Sorption Characteristics of Cr(III) onto Florisil: Kinetics, Thermodynamics and Equilibrium Studies

In this study, the efficiency of florisil was investigated for the removal of Cr(III) using batch type sorption under different experimental conditions namely pH, sorbent amount, contact time and temperature. The maximum sorption capacity of florisil for Cr(III) ions was determined as 67.5 mg g-1, at pH 6.0, with a contact time of 60.0 minutes at 25°C. The equilibrium kinetics, isotherms, and thermodynamics of Cr(III) ion sorption onto florisil were also studied and it was evaluated that the sorption kinetics of Cr(III) on florisil followed pseudo-second-order model. The equilibrium data were in good agreement with the Langmuir isotherm model indicating monolayer coverage on the sorbent surface. In addition, thermodynamic studies revealed that the sorption of Cr(III) onto florisil was spontaneous and exothermic. The presented method was applied to the determination of Cr(III) in ultra-pure, tap, bottled drinking and waste water samples and high recoveries obtained confirmed the accuracy of the proposed study. The overall results have demonstrated that florisil is a promising and efficient sorbent and a good candidate for the removal of Cr(III) from aqueous solutions.In this study, the efficiency of florisil was investigated for the removal of Cr(III) using batch type sorption under different experimental conditions namely pH, sorbent amount, contact time and temperature. The maximum sorption capacity of florisil for Cr(III) ions was determined as 67.5 mg g-1, at pH 6.0, with a contact time of 60.0 minutes at 25°C. The equilibrium kinetics, isotherms, and thermodynamics of Cr(III) ion sorption onto florisil were also studied and it was evaluated that the sorption kinetics of Cr(III) on florisil followed pseudo-second-order model. The equilibrium data were in good agreement with the Langmuir isotherm model indicating monolayer coverage on the sorbent surface. In addition, thermodynamic studies revealed that the sorption of Cr(III) onto florisil was spontaneous and exothermic. The presented method was applied to the determination of Cr(III) in ultra-pure, tap, bottled drinking and waste water samples and high recoveries obtained confirmed the accuracy of the proposed study. The overall results have demonstrated that florisil is a promising and efficient sorbent and a good candidate for the removal of Cr(III) from aqueous solutions

Atomic spectrophotometric method development for mercury determination

Bu tezde, Hg(II) ve MeHg(I)’in türlendirilmesi ve önderiştirilmesinde çapraz bağlı poli(4–vinil piridin) üzerine asılanmıs poli(akril amid) (P4–VP–g– PAm) ve nano sıfır yüklü nikel (nZVNi)’in kullanılabilirliği araştırılmıştır. P4– VP–g–PAm ile yapılan kesikli (batch) çalışmalarda, Hg(II)’nin pH 1 – 8 aralığında nicel ( %95) olarak sorplandıgı, MeHg(I)’nın pH 1 – 2 aralığında %1 den daha az sorplandıgı, pH 3 – 8 aralığında ise %20 – 50 gibi bir verimle sorplandıgı görülmüştür. Hg(II)’nin süreye bağlı sorpsiyonunun, 20 ve 500 mL’lik örnek hacimleri için 160. ve 270. dakikalarda nicel olarak gerçekleştiği görülmüştür. nZVNi ile yapılan kesikli (batch) çalışmalarda ise her iki cıva türünün de [Hg(II) ve MeHg(I)] pH 4 – 10 aralığında nicel(>%96) olarak sorplandıgı görülmüştür. Ayrıca, sorpsiyonun kinetiğinin de iyi olduğu görülmüştür. Toplam kapasiteye baktığımızda, P4–VP–g–PAm 817 mg Hg(II) g-1 sorbent’lik bir kapasiteye, nZVNi için ise 2500 mg Hg(II) g-1 sorbent gibi oldukça yüksek bir kapasiteye sahip olduğu görülmüştür. Ayrıca cıva ile sorpsiyonda yarışa giren Pb(II), Zn(II), Cu(II), Cd(II) and Fe(III) metal iyonları ile seçimlilik çalışmaları yapılmıştır. Elde edilen sonuçlardan her iki sorbentin de seçilen metal iyonları varlığında cıvayı seçimli olarak sorpladığı görülmüştür. Her iki sorbentin de önderiştirici olarak kullanılabilirliği, deniz, körfez ve içme suyu uygulamalarıyla başarıyla gerçekleştirilerek, P4–VP–g–PAm ve nZVNi için sırasıyla 2 ng L-1 ve 1.8 ng L-1 belirtme sınırlarına ulaşılmıştır

Lead and copper removal using Kula volcanics from environmental waters

The ability of Kula volcanics (the youngest volcanic rocks of western Anatolia) to remove Pb(II) and Cu(II) from aqueous solutions has been demonstrated, for the first time, in this study. The optimum parameters viz., pH, contact time and sorbent amount/solution volume ratio were evaluated using batch experiments. Langmuir isotherm model excellently described the sorption process and both of the ions followed pseudo-second-order kinetics. The method was applied to the natural river water samples and it was observed that the sorbent can successfully be used for the removal Pb(II) and Cu(II) ions with acceptable accuracy and precision