Massoud Kaykhaii; Sayedeh Samaneh Hasheminasab; Sayyed Hossein Hashemi; Mojtaba Sasani
Abstract
In this research, Sistan sand was used as a natural and inexpensive sorbent for removal of cephalexin and tetracycline antibiotics from water and wastewater samples. For a concentration 60.0 mg L-1 of cephalexin, optimum removal conditions were: pH of the sample 3.0, adsorbent amount 1.0 g, contact time ...
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In this research, Sistan sand was used as a natural and inexpensive sorbent for removal of cephalexin and tetracycline antibiotics from water and wastewater samples. For a concentration 60.0 mg L-1 of cephalexin, optimum removal conditions were: pH of the sample 3.0, adsorbent amount 1.0 g, contact time 20.0 min, added amount of sodium chloride to adjust the ionic strength of the solution 7.0 g L-1. Langmuir isotherm was the best fitted model for this adsorption process and adsorbent capacity was calculated to be 0.26 g g-1. This adsorbent was able to remove up to 68.1% of cephalexin from wastewater. In case of tetracycline, for a 90.0 mg L-1 of the analyte, the optimum adsorption conditions were achieved at pH 8.0, 1.0 g of sorbent, contact time of 35.0 min and ionic strength of the solution as sodium chloride of 7.0 g L-1. The isotherm was best in agreement with Freundlich model. Adsorbent capacity was 0.76 g g-1 and up to 76.2% of this antibiotic could be removed from wastewater.
Sayyed Hossein Hashemi; Massoud Kaykhaii; Ahmad Jamali Keikha; Enayat Saberi
Abstract
This paper describes trace determination of malachite green (MG) as a water pollutant dye by convenient spectrophotometry. A water-soluble hyper-branched polyamine was first prepared using the nuclophilic ring opening reaction of diepoxy and diamine monomer, which was then used for functionalization ...
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This paper describes trace determination of malachite green (MG) as a water pollutant dye by convenient spectrophotometry. A water-soluble hyper-branched polyamine was first prepared using the nuclophilic ring opening reaction of diepoxy and diamine monomer, which was then used for functionalization of multiwalled carbon nanotubes. This compound (named WHPA-OMCNT) was applied as a highly efficient adsorbent for the extraction of MG from seawater samples of Chabahar Bay (located in the southern east of Iran). WHPA-OMCNT was used in a pipette-tip solid phase extraction process; and for this extraction, different parameters affecting the extraction efficiency, including type and volume of eluent solvent, sample of volume, number of cycles of extraction and elution, pH of sample solution, type and amount of salt, and concentration of surfactant (triton X-114) were optimized using both one-variable-at-a-time and Box-Behnken response surface methodology techniques employing seven factors in three-levels. Under optimum conditions, the linear range of proposed method for MG was 4-250 µg L-1 with a detection limit of 0.80 µg L-1 and RSDs better than 6.4%.
