DSpace at VNU: Removal of arsenic (V) from aqueous medium using manganese oxide coated lignocellulose silica adsorbents...
Toxicological & Environmental Chemistry ISSN: 0277-2248 (Print) 1029-0486 (Online) Journal homepage: http://www.tandfonline.com/loi/gtec20 Removal of arsenic (V) from aqueous medium using manganese oxide-coated lignocellulose/ silica adsorbents Igor W K Ouédraogo, Erol Pehlivan, Hien T Tran, Samuel Paré, Yvonne L Bonzi-Coulibaly, Dieter Zachmann & Müfit Bahadir To cite this article: Igor W K Ouédraogo, Erol Pehlivan, Hien T Tran, Samuel Paré, Yvonne L Bonzi-Coulibaly, Dieter Zachmann & Müfit Bahadir (2015): Removal of arsenic (V) from aqueous medium using manganese oxide-coated lignocellulose/silica adsorbents, Toxicological & Environmental Chemistry, DOI: 10.1080/02772248.2015.1133815 To link to this article: http://dx.doi.org/10.1080/02772248.2015.1133815 Accepted author version posted online: 28 Dec 2015 Submit your article to this journal Article views: 11 View related articles View Crossmark data Full Terms & Conditions of access and use can be found at http://www.tandfonline.com/action/journalInformation?journalCode=gtec20 Download by: [University of California, San Diego] Date: 12 January 2016, At: 23:47 Igor W K Ouédraogo et al., 17/07/2015 Publisher: Taylor & Francis Journal: Toxicological & Environmental Chemistry DOI: http://dx.doi.org/10.1080/02772248.2015.1133815 Removal of arsenic (V) from aqueous medium using manganese oxide-coated lignocellulose/silica adsorbents Igor W K Ouédraogo1*, Erol Pehlivan2, Hien T Tran3, Samuel Paré4, Yvonne L BonziDownloaded by [University of California, San Diego] at 23:47 12 January 2016 Coulibaly4, Dieter Zachmann5 and Müfit Bahadir5 Biomass Energy and Biofuels Laboratory, International Institute for Water and Environmental Engineering (2iE), 01 BP 594, Ouagadougou 01, Burkina Faso Department of Chemical Engineering, Selcuk University, Campus, 42031 Konya, Turkey Hanoi University of Science, Hanoi, Vietnam Laboratoire de Chimie Analytique, Environnementale et Bio-Organique, UFR-SEA, Université de Ouagadougou, 03 BP 7021, Ouagadougou 03, Burkina Faso Institute of Ecological Chemistry and Waste Analysis, Technical University of Braunschweig, Hagenring 30, 38106 Braunschweig, Germany Abstract: Arsenic (V) adsorption on manganese oxide-coated rice wastes was investigated in this study The modified adsorbents were characterized by Fourier-transform infrared spectroscopy, scanning electron microscopy and pH measurements to determine the point of zero charge Batch adsorption equilibrium experiments were conducted to study the effects of pH, contact time and initial concentration on arsenic removal efficiency The adsorption capacity of rice waste was significantly improved after modification with permanganate The Langmuir isotherm model fitted the equilibrium data better than the Freundlich model which confirms surface homogeneity of the adsorbent Maxima adsorption capacities are determined as 10 and 12 mg/g at pH for manganese oxide-coated rice husk and straw respectively The adsorption energy indicates that the adsorption process may be dominated by chemisorption Pseudo‒second‒order rate equation described the kinetics sorption of arsenic with good correlation coefficients, better than a pseudo‒first‒order equation Manganese oxide-coated rice husk and straw appear to be promising low cost adsorbents for removing arsenic from water Keywords: Lignocellulose/silica adsorbent, Manganese oxide, Arsenic, Adsorption, Rice waste * Corresponding author Tel.: +226 25 30 70 64/ fax: +226 25 30 72 42 ; E-mail addresses: ouedigor@yahoo.fr (I W K Ouédraogo) Igor W K Ouédraogo et al., 17/07/2015 I Introduction The presence of arsenic (As) in ground and surface waters at elevated concentrations creates serious problems to human’s health and other organisms (Wu et al 1989) Anthropogenic or biological activities, as geochemical conditions may entail the mobilization of As into groundwater (Malik et al 2009), and natural processes such as soil erosion, mineral leaching and weathering are responsible of introducing As into surface waters Mining activities, combustion of fossil fuels, and the use of As additives to Downloaded by [University of California, San Diego] at 23:47 12 January 2016 livestock feed may entail additional impacts (Mohan, Charles, and Pittman 2007) High concentrations of As in groundwater were reported from Argentina, Austria, Bangladesh, Chile, China, Ghana, India, Italy, Japan, Malaysia, Mexico, Monogolia, Nepal, Poland, South