Adsorption Kinetics Of Tetracycline Research Articles

Effects of chicken manure‐modified biochar on the adsorption capacity of tetracycline and abundance of antibiotic resistance genes in soil

AbstractLarge quantities of livestock manure not only occupy farmland but also serve as the primary source of antibiotics and antibiotic resistance genes (ARGs) in agricultural soil. To enhance the resource utilization of animal manure and mitigate ecological risks associated with antibiotics in agroecosystems, chicken manure was used as a raw material for biochar production. The manure derived biochar (MB) was modified with an alkali–acid two‐step modification process. The results showed that the total pore volume and surface area of alkali–acid modified MB (AMMB) was significantly increased about three and five times, respectively after modification. The SEM images showed that the surface of AMMB had a more regular and clearer structure with fewer impurities. The improvement of surface properties of AMMB significantly increased its adsorbing capacity of tetracycline in the soil. The adsorption kinetics of tetracycline by AMMB were better fitted by the pseudo‐second‐order kinetic model, suggesting that the adsorption of tetracycline on biochar followed the process of chemisorption. The adsorption mechanisms mainly involved the pore filling, hydrophobic effect, and π–π EDA interaction. Moreover, after a 60 days amendment of AMMB, the total relative abundances (RAs) of tested tetracycline resistance genes (TRGs) in soil decreased significantly, which suggested that AMMB can be a potential material to reduce risks of antibiotics and its resistance genes.

Improved Adsorption of Tetracycline in Water by a Modified Caulis spatholobi Residue Biochar.

A potassium modified biochar (KBC) using Caulis spatholobi residue as the raw material was prepared by adopting a two-step method of pyrolysis followed by high-temperature potassium hydroxide activation, and its properties were characterized. Activation using potassium hydroxide under high temperature induced the loss of CaCO3 and partial C on biochar, which created a high specific surface area (1336.31 m2/g) together with a developed pore structure. pH displayed a slight influence on tetracycline adsorption, which signified the slight influence of the existence of tetracycline and the charge potential of biochar. Besides, pore filling, hydrogen bonding and π–π EDA stacking interactions possibly resulted in tetracycline adsorption on biochar. Tetracycline adsorption was fast in the original period, followed by a slower rate of adsorption until equilibrium was reached. Adsorption kinetics of tetracycline could be described using secondary and Elovich kinetic models. Adsorption isotherms for tetracycline were well fitted to the Langmuir isotherm model, and the maximum adsorption capacity of KBC was 830.78 mg/g at 318 K. According to a study of the thermodynamics, the adsorption of tetracycline on KBC was an endothermic reaction process. Corresponding results in the present study demonstrated that high-temperature potassium hydroxide activation enabled biochar to effectively eliminate tetracycline from water and wastewater.

Enhanced adsorption of tetracycline on polypropylene and polyethylene microplastics after anaerobically microbial-mediated aging process

Aging of microplastics (MPs) can greatly affect their behaviors with other pollutants in aquatic and terrestrial ecosystems. Effect of anaerobically microbial-mediated aging on the physicochemical properties of polypropylene (PP) and polyethylene (PE) MPs was studied, then the adsorption behavior of tetracycline on the MPs was investigated. The results indicated that microbial-mediated aging process caused an increase in crystallinity and apparent changes in the morphology and surface structure of MPs. Visible pits and grooves on PP-MPs, as well as cavities and broken edges on PE-MPs were observed, while the surface functional groups also changed. Adsorption kinetics of tetracycline were well-described by a pseudo-second model. The equilibrium adsorption capacities of the microbial-aged PP- (MA-PP, 427.7 μg g−1) and PE- (MA-PE, 1095.3 μg −1) MPs were more than 3.8 and 8.1 times higher, respectively, than virgin PP- (V-PP, 111.7 μg g−1) and PE- (V-PE, 133.6 μg g−1) MPs. Adsorption isotherms of tetracycline on V-PP and V-PE were well-fitted by the Langmuir model, but failed to describe the adsorption process of tetracycline on MA-PP and MA-PE, suggesting changes in adsorption mechanisms of tetracycline due to anaerobic biodegradation of MPs. Solution pH had an evident effect on the adsorption capacity of tetracycline due to changes in both tetracycline speciation and surface charge of MPs. This study clearly suggests that anaerobically microbial-mediated aging process may greatly change the morphology and surface structures of PP-MPs and PE-MPs, and thus act as carriers for enhanced accumulation and transport of antibiotics in the environment, posing an increasing risk to ecosystem.

