Personal Research Database

Full Text: 2009\Wat Sci Tec59, 1631.pdf

Abstract: A new biosorbent, Eriobotrya japonica (loquat) seed biomass, has been investigated in order to remove malachite green (MG) from aqueous solutions. The factors affecting the biosorption process such as adsorbent dosage, pH of the solution and contact time were studied. The results showed that as the dose of loquat seed increased, the percentage of MG biosorption decreased accordingly. The experimental data suggested that the maximum pH for efficient biosorption of MG was 5.0. The biosorption process was relatively fast and equilibrium was achieved after about 60 min. Freundlich and Langmuir adsorption isotherm models were used for adsorption equilibrium data and based on the Langmuir isotherm plots the maximum bisorption capacity (q_max) value was calculated to be 57.47 mg/g at 20°C. The biosorption kinetics was determined by fitting pseudo-first-order and pseudo-second-order kinetic models to the experimental data, with the second-order model providing the best description of MG biosorption onto loquat seed. Various thermodynamic parameters such as free energy change ΔG°, enthalpy of sorption ΔH° and entropy ΔS° were estimated. The positive value of ΔH° and negative values of ΔG° show the sorption process is endothermic and spontaneous. The positive value of ΔS° shows the increased randomness at the solid-liquid interface during the biosorption of dyes onto loquat seed.

Keywords: Adsorption, Agricultural Waste, Biosorption, Biosorption, Cone Biomass, Equilibrium, Eriobotrya Japonica Seed Biomass, Isotherm, Isotherm, Kinetics, Kinetics, Malachite Green, Mg, Reactive Dyes, Sorption, Thermodynamic, Water

? Jin, S., Cui, K.P., Fallgren, P.H., Urynowicz, M.A. and Jian, J.Z. (2009), Removal of guar and humus from water by layered double hydroxides. Water Science and Technology, 59 (8), 1641-1647.

Full Text: 2009\Wat Sci Tec59, 1641.pdf

Abstract: Natural organic matter such as guar and humus are recalcitrant to conventional pretreatment technologies and can potentially foul processes such as membranes during water treatment. An innovative method of using synthetic layered double hydroxides (LDH) was investigated for removing common natural organic matter in the form of guar gum (GG) and humic acid (HA) from water. Adsorption isotherms were evaluated with Langmuir and Freundlich models. Results show the affinity of GG and HA to LDH to be 11.31 and 9.33 mg g^-1 LDH, respectively. Kinetic isotherms indicate that the sorbing rates of LDH to GG and HA increase with initial GG and HA concentrations, fitting a pseudo-second order model. This study demonstrate that LDH may be an effective material in removing GG and HA from waters and offer an alternative to conventional pretreatment technologies for the mitigation fouling of membrane and other systems in water treatment.

Keywords: Adsorption, Adsorption Mechanism, Exchange, Guar, Gum, Humic Acid, Humic-Acid, Humus, Hydrotalcites, Layered Double Hydroxide, LDH, Membrane Fouling, Membranes, Natural Organic-Matter, Substances

? Módenes, A.N., Pietrobelli, J.M.T.D. and Espinoza-Quiñones, F.R. (2009), Cadmium biosorption by non-living aquatic macrophytes Egeria densa. Water Science and Technology, 60 (2), 293-300.

Full Text: 2009\Wat Sci Tec60, 293.pdf

Abstract: In this work the removal potential on Cd²⁺ by the non-living Egeria densa biomass has been studied. The influence of the metal solution pH, the plant drying and the metal solution temperature, and biosorbent grain size was previously studied in batch systems. The cadmium adsorption rate has increased when the pH was increasing, but at pH 5, the cadmium precipitation has begun to occur, avoiding such high pH values in other tests. The cadmium removal was around 70% at 30°C biomass dried and solution temperatures, assuming as the best temperature conditions. No significant influence was observed in cadmium removal due to the grain size effect. The biosorption kinetic data were well fitted by a pseudo-second order model. The equilibrium time in experiments was around 45 min with a 70% Cd removal. The equilibrium data at pH 5 were described rather better by the Langmuir isotherm than the Freundlich one, with an adsorption rate and maximum metal content values of 0.40 L g^-1 and 1.28 meq g^-1, respectively, for Langmuir model. The kinetic parameter values are near to other biosorbents, indicating that the macrophytes E. densa could be used as biosorbent material in industrial effluent treatment system.

Keywords: Adsorption, Adsorption Rate, Aquatic Macrophytes, Aqueous-Solutions, Batch, Biomass, Biosorbent, Biosorbents, Biosorption, Biosorption Kinetic, Cadmium, Cadmium Adsorption, Cd, Cd²⁺, Cu(II), Data, Egeria Densa, Equilibrium, Experiments, Freundlich, Heavy-Metals, Industrial Effluent, Ions, Isotherm, Kinetic, Kinetic Parameter, Kinetics, Langmuir, Langmuir Isotherm, Langmuir Model, Macrophytes, Metal, Model, Non-Living, Ph, Plant, Potential, Precipitation, Pseudo Second Order, Pseudo-Second Order, Pseudo-Second Order Model, Pseudo-Second-Order, Removal, Size, Solution, Sorption, Systems, Temperature, Treatment, Work

? Lv, K.L., Du, Y.L. and Wang, C.M. (2009), Synthesis of carboxylated chitosan and its adsorption properties for cadmium (II), lead (II) and copper (II) from aqueous solutions. Water Science and Technology, 60 (2), 467-474.

Full Text: 2009\Wat Sci Tec60, 467.pdf

Abstract: Carboxylated chitosan (CKCTS) was prepared for the removal of Cd(II), Pb(II), and Cu(II) from aqueous solutions. The effects of experimental parameters such as pH value, initial concentration, contact time and temperature on the adsorption were studied. From the results we can see that the adsorption capacities of Cd(II), Pb(II), and Cu(II) increase with increasing pH of the solution. The kinetic rates were best fitted to the pseudo-second-order model. The adsorption equilibrium data were fitted well with the Langmuir isotherm, which revealed that the maximum adsorption capacities for monolayer saturation of Cd(II), Pb(II), and Cu(II) were 0.555, 0.733 and 0.827 mmol/g, respectively. The adsorption was an exothermic process.

