İkbal Koyuncu

Decomposition of dyes in the textile wastewater with ozone

Abstract Ozone treatment of textile wastewater and recycling of this treated water as process water have been investigated. Effects of pH, temperature,dye concentration and UV radiotion on the treatment of some azo dyes such as N‐ROT‐GRE, N‐ORANGE and INDISOL‐RUBINOL with ozone were investigated. Temperature was found not to effect the decomposition rates of these dyes. The ozone treatment was found to be more ecomomical with the diluted dye solution than with concentrated solutions. No positive effect of U V radiotion on decomposition of dyes were observed. When the flow rate of ozone was 0.2 mg / sec. chemical oxygen demand ( COD ) decreases of 44 mg and 36.6 mg per minute were found for the wastewaters of cotton dying and wool dying respectively.

Simultaneous determination of Sunset Yellow and Ponceau 4R in gelatin powder by derivative spectrophotometry and partial least-squares multivariate spectrophotometric calibration.

ABSTRACT Two methods for the simultaneous determination of Sunset Yellow and Ponceau 4R in gelatin powders by first derivative spectrophotometry and by partial least-squares multivariate spectrophotometric calibration are described. These procedures do not require any separation step. These methods were applied to determine both colorants in commercial gelatin powders and the results obtained were compared. A good statistical agreement was obtained between the results.

Determination of zinc, nickel and cadmium in natural water samples by flame atomic absorption spectrometry after preconcentration with ion exchange and flotation techniques

Abstract Two preconcentration techniques, ion exchange and flotation, were used for the determination of zinc (Zn), nickel (Ni) and cadmium (Cd) in natural water samples. In the first part of our work, the adsorption of zinc(II), nickel(II) and cadmium(II) on Lewatit TP 207 chelating resin containing iminodiacetate groups was studied at different pH values by a batch process. The effects of parameters such as amount of resin, contact time, pH and initial metal concentration on the ion exchange separation were investigated. For the determination of the adsorption behavior of the resin, the adsorption isotherms of metal ions were also studied. The concentrations of metal ions were measured by batch techniques and with atomic absorption spectrometry analysis. Adsorption analysis results obtained at various concentrations showed that the adsorption pattern on the resin followed Langmuir and Freundlich isotherms. The efficiency of removal is higher for Ni and Zn than Cd ions. Here, we report the method that is applied for the sorption and separation of some toxic metals from the solutions. In the second part of our work, the flotation technique was used for preconcentration. The ability of Co(III) hexamethylenedithiocarbamate, Co(HMDTC)3, as a flotation collector for metals from natural waters was investigated. The flotation method was compared with the ion exchange method. The recoveries of Zn, Cd and Ni from natural water samples were approximately 99%. Our results showed that the two methods were very effective, but the flotation results were higher than the ion exchange results. In the present study, a method was described for the determination of Zn, Ni and Cd by flame atomic absorption spectrometry (FAAS) after preconcentration and separation in water by ion exchange resin and flotation. Results of these two methods are compared. Analytical parameters such as precision and accuracy of methods were also studied. The equilibrium experimental results of Zn, Ni and Cd ions exchanged were fitted by Langmuir-Freundlich adsorption isotherm models.

ZERO-CROSSING DERIVATIVE SPECTROPHOTOMETRIC DETERMINATION OF MIXTURES OF SUNSET YELLOW AND ERYTHROSINE IN PURE FORM AND IN TABLETS

ABSTRACT A classic analytical problem is the simultaneous determination of two or more compounds in the same sample without previous chemical separation. In this way derivative spectrophotometry is an anaytical technique of great utility and offers greater selectivity than normal spectrophotometry. The resolution of binary mixtures of compounds with overlapped spectra by derivative spectrophotometry is frequently made on the basis of zero-crossing measurements. A very simple spectrophotometric method using measurements at zero-crossing wavelength is described for resolving binary mixtures of the synthetic colorants sunset yellow (E-110) and erythrosine (E-127). The assay procedure for E-110 and E-127 in Premarin tablets involves extraction of the colorants from tablets with distilled water and measurement of first derivative absorbance values at 482.7 nm for E-127, then filtration from rough paper and measurement of 1D values at 526.3 nm for E-110. Linear correlations over the concentration ranges of 2.0–10.0 µg mL−1 for E-110 (r = 0.9997) and for E-127 (r = 0.9999) were obtained. Commercially available tablets containing E-110 and E-127 were analysed by the proposed method and the HPLC method. Mean values and standard deviations calculated from seven determinations were 122.5 µg/tablet (RSD = 1.9) of E-110, 119.3 µg/tablet (RSD = 2.3) of E-127 for the proposed method and 124.3 µg/tablet (RSD = 0.98) of E-110, 120.9 µg/tablet (RSD = 1.2) of E-127 for the HPLC method. The statistical evaluations indicated that there was no significant difference between the mean values and precisions of the two methods at 95% confidence level (t = 1.68 and 0.24; F = 3.76 and 3.67). This method was satisfactorily used for determining synthetic mixtures of these dyes in different ratios. The avarage percentage recoveries are 105.8% and 102.8% for E-110 and E-127 respectively.

Separation of Tl(I) and Tl(III) from environmental water samples by flotation method coupled with Zeeman ETAAS determination.

An accurate, fast, and simple method for determination of thallium in environmental water samples with Zeeman electrothermal atomic absorption spectrometry (ZETAAS) by previous flotation preconcentration is given. The possibility of using cobalt(III) hexamethylenedithiocarbamate as a colloidal precipitate collector for simultaneous flotation separation of Tl(I) and Tl(III) from water matrices was studied. All experimental parameters influencing a proper flotation of both thallium ions were ascertained. The developed procedure with Co(HMDTC)3 is applied for preconcentration and separation of total thallium in water matrix before ZETAAS. The results of ZETAAS analysis are compared with those obtained by inductively coupled plasma-atomic emission spectrometry. The ZETAAS limit of detection of thallium preconcentrated by Co(HMDTC)3 is 0.031 μ g/L.