Journal of environmental chemical engineering volume issue 2014 doi 10 1016 j jece 2014 06 015 pandey, ruchi prasad, ram lakhan ansari, nasreen ghazi murthy utilization of NaOH modified desmostachya bi

Accepted Manuscript Title: Utilization of NaOH modified Desmostachya bipinnata (Kush Grass) Leaves & Bambusa arundinacea (Bamboo) Leaves for Cd(II) removal from aqueous solution Author: Ruchi Pandey Ram Lakhan Prasad Nasreen Ghazi Ansari Ramesh Chandra Murthy PII: DOI: Reference: S2213-3437(14)00131-6 http://dx.doi.org/doi:10.1016/j.jece.2014.06.015 JECE 376 To appear in: Please cite this article as: Ruchi Pandey, Ram Lakhan Prasad, Nasreen Ghazi Ansari, Ramesh Chandra Murthy, Utilization of NaOH modified Desmostachya bipinnata (Kush Grass) Leaves & Bambusa arundinacea (Bamboo) Leaves for Cd(II) removal from aqueous solution, Journal of Environmental Chemical Engineering http://dx.doi.org/10.1016/j.jece.2014.06.015 This is a PDF file of an unedited manuscript that has been accepted for publication As a service to our customers we are providing this early version of the manuscript The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain Utilization of NaOH modified Desmostachya bipinnata (Kush Grass) Leaves & Bambusa arundinacea ip t (Bamboo) Leaves for Cd(II) removal from aqueous cr solution Ruchi Pandeya, b, Ram Lakhan Prasadb, Nasreen Ghazi Ansaria and a us Ramesh Chandra Murthy*, a CSIR, Indian Institute of Toxicology Research, Analytical Chemistry Section, Department of Chemistry, Faculty of Science, Banaras Hindu University, M b an Post Box-80, M.G Marg, Lucknow-226001, India Corresponding Author Abstract te * d Varanasi, 221005, India Ac ce p A fundamental investigation for the Cd(II) ions removal from aqueous solutions by NaOH modified Desmostachya bipinnata (Kush Grass) Leaves (MDBL) and Bambusa arundinacea (Bamboo) Leaves (MBAL) was conducted in batch experiments The influence of different experimental parameters such as pH, contact time, initial Cd(II) ion concentration, adsorbent dosage, on the Cd(II) adsorption was studied The Cd(II) uptake by MDBL and MBAL was quantitatively evaluated using sorption isotherms Freundlich and Langmuir isotherm models were used to fit the equilibria data, of which Langmuir model is considered better in correlation and the maximum adsorption capacity was found to be 15.22 mg g−1 for MDBL and 19.70 mgg1 for MBAL at room temperature The kinetic data were found to follow closely the pseudo second order kinetic model by both adsorbents FTIR and SEM were recorded, before and after adsorption, to explore number and position of the functional groups available for Cd(II) binding on to studied adsorbents and changes in surface morphology of adsorbent Desorption studies show 94.18% and 92.08% recovery for adsorbed Cd(II) ions from MDBL and MBAL, respectively using 0.1 N HNO3 Thermodynamic studies indicated that the adsorption reaction was a spontaneous and exothermic process It can be concluded that MDBL and MBAL are Page of 32 low-cost biosorbent alternatives for wastewater treatment, since both have a considerable high adsorption capacity Highlights Highlights • A Novel and efficient biosorbent is developed from NaOH modification of ip t • Desmostachya bipinnata (Kush Grass) Leaves (MDBL) & Bambusa arundinacea • cr (Bamboo) Leaves (MBAL) for removal of Cd(II) ions from aqueous solution • Apparent high adsorption capacity of 19.84 and 19.71 mg g−1 was shown by • 94.18 percent and 92.08% desorption of adsorbed Cd(II) ions from MDBL and an MBAL, respectively was observed using 0.1 N HNO3 Keywords d M Graphical Abstract Isotherm, Kinetics te Desmostachya bipinnata leaves, Kush grass, Bambusa arundinacea leaves, Bamboo leaves, Ac ce p • us MDBL and MBAL at pH = 6.5, respectively with a fast adsorption rate Introduction An increased flux of heavy metals in the aquatic environment due to their swift use [1] in industries, has led severe threat to human being Beyond permitted concentration, they can cause grave health disorders; therefore, considerable attention has been paid to wastewater treatment prior to its discharge in the environment