Keywords: Adsorption, Adsorption Capacities, Adsorption Equilibrium, Adsorption Properties, Aqueous Solutions, Ash, Biopolymers, Cadmium, Carboxylated, Carboxymethyl Chitosan, Cd(II), Chitosan, Concentration, Copper, Cu(II), Cu(II) Ions, Data, Derivatives, Equilibrium, Exothermic, Experimental, Isotherm, Kinetic, Kinetics, Langmuir, Langmuir Isotherm, Lead, Metal Ion, Metal-Ions, Model, Monolayer, Ni(II), Pb(II), pH, pH Value, Pseudo Second Order, Pseudo-Second-Order, Pseudo-Second-Order Model, Rates, Removal, Saturation, Solution, Solutions, Synthesis, Temperature, Value

? Long, C., Lu, J.D., Li, A.M. and Zhang, Q.X. (2009), Removal of endocrine disrupting chemicals from aqueous phase using spherical microporous carbon prepared from waste polymeric exchanger. Water Science and Technology, 60 (6), 1607-1614.

Full Text: 2009\Wat Sci Tec60, 1607.pdf

Abstract: A spherical microporous carbon adsorbent (CR-1), which was developed by carbonization and activation of the waste polysulfonated cation-exchanger, was used to remove Dimethyl phthalate (DMP) and 2,4-dichlorophenol (2,4-DCP) as the model compounds of EDCs from the aqueous solution. Four adsorption isotherm models, Langmuir, Freundlich, Toth and Polanyi-Dubinin-Manes equations were tested to correlate the experimental data, Toth and Polanyi-Dubinin-Manes isotherms models provided the best correlation. The Henry’s law constants calculated from Toth equation were found to be 705.957 and 6,724.713 L g^-1 for 2, 4-DCP and DMP at 298 K, respectively, and the larger exponents n of the Freundlich model were 9.011 and 9.93 for 2, 4-DCP and DMP at 298 K, respectively. The values of Henry’s law constants and exponent n of the Freundlich suggested that CR-1 was an effective adsorbent for removal of low concentrations of DMP and 2,4-DCP from aqueous solution. Moreover, the adsorption kinetics results showed that adsorption of 2,4-DCP and DMP on CR-1 was a pseudo-second-order process controlled by intra-particle diffusion and that adsorption uptake reached quickly half of equilibrium capacities within 20 min.

Keywords: 2,4-Dichlorophenol, 2,4-Dichlorophenol, Acid, Activated Carbon, Activation, Adsorbent, Adsorption, Adsorption, Adsorption Isotherm, Adsorption Isotherm Models, Adsorption Kinetics, Agricultural Waste, Aqueous Phase, Aqueous Solution, Carbon, Carbonization, Cation Exchanger, Chemicals, Correlation, Data, Diffusion, Dimethyl Phthalate, Equilibrium, Experimental, Freundlich, Freundlich Model, Intra Particle Diffusion, Intra-Particle Diffusion, Intraparticle Diffusion, Isotherm, Isotherm Models, Isotherms, Kinetics, Langmuir, Law, Model, Models, Phenols, Phthalate, Polymeric, Pseudo Second Order, Pseudo-Second-Order, Removal, Resin, Solution, Sorbents, Uptake, Waste, Waste Ion Exchange Resin, Water

? Chakrabarti, S., Dutta, B.K. and Apak, R. (2009), Active manganese oxide: a novel adsorbent for treatment of wastewater containing azo dye. Water Science and Technology, 60 (12), 3017-3024.

Full Text: 2009\Wat Sci Tec60, 3017.pdf

Abstract: A new variety of active manganese oxide was prepared, characterized, and tested for its potential of adsorbing Congo Red, a dis-azo dye, from aqueous solutions. Both equilibrium and kinetics were investigated over different values of process parameters such as temperature (25-45ºC), adsorbent loading (0.4-0.6%), initial dye concentration (50-500 mg/L), presence of salts (sodium sulphate, 500 mg/L) and the oxygen content (MnOx, x 1.2, 1.33 and 2) of the adsorbent. The equilibrium adsorption data were fitted to Langmuir and Freundlich isotherms. Langmuir adsorption capacity of the sorbent (x - 1.33) for Congo Red was 38.6 mg/g at room temperature which is substantially higher than those for commercial manganese dioxide, red mud, coir pith, activated carbon, and fly ash. The kinetic data were best interpreted using a pseudo-second order model. The results show that the active manganese oxide used in this work removes the dye by reversible adsorption and has the potential for practical use for remediation of textile industry effluents.

Keywords: Activated Carbon, Adsorbent, Adsorption, Adsorption, Adsorption Capacity, Aqueous Solutions, Aqueous-Solutions, Azo Dye, Basic-Dyes, Capacity, Carbon, Coir Pith, Concentration, Congo Red, Congo Red, Data, Dioxide, Dye, Dye Removal, Effluent Treatment, Effluents, Equilibrium, Fly Ash, Fly-Ash, Freundlich, Isotherms, Kinetic, Kinetics, Langmuir, Langmuir and Freundlich Isotherms, Loading, Manganese, Manganese Dioxide, Manganese Oxide, Model, Oxidation, Oxide, Oxygen, Pith, Potential, Pseudo Second Order, Pseudo-Second Order, Pseudo-Second Order Model, Pseudo-Second-Order, Red Mud, Remediation, Removal, Room Temperature, Salts, Sodium, Solutions, Sorbent, Temperature, Treatment, Wastewater, Work

? Tawabini, B., Al-Khaldi, S., Atieh, M. and Khaled, M. (2010), Removal of mercury from water by multi-walled carbon nanotubes. Water Science and Technology, 61 (3), 591-598.

Full Text: 2010\Wat Sci Tec61, 591.pdf

Abstract: The removal of mercury (Hg²⁺) ions from contaminated water using multiwalled carbon nanotubes (MWCNTs) was investigated in this study. Results of the study showed that MWCNTs slurry was very efficient in removing as high as 1.0 mg/L of Hg²⁺ from aqueous solutions via the adsorption mechanism. This removal efficiency was found to be a function of the aqueous pH level, dosage of CNTs, mixing rate, and contact time. The study showed that the Hg uptake by MWCNTs increased to 100% with an increase in pH from pH 4 to 8. The results also showed that higher dosage of MWCNTs, showed higher removal of Hg²⁺. In a 50mL water sample, 10 mg of MWCNTs was needed to remove all of the 0.1 mg/L of Hg²⁺ ions. On the other hand, increasing the mixing rate from 50 to 150 rpm improved the removal efficiency. The experimental results also showed that mercury adsorption by MWCNTs follow a pseudo second-order reaction with a rate (k) of 0.018 and it is well described by the Langmuir isotherm model with maximum adsorptive capacity (q_max) of 13.16.

