sawdust is now being investigated as an adsorbent to remove contaminants from aqueous solution. heavy metals can be decreased very effectively with the organic material. in this research, adsorption of pb (ii) onto modified beech sawdust in a batch system was investigated. sawdust was collected from timber mill of qom, iran, and modified with h2so4 and naoh. then, the effects of various paramet...

p-Nitrocalix[6]arene (CALX-N6, L) formed a 1:1 metal complex, ML, with light rare earth metal ions (M3+), such as La3+, Pr3+ and Nd3+ except Ce3+, but formed a 1:2 (M(3+):L) complex, ML2 (the charge of the complex is omitted) with heavy rare earth metal ions, such as Sm(3+)-Lu3+ including Y3+. The conditional stability constants of these 1:1 and 1:2 complexes, KML and KML2, were measured by a l...

background: the presence of heavy metals in aquatic and terrestrial ecosystems causes harmful effects to living organisms in the environment. this research aimed to determine the potential of activated pumice stone (aps) as a sorbent for the removal of cd, cu, and zn from wastewater. methods: this research was conducted during 2013 on a laboratory scale. the study was performed using batch expe...

introduction: discharging of industrial colored wastewaters especially into aqueous environments can cause adverse effects on aquatic life due to their toxic natures. in this study, montmorillonite modified by hexadecyltrimethyl ammonium bromide (hdtma-mt) was used for the adsorption of methylene blue (mb). materials and methods: the influence of surfactant loading rate, contact time, ph, adsor...

A simple and rapid procedure for SO2 determination in air was developed by using a flow injection analysis (FIA) system coupled with a 3-hole chromatomembrane cell (CMC). The CMC was applied for the on-line collection/concentration of SO2 from air into a solution of 2 g l(-1) triethanolamine (TEA) solution as an absorbing solution: SO2 was converted to SO3(2-) in the alkaline absorbing solution...

The efficiency of the application of a chemically-modified activated carbon surface was investigated. The purpose of this study was to examine the effect of treatment with CaCl2 solution at a concentration of 2000 mg.L on the sorption of nitrate ions from aqueous solutions in successive sorption/t reatment cycles. The sorbent was initially subjected to chemical treatment with CaCl2 and subseque...

In this study, the trace amounts of erythrosine, as a food dye is determined by cloud point extraction-scanometry (CPE-Scanometry) as a new, facile, available, fast, sensitive, and low cost method. The method is based on the CPE of analyte from aqueous solution, diluting the extracted surfactant-rich phase with ethanol, transfer to Plexiglas®cell and scanning the cells containing the...

In this study, noncovalent functionalization of single-walled carbon nanotubes (SWCNTs) with phospholipid-polyethylene glycols (Pl-PEGs) was performed to improve the solubility of SWCNTs in aqueous solution. Two kinds of PEG derivatives, ie, Pl-PEG 2000 and Pl-PEG 5000, were used for the PEGylation process. An experimental design technique (D-optimal design and second-order polynomial equations...

Polypyrrole (PPy) conducting polymer prepared by chemical oxidation method using FeCl3.6H2O as an oxidant has exhibited 100% adsorption efficiency for the removal of nickel ions from aqueous solution. At pH 7, 100% nickel absorption was found by the prepared polypyrrole as measured by atomic absorption spectrophotometry. At both acidic and alkaline solutions, the adsorption efficiency of PPy wa...

Spectropholornetrie technique is used to evaluate binding of the vanadium(1U) ion to a water solublecaruc[4] arene molecule in aqueous solution. On the basis of the calculated value formation constant at25rC.we found that the eomplexation of this metal on is very favored towards 25, 26, 27, 2Stetrahydroxy-5, 11, 17, 23-tetnmulphonalic acid-calix[0]areneGaussian 03 package.