Among these metallic pollutants, Cd(II), an extremely toxic heavy metal causes a potential risk to environmental and human health because it is incorporated into the food chain, mainly by plant uptake [2] The main anthropogenic pathway through which Cd(II) enters the water bodies is via wastes from industrial processes such as electroplating, plastic manufacturing, metallurgical processes, and Cd/Ni batteries Over exposures may befall even in conditions where a little amount of Cd(II) found because of its low permissible limit (0.005 mg L−1) in drinking water [3] So many surface chemistry practices for Page of 32 wastewater treatment such as precipitation, adsorption, membrane processes, ionic exchange, floatation, and others [4,5] have been studied However, because of inherent limitation of such techniques as less competent, perceptive operating settings, and production of sludge, they further require costly disposal [6], whereas, adsorption is by ip t far the most versatile and widely used method, and activated carbon is the furthermost commonly used adsorbent [7] Conversely, the use of activated carbon is expensive, so considerable interest has been shown towards the use of other efficient sorbent cr materials, particularly biosorbents [8] In recent years, agricultural by-products have been widely considered for metal sorption studies including peat, banana pith, pine bark, us peanut, shells, hazelnut shell, rice husk, wood, sawdust, wool, soybean and cottonseed hulls, orange peel, leaves and compost [9-13] In a previous study we have carried out an Cd(II) removal using Cucumber peel and obtained a maximum adsorption capacity of 7.142 mg g−1[14] In the adsorption process, various metal-binding mechanisms are thought to be involved, including ion exchange, surface adsorption, chemisorption, M complexation, and adsorption–complexation [15-18] In the present study, Cd(II) sorption using Desmostachya bipinnata (Kush Grass) d Leaves (DBL) and Bambusa arundinacea (Bamboo) Leaves (BAL), members of true te grass family: Poaceae, had been studied and as both adsorbents correspond to same family, their major constituents must be same These materials are the major organic Ac ce p components of the solid waste, comprising about 14.6% of total municipal solid waste (MSW) and about 50% of the organic fraction of the MSW [19] However, in the entire world, India has the huge rate of biomass production, including organic wastes, such as grass, leaves and flowers Therefore, it is essential to search for a better use of these abundant agricultural wastes such as, remediation of heavy metal from contaminated aqueous solutions Both materials found abundantly throughout the year, and these kinds of materials exhibit strong potential due to their high content of lignin and cellulose [20] that abide numerous polar functional groups, including phenolic and carboxylic acid groups, which may be involved in metal binding [21,22] Due to the low cost, DBL and BAL are an attractive and inexpensive option for the adsorption of Cd(II) ion from aqueous solution Further NaOH was used in the modification process because it can enhance surface characteristics of DBL and BAL with increased adsorption capacity [23] The adsorption capacity of modified DBL and BAL (MDBL & MBAL, respectively) was investigated by batch experiments The influences of parameters such as pH, Page of 32 adsorbent dosage, contact time, initial ion concentration were investigated and the experimental data obtained were evaluated and fitted using adsorption equilibrium and kinetic models ip t Materials and methods 2.1 Adsorbent & chemicals cr DBL and BAL were obtained from the Indian Institute of Toxicology Research, Gheru Campus (Lucknow, India) Both were dried under the sunlight for days then, ground, us washed several times with double distilled water (DDW) and afterwards screened to obtain 80 µm sized particles These samples were modified using 0.5 M NaOH solution with 1:20 for 30 (solid–liquid ratio) [24] The MDBL and MBAL were again dried at MDBL & MBAL are presented in Table an 100 °C for 24 h and stored in an airtight