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The adsorption behavior of Bismarck brown (BB) dye from aqueous solutions onto graphene oxide GO and graphene oxide-g-poly (n-butyl methacrylate-co-methacrylic acid) GO-g-pBCM as adsorbents was investigated. The prepared GO and GO-g-pBCM were characterized by Fourier transform infrared spectroscopy FTIR, which confirmed the compositions of the prepared adsorbents. Adsorption of BB dye onto GO and GO-g-pBCM was explored in a series of batch experiments under various conditions. The data were examined utilizing Langmuir and Freundlich isotherms. The Langmuir isotherm was seen as increasingly reasonable from the experimental information of dye on formulating adsorbents. Kinetic investigations showed that the experimental data were fitted very well to the pseudo-second-order model, and the calculated positive values of the (∆H° and ∆S°) indicated that the adsorption of BB dye onto GO and GO-g-pBCM was endothermic and increasing of the adsorption process randomness. The negative values of (∆G°) imply that the adsorption process was spontaneous.

A Semi- automated flow injection analysis (FIA) unit was build-up for determination of ammonium ion in water samples from the Shatt Al-Arab River during the period from October 2009 to September 2010. The ammonium concentrations in water have been measured, at each of the eight stations (Qurnah (Tigres), Qurnah (Euphrates), Saad Bridge, Garmat Ali, Ashar, Abu Al-Khaseeb, Al-Seeba and Fao), monthly. The results indicated that (NH4+) concentrations increasing during May, June and July, 2010 especially in stations 5 and 6 were 0.95, 1.35 µg/ml , 1.30, 1.25 µg/ml and 1.45, 1.40 µg/ml, respectively. The FIA unit was applied successfully for the determination of ammonium in Shatt Al-Arab water sample and provide simple, fast, and reproducible methods for ammonium determination in water.

T HE adsorption behavior of cationic dye Bismarck brown BB onto graphene oxide GO, graphene oxide derivatives 3,3ˊ-Diaminobenzidine GODAB, and Ethylene diamine tetraacetic acid-modified graphene oxide GODABE as adsorbents from aqueous solutions were investigated, and characterized by various techniques, like Fourier transform infrared spectroscopy, Field Emission Scanning Electron Microscopy, and X-ray diffraction spectroscopy. Adsorption of BB dye on modified graphene oxide was explored in a series of batch experiments under various conditions. The data were analyzed using Langmuir and Freundlich, models. The Langmuir model was found to be more suitable for the experimental data than other adsorption models. The maximum adsorption capacities were 714.28, 1428.5, and 1111.1 mg/g for GO, GODAB, and GODABE at optimum pH 3 for GO and GODAB, 5 for GODABE and the optimum agitation time were chosen as 45min for GO and 30min for both adsorbents GODAB and GODABE. Kinetic studies revealed that the pseudo-second-order model showed the best fitting to the experimental data. The thermodynamic parameters imply that the adsorption process was spontaneous and endothermic.

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