Homogeneous fibers with average diameters of 90 and 138 nm were formed as pure CS and CS/TEOS/APTES nanofibers and the performance of the prepared nanofibers was investigated for Ni(ii), Cu(ii) and Pb(ii) ion sorption.

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Mercury as a Heavy metal is important factor must be determined and controlled in environmental air and biological. Mercury (Hg) accumulate in living tissues of human body. By NIOSH method, the briefing work place air of petrochemical worker was measured by cold vapor atomic absorption spectrometry(CV-AAS). For preparation and preconcentration samples before analysis a new method of dispersive liquid-liquid micro-extraction with ammonium salt of 1-pyrrolidinedithiocarbamate(APTC)combined with cold vapor atomic absorption spectroscopy, was developed.The influences of various analytical parameters including pH, APDC concentration and ionic liquid volume were investigated.Quantitative recoveries were obtained at pH 7.The enrichment factor was calculated as 5.The detection of limit(LOD)and detection of quantification(LOQ)of mercury were 0.06 and 0.2 μg L-1 respectively. In order accuracy determination the method,certified reference materials, NIST SRM 3133 Lot 061204 was analyzed and the recovery value 98% obtained. So, method of DLLME-APTC had good potential for preparation and preconcentration mercury samples before analysis.

Mercury as a hazardous material caused health problem in humans.In this study,mercury vapor removed from air by nickel-coated on multi-walled carbon nanotubes(Ni-MWCNTs)as a novel sorbent.Amalgamation of mercury with Ni-MWCNTs was achieved by solid-gas phase removal method(SGPR).In bench scale set up, the mercury vapor generated and moved to sorbent at optimized flow rate.After thermal desorption of Ni-MWCNTs at 200oC, the mercury vapor flowed to quartz glass cell with argon gas and determined by cold vapor atomic absorption spectrometer technique(CV-AAS).In optimized conditions,25 mg of Ni-MWCNTs and MWCNTs with different size from 30-100nm was used.The adsorption capacity of sorbents was obtained 194 mg g-1 and 64 mg g-1,respectively.The efficient recovery was obtained at optimized conditions such as, temperature of 25-40 and flow rate of 200 mL min-1.So, Ni-MWCNTs had good potential for removal of mercury vapor from the air and can be used as a low cost and efficient sorbent in industrial workplace

A novel sorbent based on MIL-101(Cr) nanoadsorbent as MOF structure was used for nickel extraction from water and wastewater samples. In this study, 30 mg of MIL-101(Cr) nanoadsorbent dispersed in 50 mL of water or wastewater samples, after sonication and adjusting pH =8.5, the nickel ions was extracted by carboxyl groups of terephthalic acid (MOF-(C6H4 (COO)-2…. Ni2+) by dispersive suspension micro solid phase extraction (DS-μ-SPE).The MOF was separated from liquid phase with filter membrane (0.2 μm), eluted with 0.5 mL of nitric acid as back-extraction solution and finally, the nickel concentration in eluent determined by atom trap-flame atomic absorption spectrometry (AT-FAAS) after dilution with DW up to 1 mL.The LOD, the linear range and preconcentration factor were achieved 1.5 µg L−1, 5-160 µg L−1 and 49.7, respectively.The absorption capacity of MOF for nickel was obtained 136.8 mg g-1.The results of procedure were validated by spiking of samples and ET-AAS analyzer.

Background:Based on the noticeable toxicity and numerous application of mercury in industries, removal of mercury vapor through sorbent is an important environmental challenge.Purpose of the Study:Due to their highly porous and hollow structure, large specific surface area, light mass density and strong interaction, Single-Walled Carbon Nanotubes (SWCNTs) sorbent were selected for this investigation.Methods:In this study, instrumental conditions, method procedure and different effective parameters such as adsorption efficiency, desorption capacity, time, temperature and repeatability as well as retention time of adsorbed mercury were studied and optimized. Also, mercury vapor was determined by cold vapor atomic absorption spectrometry (CV-AAS). Obtained data were analyzed by Independent T- test, Multivariate linear regression and one way–ANOVA finally.Results:For 80 mg nanotubes, working range of SWCNT were achieved 0.02-0.7 μg with linear range (R2=0.994). Our data revealed that maximum absorption capacity was 0.5 μg g-1 as well as limit of detection (LOD) for studied sorbent was 0.006 μg. Also, optimum time and temperature were reported, 10 min and 250 °C respectively. Retention time of mercury on CNTs for three weeks was over 90%. Results of repeated trials indicated that the CNTs had long life, so that after 30 cycles of experiments, efficiency was determined without performance loss.Conclusion:Results showed that carbon nanotubes have high potential for efficient extraction of mercury from air and can be used for occupational and environmental purposes. The study of adsorption properties of CNTs is recommended.