Keywords: Adsorption, Adsorption Mechanism, Aqueous Solutions, Aqueous-Solution, Capacity, Carbon, Carbon Nanotubes, Carbon Nanotubes (CNTs), Copper, Diameter, Efficiency, Experimental, Function, Heavy Metals, Ions, Isotherm, Isotherm Model, Langmuir, Langmuir Isotherm, Langmuir Isotherm Model, Lead, Mechanism, Mercury, Mercury Adsorption, Metal-Ions, Mixing, Model, Multiwalled Carbon Nanotubes, Mwcnts, Nanotubes, pH, Pseudo Second Order, Pseudo Second-Order, Pseudo-Second-Order, Reaction, Removal, Removal Efficiency, Second Order, Second-Order, Solutions, Time, Uptake, Waste-Water, Water, Water Treatment

? Elwakeel, K.Z. and Yousif, A.M. (2010), Adsorption of malathion on thermally treated egg shell material. Water Science and Technology, 61 (4), 1035-1041.

Full Text: 2010\Wat Sci Tec61, 1035.pdf

Abstract: Thermally treated egg shell materials were prepared at different temperatures. The samples were investigated by means of FT-IR and thermogravimetric analysis (TGA) The adsorption. behaviour of malathion on egg shell and its thermally treated samples was studied using batch method and gave uptake capacities up to 0.964 mmol/g. Adsorption kinetics as well as the adsorption isotherms were discussed. Regeneration of the loaded adsorbent beads towards the successive cycles was also clarified The adsorption of malathion is maintained untill the third. cycle without a significant activity loss.

Keywords: Adsorbent, Adsorption, Adsorption Isotherms, Adsorption Kinetics, Analysis, Batch, Batch Method, FT-IR, FTIR, Isotherms, Kinetics, Regeneration, TGA, Uptake

? Goh, K.H., Lim, T.T. and Dong, Z.L. (2010), Removal of arsenate from aqueous solution by nanocrystalline Mg/Al layered double hydroxide: Sorption characteristics, prospects, and challenges. Water Science and Technology, 61 (6), 1411-1417.

Full Text: 2010\Wat Sci Tec61, 1411.pdf

Abstract: Removal of arsenate (As(V)) from aqueous solution using both nanocrystalline and coprecipitated Mg/Al layered double hydroxides (LDHs) was examined under different sorption/desorption conditions. The surface area, pore volume, and pore size of the nanocrystalline LDH were significantly higher than those of the coprecipitated LDH, thus resulting in a higher As(V) sorption maximum than the coprecipitated LDH. The calculated activation energy (Ea) value was 24.7 kJ/mol, suggesting the occurrence of anion exchange process for As(V) removal by the nanocrystalline LDH. The predominance of anion exchange process was further supported by the investigation of ionic strength effect, and XRD and FTIR analyses. The effect of aqueous matrix on As(V) sorption by the nanocrystalline LDH was found to increase in the order of nitrate < silica, sulfate, carbonate, phosphate. Regeneration study showed that a secondary sorption mechanism might occur concurrently for the As(V) sorption by nanocrystalline LDH besides the predominant anion exchange process. Prospects and challenges for practical application of the nanocrystalline LDH were also discussed in the latter part of this study.

Keywords: Activation, Activation Energy, Adsorption, Analyses, Application, Aqueous Solution, Arsenate, As(V), As(V) Removal, Carbonate, Characteristics, Double Hydroxide, Energy, Ftir, Hydrotalcite, Investigation, Ionic Strength, Kinetics, Layered Double Hydroxide, Layered Double Hydroxides, LDH, Matrix, Mechanism, Nanocrystalline, Nitrate, Phosphate, Pore Volume, Regeneration, Removal, Silica, Size, Solution, Sorption, Sorption Mechanism, Sorption, Desorption, Strength, Sulfate, Surface, Surface Area, Value, Volume, Water, XRD

? Sun, G.Z., Chen, X.G., Zhang, J., Feng, C. and Cheng, X.J. (2010), Adsorption characteristics of residual oil on amphiphilic chitosan derivative. Water Science and Technology, 61 (9), 2363-2374.

Full Text: 2010\Wat Sci Tec61, 2363.pdf

Abstract: In this study, a novel chitosan-based polymeric surfactant, H-Oleoyl-Carboxymethyl chitosan was used as a coagulation agent for cleaning residual oil. The characteristics of H-Oleoyl-Carboxymethyl chitosan were investigated by FTIR and XRD. And the adsorption capacities of chitosan and H-O-CMCS for removing the residue oil from the wastewater of oil extraction have been investigated. H-O-CMCS exhibited a greater rate than chitosan in cleaning the residual oil from the wastewater of oil extraction at the optimum conditions. Equilibrium study, Langmuir/Freundlich adsorption models and the pseudo first- and second-order kinetic models were applied to describe the mechanism of adsorption experiments. The experimental data fitted well with the Langmuir model and the second-order kinetic model. Regeneration studies, using by the roasting and rinsing method, were undergone for three successive adsorption/desorption processes. H-O-CMCS still retained the residual oil removal capacity after regeneration.

Keywords: Adsorption, Adsorption Capacities, Adsorption, Desorption, Air Flotation, Biosorption, Capacity, Characteristics, Chitin, Chitosan, Coagulation, Data, Equilibrium, Experimental, Experiments, Extraction, First, FTIR, H-O-CMCS, Heavy-Metals, Kinetic, Kinetic Model, Kinetic Models, Langmuir, Langmuir Model, Mechanism, Mechanism of Adsorption, Mill Effluent, Model, Models, Oil Removal, Phenol, Polymeric, Regeneration, Removal, Residual Oil, Second Order, Second-Order, Sorbents, Surfactant, Wastewater, XRD

? Dos Santos, V.C.G., Tarley, C.R.T., Caetano, J. and Dragunski, D.C. (2010), Assessment of chemically modified sugarcane bagasse for lead adsorption from aqueous medium. Water Science and Technology, 62 (2), 457-465.