container The physical characteristics of the M Table Physical characteristic of MDBL & MBAL Parameter MBAL ≤ 80 0.144 0.196 0.127 0.166 Porosity (%) 0.113 0.15 Moisture content (%) 10.93 8.30 Ash content (%) 2.57 1.42 Phzpc 5.50 Particle density Ac ce p Bulk density (g ml−1) d ≤ 80 te Particle size (µm) MDBL The stock solution of Cd(II) (1000 mg L−1) was prepared in DDW using Cd (NO3)2.4H2O salt (Merck); all working solutions were prepared by diluting the stock solution with DDW 2.2 Biosorption experiments Batch experiments were executed for adsorption studies A Pre-weighted sample of the adsorbents (MDBL & MBAL) with a measured volume of Cd(II) solution were taken in 100 mL Erlenmeyer flask and stirred in an incubator shaker (250 rpm) at a steady Page of 32 temperature (25 ± °C), for 240 to ensure equilibrium After shaking the flasks for regular intervals, samples were withdrawn, filtered and the filtrates were analyzed by Atomic absorption Spectrophotometer (PerkinElmer AAnalyst 300, USA) for the concentration of Cd(II) A first series of sorption experiments was carried out with an ip t initial concentration of 20 mg L−1 In these experiments the most favorable pH of biosorption was determined Subsequently, the influence of adsorbent dosage, contact time, initial ion concentration was also evaluated Percentage metal removal was us cr calculated using the following formula: (1) where C0 is initial and Ct is the final concentration of Cd(II) The morphological characteristics of adsorbents were evaluated by using a scanning electron microscope an (SEM) and disposition of the functional group present on the adsorbent surface were spectrophotometer 2.3 Adsorption isotherms studies M studied before and after biosorption using Fourier Transform Infrared (FTIR) d Isotherm studies were recorded by varying the initial concentration of Cd(II) solutions te from 10–150 mg L−1 with MDBL and MBAL separately A known amount of adsorbents was then added into solutions in different flasks followed by agitating them at 250 rpm till Ac ce p equilibrium The metal ion concentrations, retained in the adsorbent phase qe (mgg−1) which is defined as adsorption capacity, was calculated by using the following mass balance equation for the process at equilibrium condition: (2) where V is the volume of solution (L) and W is the mass of adsorbate (g) 2.4 Desorption study Desorption experiments were performed to consider the practical usefulness of the biosorbents After the biosorption studies, 0.2 g of metal loaded sorbent were agitated in 100 mL of 0.1 M HCl and 0.1 M HNO3 same as described by Witek-Krowiak [25] After 60 of contact time the metal concentration in the solution was determined To check the applicability as the best eluent the sorption desorption steps were repeated five times Page of 32 Results and discussion 3.1 Characteristic of MDBL & MBAL before and after adsorption Presence of functional groups on MDBL & MBAL powder were analyzed using FTIR, as ip t shown in Fig 1(A) and (B) Occurrences of diverse type of functional groups are confirmed by the peaks, and their detailed illustration is shown in Table Mainly, metal ions were bonded by functional groups such as carboxylic groups (pectin, hemicellulose cr and lignin), phenolic groups (lignin and extractives) and a little amount may also adsorbed by hydroxyl (cellulose, lignin, extractives, and pectin) and carbonyl groups us (lignin) [26] After sorption, several functional groups which were initially present disappear, while some other had their position altered and thus confirming the active an participation of bonded OH groups, secondary amine group, carboxyl groups, C−O stretching of ether groups and −C−C− group [3,27] as shown in Fig 1(A) and (B) and Table Hence, the good sorption properties of both MDBL and MBAL towards Cd(II) M ions can be ascribed to the presence of these functional groups on their surfaces Fig 2(A) and (B) shows SEM images for MDBL and MBAL before and after the adsorption process, respectively From Fig 2(A & B), it is clearly visible that before d adsorption, both the adsorbents have rough heterogeneous