Tetracycline adsorption on magnetic sludge biochar: size effect of the Fe3O4 nanoparticles.

Activated sludge, which is difficult and expensive to treat and dispose of, is a key concern in wastewater treatment plants. In this study, magnetic sludge biochar containing activated sludge and different sizes (14.3, 40.2 and 90.5 nm) of Fe3O4 nanoparticles was investigated as an effective adsorbent for tetracycline (TC) adsorption. Magnetic sludge-based biochar was prepared by a facile cross-linking method and characterized by transmission electron microscopy, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction, X-ray photoelectron spectroscopy (XPS) and zeta potential analysis. The adsorption performances of TC on three kinds of adsorbents were investigated. Although 14.3 nm Fe3O4 nanoparticles could be inclined to aggregate and partially filled with pores of biochar, it turned out that magnetic sludge biochar with 14.3 nm Fe3O4 nanoparticles exhibited optimum performance for TC removal with adsorption capacity up to 184.5 mg g−1, due to the larger amounts of functional groups and the change of zeta potential. Furthermore, the adsorption kinetics of TC on three kinds of adsorbents were studied, which implied that the pseudo-second-order kinetic model exhibited the better fit for the entire sorption process.

Chitosan-graft-poly(N‑tert‑butylacrylamide) Copolymer: Synthesis, Characterization and Optimization of Tetracycline Removal Using RSM

In the present study, a graft copolymer was synthesized in accordance with the free radical method using N-tertiary butylacrylamide monomer on chitosan, which is an environmentally friendly polymer. The chemical structure and surface morphology of the newly synthesized graft copolymer were determined by Fourier transform infrared spectroscopy, scanning electron microscopy and X-ray diffraction. Moreover, the thermal behavior was analyzed by thermogravimetric analysis. The chitosan-graft-poly(N‑tert‑butylacrylamide) graft copolymer was used as an adsorbent for the rapid removal of tetracycline from aqueous solutions in order to investigate its applicability. Response surface methodology (RSM) was employed for the optimization of the study conditions, namely adsorbent dosage (0.01–0.04 g 100 mL−1), reaction time (10–90 min) and initial tetracycline concentration (10–100 mg 100 mL−1). The effects of these conditions on tetracycline uptake capacity were examined and the results were statistically analyzed. The RSM results showed that the maximum tetracycline uptake capacity of 104.81 mg g−1 was achieved under the following conditions: adsorbent dose of 0.03 mg 100 mL−1, reaction time of 51.12 min and initial tetracycline concentration of 97.99 mg L−1. ANOVA based on central composite design combined with RSM showed a good agreement between the experimental values and quadratic model estimates, thus resulting in a coefficient (R2) of 0.9118 for tetracycline uptake. The kinetics, isotherms, and thermodynamics of adsorption were examined, and results showed that equilibrium data fitted the Freundlich isotherm model, and the adsorption kinetics of tetracycline followed pseudo-second-order model. Thermodynamic parameters like the enthalpy − 10.39 kJ mol−1 (ΔH°), entropy 0.044 kJ mol−1 K−1 (ΔS°) and Gibbs free energy − 23.26 kJ mol−1 (ΔG°) were evaluated and also, ΔG° shows a negative values indicating that the adsorption process was exothermic and spontaneous. The findings demonstrated that the chitosan-graft-poly(N‑tert‑butylacrylamide) copolymer is an effective adsorbent for pharmaceutical wastewater treatment.

Removal of Tetracycline from Aqueous Solution Using Nanocomposite Based on Polyanion-Modified Laterite Material.

This work investigated the removal of antibiotic tetracycline (TC) from wastewater using nanocomposite material based on laterite modified with polyanion, polystyrene sulfonate (PSS). The effective factors influenced on the TC removal using nanocomposite PSS-modified laterite (NCPML) were optimized and found to be pH 4, solid-liquid ratio 5 mg/mL, and contact time 180 min. The highest removal of TC reached about 88% under the optimum adsorption conditions. The adsorption isotherm and kinetics of TC adsorption onto NCPML were in good agreement with the Langmuir and pseudo-second-order models, respectively. The characteristics of the NCPML material before and after TC adsorption were examined by zeta (ζ) potential measurements, Brunauer–Emmett–Teller (BET) method, and Fourier transform infrared spectroscopy (FT-IR). The TC adsorption onto NCPML was induced by electrostatic interaction, hydrogen bonding, and diffusion interaction. The TC removal from wastewater was approximately 94% while efficiency still reached 66% after five regenerations. Our research reveals that NCPML is a high-performance adsorbent for TC removal from wastewater.