Full Text: 2010\Wat Sci Tec62, 457.pdf

Abstract: This study evaluated the adsorption capacity of chemically modified sugarcane bagasse with citric acid (B-CA), sodium hydroxide (B-S) and citric acid and sodium hydroxide (B-CAS) for Pb²⁺ ion adsorption in aqueous medium. Infrared spectroscopy (FT-IR) was used to characterise the materials, where the chemical modification was confirmed by the presence of carboxylate groups created at 1,730cm^-1 peak. All assays related to Pb²⁺ ion adsorption onto adsorbent, i.e. equilibrium time between Pb²⁺ ions and adsorbate (24 h), as well as Pb²⁺ ion concentration, were performed in batch system. The initial and final Pb²⁺ ion concentration after shaking time was determined by Flame Atomic Absorption Spectrometry (FAAS). Isotherm adsorptions were applied to Langmuir and Freundlich linear models and maximum adsorption capacity (MAC) of materials towards Pb²⁺ ions was calculated in function of modifications. A significant improvement regarding Pb²⁺ ion adsorption after the bagasse treatment with citric acid, in which MAC was 52.63 mg g^-1, was observed. The adsorptions followed the behaviour described by the Langmuir linear model and its kinetics follow the behaviour described by the pseudo-second-order equation.

Keywords: Adsorbent, Adsorption, Adsorption Capacity, Aqueous Medium, Bagasse, Batch, Batch System, Behaviour, Biosorption, Capacity, Cd(II), Chemical, Chemical Modification, Citric Acid, Concentration, Cu(II), EDTA Dianhydride EDTAD, Equilibrium, FAAS, Freundlich, FT-IR, FTIR, Function, Heavy-Metals, Improvement, Ions, Isotherm, Kinetics, Langmuir, Lead, Mac, Mercerized Cellulose, Model, Models, Modification, Modified, Pb²⁺, Pseudo Second Order, Pseudo-Second-Order, Pseudo-Second-Order Equation, Removal, Single Metal Solutions, Sodium, Spectroscopy, Sugarcane, Sugarcane Bagasse, Treatment, Waste

? Weng, C.H., Lin, Y.T., Yeh, C.L. and Sharma, Y.C. (2010), Magnetic Fe₃O₄ nanoparticles for adsorptive removal of acid dye (new coccine) from aqueous solutions. Water Science and Technology, 62 (4), 844-851.

Full Text: 2010\Wat Sci Tec62, 844.pdf

Abstract: The ability of magnetic Fe₃O₄ nanoparticles (MFN) to remove new coccine (NC), an acidic dye, from aqueous solutions was studied Parameters including ionic strength, pH, and temperature were evaluated MFN, prepared by precipitation method, exhibits an average particle size of 12 5 nm, specific surface area of 85 5 m(2)/g, and pH(zpc) of 5 9 Results of kinetic adsorption experiments indicated that the pseudo-second-order rate of adsorption increased with increasing initial NC concentration Findings also revealed that the equilibrium data could be fitted into Langmuir adsorption isotherm The adsorption is favored at low pH, high temperature, and low ionic strength, whereupon a maximum adsorption capacity of 1 11×10^-4 mol/g was determined for NC Thermodynamic functions indicated that the adsorption process is spontaneous and exothermic in nature Tests of regeneration showed that after 5 regeneration cycles the adsorption capacity of NC decreased to 35% to its original capacity.

Keywords: Acid Dye, Acidic Dye, Adsorption, Adsorption Capacity, Adsorption Isotherm, Aqueous Solutions, Capacity, Concentration, Data, Dye, Equilibrium, Exothermic, Experiments, Fe₃O₄, Functions, Ionic Strength, Iron, Isotherm, Kinetic, Kinetic Adsorption, Langmuir, Langmuir Adsorption Isotherm, Magnetic, Magnetite, Nanoparticles, New Coccine, Particle Size, pH, pH(zpc), Precipitation, Pseudo Second Order, Pseudo-Second-Order, Pseudo-Second-Order Rate, Regeneration, Removal, Size, Solutions, Specific Surface, Specific Surface Area, Strength, Surface, Surface Area, Temperature, Thermodynamic, Waste

? Zhao, Y.F., Zhang, B., Zhang, X.A., Wang, J.H., Liu, J.D. and Chen, R.F. (2010), Ammonium removal from aqueous solution by zeolite X synthesized from halloysite mineral. Water Science and Technology, 62 (4), 937-946.

Full Text: 2010\Wat Sci Tec62, 937.pdf

Abstract: Zeolite X was successfully synthesized from natural halloysite mineral by hydrothermal method The synthesized zeolite X was characterized by XRD, SEM, TEM and HRTEM The characterization indicated that zeolite X had high crystallinity together with symmetrical and uniform pore channels Ammonium (NH₄⁺) adsorption properties of zeolite X were studied using batch experiments. The results revealed that high initial concentration and low temperature favored NH₄⁺ adsorption on zeolite X Both Langmuir and Freundlich isotherms fit well with the equilibrium data Kinetic studies showed that the adsorption followed pseudo-second-order model Intra-particle diffusion analysis demonstrated that Nit; diffused quickly among the particles at the initial 20 min of the adsorption process, and then the diffusion slowed down and stabilized Thermodynamic parameters such as change in free energy (ΔG(0)), enthalpy (ΔH-0) and entropy (ΔS-0) indicated that the adsorption was spontaneous and exothermic at ambient conditions The reusable ability of zeolite X was also evaluated Due to its low cost, high adsorption capacity and fast adsorption rate, zeolite X synthesized from halloysite could be used as an effective and environmental-friendly adsorbent for NH⁴⁺ removal.

Keywords: Adsorbent, Adsorption, Adsorption, Adsorption Capacity, Adsorption Properties, Adsorption Rate, Ammonium, Ammonium Removal, Analysis, Aqueous Solution, Batch, Batch Experiments, Capacity, Characterization, Clinoptilolite, Concentration, Cost, Crystallinity, Data, Diffusion, Energy, Enthalpy, Entropy, Equilibrium, Exothermic, Experiments, Freundlich, Halloysite Mineral, Hrtem, Hydrothermal Method, Intra Particle Diffusion, Intra-Particle Diffusion, Intraparticle Diffusion, Ion-Exchange, Isotherms, Kinetic, Kinetic Studies, Langmuir, Langmuir And Freundlich Isotherms, Low Cost, Low Temperature, Model, Natural, Particles, Pseudo Second Order, Pseudo-Second-Order, Pseudo-Second-Order Model, Removal, SEM, Solution, Tem, Temperature, Thermodynamic, Thermodynamic Parameters, Waste-Water, XRD, Zeolite, Zeolite X

? Ibrahim, S., Fatimah, I., Ang, H.M. and Wang, S.B. (2010), Adsorption of anionic dyes in aqueous solution using chemically modified barley straw. Water Science and Technology, 62 (5), 1177-1182.