porous surface and a large te number of steps and kinks on the adsorbent surface, with wrecked edges [28] The change in the morphology of the adsorbent after adsorption indicates that there is a Ac ce p good possibility for Cd(II) ions to be trapped and adsorbed onto the surface Fig 1FTIR spectra of MDBL (A) and MBAL (B) before and after Cd(II) adsorption Table Functional groups and mode of vibration from the FTIR spectrum of MDBL and MBAL before and after adsorption Functional group Stretching vibration of bonded −OH Cd (II) Cd (II) loaded loaded MDBL MDBL MBAL MDBL (cm ) (cm ) (cm ) (cm−1) 3418.35 3415.14 3402.93 3431.08 −1 −1 −1 Page of 32 group on surface Asymmetrical stretching vibration of 2922.73 2920.52 2922.59 2923.30 1631.46 1639.24 1634.58 1644.39 − 1516.20 − Strong stretching vibration of C−O from carboxylic acid in presence of Generation of this peak after adsorption cr intermolecular H bonding bending vibration of N−H and stretching vibration of C−N Bending vibration oh OH and stretching vibration of C−O−C in lignin structure Bending vibration of OH and stretching − 1376.61 1514.93 1059.02 1103.39 1246.16 1252.85 − − 1049.61 1073.96 − − 664.60 563.42 602.96 466.37 469.10 M C−O stretching of carboxylic acid 1377.07 an 1380.35 us is outcome of an overlapped band of C−C stretching of aromatic ring ip t −CH3 d vibration of C−O−C in lignin structure te Fingerprint region: adsorption cannot be clearly assigned to any particular Ac ce p vibration because they correspond to 605.21 complex interacting vibration systems Fig 2Scanning electron micrograph showing morphology of MDBL (A) and MBAL (B) before and after Cd(II) adsorption 3.2 Effect of pH The pH plays a very significant role in the sorption of heavy metals by affecting the surface charge of adsorbent, the degree of ionization, and speciation of adsorbate Thus, the effects of initial pH of the solution on the Cd(II) removal efficiency were studied at different pH ranging from 3.5 to 8.5 A sharp increase in the Cd(II) removal was observed from 64.4% to 77.6% and 60.88%–75.2% at pH 6.5 (Fig 3) for MDBL and MBAL, respectively and after that with a slight decrease, the value became constant Page of 32 because of saturation of active sites on the adsorbents surface So the pH 6.5 was selected as the best pH to study the overall adsorption process Precipitation of Cd(II) ions was observed at pH [29] At low pH, the little removal efficiency is due to occurrence of higher concentration of protons in the solution which compete with the ip t Cd(II) ions for the adsorption sites of the adsorbents As the pH increases, the H+ concentration decreases, leading to enhanced Cd(II) uptake The effect of pH can be explained in terms of pHzpc of the adsorbent The pH at, which the charge of the whole cr surface is zero is referred as the zero point of charge (pHzpc) and above which the surface become negatively charged The obtained pHzpc of MDBL and MBAL is and 5.5 us respectively by using the batch equilibration technique [30] Positively charged Cd(II) species are soft acids and as a rule the interaction of Cd2+ and Cd (OH)+ with the an negatively charged adsorbent surface containing carboxyl and hydroxyl groups are responsible for the sorption of Cd(II) ions and also supported by FTIR studies At low pH, particularly below pHzpc the Cd2+ and Cd (OH) + species present in the solution may M exchange with H+ from peripheral Apparently, at very low pH (≤ 3), the presence of higher concentrations of H+ ions in the mixture, owes electrostatic repulsion between both positively charged adsorbent surface and metal ion A decreasing trend in d adsorption was also observed at very high pH also, and this may be due to the formation te of soluble hydroxy complexes [31] Dissociation of the –COOH groups (pKa = 8-5.0) is the plausible reason for becoming the surface of MDBL and MBAL negatively charged at Ac ce p optimum pH 6.5 and thus, favorable to the adsorption of Cd(II) at this pH [32] Cd(II) may most likely be bound on the MDBL and MBAL surface via an ion exchange mechanism as following equation: (3) Fig 3Effect of pH on Cd(II) adsorption