Preparation of diatomite-modified wood ceramics and the adsorption kinetics of tetracycline

Taking corn straw as the main raw material, diatomite-modified wood ceramics were prepared by carbonizing a phenolic resin-corn straw powder composite under vacuum. The structure and properties of as-prepared materials were characterized by a scanning electron microscope, X-ray diffraction(XRD), Fourier transform infrared spectroscopy(FT-IR), Scanning electron microscope(SEM) and Mercury injection. Using tetracycline as the target pollutant, the adsorption isotherms and adsorption kinetics of the samples on tetracycline were investigated. Results indicated that the diatomite-modified wood ceramics were mainly amorphous, containing a small amount of quartz phase and crystalline graphite. The pore size range, the porosity, and the specific surface area of the wood ceramics were 1000 nm to3800 nm, 48.6 %, and 7.83 m2/g respectively. According to the correlation coefficient R2, a Langmuir isothermal adsorption model could better describe the adsorption process of tetracycline on wood ceramics than the Freundlich model (0.999 versus 0.975). Adsorption kinetics of tetracycline (initial concentration 5 mg/L) on wood ceramics were analyzed at pH values of 3, 5, 7, and 9. Results of the kinetic model fitting showed that the quasi-second-order kinetic model parameter (R2 > 0.98) could better fit the adsorption process of tetracycline. After repetitive use of the wood ceramics, the removal efficiency decreased due to blockage of pores. After regeneration, the removal efficiency for tetracycline exceeded 90%.

Tetracycline-induced effects on the nitrogen transformations in sediments: Roles of adsorption behavior and bacterial activity

Nitrification and denitrification are the most important nitrogen transformation processes in the environment. Recently, due to widespread use, antibiotics have been reported to lead to environmental risks. Tetracycline (TC) is one of the most extensively used antibiotics in many areas. However, its reported effects on nitrogen transformations were conflicting in previous studies. In this study, the effects of TC on nitrogen transformations in sediment were investigated by analyzing TC transport and bacterial activity. It was found that the adsorption of TC onto the sediment was favorable and spontaneous, with adsorption capacity 54.3 mg/kg. The adsorption kinetics of TC onto the sediment and the isotherm fitted the Elvoich and Freundlich models, respectively, indicating that the adsorption was a chemisorption process, including electrostatic interactions and chemical bonding between TC and the sediment. TC showed no effect on nitrification in the sediment, but significantly inhibited the reduction of nitrate and nitrite during denitrification, consistent with observations made for the model denitrifier Paracoccus denitrificans under TC stress. Mechanistic study indicated that TC at 130 μg/g-cell inhibited 50.7% of P. denitrificans growth and 61.6% of cell viability. Meanwhile, the catalytic activities of the key denitrifying enzymes, nitrate reductase (NAR) and nitrite reductase (NIR), decreased to 29.1% and 68.0% of the control levels when the TC concentration was 130 μg/g-cell, suggesting that NAR was more sensitive to the TC than NIR, which contributed to a delay in nitrite accumulation.

Green Synthesis of Magnetic Adsorbent Using Groundwater Treatment Sludge for Tetracycline Adsorption

Abstract Groundwater treatment sludge is an industrial waste that is massively produced from groundwater treatment plants. Conventional methods for treatment of this sludge, such as discharge into deep wells or the sea, or disposal at landfills, are not environmentally sustainable. Here, we demonstrate an alternative strategy to recycle the sludge by preparing a magnetic maghemite adsorbent via a one-step hydrothermal method with NaOH solution as the only solvent. With this method, the weakly magnetized sludge, which contained 33.2% iron (Fe) and other impurities (e.g., silicon (Si), aluminum (Al), and manganese (Mn)), was converted to magnetic adsorbent (MA) with the dissolution of Si/Al oxides (e.g., quartz and albite) into the liquid fraction. At a NaOH concentration of 2 mol·L−1, approximately 18.1% of the ferrihydrite in the Fe oxides of the sludge was converted into 11.2% maghemite and 6.9% hematite after the hydrothermal treatment. MA2 (i.e., MA produced by a 2 mol·L−1 NaOH concentration) exhibited a good magnetic response of 8.2 emu·g−1 (1 emu = 10−3 A·m2), and a desirable surface site concentration of 0.75 mmol·g−1. The synthesized MA2 was used to adsorb the cationic pollutant tetracycline (TC). The adsorption kinetics of TC onto MA2 fitted well with a pseudo-second-order model, and the adsorption isotherms complied well with the Langmuir model. The maximum adsorption capacity of MA2 for TC was 362.3 mg·g−1, and the main mechanism for TC adsorption was cationic exchange. This study is the first to demonstrate the preparation of an MA from recycled sludge without a reductant and/or exogenous Fe source. The prepared adsorbent can be used as a low-cost adsorbent with high capacity for TC sorption in the treatment of TC-containing wastewater.