Full Text: 2010\Wat Sci Tec62, 1177.pdf

Abstract: An agricultural waste derived adsorbent was prepared by chemically modified barley straw with NaOH and a cationic surfactant hexadecylpyridinium chloride monohydrate (CPC). The prepared adsorbent, BMBS, was used for removal of anionic dyes; Acid Blue (AB40) and Reactive Blue 4 (RB4) from aqueous solution in a batch adsorption system. The adsorbent was characterized by FT-IR and elemental composition. The stability of CPC adsorbed on straw surface was also evaluated by exposing to aqueous solution. In adsorption tests, influence of operation parameters such as contact time, initial concentration and pH of solution on AB40 and RB4 uptake were investigated and discussed. The CPC was observed strongly attached to straw surface and removal percentage of AB40 and RB4 was increased with increasing in contact time. The adsorption of dyes on modified straw surface was favorable at high acidic condition and desorption was found relatively low upon exposing to the desorption agent (i.e water). Dynamic experiment revealed that the kinetic data fitted well to the pseudo-second-order model for both of the dyes. The isotherm study also indicated that RB4 and AB40 adsorption suited well with the Langmuir model, The maximum adsorption capacity determined from the Langmuir isotherm at 25ºC was 51.95 mgg^-1 and 31.5 for AB40 and RB4, respectively.

Keywords: Ab40, Acid, Activated Carbon, Adsorbent, Adsorption, Adsorption Capacity, Agricultural, Agricultural Waste, Anionic Dyes, Aqueous Solution, Barley Straw, Batch, Batch Adsorption, Capacity, Cationic Surfactant, Chloride, Coconut Coir Pith, Composition, Concentration, Data, Desorption, Dyes, Equilibrium, Experiment, Fly-Ash, FT-IR, FTIR, Isotherm, Kinetic, Kinetics, Langmuir, Langmuir Isotherm, Langmuir Model, Model, Modified, Modified Barley Straw, NaOH, Operation, Parameters, pH, Pseudo Second Order, Pseudo-Second-Order, Pseudo-Second-Order Model, Reactive Blue 4, Removal, Solution, Sorption, Stability, Straw, Surface, Surfactant, Uptake, Waste, Waste-Water, Water

? Pratt, C. and Shilton, A. (2010), Active slag filters-simple and sustainable phosphorus removal from wastewater using steel industry byproduct. Water Science and Technology, 62 (8), 1713-1718.

Full Text: 2010\Wat Sci Tec62, 1713.pdf

Abstract: Active filtration, where effluent is passed through a reactive substrate such as steel slag, offers a simple and cost-effective option for removing phosphorus (P) from effluent This work summarises a series of studies that focused on the world's only full-scale active slag filter operated through to exhaustion The filter achieved 75% P-removal during its first 5 years, reaching a retention capacity of 1 23g P/kg slag but then its performance sharply declined Scanning electron microscopy, X-ray diffraction, X-ray fluorescence, and chemical extractions revealed that P sequestration was primarily achieved via adsorption onto iron (Fe) oxyhydroxides on the slag's surface It was concluded that batch equilibrium tests; whose use has been repeatedly proposed in the literature, cannot be used as an accurate predictor of filter adsorption capacity because Fe oxyhydroxides form via chemical weathering in the field, and laboratory tests don't account for this Research into how chemical conditions affect slag's P retention capacity demonstrated that near-neutral pH and high redox are optimal for Fe oxyhydroxide stability and overall filter performance However, as Fe oxyhydroxide sites fill up, removal capacity becomes exhausted. Attempts to regenerate P removal efficiency using physical techniques proved ineffective contrary to dogma in the literature Based on the newly-developed understanding of the mechanisms of P removal, chemical regeneration techniques were investigated and were shown to strip large quantities of P from filter adsorption sites leading to a regenerated P removal efficiency. This raises the prospect of developing a breakthrough technology that can repeatedly remove and recover P from effluent.

Keywords: Active Filters, Adsorption, Equilibrium, Industry, Iron, Literature, Microscopy, pH, Phosphorus, Phosphorus Removal, Regeneration, Research, Retention, Slag, Steel Slag, Systems, Wastewater

? Chen, N., Zhang, Z.Y., Feng, C.P., Li, M.A., Chen, R.Z. and Sugiura, N. (2010), Removal of fluoride from aqueous solution by adsorption onto Kanuma mud. Water Science and Technology, 62 (8), 1888-1897.

Full Text: 2010\Wat Sci Tec62, 1888.pdf

Abstract: Kanuma mud, a geomaterial, is used as an adsorbent for the removal of fluoride from water The influences of contact time, solution pH, adsorbent dosage, initial fluoride concentration and co-existing ions were investigated by batch equilibration studies The rate of adsorption was rapid with equilibrium being attained after about 2h, and the maximum removal of fluoride was obtained at pH 5 0-8 0 The Freundlich isotherm model was found to represent the measured adsorption data well The negative value of the thermodynamic parameter Delta G suggests the adsorption of fluoride by Kanuma mud was spontaneous, the endothermic nature of adsorption was confirmed by the positive Delta H value The negative Delta S value for adsorbent denoted decreased randomness at the solid/liquid interface The adsorption process using Kanuma mud followed the pseudo-second-order kinetic model Fluoride uptake by the Kanuma mud was a complex process and intra-particle diffusion played a major role in the adsorption process It was found that adsorbed fluoride could be easily desorbed by washing the adsorbent with a solution of pH 12 This indicates the material could be easily recycled.

Keywords: Adsorbent, Adsorption, Adsorption Isotherms, Adsorption Kinetics, Alumina, Batch, Cement, Complex, Contact Time, Data, Diffusion, Earth, Equilibrium, Fluoride, Fluoride Removal, Freundlich, Freundlich Isotherm, Intra Particle Diffusion, Intra-Particle Diffusion, Intraparticle Diffusion, Isotherm, Kanuma Mud, Kinetic, Kinetic Model, Kinetics, Model, pH, Process, Pseudo Second Order, Pseudo-Second-Order, Red Mud, Removal, Sorption, Thermodynamic, Uptake, Waste-Water, Water

? Chai, L.Y., Wang, Q.W., Li, Q.Z., Yang, Z.H. and Wang, Y.Y. (2010), Enhanced removal of Hg(II) from acidic aqueous solution using thiol-functionalized biomass. Water Science and Technology, 62 (9), 2157-2166.

