Adsorbent For Removal Of Tetracycline Research Articles

Adsorptive removal of tetracycline from water using Fe(III)-functionalized carbonized humic acid

Humic acid (HA) was carbonized at 300, 400 and 500 °C and then functionalized with 1 wt%–12 wt% Fe(III) respectively [CHA300/400/500-Fe(III)]. Adsorption of such Fe(III)-functionalized carbonized HA as adsorbents to aqueous tetracycline (TC: 25 mg·L −1 ) was studied. The adsorption equilibrium time for CHA400-Fe(III) to TC was 6 h faster and the adsorption removal efficiency ( R e ) was two times higher than that of HA/CHA. The adsorption R e of CHA400-Fe(III) loaded 10% iron [CHA400-(10%)Fe(III)] to TC could reach 99.8% at 8 h and still kept 80.6% after 8 cycles. The adsorption kinetics were well fitted to the pseudo-second-order equation and the adsorption isotherms could be well delineated via Langmuir equations( R 2 > 0.99), indicating that the homogeneous chemical adsorption of TC occurred on the adsorbents. The main adsorption mechanisms of TC were complexation Fe(III) and hydrophobic distribution. Electropositive and electronegative repulsion between TC and CHA400-(10%)Fe(III) at lowly pH(2) and highly pH(8–10) respectively, leaded to the relatively low adsorption capacity and more notable influence of ion concentration. When the pH was between 4 and 8, TC mainly existed in neutral molecules (TCH 2 ), so the influence of ion concentration was not obvious. The dynamic adsorption results showed that the CHA400-(10%)Fe(III) could continuously treat about 2.4 L TC(27 mg·L −1 ) wastewater with the effluent concentration as low as 0.068 mg·L −1 . Our study suggested a broad application prospect of a new, effective, low-cost and environment-friendly adsorbent CHA400-(10%)Fe(III) for treatment of low-concentration TC polluted wastewater. • HA and Fe(III)-functionalized carbonized HA were used to remove tetracycline. • CHA400-(10%)Fe(III) showed the highest removal efficiency (99.8%) to TC (25 mg·L −1 ). • CHA400-(10%)Fe(III) has a double strong adsorption force of iron coordination and CHA's hydrophobic distribution. • CHA400-(10%)Fe(III) can be easily regenerated by ethanol and maintain high reusability. • CHA400-(10%)Fe(III) is effective in treating low-concentration TC wastewater.

Adsorptive removal of tetracycline from aqueous solution by maple leaf-derived biochar

The present study evaluates the physicochemical properties of maple leaf-derived biochars (M-BCs) produced at different pyrolytic temperatures (i.e., 350, 550, and 750 °C) and their adsorptive properties for tetracycline onto M-BCs. The increase in pyrolysis temperature to produce M-BCs led to a significant increase in the biochar’s hydrophobicity, surface area, and calcite (CaCO3) crystallization. The M-BC750 produced without functionalization or activation possessed a high calcite composition and a hydrophobic nature with lower O/C and H/C, hydroxyl groups (–OH) on the surface, and functional groups (i.e., O-containing) as H-bond acceptors. Among M-BCs, the M-BC750 present a highest TC adsorption capacity owing to possible mechanisms such as metal complexation, H-bonding, and hydrophobic interactions. The isotherm and kinetic models for TC adsorption followed the Freundlich models and pseudo-second-order models, respectively. M-BCs produced from the waste fallen maple leaves could be applied as low-cost environmental adsorbents for TC removal.

Adsorptive removal of tetracycline by sustainable ceramsite substrate from bentonite/red mud/pine sawdust

In this study, a novel, sustainable and efficient ceramsite substrate of constructed wetlands (CWs) were prepared for tetracycline (TC) removal by employing bentonite (Ben) and red mud (Rm) as the main materials and pine sawdust (Ps) as the additive. The optimal parameters for Ben/Rm/Ps ceramsite preparation were obtained via orthogonal and one-factor experimental designs, and the optimal parameters were presented as follows: mass ratio of Ben: Rm: Ps = 4:1:0.9, preheating temperature = 240 °C, preheating time = 20 min, calcining temperature = 1150 °C, and calcining time = 14 min. The properties of Ben/Rm/Ps-op ceramsite (obtained at the optimal condition) were first analyzed, including XRD and SEM, and demonstrated a microporous structure with some crystal strength components. Neutral condition and higher temperature were indicated conducive to improve the TC removal efficiency, while coexisting ions (Na+ or Ca2+) showed adverse effect for TC adsorption by Ben/Rm/Ps-op. In addition, adsorption kinetics and isotherm could be well described by the second-order kinetics and linear isothermal model, respectively, which suggested chemisorption and multilayer adsorption thickness increased infinitely. The theoretical maximum TC adsorption capacity of Ben/Rm/Ps-op at 20 °C reached up to 2.5602 mg/g. In addition, Ben/Rm/Ps-op could effectively remove TC as the CWs substrate under a dynamic flow condition. Further, Ben/Rm/Ps-op exhibited high reusability capability and stability for TC removal, and the adsorption amount still remained for 2.13 mg/g (C0 = 80 mg/L) after three consecutive cycles.

