The nanostructured MnO2 /carbon fiber (CF) composite electrode was prepared using the anodic electrodeposition process. The crystal structure and morphology of MnO2 particles were determined with X-ray diffraction and field-emission scanning electron microscopy. The electrosorptive properties of the prepared electrode were investigated in the removal of cadmium ions from aqueous solution, and the effect of pH, cell voltage, and ionic strength was optimized and modeled using the response surface methodology combined with Box–Behnken design. The results confirm that the optimum conditions to remove Cd(II) ions were: pH of 6.03, a voltage of 2.77 V, and NaCl concentration of 3 g/L. The experimental results showed a good fit for the Freundlich isotherm model and the pseudo-second-order kinetic model.
Biosorption of cadmium ions from simulated wastewater using rice husk was studied with initial concentration of 25 mg/l. Equilibrium isotherm was studied using Langmuir, Freundlich, BET and Timken models. The results show that the Freundlich isotherm is the best fit model to describe this process with high determination coefficient equals to 0.983. There was a good compliance between the experimental and theoretical results. Highest removal efficiency 97% was obtained at 2.5g of adsorbent, pH 6 and contact time 100 min.
The effect of applied current on protection of carbon steel in 0.1N NaCl solution (pH=7) was investigated under flow conditions (0-0.262 m/s) for a range of temperatures (35-55°C) using rotating cylinder electrode. Various values of currents were applied to protect steel from corrosion, these were Iapp.=Icorr., Iapp.=2Icorr. and Iapp.=2.4Icorr. under stationary and flow conditions. Corrosion current was measured by weight loss method. The variation of protection potential with time and rotation velocity at various applied currents was assessed. It is found that the corrosion rate of carbon steel increases with rotation velocity and
has unstable trend with temperature. The protection current required varies with temperature and it inc
Lead remediation was achieved using simple cost, effective and eco-friendly way from industrial wastewater. Phragmitesaustralis (P.a) (Iraqi plant), was used as anovel biomaterial to remove lead ions from synthesized waste water. Different parameters which affected on adsorption processes were investigated like adsorbent dose, pH, contact time, and adsorbent particle size, to reach the optimized conditions (maximum adsorption). The adsorption of Pb (?) on (P.a) involved fast and slow process as a mechanism steps according to obey two theoretical adsorption isotherms; Langmuir and Freundlich. The thermos dynamic adsorption parameters were evaluated also. The (?H) obtained positive value that meanes adsorption of lead ions was an endothermic
... Show MoreThis studies deals with investigated the potential of a Iraqi bentonite clay for the adsorption of bromo phenol red dye from contaminated water. Impulse adsorption experiments were performed. The contact time influence of initial dye concentration, temperature, pH, ionic strength, partical size adsorbent and adsorbent dosage on bromo phenol red adsorption are investigated in a series of batch adsorption experiments. Adsorption equilibrium data were analyzed and described by the Freundlich, Langmuir and temkin isotherms equations. Thermodynamic parameters inclusive the Gibbs free energy (∆G• ), enthalpy (∆H• ), and entropy (∆S• ), were also calculated. These parameters specified that adsorption of bromo phenol red onto bentonite
... Show MoreThe development of economic and environmentally friendly extractants to recover cobalt metal is required due to the increasing demand for this metal. In this study, solvent extraction of Co(II) from aqueous solution using a mixture of N,N0-carbonyl difatty amides (CDFAs) synthesised from palm oil as the extractant was carried out. The effects of various parameters such as acid, contact time, extractant concentration, metal ion concentration and stripping agent and the separation of Co(II) from other metal ions such as Fe(II), Ni(II), Zn(III) and Cd(II) were investigated. It was found that the extraction of Co(II) into the organic phase involved the formation of 1:1 complexes. Co(II) was successfully separated from commonly associated metal
... Show MoreAdsorption techniques are widely used to remove organics pollutants from waste water particularly, when using low cost adsorbent available in Iraq. Al-Khriet powder which was found in legs of Typha Domingensis is used as bio sorbent for removing phenolic compounds from aqueous solution. The influence of adsorbent dosage and contact time on removal percentage and adsorb ate amount of phenol and 4- nitro phenol onto Al-Khriet were studied. The highest adsorption capacity was for 4-nitrophenol 91.5% than for phenol 82% with 50 mg/L concentration, 0.5 gm. dosage of adsorbent and pH 6 under a batch condition. The experimental data were tested using different isotherm models. The results show that Freundlich model resulted in the best fit also
... Show MoreThis studies deals with investigated the potential of a Iraqi bentonite clay for the adsorption of bromo phenol red dye from contaminated water. Impulse adsorption experiments were performed. The contact time influence of initial dye concentration, temperature, pH, ionic strength, partical size adsorbent and adsorbent dosage on bromo phenol red adsorption are investigated in a series of batch adsorption experiments. Adsorption equilibrium data were analyzed and described by the Freundlich, Langmuir and temkin isotherms equations. Thermodynamic parameters inclusive the Gibbs free energy (∆G•), enthalpy (∆H•), and entropy (∆S•), were also calculated. These parameters specified tha
... Show MoreApplication of a Fe-bentonite nano clay (Fe-BNC) as modified clay has been investigated for the removal of birlliant green (BG) from aqueous solutions. Atomic force microscope measurements give a detailed information on pore shape and pore size distribution about the clay. These measurements show that the average diameter of the improved clay is 346.84 nm. Batch adsorption experiments were carried out for the removal of (BG) from aqueous solutions onto Fe-BNC. Equilibrium data were fitted to Freundlich and Langmuir isotherm equations and the isotherm constants were determined. Thermodynamic parameters such as free energy, entropy and enthalpy, have been calculated. &n
... Show MoreIn this work Aquatic plant (Nile rose) was used to study adsorption of industrial dye (safranin-O from aqueous solution within several operation conditions. The dried leaves of Nile rose plant were used as adsorbents safranin-O from aqueous solution after different activations such as wet and dry enhancements. The data show increasing in dye solution removal percentage for both activation methods of the adsorbent and also dye removal percentage that was obtained by using adsorbent without any treatment with the progress contact time. The dye removal percentages at equilibrium time 40 minutes were 88.7% at non-activation, 92.3% at thermal activation, and 98.3% at acidic activation. The samples adsorbents before and after adsorption which wer
... Show Moren the present work, a study is carried out to remove chromium (III) from
aqueous solution by: activated charcoal , attapulgite and date palm leaflet powder
(pinnae). The effect of various parameters such as contact time, and temperature has
been studied. The isotherm equilibrium data were well fitted by Freundlich and
Langmuir isotherm models. The adsorption capacity of chromium (III) that was
observed by activated charcoal , attapulgite and date palm leaflet powder (pinnae)
increased with the rise of temperature when the concentrations of Cr (III) were 600,
700 and 100mg/L respectively. The greatest adsorption capacity ofactivated
charcoal , attapulgite and date palm leaflet powder (pinnae) at 10°C was 7.51, 5.3