Adsorption of Heavy Metals by Sodium Polyacrylate-Humic Acid-Rectorite Composite as a Novel Adsorbent

2012 ◽  
Vol 550-553 ◽  
pp. 2428-2435
Author(s):  
Fang Yan Chen ◽  
Wei Ye ◽  
Yu Bin Tang
Keyword(s):  
Heavy Metals ◽  
Aqueous Solution ◽  
Humic Acid ◽  
Metal Ions ◽  
Adsorption Kinetics ◽  
Removal Rate ◽  
Polymerization Reaction ◽  
Sodium Polyacrylate ◽  
Adsorbent Dosage ◽  
Adsorption Reaction

A novel organic-inorganic composite sodium polyacrylate-humic acid-rectorite was prepared by polymerization reaction of acrylic acid, humic acid and rectorite in aqueous solution and used as adsorbent for removal of heavy metals Pb(II), Cd(II), Cu(II) and Zn(II) ions from aqueous solution. The effects of contact time, pH, temperature and adsorbent dosage on adsorption capability were investigated. Adsorption kinetics, adsorption isotherm and desorption of adsorbed heavy metal ions were also researched. The results indicated that the adsorption reaction of heavy metals was rapid and reached equilibrium in 30 min. Adsorption capacities of heavy metals increased with increasing initial pH, temperature and adsorbent dosage. Adsorption reaction is endothermic. The optimum pH for all the four ions adsorption was observed at 5.5-6.5. The removal rate of Pb(II), Cd(II), Cu(II) ions with initial concentration of 50mg/L are more than 98%, and Zn(II) ions removal is about 90%. The suitability of adsorption kinetics for heavy metals to a pseudo-second-order kinetics model suggested that the adsorption rate may be governed by chemiadsorption involving ions exchange or sharing between adsorbent and metal ions. The adsorption equilibrium data was well interpreted by Langmuir and Freundlich isotherm model. The adsorption behaved as monomolecular layer. The maximum monolayer adsorption capacity was 1666.7, 666.7, 303.0 and 454.6 mg∙g-1 for Pb(II), Cd(II), Cu(II) and Zn(II) ions, respectively, at 25°C. Adsorbed metal ions were desorbed effectively by 0.1M HCl solution. Desorption rate was about 95.2, 92.4, 98.7 and 94.3% for Pb(II), Cd(II), Cu(II) and Zn(II) ions, respectively. Adsorbent can be reused for three cycles without any significant loss in adsorption performance.

Zinc removal from aqueous solution using novel adsorbent MISCBA

2016 ◽  
Vol 6 (3) ◽  
pp. 377-388 ◽  
Author(s):  
Ibrahim Umar Salihi ◽  
Shamsul Rahman Muhamed Kutty ◽  
Muhamed Hasnain Isa ◽  
Nasir Aminu
Keyword(s):  
Heavy Metals ◽  
Aqueous Solution ◽  
Metal Ions ◽  
Contact Time ◽  
Adsorption Process ◽  
Negative Impact ◽  
Batch Adsorption ◽  
Maximum Adsorption Capacity ◽  
Adsorbent Dosage ◽  
Zinc Removal

Pollution caused by heavy metals has become a serious problem to the environment nowadays. The treatment of wastewater containing heavy metals continues to receive attention because of their toxicity and negative impact on the environment. Recently, various types of adsorbents have been prepared for the uptake of heavy metals from wastewater through the batch adsorption technique. This study focused on the removal of zinc from aqueous solution using microwave incinerated sugarcane bagasse ash (MISCBA). MISCBA was produced using microwave technology. The influence of some parameters such as pH, contact time, initial metal concentration and adsorbent dosage on the removal of zinc was investigated. The competition between H+ and metal ions has affected zinc removal at a low pH value. Optimum conditions for zinc removal were achieved at pH 6.0, contact time 180 min and adsorbent dosage of 10 g/L, respectively. The maximum adsorption capacity for the removal of zinc was found to be 28.6 mg/g. The adsorption process occurred in a multilayered surface of the MISCBA. Chemical reaction was the potential mechanism that regulates the adsorption process. MISCBA can be used as an effective and cheap adsorbent for treatment of wastewater containing zinc metal ions.