Adsorption of tetracycline, ofloxacin and cephalexin antibiotics on boron nitride nanosheets from aqueous solution

Due to their ability to treat infections, antibiotics are being used in large quantities for human, animals and plants. Although they treat diseases well, they pose serious environmental risk as a result of non-consumption of a large fraction in metabolism. These unmodified antibiotics have been found to pollute surface, ground and drinking water. Against this backdrop, we report the synthesis of large surface area boron nitride nanosheets (BNNSS) and their application as adsorbent for removal of tetracycline (TC), ofloxacin (OFL) and cephalexin (CFX) from water. The synthesized adsorbent has been characterized using field emission scanning electron microscopy (FESEM), high resolution transmission electron microscopy (HR-TEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), zeta potential, X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR)and surface area analysis. The largest specific surface area (SBET = 1801.9 m2 g−1) of the synthesized sheets was obtained by optimizing the mixing time. The effect of pH, dose and contact time has been investigated to obtain the optimum parameters for maximum adsorption. The maximum adsorption capacities of BNNSs have been found to be 346.66 mg g−1 (TC), 72.50 mg g−1 (OFL) and 225.0 mg g−1 (CFX). This superior adsorption behavior demonstrates the potential of BNNSs for commercial applications for potable and waste water treatment.

Mn-doped zirconium metal-organic framework as an effective adsorbent for removal of tetracycline and Cr(VI) from aqueous solution

Abstract Metal-organic frameworks (MOFs) with porous property have gained much concern in environment remediation. Herein, the Mn-doped UiO-66 (denoted as MnUiO-66) with cubic morphology was fabricated with a facile solvothermal method. To investigate the adsorption performance of MnUiO-66, tetracycline (TC) and Cr(VI) were chosen as the target pollutant. The maximum adsorption capacity of MnUiO-66 for TC and Cr(VI) were 184.493 mg g−1 and 32.773 mg g−1, respectively, which were 4.9 and 3.1 times higher than the pristine UiO-66. Effects of the solution pH values, initial concentrations and coexisting ions on adsorption capacity were investigated and the adsorption mechanism based on zeta potential measurement was proposed. The adsorption process of MnUiO-66 over TC and Cr(VI) had the most accordance with pseudo-second-order and Langmuir models, which suggested that chemisorption was dominant in adsorption reaction and the MnUiO-66 adsorbent had a homogenous surface for adsorption. Adsorption thermodynamic studies implied that the adsorption process of TC and Cr(VI) on MnUiO-66 were spontaneous and exothermic. In addition, the MnUiO-66 showed excellent adsorption performance in TC-Cr(VI) mixed sample and pharmaceutical wastewater. More importantly, the regeneration experiment indicated the MnUiO-66 adsorbent was recyclable. This work provided a useful insight into the fabrication MOFs-based adsorbent for water purification.

New use for spent coffee ground as an adsorbent for tetracycline removal in water

Spent coffee grounds (SCG-1 and SCG-2) were used to study the adsorption of tetracycline (TC) antibiotics and the effects of adsorption time, initial pH, amount of adsorbent and ionic strength were detected. The TC adsorption isotherm on SCG-1 was compared with SCG-2. The results showed that the removal efficiencies of TC (50 mg/L) of SCG-1 and SCG-2 were 83.1% and 97.2%, respectively, shake for 2 h. The probability of adsorption is high and balances in about 20 min. The estimate of parameters got for TC from the Langmuir isotherm saturated adsorption quantity and adsorption balance constant were 64.89 mg/g, 0.0557 L/mg, respectively for SCG-1 and 123.46 mg/g, 0.4735 L/mg, respectively for SCG-2. The adsorption mechanism might be a π–π interaction that occurs in the interface by hydrogen bonding and the between the TC molecular and the SCGs. At last, we found that SCG has a high adsorption size for TC.

