scholarly journals Expanded perlite: potential for removing antibiotics from water

Water SA ◽  
2021 ◽  
Vol 47 (4 October) ◽  
Author(s):  
Bruna Martins Vicentin ◽  
Raquel Dalla Costa da Rocha

This work aims to study the potential of expanded perlite (EP) for amoxicillin (AMX) removal in aqueous solution. For this purpose, chemical, morphological, and textural characteristics of the EP were evaluated, in addition to AMX removal by the adsorption process. The kinetic, isothermal, and thermodynamic parameters were also assessed. The EP presented an isoelectric point of 6.5 and a surface with hydroxyl bands, which favour the adsorption process. Air bubbles were sealed and randomly connected with each other, increasing the surface area relative to the adsorption sites. These non-porous or macro-porous sites demonstrate efficiency in the mechanisms of mass transfer. AMX removal was determined to be a pseudo-second-order process since the adsorption velocity was proportional to the square of the available adsorption sites and indicates heterogeneity in the surface interactions between the adsorbed molecules. Also, the interactions were considered multilayer for low concentrations and monolayer for high concentrations (Sips isotherm). The adsorption process was endothermic and utilised a physical adsorption mechanism. Considering that no modification treatment was applied to the EP, and due to its neutral isoelectric point, macropores, amorphous and dipole induction force (physical adsorption) characteristics, favourable affinity between EP and AMX was observed.

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2133 ◽  
Author(s):  
Xuli Li ◽  
Yue Zeng ◽  
Fangyuan Chen ◽  
Teng Wang ◽  
Yixin Li ◽  
...  

Zeolite analcime (EMANA) was synthesized through the hydrothermal method by using carbothermal reduction electrolytic manganese residue (CR-EMR). The structural properties of EMANA and CR-EMR were studied using various characterization techniques. After hydrothermal synthesis, the CR-EMR became super-microporous, and the surface area increased by 4.76 times than before. Among the various synthesized zeolites, 6 h-synthesized EMANA was selected as the best adsorbent for macrolide antibiotics in aqueous solution. The adsorption performance of EMANA on the adsorption capacity was examined by using various experimental parameters, such as contact time (0–24 h), initial concentration (50–300 mg/L), temperature (30–50 °C) and pH (3–13). The experimental results were also analyzed by the Langmuir and Freundlich adsorption models, with the latter obtaining better representation. The adsorption process could be described well by the pseudo-second-order model, even under a low concentration (50 mg/L). This result suggests that the adsorption process of macrolide antibiotics is due to chemisorption. According to the Fourier Transform infrared spectroscopy (FT-IR) results, the adsorption of zeolite was mainly due to its hydroxyl group, which played an important role during the adsorption process. Moreover, EMANA is more suitable for treatment of roxithromycin (ROX) than azithromycin (AZM), because ROX has more adsorption sites for the hydroxyl group.


2018 ◽  
Vol 77 (5) ◽  
pp. 1313-1323 ◽  
Author(s):  
Jianjun Zhou ◽  
Xionghui Ji ◽  
Xiaohui Zhou ◽  
Jialin Ren ◽  
Yaochi Liu

Abstract A novel magnetic bio-adsorbent (MCIA) was developed, characterized and tested for its Cd(II) removal from aqueous solution. MCIA could be easily separated from the solution after equilibrium adsorption due to its super-paramagnetic property. The functional and magnetic bio-material was an attractive adsorbent for the removal of Cd(II) from aqueous solution owing to the abundant adsorption sites, amino-group and oxygen-containing groups on the surface of Cyclosorus interruptus. The experimental results indicated that the MCIA exhibited excellent adsorption ability and the adsorption process was spontaneous and endothermic. The adsorption isotherm was consistent with the Langmuir model. The adsorption kinetic fitted the pseudo-second-order model very well. The maximum adsorption capacity of Cd(II) onto MCIA was 40.8, 49.4, 54.6 and 56.6 mg/g at 293, 303, 313 and 323 K, respectively. And the MCIA exhibited an excellent reusability and impressive regeneration. Therefore, MCIA could serve as a sustainable, efficient and low-cost magnetic adsorbent for Cd(II) removal from aqueous solution.