by MDBL and MBAL at 25 °C (condition: 20 mg L−1 of Cd(II) solution, 250 rpm, g L−1 adsorbent dosage, 60 min) (where -R represents the matrix of the adsorbents) 3.3 Effect of biosorbent dosage Page of 32 One of another important parameter that strongly affects the sorption capacity is the biosorbent dosage As shown in Fig with the increasing adsorbent dosage from to 12 g L−1, it can easily be inferred that the percent removal of metal ions boosts from 63.95% to 85.50% and 65.50%–82.05% for MDBL and MBAL, respectively, whereas the ip t amount adsorbed per unit mass decreases It is apparent that the percent removal of heavy metals increases rapidly with an increase in the dosage of the adsorbents due to the greater availability of the exchangeable sites or surface area [3], whereas the cr decrease in Cd(II) uptake with increasing adsorbent dosage is mainly due to unsaturation of adsorption sites through the adsorption reaction and the similar results an us were obtained in a study performed by Chen et al [33] Fig 4Effect of adsorbent dosage for Cd(II) adsorption by MDBL and MBAL at M 25 °C (condition: 20 mg L−1 of Cd(II) solution, 250 rpm, 60 min) 3.4 Effect of initial ion concentration d The Cd(II) ion uptake is particularly reliant on the initial Cd(II) concentration At the lower range, Cd(II) is adsorbed by specific active sites, while at higher sides; decreased te adsorption is due to the saturation of adsorption sites and also because of lack of sufficient surface area to accumulate further available ions This is due to the Ac ce p competition for the available active sites on the surface The influence of the initial Cd(II) concentration on its removal with MDBL and MBAL shown in Fig 5, where a decrease in removal percent from 74.2–66.60% and 77.90-62.61% (for Co = 10 − 150 mg L−1) could be observed respectively Fig 5Effect of initial Cd(II) ion concentration for adsorption process by MDBL and MBAL at 25 °C (condition: g L−1 adsorbent dosage, 250 rpm, 60 min) 3.5 Effect of contact time The effect of contact time on adsorption was studied up to 240 It appeared from Fig that the metal uptake is very rapid up to 90 and 180 of equilibrium for MBAL and MDBL respectively, after that Cd(II) uptake does not significantly change with time Page of 32 ion concentrations evidently affected the removal efficiency The Langmuir adsorption isotherm fits well to the equilibrium adsorption data and suggest that the monolayer and homogeneous adsorption process take place The adsorption process follows a pseudosecond-order kinetics rate model The overall mechanism involves adsorption and intra- ip t particle diffusion Regeneration of used MDBL and MBAL can be performed efficiently using 0.1 N HNO3 as an eluting agent The adsorption process was spontaneous and exothermic under natural conditions These results demonstrate the remarkable potential cr of MDBL and MBAL as the low-cost substitutes with a considerable high adsorption us capacity of 15.22 mg g−1 and 19.70 mg g−1, respectively at room temperature Acknowledgments an The authors would like to acknowledge and extend their heartfelt gratitude to the Director, CSIR-Indian Institute of Toxicology Research, Lucknow, and to, the HOD, M Department of Chemistry, Faculty of Science, BHU, Varanasi for taking interest in the study The authors thank the Council of Science and Technology, Uttar Pradesh, India te References d (Project Code, GAP-271) for providing their financial support for this research work Volesky B., Holan Z.R Biosorption of heavy metals Biotechnology Progress 1995;11:235- Ac ce p 250.7619394 DOI:10.1021/bp00033a001 Ayuso E.A Cadmium in soil-plant systems: An overview International Journal of Environment and Pollution 2008;33:275-291 DOI:10.1504/IJEP.2008.019399 Rao M.M., Ramesh A., Rao G.P., Seshaiah K Removal of copper and cadmium from the aqueous solutions by activated carbon derived from Ceiba pentandra hulls Journal of Hazardous Materials 2006;129:123-129.16191464 DOI:10.1016/j.jhazmat.2005.08.018 Kocaoba S., Akcin G Removal of chromium (III) and cadmium (II) from aqueous solutions Desalination 2005;180:151-156 