Box-Behnken design: An alternative for the optimization of analytical methods

Über die Adsorption in Lösungen

Dye effluents released from numerous dye-utilizing industries are harmful towards the environment and living things. Consequently, existence of dye effluent in environmental water bodies is becoming a growing concern to environmentalists and civilians. A long term sustainable and efficient dye effluent treatment method should be established to eliminate this issue. Dye wastewater should be treated first before release to minimize its negative impacts towards the environment and living things. However, due to lack of information on efficient dye removal methods, it is difficult to decide on a single technique that resolves the prevailing dye effluent issue. Therefore, this paper reviews existing research papers on various biological, chemical and physical dye removal methods to find its efficiency through percentage of dye removal. Although there are numerous existing tried and tested methods to accomplish dye removal, most of them have a common disadvantage which is the generation of secondary pollution to the environment. This paper highlights enzyme degradation (biological) and adsorption (physical) dye removal as these are known as one of the most efficient dye removal techniques these days. This paper also suggests the usage of a combined adsorbent as it is envisioned that this technique has better efficiency and is able to remove dyes at a faster rate.

Efficiency of various recent wastewater dye removal methods: A review

Evolution of dispersive liquid-liquid microextraction method.

We discuss the origins and the fundamentals of Green Analytical Chemistry (GAC), based on the literature published about clean, environmentally-friendly or GAC methods. We pay special attention to the strategies and the tools available to make sample-pretreatment and analytical methods greener. We consider that the main principles are to replace toxic reagents, to miniaturize and to automate methods, making it possible to reduce dramatically the amounts of reagents consumed and wastes generated, so reducing or avoiding side effects of analytical methods. We also consider on-line decontamination or passivation of wastes to be of special interest in making analytical chemistry sustainable.

/pdf/green-analytical-chemistry-2j89cop1pd.pdf

Green Analytical Chemistry

Synthesis of benzo[h]quinolone and benzo[c]acridinone derivatives by Fe3O4@PS-Arginine[HSO4] as an efficient magnetic nanocatalyst

A PVC membrane La (III) ion-selective electrode has been constructed using ethyl1,2,3,4-tetrahydro-6-methyl-4-phenyl-2-thioxopyrimidine-5-carboxylate (ETMPTC) as a neutral ionophore. This electrode responds to La (III) ion with a sensitivity of 19.9 ± 0.3 mV/decade over the range 9.3 × 10-8 to 1.0 × 10-1 M at pH 3.0-10.0. The limit of detection was 1.7 × 10-8 M. It has a response time of < 11s and can be used for at least 3 months without any divergence in potentials. The proposed electrode shows fairly good discrimination of La (III) ion from several cations. The effect of organic solvents on electrode response was examined. The results show that this electrode can be used in ethanol media until 20% (v/v) concentration without interference. The isothermal temperature coefficient of this electrode amounted to 0.00013 V/ °C. This sensor not only was used as an indicator electrode in potentiometric titration of lanthanum ion against EDTA but also was used to determination of La3+ concentration in the presence of certain interfering ions.

A Fast Response Membrane Sensor based on Ethyl 1, 2, 3, 4-tetrahydro-6-methyl-4-phenyl-2-thioxopyrimidine-5-carboxylate for Detection of Lanthanum (III) Ions at Wide Concentration Range.

In the present study, polystyrene nanofibers (PS NFs) were synthesized by electrospinning method and used as adsorbents in solid phase extraction of phenol from aqueous solutions. Phenol was reacted with 4-aminoantipyrine (4-AAP) reagent in presence of potassium hexacyanoferrate (III). The coloured product was extracted by solid phase extraction using electrospun synthesized polystyrene nanofibers and determined by UV-Vis spectrophotometer. At certain conditions of electrospinning process, the variables affecting the solid phase extraction efficiency were studied and optimized. Under the optimized conditions, (sorbent mass: 0.025 g PS NF, sample flow rate: 2.5 mL min−1, eluent: acetone: NaOH 0.1 M (1:1 v/v)), the linear dynamic range (LDR) and limit of detection (LOD as 3 Sb/m) for extraction of phenol from 50 mL of aqueous solutions were determined as 15-2500 µg L-1 and 10 µg L-1, respectively. The precision (as RSD %) of the extraction method using the proposed adsorbent was lower than 7.6%. Finally, the applicability of the proposed method for the extraction of phenol from industrial aqueous samples was examined and satisfactory results were obtained.

http://www.echemcom.com/article_95607_aa3ff45f004040052ae4ada40c87910c.pdf

Electrospun polystyrene nanofiber adsorbent for solid phase extraction of phenol as its quinoid derivative from aqueous solutions

Magnetite nanoparticles catalyzed preparation of isatin ketals under solvent free conditions promoted by ultrasound irradiation

In this study, we aimed to remove reactive yellow 160 (RY 160) dye from aqueous solutions, and for this, collected Azolla was modified with magnetite nanoparticles. The size and structure of magnetite modified Azolla nanocomposite were studied by scanning electron microscopy and Fourier-transform infrared spectroscopy. The factors affecting the dye removal efficiency including pH, ionic strength, stirring time, solution volume, and adsorbent weight were investigated using Taguchi fractional orthogonal array design (OA16). The results of adsorption kinetics at 50 and 100 mg L–1 under optimum conditions (pH = 2, ionic strength = no salt addition, the solution volume = 25 mL, stirring time = 10 min and adsorbent weight = 0.15 g) showed that removal of RY 160 was performed through a pseudo-second-order kinetic model (qe = 30.2 mg g–1, R2 = 1). Isotherm models at three contact times of 10, 25, and 50 min showed that adsorption follows the Freundlich model (n = 1.2, KF = 2.3). Reusability experiments under optimum conditions confirmed the removal efficiency of more than 95% after 16 repetitive adsorption usage. The results of real samples showed that this nanocomposite is an effective adsorbent for the rapid removal of RY 160. Low-cost, reusability and fast elimination have made the synthesized nanocomposite as a useful adsorbent in RY 160 removal.

/pdf/application-of-magnetite-nanoparticles-modified-azolla-as-an-5dipldn9rz.pdf

Shahab Shariati

Papers

Synthesis of benzo[h]quinolone and benzo[c]acridinone derivatives by Fe3O4@PS-Arginine[HSO4] as an efficient magnetic nanocatalyst

A Fast Response Membrane Sensor based on Ethyl 1, 2, 3, 4-tetrahydro-6-methyl-4-phenyl-2-thioxopyrimidine-5-carboxylate for Detection of Lanthanum (III) Ions at Wide Concentration Range.

Electrospun polystyrene nanofiber adsorbent for solid phase extraction of phenol as its quinoid derivative from aqueous solutions

Magnetite nanoparticles catalyzed preparation of isatin ketals under solvent free conditions promoted by ultrasound irradiation

Application of magnetite nanoparticles modified Azolla as an adsorbent for removal of reactive yellow dye from aqueous solutions