2016 ◽  
Vol 74 (1) ◽  
pp. 276-286 ◽  
Author(s):  
Bin Huang ◽  
Dan Xiong ◽  
Tingting Zhao ◽  
Huan He ◽  
Xuejun Pan

Biomorphic nano-hydroxyapatite (HAP) was fabricated by a co-precipitation method using cotton as bio-templates and employed in adsorptive removal of ofloxacin (OFL) and triclosan (TCS) that are two representative pharmaceuticals and personal care products (PPCPs). The surface area and porosity, crystal phase, functional group, morphology and micro-structure of the synthesized HAP were characterized by Brunauer–Emmett–Teller isotherm, X-ray powder diffraction, Fourier transform infrared spectroscopy, scanning electron macroscopic and transmission electron microscopy. The effects of initial pH, ionic strength, initial concentration, contact time and temperature on the removal of PPCPs were studied in a batch experiment. The adsorption of OFL and TCS was rapid and almost accomplished within 50 min. Kinetic studies indicated that the adsorption process of OFL and TCS followed the pseudo-first-order and pseudo-second-order models, respectively. The Freundlich isotherm described the OFL adsorption process well but the adsorption of TCS fitted the Langmuir isotherm better. Thermodynamics and isotherm parameters suggested that both OFL and TCS adsorption were feasible and spontaneous. Hydrogen bond and Lewis acid–base reaction may be the dominating adsorption mechanism of OFL and TCS, respectively. Compared to other adsorbents, biomorphic HAP is environmentally friendly and has the advantages of high adsorption capacity, exhibiting potential application for PPCPs removal.


BioResources ◽  
2019 ◽  
Vol 14 (2) ◽  
pp. 4430-4453
Author(s):  
Wenqi Li ◽  
Liping Zhang ◽  
Ying Guan ◽  
Zhihan Tong ◽  
Xiang Chen ◽  
...  

Biochar derived from Tetrapanax papyriferum petioles at different pyrolysis temperatures was used to remove copper from aqueous solution. Abundant porous structures were observed with scanning electron microscopy, and transmission electron microscope images revealed a unique layered nanopore structure. A high pyrolytic temperature resulted in a biochar with a higher surface area, ash content, and mineral element content. The maximum adsorption capacity of T. papyriferum petiole biochar (TBC) was 182 mg/g. The Langmuir adsorption isotherm model and pseudo-second-order kinetics model were most suitable for describing the adsorption process, indicating that adsorption takes place at specific homogeneous sites within the adsorbent. The calculated ΔH° values indicated that the adsorption process was endothermic. The adsorption mechanism for TBC was attributed to precipitation, ion exchange, C-π interactions, and complexation. Thus, the biochar used in this study is a promising environmentally friendly and effective adsorbent for removing Cu2+ ions from an aqueous solution.


2007 ◽  
Vol 95 (5) ◽  
Author(s):  
C. L. Chen ◽  
X. L. Li ◽  
X. K. Wang

Th(IV) adsorption onto oxidized multi-wall carbon nanotubes (MWCNTs) was carried out at 293±2K. The effects of MWCNT concentration, pH, and ionic strength were studied. The results showed that Th(IV) adsorption onto oxidized MWCNTs strongly depended on MWCNT concentration and pH, and was weakly dependent on ionic strength. Oxidized MWCNTs showed a higher Th(IV) adsorption capacity than as-grown MWCNTs. The adsorption process followed pseudo second order kinetics. The Freundlich isotherm model described the data better than the Langmuir model. The adsorption mechanism of Th(IV) may be surface complexation. Oxidized MWCNTs may be a promising candidate for the concentration of Th(IV), or its analogue actinides from large volumes.


2015 ◽  
Vol 72 (7) ◽  
pp. 1051-1061 ◽  
Author(s):  
Zhufeng Lu ◽  
Hongmei Wang ◽  
Jiayou Li ◽  
Lixia Yuan ◽  
Lianwen Zhu

The removal of chromium(III) (Cr(III)) from industrial wastewater by various low-cost methods has been widely investigated. In this paper, a type of bio-adsorbent was prepared using rice straw modified by fermentation and simple chemical treatment. The aim is to detect the adsorption mechanism and characteristics on Cr(III) ions. The analysis shows that the bio-adsorbent possesses four modified characteristics for Cr(III) adsorption. The first one is the acquired physical adsorption involving concave and convex structures. The second one is the effects of the hydrogen bonding surface hydroxyl groups and the metal chromium ion with complexation. The third one is mainly caused by hydrophilic active groups that possess carboxyl and hydroxyl groups during microbial degradation to combine with ions. The final one is the bio-adsorbent had high adsorption for low concentration of Cr(III) ions. The highest removal of around 97.45% was obtained at pH 5.0, bio-adsorption dosage of 0.5 g L−1, and initial Cr(III) concentration of 20 mg L−1. The adsorption process followed the pseudo second-order model (R2 > 0.99), while the isotherms were fitted to the Freundlich equation (68.1926 mg g−1), mainly by chemical adsorption. This study demonstrates the potential of using this biosorbent to remove Cr(III) from both synthetic and industrial wastewater.