Adsorption of Cu2+ from Aqueous Solution by Walnut Shell

2013 ◽  
Vol 864-867 ◽  
pp. 1327-1332 ◽  
Author(s):  
Xiu Guo Lu ◽  
Pei Pei Yan ◽  
Xiao Fang Dang
Keyword(s):  
Aqueous Solution ◽  
Particle Size ◽  
Metal Ions ◽  
Adsorption Capacity ◽  
Removal Rate ◽  
Equilibrium Concentration ◽  
Walnut Shell ◽  
Adsorption Time ◽  
Adsorbent Dosage ◽  
Initial Ph

Walnut shell was used as adsorbent to remove Cu2+ metal ions from the simulated aqueous solution. The influence of factors, namely: particle size, initial pH, oscillation intensity, adsorbent dosage and adsorption time were investigated through single factor experiments.The results show that, the adsorption capacity reached the peak for Cu2+ in 25°C when the initial pH was 5, particle size was 1.25~1.6mm, adsorbent dosage was2.5g, oscillation speed reached 200r/min, and the adsorption time was 360min, all above leads the removal rate of Cu2+reached 75.7%, and the adsorption capacity of Cu2+ 0.702 mg/g. The pseudo-second-order model was fitted to describe the adsorption of Cu2+ , it was shown that adsorption rate for the metal ions in proportion to the square of the concentration.The equilibrium concentration of adsorption fitted well with Langmuir isotherm equation, the process of adsorption was single molecular layer adsorption.

Removal of Heavy Metals from Aqueous Solution by Hydroxyapatite/Chitosan Composite

2013 ◽  
Vol 789 ◽  
pp. 176-179 ◽  
Author(s):  
Eny Kusrini ◽  
Nofrijon Sofyan ◽  
Dwi Marta Nurjaya ◽  
Santoso Santoso ◽  
Dewi Tristantini
Keyword(s):  
Heavy Metals ◽  
Aqueous Solution ◽  
Metal Ions ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Removal Of Heavy Metals ◽  
Sem Micrograph ◽  
Pseudo Second Order ◽  
Chitosan Composite

Hydroxyapatite/chitosan (HApC) composite has been prepared by precipitation method and used for removal of heavy metals (Cr6+, Zn2+and Cd2+) from aqueous solution. The HAp and 3H7C composite with HAp:chitosan ratio of 3:7 (wt%) were characterized by Fourier transform infrared spectroscopy, X-ray diffraction and scanning electron microscopy-energy dispersive X-ray spectroscopy. The SEM results showed that HAp is spherical-shaped and crystalline, while chitosan has a flat structure. SEM micrograph of 3H7C composite reveals crystalline of HAp uniformly spread over the surface of chitosan. The crystal structure of HAp is maintained in 3H7C composite. Chitosan affects the adsorption capacity of HAp for heavy metal ions; it binds the metal ions as well as HAp. The kinetic data was best described by the pseudo-second order. Surface adsorption and intraparticle diffusion take place in the mechanism of adsorption process. The binding of HAp powder with chitosan made the capability of composite to removal of Cr6+, Zn2+and Cd2+from aqueous solution effective. The order of removal efficiency (Cr6+> Cd2+> Zn2+) was observed.

Comparison of Coal Ash and Activated Carbon for Removal of Humic Acid from Aqueous Solution

2013 ◽  
Vol 864-867 ◽  
pp. 1509-1512
Author(s):  
Xue Mei Zhang ◽  
Yan Zhang ◽  
Di Fan
Keyword(s):  
Aqueous Solution ◽  
Humic Acid ◽  
Activated Carbons ◽  
Removal Rate ◽  
Coal Ash ◽  
Cost Effective ◽  
Solution Ph ◽  
Adsorption Behaviors ◽  
Calcium Loading ◽  
Working Solution

This paper presents the adsorption behaviors of humic acid (HA) on coal ashes and powdered activated carbons (PACs). A bituminous coal, with or without calcium-loading, was used as a feedstock for coal ash preparation. The working solution of HA with a concentration of 20 mg/L was used in all adsorption tests. The results showed that calcium-enriched coal ash (CECA) gave rise to the removal rate of HA as high as 84.05%, much higher than those of raw coal ash (RCA) and PACs. The impacts of solution pH and adsorbent dosage on HA adsorption capacity were also investigated. It was found that lower pH facilitated to the removal of HA from aqueous solution by means of CECA, and the optimal CECA dosage was about 1.0g/L at pH 7.00. The data obtained in this study suggested that calcium-enriched coal ash could be useful and cost-effective in the treatment of wastewaters containing HA-like organic macro-molecules.