Full Text: 2010\Wat Sci Tec62, 2157.pdf

Abstract: Spent grain, the low-cost and abundant biomass produced in the brewing industry, was functionalized with thiol groups to be used as an adsorbent for Hg(II) removal from acidic aqueous solution. The adsorbents were characterized by the energy-dispersive X-ray analysis (EDAX) and Fourier transform infrared (FTIR) spectroscopy. Optimum pH for Hg(II) adsorption onto the thiol-functionalized spent grain (TFSG) was 2.0. The equilibrium and kinetics of the adsorption of Hg(II) onto TFSG from acidic aqueous solution were investigated. From the Langmuir isotherm model the maximum adsorption capacity of TFSG for Hg(II) was found to be 221.73 mg g(-1), which was higher than that of most various adsorbents reported in literature. Moreover, the adsorption of Hg(II) onto TFSG followed pseudo-second-order kinetic model.

Keywords: Activated Carbon, Adsorbent, Adsorbents, Adsorption, Adsorption, Adsorption Capacity, Analysis, Biomass, Biosorption, Capacity, Cd(II), Equilibrium, Equilibrium, Fourier Transform Infrared, FTIR, Heavy-Metals, Hg(II), Infrared, Ion, Isotherm, Kinetic, Kinetic Model, Kinetics, Langmuir, Langmuir Isotherm, Literature, Mercury(II), Model, pH, Pseudo Second Order, Pseudo-Second-Order, Removal, Sludge, Thiol-Functionalized Spent Grain, Waste, X-Ray

? Malarvizhi, R., Venkateswarlu, Y., Babu, V.R. and Begum, S.S. (2010), Studies on removal of chromium(VI) from water using chitosan coated Cyperus pangorei. Water Science and Technology, 62 (10), 2435-2441.

Full Text: 2010\Wat Sci Tec62, 2435.pdf

Abstract: Environmental contamination by toxic heavy metals is a significant universal problem. The main objective of the study is to use a biodegradable materials like Cyperus pangorei and Chitosan as a composite biosorbent for the removal of Cr(VI) from water. The newly prepared biosorbent is characterized and the capacity of Cr(VI) removal of the biosorbent is carried out systematically by batch mode operations. The adsorption capacity of the biosorbent is examined by changing the parameters like biosorbent dose, varying the initial contact time, varying initial concentration of metal ion and pH of the metal ion solution to know the actual mechanism taking place during the initial sorption process. The experimental data obtained were fitted with the Freundlich, Langmuir and Redlich-Peterson isotherm models and the pseudo first order and the pseudo second order kinetic models. Equilibrium data were fitted very well to the Langmuir Isotherm model and pseudo second order kinetic model. Desorption of the metal ion is also carried out using different concentration of NaOH.

Keywords: Adsorption, Adsorption Capacity, Aqueous-Solutions, Batch, Batch Mode, Biosorbent, Biosorption, Capacity, Chitosan, Chromium, Composite, Contact Time, Cr(VI), Cr(VI) Removal, Crab Shells, Cyperus Pangorei, Data, Desorption, Equilibrium, Freundlich, Heavy Metals, Ions, Isotherm, Isotherm Models, Kinetic, Kinetic Model, Kinetic Models, Kinetics, Langmuir, Langmuir Model, Mechanism, Metals, Model, Models, pH, Process, Pseudo Second Order, Pseudo-Second-Order, Redlich-Peterson, Removal, Second-Order, Sorption, Sorption Isotherm, Toxic, VI, Waste-Water, Wastewaters, Water

? Norouzi, Sh., Badii, Kh. and Ardejani, F.D. (2010), Activated bauxite waste as an adsorbent for removal of Acid Blue 92 from aqueous solutions. Water Science and Technology, 62 (11), 2491-2500.

Full Text: 2010\Wat Sci Tec62, 2491.pdf

Abstract: Bauxite waste, known as red mud, is produced in some industrial processes, such as aluminum production process. In this process, the waste material is produced from leached bauxite as a by product. In this research, the removal of Acid Blue 92 (AB92) dye was investigated from aqueous solution onto the activated bauxite waste (red mud) in a batch equilibration system. Besides, the influences of pH, adsorbent dosage, contact time, initial concentration of dye and temperature have been considered. It was found that the OH group is an effective functional group for the adsorption process. The intensity of the peaks correspond to OH group has been significantly climbed after the activation process. The adsorption kinetics of AB92 can be well described by the pseudo-second-order reaction model. Based on the isotherm data obtained from the fittings of the adsorption kinetics, the Langmuir model appears to fit the adsorption process better than the Freundlich and Brunauer-Emmett-Teller (BET) models.

Keywords: Acid Blue 92 (Ab92), Activation, Adsorbent, Adsorption, Adsorption, Adsorption Kinetics, Aqueous Solutions, Arsenate, Batch, Bet, Concentration of Dye, Congo Red, Contact Time, Data, Dye, Dyes, Equilibrium, Fly-Ash, Freundlich, Industrial, Isotherm, Kinetics, Kinetics Model, Langmuir, Langmuir Model, Model, Models, Neutralized Red Mud, Oil, pH, Process, Processes, Production, Pseudo Second Order, Pseudo-Second-Order, Red Mud, Removal, Research, Sorption, System, Temperature, Waste Red Mud, Water

? Deng, L.Y., Xu, G.R., Yan, Z.C., Liu, Q.H. and Li, G.B. (2010), Removal effect of Cr(VI) by adsorbent made from sewage sludge. Water Science and Technology, 62 (12), 2961-2969.

Full Text: 2010\Wat Sci Tec62, 2961.pdf

Abstract: Adsorbent made from sewage sludge is used to remove the Cr (VI) in wastewater. In this paper, the adsorption capacity, adsorption mechanism and regeneration of the adsorbent are studied. A systematic research is carried out to investigate the influence of adsorption capacities in various conditions, such as contact time, pH and initial dosage of adsorbent. The results show that: the equilibrium time is 6 h; the optimal pH is 2.5. The adsorption capacity increases as the initial concentration increase and as the dosage of activated carbon decrease. The data of adsorption capacity are more fit in Langmuir isotherms. The adsorption follows a pseudo-second-order kinetic model perfectly. From this research, the adsorption rate controlling step is film diffusion when the Cr (VI) concentration is low; otherwise, the adsorption rate controlling step is the diffusion among particles. The results of regeneration of saturated adsorbent show that the saturated adsorbent can be perfectly regenerated using alkali treatment. The regeneration ratio of the saturated adsorbent can reach more than 90% with proper concentration of alkali.

