Synthesis of ZnO-TiO2/activated carbon (ACαZnO/TiO2) nanoparticles and its application in adsorption of arsenic from aqueous media: study of isotherm and adsorption kinetics and optimization using response surface methodology-central composite design (original) (raw)
Related papers
Evaluation of the adsorption potential of titanium dioxide nanoparticles for arsenic removal
Journal of Environmental Sciences-china, 2009
The adsorption potential of titanium dioxide (TiO 2 ) nanoparticles for removing arsenic from drinking water was evaluated. Pure and iron-doped TiO 2 particles are synthesized via sol-gel method. The synthesized TiO 2 nanoparticles were then immobilized on ordinary sand for adsorption studies. Adsorption isotherms were conducted on the synthesized nanoparticles as well as the sand coated with TiO 2 nanoparticles under varying conditions of air and light, namely, the air-sunlight (A-SL), air-light (AL), air-dark (AD) and nitrogen-dark (ND). X-ray diffraction (XRD) analysis showed that the pure and iron-doped TiO 2 nanoparticles were in 100% anatase crystalline phase with crystal sizes of 108 and 65 nm, respectively. Adsorption of arsenic on the three adsorbents was non-linear that could be described by the Freundlich and Langmuir adsorption models. Iron doping enhanced the adsorption capacity of TiO 2 nanoparticles by arresting the grain growth and making it visible light responsive resulting in a higher affinity for arsenic. Similarly, the arsenic removal by adsorption on the sand coated with TiO 2 nanoparticles was the highest among the three types of sand used. In all cases, As(V) was adsorbed more compared with As(III). The solution pH appeared to be the most important factor in controlling the amount of arsenic adsorbed.
Environmental Progress & Sustainable Energy, 2012
This research article deals with the uptake of arsenic from contaminated water using acetate functionalized zinc oxide (ZnO) nanomaterials. The ZnO nanomaterials of various sizes (6-60 nm) have been synthesized following different wet chemical routes. The arsenic removal efficacy of acetate functionalized ZnO nanomaterials was carried out at different pH and time interval. It has been concluded from the study that ZnO nanomaterials (<60 nm) prepared by zinc acetate precursor effectively removes arsenic, while ZnO of same size prepared from zinc chloride, zinc nitrate, zinc sulphate precursor could not remove arsenic considerably. However, ZnO of same size synthesized using other than zinc acetate precursor and functionalized with acetate ions removes arsenic effectively. It is also proposed that acetate ions over the surface of ZnO adsorb arsenic by an oxo-coordination mechanism and purifies water up to permissible limits of arsenic at pH 5.8-6.8.
Zinc Oxide Nanoparticles for Removal of Arsenic from Water
International Journal of Recent Technology and Engineering, 2019
Removal of arsenate, As(V) from water was achieved using zinc oxide nanoparticles. The nanoparticles were synthesised from zinc acetate dihydrate and sodium hydroxide (NaOH) using the wet chemical sol-gel method. Different synthesis parameters were explored; including different ratios of Zn:NaOH and calcination temperatures. The synthesised samples were subsequently characterised and tested to investigate the adsorption capabilities of ZnO towards As(V). The colourimetric approach was utilised to analyse the samples’ performance. The particles had a relatively large average size as tested by the nanoparticle size analyser and the X-Ray Diffraction (XRD) characterisation of the samples confirmed the formation of ZnO. The peaks were narrow with high intensity, which indicates a larger crystal size and stable crystallinity. The samples showed a linear trend of increased adsorption capacity with the contact time. However, as indicated by the XRD and nanoparticle size analyser results, t...
European Journal of Chemistry
The groundwater is one of the biggest natural resources for providing drinking water to millions of people all around the globe. However, the presence of large amount of arsenic(V) in water causes serious health hazards to the consumers which necessitates the development of cost-effective remediation. The CuO/TiO2 nanocomposites were prepared by the precipitation-deposition method for the removal of the arsenate ion (AsO43-) from water. The prepared samples were characterized by powder X-ray diffraction, Fourier transform infrared, and scanning electron microscopy to examine crystallite size and structure, material purity, textural features, morphology, and surface area. The effect of different operating parameters such as pH, contact time, initial concentration of arsenic(V) and nanocomposite dose on the removal rate of arsenic(V) was examined to optimize the adsorption performance of the CuO/TiO2 nanocomposite. In addition, the adsorption mechanism was studied by employing Langmui...