scholarly journals Investigations on the mechanism, kinetics and isotherms of ammonium and humic acid co-adsorption at low temperature by 4A-molecular sieves modified from attapulgite

RSC Advances ◽  
2017 ◽  
Vol 7 (28) ◽  
pp. 17095-17106 ◽  
Author(s):  
Nan Sun ◽  
Wenxin Shi ◽  
Lixin Ma ◽  
Shuili Yu
Keyword(s):  
Heavy Metals ◽  
Aqueous Solution ◽  
Humic Acid ◽  
Low Temperature ◽  
Molecular Sieves ◽  
Co Adsorption ◽  
Aluminum Silicate ◽  
Silicate Mineral ◽  
Magnesium Aluminum Silicate ◽  
Kinetics And Isotherms

Attapulgite (ATP) is a type of natural magnesium aluminum silicate mineral and has been applied as an adsorbent to remove organic pollutants and heavy metals in aqueous solution.

Application of Photocatalytic Metal Membrane System for Water Purification

2006 ◽  
Vol 326-328 ◽  
pp. 1317-1320 ◽  
Author(s):  
Jong Oh Kim ◽  
Jong Tae Jung ◽  
Won Youl Choi
Keyword(s):  
Heavy Metals ◽  
Humic Acid ◽  
Uv Light ◽  
Removal Rate ◽  
Membrane System ◽  
Tio2 Powder ◽  
Metal Membrane ◽  
Tio2 Particles ◽  
Positive Effect

This study was conducted to evaluate the applicability of photocatalytic metal membrane system for the treatment of humic acid and heavy metals in aqueous solution. The catalysts, TiO2 powder P25 Degussa and metal membrane with 0.5 μm nominal pore size were used for experiments. Removal efficiency of humic acid and heavy metals increased with the increase of TiO2 dosage, however decreased over 0.3 g/L of TiO2 dosage. The addition of H2O2 as an oxidation reagent had a positive effect for the removal rate of humic acid and heavy metals. Metal membrane with stainless steel seemed to be quite stable to UV light with oxidation reagent in long-term operational periods over 6 months. Moreover, TiO2 particles can be effectively separated from the treated water by membrane rejection and the permeation flux was also enhanced by the combination of photocatalytic reaction.

scholarly journals Cadmium(II) Removal from Aqueous Solution Using Microporous Eggshell: Kinetic and Equilibrium Studies

2018 ◽  
Vol 18 (2) ◽  
pp. 265 ◽  
Author(s):  
Behzad Shamsi Zadeh ◽  
Hossein Esmaeili ◽  
Rauf Foroutan
Keyword(s):  
Heavy Metals ◽  
Aqueous Solution ◽  
High Efficiency ◽  
Second Order ◽  
Order Kinetic ◽  
Mixing Rate ◽  
Equilibrium Studies ◽  
Initial Concentration ◽  
Adsorbent Dosage ◽  
Pseudo Second Order

Heavy metals are soluble in the environment and can be dangerous for many species. So, removal of heavy metals from the water and wastewater is an important process. In this study, an adsorbent made of eggshell powder was employed to remove cadmium ions from aqueous solution. A number of parameters were studied including pH of the aqueous solution, adsorbent dosage, contact time, the initial concentration of cadmium ion and mixing rate. The best efficiency for the removal of Cd(II) was obtained 96% using this adsorbent. The optimal parameters were ambient temperature of 30 °C, mixing rate of 200 rpm, pH of 9, an adsorbent dosage of 5 g/L and initial concentration of cadmium was 200 ppm. In order to study the kinetics of adsorbent, the pseudo-first-order and pseudo-second-order kinetic models and intra-particle diffusion model were applied. According to the pre-determined correlation coefficients (R2), the pseudo-second-order kinetic model showed a better correlation between the kinetic behaviors of the adsorbent. Furthermore, to study the equilibrium behavior of adsorbent, Langmuir and Freundlich models used and both models showed high efficiency in isotherm behavior of the adsorbent. So, this adsorbent can be used as a natural and cheap adsorbent.

scholarly journals Adsorption and desorption studies of <i>Delonix regia</i> pods and leaves: removal and recovery of Ni(II) and Cu(II) ions from aqueous solution