DOI:10.1016/j.desal.2004.12.034 Govindasamy, V., Rengasamy, T., Mahendra Das, D.K., Removal of Cd2+ ions from aqueous solution using live and dead Bacillus subtilis (2011) Page 18 of 32 Ahluwalia S.S., Goyal D Microbial and plant derived biomass for removal of heavy metals from wastewater Bioresource Technology 2007;98:2243-2257.16427277 DOI:10.1016/j.biortech.2005.12.006 Starvin A.M., Rao T.P Removal and recovery of mercury(II) from hazardous wastes using 1- ip t (2-thiazolylazo)-2-naphthol functionalized activated carbon as solid phase extractant Journal of Hazardous Materials 2004;113:75-79.15363516 DOI:10.1016/j.jhazmat.2004.04.021 Ng J.C., Cheung W.H., McKay G Equilibrium studies for the sorption of lead from effluents cr using chitosan Chemosphere 2003;52:1021-1030.12781235 DOI:10.1016/S0045- us 6535(03)00223-6 Nagy B., Măicăneanu A., Indolean C., Burcă S., Silaghi-Dumitrescu L., Majdik C Cadmium (II) ions removal from aqueous solutions using Romanian untreated fir tree sawdust a green an biosorbent Acta Chimica Slovenica 2013;60:263-273.23878929 10 Saeed A., Iqbal M., Höll W.H Kinetics, equilibrium and mechanism of CD2+ removal from aqueous solution by mungbean husk Journal of Hazardous Materials 2009;168:1467- M 1475.19386413 DOI:10.1016/j.jhazmat.2009.03.062 11 Shaheen S.M., Eissa F.I., Ghanem K.M., Gamal El-Din H.M., Al Anany F.S.Al Heavy metals d removal from aqueous solutions and wastewaters by using various byproducts Journal of Environmental Management 2013;128:514-521.23831673 te DOI:10.1016/j.jenvman.2013.05.061 Ac ce p 12 Feng N.-c., Guo X.-y., Liang S Kinetic and thermodynamic studies on biosorption of Cu(II) by chemically modified orange peel Transactions of Nonferrous Metals Society of China 2009;19:1365-1370 DOI:10.1016/S1003-6326(08)60451-3 13 Vassileva P., Detcheva A., Uzunov I., Uzunova S Removal of metal ions from aqueous solutions using pyrolyzed rice husks: Adsorption kinetics and equilibria Chemical Engineering Communications 2013;200:1578-1599 DOI:10.1080/00986445.2012.755519 14 Pandey R., Ansari N.G., Murthy R.C., Prasad R.L Cd(II) adsorption from aqueous solution onto Cucumis sativus Peel: Equilibrium, thermodynamic and Kinetic Study Journal of Ecophysiology & Occupational Health 2013;13:75-84 15 Alyüz B., Veli S Kinetics and equilibrium studies for the removal of nickel and zinc from aqueous solutions by ion exchange resins Journal of Hazardous Materials 2009;167:482488.19201087 DOI:10.1016/j.jhazmat.2009.01.006 Page 19 of 32 16 Kumar A., Rao N.N., Kaul S.N Alkali-treated straw and insoluble straw xanthate as low cost adsorbents for heavy metal removal - Preparation, characterization and application Bioresource Technology 2000;71:133-142 DOI:10.1016/S0960-8524(99)00064-4 17 Gu X., Evans L.J Surface complexation modelling of Cd(II), Cu(II), Ni(II), Pb(II) and Zn(II) ip t adsorption onto kaolinite Geochimica et Cosmochimica Acta 2008;72:267-276 DOI:10.1016/j.gca.2007.09.032 18 Schneider I.A.H., Rubio J., Smith R.W Biosorption of metals onto plant biomass: Exchange us 2001;62:111-120 DOI:10.1016/S0301-7516(00)00047-8 cr adsorption or surface precipitation? International Journal of Mineral Processing 19 Hameed B.H Grass waste: A novel sorbent for the removal of basic dye from aqueous solution Journal of Hazardous Materials 2009;166:233-238.19111987 an DOI:10.1016/j.jhazmat.2008.11.019 20 Mann D.G.J., Labbé N., Sykes R.W., Gracom K., Kline L., Swamidoss I.M., Burris J.N., Davis M., Stewart C.N Rapid assessment of lignin content and structure in switchgrass (Panicum M virgatum L.) grown under different environmental conditions BioEnergy Research 2009;2:246-256 DOI:10.1007/s12155-009-9054-x d 21 Matheickal J.T., Yu Q., Woodburn G.M Biosorption of cadmium(II) from aqueous solutions by pre-treated biomass of marine alga DurvillAea potatorum Water Research 1999;33:335-342 te DOI:10.1016/S0043-1354(98)00237-1 Ac ce p 22 Ting Y.P., Prince I.G., Lawson F Uptake of cadmium and zinc by the alga chlorella vulgaris: II Multi-ion situation Biotechnology and Bioengineering 1991;37:445-455.18597390 DOI:10.1002/bit.260370506 23 Ghali L., Msahli