Nanomaterials
Arsenic (III) is a toxic contaminant in water bodies, especially in drinking water reservoirs, and it is a great challenge to remove it from wastewater. For the successful extraction of arsenic (III), a nanocomposite material (ZnO–CuO/g–C3N4) has been synthesized by using the solution method. The large surface area and plenty of hydroxyl groups on the nanocomposite surface offer an ideal platform for the adsorption of arsenic (III) from water. Specifically, the reduction process involves a transformation from arsenic (III) to arsenic (V), which is favorable for the attachment to the –OH group. The modified surface and purity of the nanocomposite were characterized by SEM, EDX, XRD, FT–IR, HRTEM, and BET models. Furthermore, the impact of various aspects (temperatures, pH of the medium, the concentration of adsorbing materials) on adsorption capacity has been studied. The prepared sample displays the maximum adsorption capacity of arsenic (III) to be 98% at pH ~ 3 of the medium. Nota...
Environmental Pollution, 2009
A nanocrystalline TiO 2 -based adsorbent could be used for the simultaneous removal of As(V), As(III), MMA, and DMA in contaminated groundwater. a b s t r a c t A nanocrystalline TiO 2 -based adsorbent was evaluated for the simultaneous removal of As(V), As(III), monomethylarsonic acid (MMA), and dimethylarsinic acid (DMA) in contaminated groundwater. Batch experimental results show that As adsorption followed pseudo-second order rate kinetics. The competitive adsorption was described with the charge distribution multi-site surface complexation model (CD-MUSIC). The groundwater containing an average of 329 mg L À1 As(III), 246 mg L À1 As(V), 151 mg L À1 MMA, and 202 mg L À1 DMA was continuously passed through a TiO 2 filter at an empty bed contact time of 6 min for 4 months. Approximately 11 000, 14 000, and 9900 bed volumes of water had been treated before the As(III), As(V), and MMA concentration in the effluent increased to 10 mg L À1 .
Water Science & Technology Water Supply
Arsenic can be selectively removed from water through adsorption on a natural manganese oxide. This paper presents some of the key parameters controlling such a process. Both production and regeneration steps were studied and the influence of three main controlling parameters was put to light. The water pH greatly influenced the adsorption capacity. Low water pH highly improved the treatment. The adsorption being under mass transfer limitation, flow rate influence was measured and optimization solutions were proposed. Finally, the impact of the regeneration procedure was evaluated on the adsorbent stability. It gave good arsenic elution results but the caustic elution step generated fine particles that could not be avoided. The following neutralization could however be adjusted in order to minimize further adsorbent dissolution.
Asian Journal of Chemical Sciences
Millions of people worldwide are adversely affected by Arsenic continuing exposure, so providing arsenic-free consumption of water is an immense task for the researchers. The chemistry, content of arsenic-contaminated water as well as adsorption play a big role in arsenic elimination. The mechanism of adsorption technology's elimination of As (V) from the water was simply presented as the elements that govern various adsorption paths. The effects of a variety of adsorbents on As (V) elimination from aquatic were explored in the present research, which classified the materials used as adsorbents based on physical, chemical, and biological processes. When choosing an adsorbent, adsorption capability is an important factor to consider. As a result, developing As (V) elimination from aquatic adsorption strategies includes developing environmentally acceptable materials with effectual adsorption abilities, refining the preparation and alteration procedures of recent adsorbents, and b...
Efficiency of Low Cost Adsorbents for the Removal of Arsenic from Water
Tribhuvan University Journal
Adsorption is one of the primary processes for removing arsenic from drinking water. This study focuses on developing inexpensive and effective adsorbents to remove arsenic from ground water. Eight different types of adsorbents were prepared. Some of these materials were chemically modified. The efficiency of percentage adsorption of arsenate, As (+III) on different materials were investigated at different pH, contact time and initial concentrations. Out of eight different types of adsorbents, the iron-loaded x ant hated orange waste (Fe-XOW) showed high efficiency for the removal of arsenic. It was found that approximately 83 % of arsenate, As (+III) and 87% of arsenate, As (+V) removal could be achieved at optimum pH of 10 and 4respectively. The significant effect of pH was in the range of 9 to12 for As (+III) and 3 to 5 for As (+V). Time dependency experiments for the arsenite uptake showed that the adsorption rate on Fe-XOW was fast initially for 1 hour, followed by slow attainm...
Removal of arsenic from water by different adsorbents
Indian Journal of Chemical Technology, 2004
Present study is carried out for the removal of As(III) from water using commonly available adsorbents such as sand, from Yamuna river ( Delhi ), as well as from Ganga river (Kolkata), activated carbon, Hametite ore and sand -iron scrap mixture. All these adsorbents are used as received but sand and activated carbon which do not show much adsorption for As(III) are modified by treating with different metal ions in order to improve their adsorption efficiency. Results of the laboratory experiments under static conditions have confirmed that iron impregnated granular activated carbon (GAC), spherical activated carbon (SAC) as well as sand - iron scrap mixture have much promise as a medium for the removal of As(III) in drinking water. Various parameters like adsorbent dose, contact time, pH and arsenic concentration are optimized. A simple and economical domestic arsenic removal kit has been designed and successfully evaluated in the laboratory using sand-iron scrap mixture as media fo...