Keywords: Activated Carbon, Adsorbent, Adsorption, Adsorption, Adsorption Capacities, Adsorption Capacity, Adsorption Mechanism, Adsorption Rate, Aqueous-Solution, Capacity, Carbon, Chromium(VI), Concentration, Cr(VI), Data, Diffusion, Equilibrium, Film Diffusion, Isotherms, Kinetic, Kinetic Model, Langmuir, Langmuir Isotherms, Mechanism, Model, Particles, pH, Pseudo Second Order, Pseudo-Second-Order, Pseudo-Second-Order Kinetic Model, Regeneration, Removal, Research, Sewage, Sewage Sludge, Sludge, Treatment, Wastewater

? Martins, R.J.E. and Boaventura, R.A.R. (2011), Modelling of lead removal by an aquatic moss. Water Science and Technology, 63 (1), 136-142.

Full Text: 2011/Wat Sci Tec63, 136.pdf

Abstract: Aquatic bryophytes are frequently used as biomonitors for trace metals in aquatic ecosystems. Nevertheless, their special characteristics also allow using them as biosorbents to clean industrial wastewaters. As biosorption is a low cost and effective method for treating metal-bearing wastewaters, understanding the process kinetics is relevant for design purposes. In this study, the ability of the aquatic bryophyte Fontinalis antipyretica to remove lead from simulated wastewaters was evaluated. Three kinetic models (pseudo-first order, pseudo-second order and Elovich) were fitted to the experimental data and compared by the F-test. Previously, the effect on biosorption of parameters such as the initial solution pH, contact time and initial metal ion concentration was investigated. The initial pH of the solution was found to have an optimum value is in the range 4.0-6.0. The equilibrium sorption capacity of lead by Fontinalis antipyretica increased with the initial metal concentration. For an initial metal concentration of 10 mgL(-1), the uptake capacity at equilibrium was 4.8 mgg(-1). Nevertheless, when the initial concentration increased up to 100 mgL(-1), the uptake of lead was 10 times higher. The pseudo-second order biosorption kinetic model provided the better correlation with the experimental data (R-2=1.00). The applicability of the Langmuir and Freundlich adsorption isotherms to the present system was also assessed. The maximum lead sorption capacity by Fontinalis antipyretica was 68 mgg(-1).

Keywords: Adsorbents, Adsorption, Adsorption Isotherms, Aquatic Ecosystems, Aquatic Moss, Aquatic Mosses, Aqueous-Solutions, Biomonitors, Biosorbents, Biosorption, Biosorption, Biosorption Kinetic, Cadmium, Capacity, Characteristics, Concentration, Correlation, Cost, Data, Design, Ecosystems, Elovich, Equilibrium, Experimental, Fontinalis Antipyretica, Freundlich, Isotherms, Kinetic, Kinetic Model, Kinetic Models, Kinetics, Kinetics, Langmuir, Lead, Lead Removal, Low Cost, Metal, Metal-Ions, Metals, Model, Modelling, Models, Pb(II), pH, Pseudo First Order, Pseudo Second Order, Pseudo-First Order, Pseudo-First-Order, Pseudo-Second Order, Pseudo-Second-Order, Removal, Solution, Sorption, Sorption Capacity, Trace Metals, Understanding, Uptake, Value, Wastewaters

? Aber, S., Salari, D. and Feiz, B.A. (2011), The sorption of copper on almond shell: Optimization and kinetics. Water Science and Technology, 63 (7), 1389-1395.

Full Text: 2011\Wat Sci Tec63, 1389.pdf

Abstract: Batch sorption studies using almond shell as an sorbent for the removal of Cu (II) from aqueous solutions, showed that copper removal decreased from 74.9% to 45.6% with increasing its concentration from 10 to 70 ppm. The removal increased with increasing sorbent dose and pH, respectively. Copper removal was obtained equal to 63.7%, 69.6% and 58.6% at 26ºC, 40ºC and 55ºC. The sorption of Cu (II) on almond shell was also optimized by Taguchi method. The optimized conditions were the sorbent mass of 4 g, the ion initial concentration of 10 ppm, pH 7, the temperature of 40ºC and contact time equal to 60 min. The pH and initial Cu (II) concentration with respectively 32.75% and 31.20% contribution had more influence on the removal of Cu (II). The kinetic data fit pseudo-second-order model with correlation coefficients greater than 0.99 and rate constants in the range of 0.26-7.87 g mg^-1 min^-1.

Keywords: Adsorbent, Adsorption, Almond Shell, Aqueous-Solution, Batch, Copper, Cu(II), Equilibrium, Ions, Kinetic, Kinetics, Optimization, pH, Removal, Sorption, Taguchi, Waste-Water

? Senevirathna, S.T.M.L., Tanaka, S., FujII, S., Kunacheva, C., Harada, H., Shivakoti, B.R., Dinh, H. and Ariyadasa, T. (2011), Adsorption of four perfluorinated acids on non ion exchange polymer sorbents. Water Science and Technology, 63 (10), 2106-2113.

Full Text: 2011\Wat Sci Tec63, 2106.pdf

Abstract: Perfluorinated compounds (PFCs) have attracted global concern due to their ubiquitous distribution and properties of persistence, bio accumulation and toxicity. The process of adsorption has been identified as an effective technique to remove PFCs in water. Different non ion-exchange polymeric adsorbents were tested with regard to their sorption kinetics and isotherms at low PFCs concentrations. Selected PFCs were perfluorobutanoic acid (PFBA), perfluoroheptanoic acid (PFHpA), perfluorooctanoic acid (PFOA) and perfluorodecanoic acid (PFDA) and the tested polymers were three types of Dowex optopores (V-493, V503, and L493), Amberlite XAD-4, and Filtrasorb 400 (Granular Activated Carbon-GAC). We observed the selective adsorption of PFCs on synthetic polymers. For PFDA, Amberlite XAD-4 gave the Freundlich adsorption constant of 2,965 (mu g PFCs, g sorbent)(mu g PFCs, L)(-n), which was higher than that of GAC (121.89 (mu g PFCs, g sorbent) (mu g PFCs, L)(-n)). In the case of PFBA, GAC showed better performance (13.36) (mu g PFCs, g sorbent) mu g PFCs, L)(-n) than synthetic polymers (0.62-5.23) (mu g PFCs, g sorbent) (mu g PFCs, L)(-n). Adsorption kinetics of all adsorbents were well described (R² = 0.85-1) by pseudo-second order kinetic model. Sorption capacity was influenced by initial PFCs concentration for all adsorbents. GAC reached the equilibrium concentration within 4 hours, Amberlite XAD 4 reached it within 10 hours and other polymers took more than 70 hours.