S., Zidi M., Sakli F Effect of pre-treatment of luffa fibres on the structural properties Materials Letters 2009;63:61-63 DOI:10.1016/j.matlet.2008.09.008 24 Carvalho M.L., Sousa Jr R Jr., Rodríguez-Zúđiga U.F., Suarez C.A.G., Rodrigues D.S., Giordano R.C., Giordano R.L.C Kinetic study of the enzymatic hydrolysis of sugarcane bagasse Brazilian Journal of Chemical Engineering 2013;30:437-447 DOI:10.1590/S010466322013000300002 25 Witek-Krowiak A Application of beech sawdust for removal of heavy metals from water: Biosorption and desorption studies European Journal of Wood and Wood Products 2013;71:227-236 DOI:10.1007/s00107-013-0673-8 Page 20 of 32 26 Prasanna Kumar Y.P , King P., Prasad V.S.R.K Adsorption of zinc from aqueous solution using marine green algae-Ulva fasciata sp Chemical Engineering Journal 2007;129:161166 DOI:10.1016/j.cej.2006.10.023 27 Sheng P.X., Ting Y.-P., Chen J.P., Hong L Sorption of lead, copper, cadmium, zinc, and ip t nickel by marine algal biomass: Characterization of biosorptive capacity and investigation of mechanisms Journal of Colloid and Interface Science 2004;275:131-141.15158390 DOI:10.1016/j.jcis.2004.01.036 cr 28 Bhattacharyya K.G., Sharma A Adsorption of Pb(II) from aqueous solution by Azadirachta indica (Neem) leaf powder Journal of Hazardous Materials 2004;113:97-109.15363519 us DOI:10.1016/j.jhazmat.2004.05.034 29 Leyvaramos R., Bernaljacome L.A., Acostarodriguez I Adsorption of cadmium(II) from an aqueous solution on natural and oxidized corncob Separation and Purification Technology 2005;45:41-49 DOI:10.1016/j.seppur.2005.02.005 30 Stankovic J.B., Milonjic S.K., Zec S.P The influence of chemical and thermal treatment on the M point of zero charge of hydrous zirconium oxide Journal of the Serbian Chemical Society 2013;78:987-995 DOI:10.2298/JSC121010149S d 31 Raji C., Manju G.N., Anirudhan T.S Removal of heavy metal ions from water using sawdust260 te based activated carbon Indian Journal of Engineering and Materials Sciences 1997;4:254- Ac ce p 32 Huang X., Gao N.Y., Zhang Q.L Thermodynamics and kinetics of cadmium adsorption onto oxidized granular activated carbon Journal of Environmental Sciences (China) 2007;19:1287-1292.18232220 DOI:10.1016/S1001-0742(07)60210-1 33 Chen G., Zeng G., Tang L., Du C., Jiang X., Huang G., Liu H., Shen G Cadmium removal from simulated wastewater to biomass byproduct of Lentinus edodes Bioresource Technology 2008;99:7034-7040.18313919 DOI:10.1016/j.biortech.2008.01.020 34 Feng N.-c., Guo X.-y Characterization of adsorptive capacity and mechanisms on adsorption of copper, lead and zinc by modified orange peel Transactions of Nonferrous Metals Society of China 2012;22:1224-1231 DOI:10.1016/S1003-6326(11)61309-5 35 Tofighy M.A., Mohammadi T Adsorption of divalent heavy metal ions from water using carbon nanotube sheets Journal of Hazardous Materials 2011;185:140-147.20926186 DOI:10.1016/j.jhazmat.2010.09.008 Page 21 of 32 36 Foo K.Y., Hameed B.H Insights into the modeling of adsorption isotherm systems Chemical Engineering Journal 2010;156:2-10 DOI:10.1016/j.cej.2009.09.013 37 Ho Y.S., McKay G The kinetics of sorption of divalent metal ions onto sphagnum moss peat Water Research 2000;34:735-742 DOI:10.1016/S0043-1354(99)00232-8 ip t 38 Boparai H.K., Joseph M., O’Carroll D.M Kinetics and thermodynamics of cadmium ion removal by adsorption onto nano zerovalent iron particles Journal of Hazardous Materials cr 2011;186:458-465.21130566 DOI:10.1016/j.jhazmat.2010.11.029 39 Ozer A., Ozer D Comparative study of the biosorption of Pb(II), Ni(II) and Cr(VI) ions onto S us cerevisiae: Determination of biosorption heats Journal of Hazardous Materials 2003;100:219-229.12835024 DOI:10.1016/S0304-3894(03)00109-2 40 Saltali K., Sari A., Aydin M Removal of ammonium ion from aqueous solution by natural an Turkish (Yildizeli) zeolite for environmental quality Journal of Hazardous Materials 2007;141:258-263.16930832 DOI:10.1016/j.jhazmat.2006.06.124 M 41 Horsfall M Jr., Spiff A.I Sorption of lead, cadmium, and zinc on sulfur-containing chemically modified wastes of fluted pumpkin (Telfairia occidentalis Hook f.) Chemistry & Biodiversity 2005;2:373-385 DOI:10.1002/cbdv.200590017 d 42 Zaki A.B., El-Sheikh M.Y., Evans J., El-Safty S.A Kinetics and mechanism of the sorption of te some aromatic amines onto Amberlite IRA-904 anion-exchange resin Journal of Colloid and Interface Science 2000;221:58-63.10623452 DOI:10.1006/jcis.1999.6553 Ac ce p 43 Bekỗi Z., Seki Y., Yurdakoỗ M.K Equilibrium studies for trimethoprim adsorption on montmorillonite KSF Journal of Hazardous Materials 2006;133:233-242.16310307 DOI:10.1016/j.jhazmat.2005.10.029 44 Singh B.K., Rawat N.S Comparative sorption equilibrium studies of toxic phenols on fly ash and impregnated fly ash Journal of Chemical Technology AND Biotechnology 1994;61:307317 DOI:10.1002/jctb.280610405 45 Malkoc E., Nuhoglu Y Determination of kinetic and equilibrium parameters of the batch adsorption of Cr(VI) onto waste acorn of Quercus ithaburensis Chemical Engineering and Processing: Process Intensification 2007;46:1020-1029 DOI:10.1016/j.cep.2007.05.007 46 Cardoso N.F., Lima E.C., Royer B., Bach M.V., Dotto G.L., Pinto L.A.A., Calvete T Comparison of Spirulina platensis microalgae and commercial activated carbon as adsorbents for the removal of reactive Red 120 dye from aqueous effluents Journal of Page 22 of 32 Hazardous Materials 2012;241–242:146-153.23040660 DOI:10.1016/j.jhazmat.2012.09.026 47 El-Khaiary M.I., Malash G.F., Ho Y.-S On the use of linearized pseudo-second-order kinetic equations for modeling adsorption systems Desalination 2010;257:93-101 ip t DOI:10.1016/j.desal.2010.02.041 48 Yuh-Shan H Citation review of Lagergren kinetic rate equation on adsorption reactions cr Scientometrics 2004;59:171-177 DOI:10.1023/B:SCIE.0000013305.99473.cf 49 Ho Y.S., McKay G The sorption of lead(II) ions on peat Water Research 1999;33:578-584 us DOI:10.1016/S0043-1354(98)00207-3 50 Chatterjee S., Woo S.H The removal of nitrate from aqueous solutions by chitosan hydrogel beads Journal of Hazardous Materials 2009;164:1012-1018.18977085 an DOI:10.1016/j.jhazmat.2008.09.001 51 Wu F.C., Tseng R.L., Juang R.S Comparisons of porous and adsorption properties of M carbons activated by steam and KOH Journal of Colloid and Interface Science 2005;283:4956.15694423 DOI:10.1016/j.jcis.2004.08.037 52 Cheung W.H., Szeto Y.S., McKay G Intraparticle diffusion processes during acid dye d adsorption onto chitosan Bioresource Technology 2007;98:2897-2904.17110098 te DOI:10.1016/j.biortech.2006.09.045 53 Gerỗel ệ., Gerỗel H.F Adsorption of lead(II) ions from aqueous solutions by activated carbon Ac ce p prepared from biomass plant material of Euphorbia rigida Chemical Engineering Journal 2007;132:289-297 DOI:10.1016/j.cej.2007.01.010 54 Memon S.Q., Memon N., Shah S.W., Khuhawar M.Y., Bhanger M.I Sawdust a green and economical sorbent for the removal of cadmium (II) ions Journal of Hazardous Materials 2007;139:116-121.16844287 DOI:10.1016/j.jhazmat.2006.06.013 55 Min S.H., Han J.S., Shin E.W., Park J.K Improvement of cadmium ion removal by base treatment of juniper fiber Water Research 2004;38:1289-1295.14975662 DOI:10.1016/j.watres.2003.11.016 56 Kumar U., Bandyopadhyay M Sorption of cadmium from aqueous solution using pretreated rice husk Bioresource Technology 2006;97:104-109.15936939 DOI:10.1016/j.biortech.2005.02.027 57 Sousa F.W., Oliveira A.G., Ribeiro J.P., De Keukeleire D., Sousa A.F., Nascimento R.F Single and multielementary isotherms of toxic metals in aqueous solution using treated Page 23 of 32 coconut shell powder Desalination and Water Treatment 2011;36:289-296 DOI:10.5004/dwt.2011.2597 58 Low K.S., Lee C.K., Liew S.C Sorption of cadmium and lead from aqueous solutions by spent Ac ce p te d M an us cr ip t grain Process Biochemistry 2000;36:59-64 DOI:10.1016/S0032-9592(00)00177-1 Page 24 of 32 ip t cr us an M Ac ce p te d fig Page 25 of 32 ip t cr us an M Ac ce p te d fig copy Page 26 of 32 ip t cr us an M Ac ce p te d fig copy Page 27 of 32 Page 28 of 32 d te Ac ce p us an M cr ip t Page 29 of 32 d te Ac ce p us an M cr ip t Page 30 of 32 d te Ac ce p us an M cr ip t Page 31 of 32 d te Ac ce p us an M cr ip t Page 32 of 32 d te Ac ce p us an M cr ip t