background and purpose: recently, release of pollutants such as heavy metal ions to the environment becomes one of the most important problems for soil and water. the present study was conducted to introduce modified rice husk (rh) as a new low-cost adsorbent. materials and methods: in this study, tartaric acid modified rh (tarh), was used as an adsorbent for removal of ni(ii) and cd(ii) from w...

We solve the problem of discrete translocation of a polymer through a pore, driven by the irreversible, random sequential adsorption of particles on one side of the pore. Although the kinetics of the wall motion and the deposition are coupled, we find the exact steady-state distribution for the gap between the wall and the nearest deposited particle. This result enables us to construct the mean...

in this research, chitosan was used for the removal of cr (vi) ions from aqueous solution. the effect of parameters like solution ph, initial cr (vi) concentration, agitation time, amount of adsorbent and agitation speed on the adsorption process was studied. the experimental equilibrium data were analyzed by using various models such as langmuir and freundlich. freundlich isotherm model fitted...

Chelation efficiency of stimuli-responsive poly(N-iospropylacrylamide-co-methyacrylic acid) (PNIPAAm-MAA) nanoparticles with Cu ions from CuSO4 5H2O solution and from wood treated with copper-based preservatives was studied. It was shown that particle size played a very important role in the adsorption process. The nano-scale particles showed much improved Cu ion adsorption efficiency, compared...

introduction: colored compounds which often are toxic and carcinogen is one of the environmental pollutants. these pollutants should be removed prior than discharge to the environment. the aim of this study was the evaluation of maize tassel powder efficiency for the removal of reactive red 198 dye from synthetic textile wastewater. materials & methods: this experimental study was performed in ...

co-precipitation procedure was applied in order to obtain different kinds of magnetic nanoadsobents for the removal of pb(ii) and cu(ii) toxic metal ions from wastewater samples. prepared nanoadsorbents were characterized by fourier transform infrared spectroscopy (ft-ir), x-ray diffractometer (xrd), scanning electron microscopy (sem) and thermogravimetric analysis (tga). the average sizes of t...

background: heavy metals have been recognized as harmful environmental pollutant known to produce highly toxic effects on different organs and systems of both humans and animals. the aim of this paper is to evaluate the adsorption potential of chitosan for the removal of pb(ii), fe(ii) and cu(ii) ions from aqueous solutions. methods: this study was conducted in laboratory scale. in this paper c...

−Three kinds of biochars (called poplar branch biochar (PBC), water hyacinth biochar (WHC), and corn straw biochar (CSC)) were prepared in a fixed-bed pyrolyzer at different pyrolysis temperature of 300-700 C. The effects of biochar species, pyrolysis temperature and biochar addition on adsorption characteristics of typical heavy metals (HMs) of Pb and Zn in vegetable soil (collected from lead-...

In order to improve adsorption capacity of granular activated carbon (GAC), potassium permanganate was used to react with GAC to change the surface properties and improve the adsorption capacity of GAC. By batch experiments, improvement of adsorption capacity of potassium permanganate modified GAC (GACM) was studied. The influence of adsorption time, temperature, ratio of phenol with GAC/GACM, ...

In this study, the adsorption of synthetic landfill leachate onto four kinds of activated carbon has been investigated. From the equilibrium and kinetics experiments, it was observed that coal based PAC presented the highest organic pollutants removal efficiency (54%), followed by coal based GAC (50%), wood based GAC (33%) and wood based PAC (14%). The adsorption equilibrium of PAC and GAC was ...