Keywords: Adsorption, Adsorption Kinetics, Decomposition, Isotherms, Kinetics, Model, Non Ion-Exchange Polymers, Perfluorooctane Sulfonate, PFCS, Pseudo-Second Order, Pseudo-Second-Order, Sorption, Sorption Isotherm, Sorption Kinetics, Water

? Zhou, Q., Gong, W.Q., Li, Y.B., Chen, S.H., Yang, D.J., Bai, C.P., Liu, X.F. and Xu, N. (2011), Biosorption of Methylene Blue onto spent corncob substrate: Kinetics, equilibrium and thermodynamic studies. Water Science and Technology, 63 (12), 2775-2780.

Full Text: 2011\Wat Sci Tec63, 2775.pdf

Abstract: This study focuses on the possible use of the spent corncob substrate (SCS), an agricultural waste used after the cultivation of white rot fungus Pleurotus ostreatus, to adsorb Methylene Blue (MB) from aqueous solutions. A batch adsorption study was carried out with variable solution pH, adsorption time, temperature and initial MB concentration. It was found that MB uptake was favorable at pH ranging from 4.0 to 12.0 and the equilibrium adsorption capacity can be reached promptly within about 180 min. The biosorption data were also calculated by the pseudo-second-order kinetic model and Langmuir isotherm model. Thermodynamic parameters show that the adsorption is a spontaneous and endothermic process. The study highlighted a new pathway to develop potential low-cost biosorbent for the removal of dye pollutants from wastewater.

Keywords: Adsorption, Aqueous-Solution, Basic Dye, Biomass, Biosorption, Cationic Dye, Equilibrium, Isotherm, Isotherms Thermodynamics, Kinetics, Langmuir Isotherm, Low-Cost Adsorbent, Methylene Blue, Model, pH, Pseudo-Second-Order, Red, Removal, Sorption, Spent Corncob Substrate, Thermodynamic, Thermodynamic Parameters, Waste, Wastewater

? Chen, Y., Jiang, W.J., Jiang, L. and Ji, X.J. (2011), Adsorption behavior of activated carbon derived from pyrolusite-modified sewage sludge: Equilibrium modeling, kinetic and thermodynamic studies. Water Science and Technology, 64 (3), 661-669.

Full Text: 2011\Wat Sci Tec64, 661.pdf

Abstract: Activated carbon was developed from sewage sludge using pyrolusite as an additive. It was demonstrated that the removal efficiency of two synthetic dyes (Tracid orange GS and Direct fast turquoise blue GL) by the produced adsorbent was up to 97.6%. The activated carbon with pyrolusite addition had 38.2% higher surface area, 43.8% larger micropore and 54.4% larger mesopore production than ordinary sludge-based activated carbons. Equilibrium adsorption isotherms and kinetics were also investigated based on dyes adsorption tests. The experimental data were analyzed by the Langmuir and Freundlich models of adsorption, and the results fitted well to the Langmuir isotherm. The kinetic data have been analyzed using pseudo-first-order, pseudo-second-order and intraparticle diffusion equation. The experimental data fitted very well with pseudo-second-order kinetic model. Activation energies for the adsorption processes ranged between 8.7 and 19.1 kJ mol^-1. Thermodynamic parameters such as standard free energy (ΔG(0)), standard enthalpy (ΔH(0)) and standard entropy (ΔS(0)) were evaluated. The adsorption of these two dyes on the activated carbon was found to be a spontaneous and endothermic process in nature.

Keywords: Activated Carbon, Adsorbent, Adsorption, Adsorption Isotherms, Aqueous-Solutions, Basic Dye, Degradation, Diffusion, Diffusion Equation, Dyes, Equilibrium, Freundlich, Industrial-Waste, Isotherm, Isotherms, Kinetic, Kinetic Model, Kinetics, Langmuir, Langmuir And Freundlich Models, Langmuir Isotherm, Low-Cost Adsorbent, Modeling, Pyrolusite, Removal, Sewage Sludge, Thermodynamic, Thermodynamic Parameters, Thermodynamics, Waste-Water

? Módenes, A.N., Espiñoza-Quinones, F.R., Borba, C.E., Trigueros, D.E.G., Lavarda, F.L., Abugderah, M.M. and Kroumov, A.D. (2011), Adsorption of Zn(II) and Cd(II) ions in batch system by using the Eichhornia crassipes. Water Science and Technology, 64 (9), 1857-1863.

Full Text: 2011\Wat Sci Tec64, 1854.pdf

Abstract: In this work, the displacement effects on the sorption capacities of zinc and cadmium ions of the Eichornia crassipes-type biosorbent in batch binary system has been studied. Preliminary single metal sorption experiments were carried out. An improvement on the Zn(II) and Cd(II) ions removal was achieved by working at 30 degrees C temperature and with non-uniform biosorbent grain sizes. A 60 min equilibrium time was achieved for both Zn(II) and Cd(II) ions. Furthermore, it was found that the overall kinetic data were best described by the pseudo second-order kinetic model. Classical multi-component adsorption isotherms have been tested as well as a modified extended Langmuir isotherm model, showing good agreement with the equilibrium binary data. Around 0.65 mequiv./g maximum metal uptake associated with the E. crassipes biosorbent was attained and the E. crassipes biosorbent has shown higher adsorption affinity for the zinc ions than for the cadmium ones in the binary system.

Keywords: Activated Carbon, Adsorption, Aqueous-Solution, Biomass, Biosorbent, Biosorption, Cadmium(II), Cd(II), Egeria-Densa, Heavy-Metal Biosorption, Isotherm, Isotherm Models, Isotherms, Kinetic, Kinetics, Langmuir, Macrophytes, Metals, Sorption