Africa, Taiwan, Vietnam, and some parts of the United States (Malik et al 2009; Mohan, Charles, and Pittman 2007) Smedley, Knudsen, and Maiga (2007) investigated As concentrations in groundwater in the area of the city of Ouahigouya, located in the North of Burkina Faso Most of them had As concentrations ranging between 0.5 and 1630 μg/L Other studies in Essakane (Barro-Traoré et al., 2008) showed As concentrations of 13‒212 μg/L in human urine and 69‒101 μg/L in drinking water; while an As concentration of 10 μg/L is recommended by the World Health Organization as guideline value for drinking water The presence of As in streams and lakes at elevated concentrations may lead to bioaccumulation in living organisms, potentially causing health problems to plants, animals, and humans Chronic human intake of As has been associated with increased risk of skin, liver and lung cancer, diabetes, developmental and reproductive problems, and cardiovascular diseases (Wu et al 1989) Co-precipitation, liquid–liquid extraction, ion-exchange, ultrafiltration and reverse osmosis process have been so far used to remove As from aqueous media (Biswas et al 2008) Most of them are cost-intensive and have disadvantages such as incomplete removal, require high energy, and may generate toxic sludge or waste products which are difficult to dispose (Choonga et al 2007) Adsorption is considered to be one of the most promising technologies because it is low cost and easy to set up (Malik et al 2009) Removal of As from drinking water using low cost sorbents, simple and appropriate methods is highly desirable Rice husk (RH) and straw (RS) are two of the most abundant lignocellulose and silica waste materials in the world, with 155.7 million hectares of land cultivated in 2008 (USDA 2009) These natural materials are considered to be economic precursors for the production of adsorbents that are extensively used for many purposes of separation and purification Igor W K Ouédraogo et al., 17/07/2015 techniques (Sharma et al 2014) However, the adsorption capacities of lignocellulose for As removal are low and slow (Al Rmalli et al 2005; Asif and Chen 2015; Haque et al 2007; Ranjan, Talat, and Hasan 2009; Shafique et al 2012) Therefore, chemical modifications have been often used to synthesize appropriated and efficient adsorbents for As ions removal (Anirudhan et al 2012; Ouédraogo et al 2015) Manganese oxides is a subject of interest in various fields including molecular adsorption due to their outstanding structural multiformity combined with novel chemical and physical properties In addition to their ability to remove a wide range of ions from wastewater Downloaded by [University of California, San Diego] at 23:47 12 January 2016 (Mandal and Suzuki 2002), manganese oxides have various advantages such as low cost, ecofriendliness and abundance as well as their excellent electrochemical properties (Subramanian, Zhu, and Wei 2008) However, the particle nanosizes agglomerate in contact with aqueous system To overcome this difficulty, the nanoparticles were functionalized by organic, inorganic and composite materials which provide chemical stability and better distribution of manganese oxides in aqueous system A recent investigation shows that various manganese oxides sorbents can be prepared through a simple method by KMnO4 reduction (Subramanian, Zhu, and Wei 2008) Some of the reported modifications used natural clinoptilolite zeolite (Camacho, Parra, and Deng 2011), bentonite (Eren, Afsin, and Onal 2009), polystyrene resin (Lenoble et al 2004) and cellulose fiber (Maliyekkal, Lisha, and Pradeep 2010; Wang et al 2014) by forming manganese oxides on the surface, which improves the metal adsorption capacity Though limited reports are available on cellulose as a support for metal oxide nanoparticles, to the best of our knowledge, no studies have been reported on the synthesis of manganese oxide-coated rice waste fiber and its application as an adsorbent for As removal This work is related to the preparation and evaluation of hybrid organic-inorganic manganese oxide-coated RH and RS adsorbents, which mainly consist of hemicelluloses, cellulose, lignins and silica, for removal of As(V) from aqueous solutions Adsorbents were characterized with Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and pH measurements to determine the point of zero charge (pHpzc) As(V) adsorption on the adsorbents was investigated through different parameters effects : pH, contact time and initial concentration Materials and methods 2.1 Chemicals All reagents used in this work were of analytical-grade purity A stock solution (1000 mg/L) of arsenate was purchased from Merck (Darmstadt, Germany) Diluted standard solutions of Igor W K Ouédraogo et al., 17/07/2015 As(V) were prepared daily before use NH4OH and HCl, purchased from Merck, were used to adjust the pH of solutions KI used for reduction of As(V) to As(III) was obtained from Roth (Karlsruhe, Germany) KMnO4 used for RH and RS modification was purchased from Fluka (Taufkirchen, Germany) NaBH4 (Fluka), NaOH (Merck) and HCl (Merck) were used for hydride generation All glassware and plastic bottles were cleaned with 10% HNO3 (Merck) solution and rinsed with deionized water Whatman cellulose acetate membrane (0.2 μm pore size), used for As(V) solution filtration, was purchased from Sigma-Aldrich (Taufkirchen, Germany) Water was purified using a Seralpur purification system Downloaded by [University of California, San Diego] at 23:47 12 January 2016 Pro90CN (Ransbach-Baumbach, Germany) 2.2 Modification of RH and RS RH and RS used in this work were collected from local rice fields in Burkina Faso The dried materials were powdered in a ball mill (BLB Braunschweig, Germany) and sieved with a sieve shaker machine (Retsch, Haan, Germany) The fractions size of 0.063‒0.125 mm were washed several times with pure water to remove dust and fines, and dried in an oven at 60°C for 24 h The adsorbents were prepared by impregnation method: 200 mL of an aqueous solution of KMnO4 (0.1 mol/L) and g of RH or RS were mixed in a 500 mL flask under continuous stirring After h, the suspension was filtered The formation of manganese oxide on the matrix is shown by the change of the adsorbents’ color from golden brown to brownish black The manganese oxide-coated RH (MOCRH) and RS (MOCRS) were thoroughly washed with deionized water Samples were dried in an oven at 50°C for 24 h and stored in a desiccator 2.3 Adsorbent characterization The functional groups present in RS and MOCRS were characterized by FTIR (BX II, Perkin Elmer, Waltham, USA) using the KBr pellet method The spectra were recorded from 4000 to 500 cm‒1 for scans The pHpzc of adsorbents was determined by the following procedure A definite amount, i.e 0.2 g of sample was added to 50 mL of deionized water at 22±2°C Next, the initial pH (pHi) values of the solution were adjusted roughly from pH to 10 by adding 0.1 mol/L of HCl or NH4OH After a shaking time of h, the top solution was filtered and the final pH (pHf) value of the filtrate was measured (Ouédraogo et al 2015) The difference between pHi and pHf values (ΔpH = pHf‒pHi) was plotted versus the pHi The pHpzc of the sorbent was determined from the point of intersection of the resulting curve, at Igor W K Ouédraogo et al., 17/07/2015 which ΔpH = The surface morphology of samples was characterized using a microscope (JEOL JSM‒6480, Tokyo, Japan) The surface area was characterized from N2 adsorption– desorption isotherms at ‒196°C obtained using an adsorption instrument (Micromeritics ASAP 2020, Georgia, USA) The specific surface areas were assessed using the BET (Brunauer–Emmett–Teller) equation Thermal degradation characteristics were carried out with a thermogravimetric analyzer (SETSYS Evolution TGA 16/18, Setaram Instrumentation, Caluire-et-Cuire, France) The ramping rate was 10°C/min up to 900°C using N2 as the carrier gas The results were reported in percentage weight (TG) and Downloaded by [University of California, San Diego] at 23:47 12 January 2016 differential weight (dTG) versus temperature Sample ash contents have been determined using NF MO3-003/ EN 14775 / ISO 1171 standard method Ashes were digested with 37% HCl and the manganese contents were determined by atomic absorption spectrometry (AAS) 2.4 Batch sorption experiments Batch experiments were carried out in plastic bottles (50 mL) by adding 0.2 g sorbent to 50 mL of aqueous As(V) solution The initial pH of the solution was adjusted to between -10 by adding 0.1 mol/L HCl or NH OH solution The plastic bottles were gently agitated in an electric shaker (Guwina-Hofmann, Berlin, Germany) at 150 rpm for h The sorbent was removed by filtration with cellulose acetate membrane and the remaining As was determined The influence of contact time was studied at pH for 0.25 to h and for initial concentrations of to 150 mg/L All experiments were performed in triplicates and the average values were taken Maximum deviation was