2020 ◽  
Vol 13 (2) ◽  
pp. 15-27 ◽  
Author(s):  
Bolanle M. Babalola ◽  
Adegoke O. Babalola ◽  
Cecilia O. Akintayo ◽  
Olayide S. Lawal ◽  
Sunday F. Abimbade ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Metal Ions ◽  
Metal Ion ◽  
Agricultural Waste ◽  
Waste Product ◽  
Operating Conditions ◽  
Batch Adsorption ◽  
Order Kinetic ◽  
Adsorbent Dosage ◽  
Delonix Regia

Abstract. In this study, the adsorption of Ni(II) and Cu(II) ions from aqueous solutions by powdered Delonix regia pods and leaves was investigated using batch adsorption techniques. The effects of operating conditions such as pH, contact time, adsorbent dosage, metal ion concentration and the presence of sodium ions interfering with the sorption process were investigated. The results obtained showed that equilibrium sorption was attained within 30 min of interaction, and an increase in the initial concentration of the adsorbate, pH and adsorbent dosage led to an increase in the amount of Ni(II) and Cu(II) ions adsorbed. The adsorption process followed the pseudo-second-order kinetic model for all metal ions' sorption. The equilibrium data fitted well with both the Langmuir and Freundlich isotherms; the monolayer adsorption capacity (Q0 mg g−1) of the Delonix regia pods and leaves was 5.88 and 5.77 mg g−1 for Ni(II) ions respectively and 9.12 and 9.01 mg g−1 for Cu(II) ions respectively. The efficiency of the powdered pods and leaves of Delonix regia with respect to the removal of Ni(II) and Cu(II) ions was greater than 80 %, except for the sorption of Ni(II) ions onto the leaves. The desorption study revealed that the percentage of metal ions recovered from the pods was higher than that recovered from the leaves at various nitric acid concentrations. This study proves that Delonix regia biomass, an agricultural waste product (“agro-waste”), could be used to remove Ni(II) and Cu(II) ions from aqueous solution.

scholarly journals Phytoremediation of some heavy metals in contaminated soil

2019 ◽  
Vol 43 (1) ◽  
Author(s):  
Sherine M. Shehata ◽  
Reham K. Badawy ◽  
Yasmin I. E. Aboulsoud
Keyword(s):  
Heavy Metals ◽  
Humic Acid ◽  
Metal Ions ◽  
Foliar Application ◽  
Drainage System ◽  
Hibiscus Cannabinus ◽  
Favorable Effect ◽  
Hyperaccumulator Plants ◽  
Cr Uptake ◽  
Cultivated Soils

Abstract Background Several cultivated areas are irrigated with low-quality waters from the drainage system due to the shortage of suitable source of water for agricultural activities. Most of these drainage waters are contaminated with heavy metals which are concentrated in surface layer of the soil and translocated to plant and food chains. The region of Sahl El Husseiniya, Alsharqia government, is mainly irrigated with wastewater of Bahr El-Baqar drain. Objective Two types of hyperaccumulator plants represented by kenaf (Hibiscus cannabinus L.) and flax (Linum usitatissimum L.) were cultivated successively in the study area. Humic acid and gibberellin were used in this experiment as foliar sprayings to enhance the plant ability to absorb heavy metal ions from the soil. In addition, three soil additives represented by sulfur, vermiculite, and compost were also applied. Results Sulfur was the soil additive of the most pronounced effect on the uptake of Cr, Co, Cd, and Mn by the hyperaccumulator plants, while humic acid was of more favorable effect as a foliar treatment on Co and Cr uptake by flax and Cd and Mn uptake by kenaf. However, the foliar application of gibberellin enhanced plant growth and was of the best effect on both Co and Cr uptake by kenaf-cultivated soils and both Cd and Mn in flax-cultivated soils. In general, heavy metals were more concentrated in roots than in shoots. Comparing the efficiency of the two crops in cleaning soils, results implied that kenaf was of more favorable effect on the removal of Cr, Co, and Cd, while flax was of higher superiority in the removal of Mn. The efficiency of kenaf on removal of the studied metal ions followed the descending order of Cr > Co > Mn > Cd where their removal percentage values reached 50.71, 38.27, 33.98, and 14.43%, respectively. Flax phytoremediation efficiency followed the descending order of Mn > Cr > Co > Cd, where their removal percentage values reached 54.36, 36.95, 28.72, and 11.37%, respectively. Double season phytoremediation efficiency followed the order of Cr ≥ Mn > Co > Cd achieving 66.87, 65.63, 54.66, and 23.40%, respectively.

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