Recycling flue gas desulphurization gypsum (FGDG) for removal of tetracycline from aqueous solutions

ABSTRACTThe present research aimed to explore the feasibility of removing tetracycline (TC) by flue gas desulphurization gypsum (FGDG). The adsorptive properties of FGDG for TC, such as pH values, adsorption isotherms and kinetics, and thermodynamics parameters, were investigated in the batch experiments. The results revealed that the process of TC adsorption was pH dependent and the optimal pH value was pH 8.0. The adsorption mechanism could attribute to the formation of TC-FGDG complexation. Langmuir isotherm model and the pseudo-second-order kinetic model can be described the better adsorption behaviors. The thermodynamics parameters indicated that adsorption process was endothermic and chemisorption in nature. FGDG would be an ideal adsorbent for removal of TC from aqueous solutions with the characteristics of low-cost and good adsorption properties.

Adsorptive Removal of Tetracycline on Graphene Oxide Loaded with Titanium Dioxide Composites and Photocatalytic Regeneration of the Adsorbents

Graphene oxide loaded with titanium dioxide composites (GO-TiO2) was successfully prepared by hydrolysis of titanium tetrachloride in the presence of an aqueous dispersion of graphene oxide, and characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), transmission electron microscope (TEM), and X-ray diffraction (XRD). Characterized results exhibited that TiO2 was successfully loaded on the surface of GO. Adsorptive removal of tetracycline (TC) by GO-TiO2 and photocatalytic regeneration of adsorbent was investigated. Adsorption isotherms of TC onto GO-TiO2 proved that the adsorption process was multilayered, and the adsorption capacity of GO-TiO2 for aqueous TC in the tested range was 99.46, 117.98, and 133.05 mg/g at 15, 25, and 35 °C, respectively. TC adsorption by GO-TiO2 followed the pseudo-second-order kinetic model. TC adsorption by GO-TiO2 was favored at lower pH and decreased with an increase of solution pH. Additionally, Ca2+ had a more powerful in...

Chitosan Modified by Polyacrylamide for Adsorptive Removal of Tetracycline from Wastewater

Chitosan Modified by Polyacrylamide for Adsorptive Removal of Tetracycline from Wastewater

Adsorption of tetracycline and ciprofloxacin on activated carbon prepared from lignin with H3PO4 activation

Adsorption of tetracycline (TC) and ciprofloxacin (CPX) onto activated carbon prepared from lignin by H3PO4 impregnated was investigated. Lignin-activated carbon (LGAC) was carbonized at 450°C in a muffle furnace for 1 h. Scanning electron microscope, N2 adsorption–desorption isotherms, X-ray diffraction, pH at the point of zero charge and Boehm titration analysis need to characterize the properties of LGAC. Batched adsorption experiments were performed to study the adsorption properties and interaction mechanisms between TC/CPX and LGAC. The prepared activated carbon was found to have a porous structure with surface area of 931.53 m2/g and many functional groups (acidic groups, basic groups). The adsorption kinetics for the two adsorbates both well fitted the pseudo-second-order model (R2 ##xgt; 0.99). Compared with Temkin isotherm and Freundlich isotherm, the adsorption equilibrium data were very well represented by the Langmuir isotherm. The maximum adsorption capacities for the TC and CPX calculated by the Langmuir isotherm model were high at 475.48 and 418.60 mg/g, respectively. Thermodynamics study showed that the adsorption was spontaneous and favorable. These results suggested that LGAC could be an effective adsorbent for removal of TC and CPX.

Mechanisms for strong adsorption of tetracycline to carbon nanotubes: A comparative study using activated carbon and graphite as adsorbents

Significant concerns have been raised over the presence of antibiotics including tetracyclines in aquatic environments. We herein studied single-walled carbon nanotubes (SWNT) and multi-walled carbon nanotubes (MWNT) as potential effective adsorbents for removal of tetracycline from aqueous solution. In comparison, a nonpolar adsorbate, naphthalene, and two other carbonaceous adsorbents, pulverized activated carbon (AC) and nonporous graphite, were used. The observed adsorbent-to-solution distribution coefficient (Kd, L/kg) of tetracycline was in the order of 10(4)-10(6) L/kg for SWNT, 10(3)-10(4) L/kg for MWNT, 10(3)-10(4) L/kg for AC, and 10(3)-10(5) L/kg for graphite. Upon normalization for adsorbent surface area, the adsorption affinity of tetracycline decreased in the order of graphite/ SWNT > MWNT >> AC. The weaker adsorption of tetracycline to AC indicates that for bulky adsorbates adsorption affinity is greatly affected by the accessibility of available adsorption sites. The remarkably strong adsorption of tetracycline to the carbon nanotubes and to graphite can be attributed to the strong adsorptive interactions (van der Waals forces, pi-pi electron-donor-acceptor interactions, cation-pi bonding) with the graphene surface. Complexation between tetracycline and model graphene compounds (naphthalene, phenanthrene, pyrene) in solution phase was verified by ring current-induced 1H NMR upfield chemical shifts of tetracycline moieties.