2020 ◽  
Vol 40 (3) ◽  
pp. 22-28
Author(s):  
Angel Villabona Ortíz ◽  
Candelaria Nahir Tejada-Tovar ◽  
Rodrigo Ortega Toro

The effect of temperature on the adsorption of Cr (VI) was determined with waste materials from the agroindustry, such as palm bagasse and plantain peels, by determining the thermodynamic parameters which allow to establish the mechanisms that control the process. The methodology included an initial preparation of the biomass, its characterization, and subsequent adsorption tests by setting the initial concentration of the metal to 100 ppm, a particle size of 0,5 mm, a biomass amount of 0,325 g, pH 2, and a volume of 100 mL. The process temperature varied between 303,15, and 352,15 K. The concentration of the remaining metal in the solution was performed using the diphenyl carbazide colorimetric method through a UVVis spectroscopy at a wavelength of 540 nm. The results show that the effect of temperature does not present a defined trend for palm bagasse, whereas it is linear for adsorption using plantain peels. Furthermore, the process of adsorption of Cr (VI) with palm bagasse is more favorable at higher temperatures, since it is a spontaneous process with a physical adsorption mechanism. On the other hand, the adsorption process with plantain peels is thermodynamically feasible at temperatures from 40 to 55 °C and not spontaneous at higher temperatures. Also, a physicochemical adsorption mechanism was evinced. It is concluded that the use of the studied materials is possible in the removal of the Cr (VI) ion in aqueous solutions.


2013 ◽  
Vol 14 (2) ◽  
pp. 321-328 ◽  
Author(s):  
Wenjian Shi ◽  
Haixin Gu ◽  
Xuan Chen ◽  
Yuanxing Huang ◽  
Wei Wu ◽  
...  

Etherifying agent, 3-chloro-2-hydroxypropyl trimethylammonium chloride (CHPTA) was modified by grafting on cellulose to make quaternary ammonium cationic cellulose (QACC) with 2.01% nitrogen content and a degree of substitution of 0.289. The experiment results showed that at 318 K, the adsorption capacities of QACC on monochloroacetic acid (MCAA), dichloroacetic acid and trichloroacetic acid (TCAA) were 1.80, 1.87 and 2.01 mmol/g, respectively. The adsorption process could be modeled by pseudo second-order kinetics very well. The adsorption rate constant increased with temperature, and the adsorption pattern fitted Langmuir isotherms, which was monomolecular layer absorption. ΔH of the three chlorinated acetic acids were all above zero, and ΔS of them were above zero too. At 298 K, ΔG of the adsorption processes were below zero. These experiment results showed that it was main chemical adsorption accompanied by physical adsorption.


2014 ◽  
Vol 1073-1076 ◽  
pp. 955-959
Author(s):  
Ruo Zheng Li ◽  
Hong Yang ◽  
Xin Jin

Lignite activated carbon was provided through lignite which is treated specially. The adsorption capacity and mechanism of COD from Coal gasification wastewater by lignite activated carbon have been studied.The adsorption capacities of lignite activated carbon at different times were obtained by concentration of COD in the remainder solution. Three simplified kinetic models: pseudo-first-order, pseudo-second-order, intraparticle diffusion equations were adopted to examine the mechanism of the adsorption process. The results showed that the adsorption can be expressed by the pseudo-second-order model. The adsorption balance capacity was obtained as 50.8mg·g-1 (298K), and the adsorption balance capacity decreased with increasing of temperature, which showed that the adsorption process was exothermic. The adsorption activation energy (Ea) was calculated as 5.76kJ·mol-1, and it showed that the adsorption process was Physical adsorption. This study explored new treatment channels for lignite comprehensive utilization..


2015 ◽  
Vol 73 (6) ◽  
pp. 1269-1278 ◽  
Author(s):  
Hejun Gao ◽  
Luanluan Zhang ◽  
Yunwen Liao

A novel adsorbent consisting of polyethyleneimine-modified multi-wall carbon nanotubes (PEI-MWCNTs) was synthesized by grafting PEI on the carboxyl MWCNTs. The surface properties of the PEI-MWCNTs were measured by scanning electron microscopy, thermogravimetric analysis, Fourier transform infrared, and zeta potential. The adsorption behavior of the PEI-MWCNTs was investigated using sunset yellow FCF as adsorbate. The effects of dosage of adsorbent, the initial pH of solution, contact time and temperature on the adsorption capacity were studied. Then, the kinetics and thermodynamics of the adsorption process were further investigated. Experimental results showed that the adsorption kinetics fitted a pseudo-second-order model and the adsorption isotherms agreed well with the Langmuir model. The adsorption process occurred very fast and the adsorption capacity of PEI-MWCNTs was much higher than that of many of the previously reported adsorbents. Additionally, the plausible adsorption mechanism was discussed.


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