, eluting agents, stability of the column, sample volume and interfering ions has been investigated in detail. The adsorbed complex could be eluted using environmentally benign HNO34M and the concentration of Lead (II) was determined flame atomic absorption spectrometry. A detection limit of 50 µgL−1 could be achieved and the developed procedure was successfully applied for the determination of Lead (II) in tap water and waste water samples.

Marine ecosystem pollution is one of the important problems of today environment. In this study the existence of heavy metal in the Namrood River, situated in Firoozkooh in Tehran province, Iran has been investigated. The Namrood River is located near Firoozkooh route, and is affected by pollutant from tourist centers, entertainment, gas stations, nearby villages’ sewage systems, farming effluent, and hatchery farms. In some areas, its water is heavily polluted possibly by heavy metals. After selecting two stations in upstream and downstream of the river, they were sampled three times in both cold and hot seasons of year (mid-March, and June) for Chironomidae, and Gammarus plux sediments. The measured heavy metals were cadmium and lead. The results showed that the concentration of cadmium in measured samples varied from 0.010-0.2033 ppm. The concentration of lead in samples varied from 0.11-2.16 ppm. The results also indicated that sediments of samples taken from the upper station in the cold season had a higher proportion of cadmium and a higher concentration of lead than sediments in the lower station during the hot season.