Development and physicochemical characterization of a new magnetic nanocomposite as an economic antibiotic remover

Maghemite (ϒ-Fe2O3) nanoparticles were impregnated to nanoporous carbon obtained from tomato waste (TWNC). The prepared magnetic composite (MTWNC) was characterized and used to remove tetracycline (TC) from water and then easily be separated from the medium by a magnetic technique. The morphologies and surface chemistries of both magnetic and non-magnetic nanoporous carbons were studied by FTIR, XRD, SEM, SEM-EDX, VSM, BET surface area, proximate and elemental analysis determinations. Batch adsorption studies were carried out and the effects of pH, initial TC concentration, adsorbent dose, ionic strength and temperature were investigated. The adsorption kinetics of TC on MTWNC could be expressed well by the pseudo-second order model, and sorption isotherms were described by Langmuir equation with maximum adsorption capacity of 60.60mg/g at pH 4 and 50°C. Thermodynamic parameters showed that the adsorption of TC onto MTWNC was feasible, spontaneous and endothermic. Furthermore, the recyclability of the adsorbent was tested with 0.01M NaOH solution, and the results show that the synthesized composite adsorbent could be employed repeatedly in wastewater treatment.

Adsorption of tetracycline from aqueous solutions onto multi-walled carbon nanotubes with different oxygen contents.

Oxidized multi-walled carbon nanotubes (MWCNTs) with different oxygen contents were investigated for the adsorption of tetracycline (TC) from aqueous solutions. As the surface oxygen content of the MWCNTs increased, the maximum adsorption capacity and adsorption coefficient of TC increased to the largest values and then decreased. The relation can be attributed to the interplay between the nanotubes' dispersibility and the water cluster formation upon TC adsorption. The overall adsorption kinetics of TC onto CNTs-3.2%O might be dependent on both intra-particle diffusion and boundary layer diffusion. The maximum adsorption capacity of TC on CNTs-3.2%O was achieved in the pH range of 3.3–8.0 due to formation of water clusters or H-bonds. Furthermore, the presence of Cu2+ could significantly enhanced TC adsorption at pH of 5.0. However, the solution ionic strength did not exhibit remarkable effect on TC adsorption. In addition, when pH is beyond the range (3.3–8.0), the electrostatic interactions caused the decrease of TC adsorption capacity. Our results indicate that surface properties and aqueous solution chemistry play important roles in TC adsorption on MWCNTs.

Adsorption of tetracycline on montmorillonite: influence of solution pH, temperature, and ionic strength

The adsorption of tetracycline (TC) from aqueous solution by different types of montmorillonite (MMT) was studied under varying pH, temperature, and ionic strength conditions. The adsorption data obeyed the Langmuir isotherm with maximum TC adsorption at 468, 404, and 243 mg/g on SAz-1, SWy-2, and SYn-1 at pH 1.5, and at 375 mg/g on SHCa-1 at pH 8.7, corresponding to 0.86, 1.07, 0.78, and 1.28 of their cation exchange capacities, respectively. The kinetics of TC adsorption was very fast and reached equilibrium in almost 2 h and the results followed the pseudo-second-order kinetic model. In general, lower solution pH facilitated TC adsorption except for SHCa-1. Ionic strength had minimal influences on TC adsorption. The adsorption of TC on MMTs was endothermic, suggesting a strong physical adsorption. Under a weak alkaline condition, the TC adsorption resulted in extensive MMT delamination or exfoliation. Because of its high TC adsorption capacity, the results suggested that MMT could be a very good candidate to remove TC from wastewater containing high amounts of TC.

Investigation of kinetic and thermodynamic characteristics of removal of tetracycline with sponge like, tannin based cryogels

The removal of tetracycline (TC) from aqueous environment by new type of sorbents, tannin based cryogels (TAB CRGs) and control cryogels (CRGs) was studied in a batch system. The experimental parameters that affect the sorption of TC were optimized to achieve maximum removal yield. Prepared cryogels were characterized by SEM imaging, IR spectroscopy (ATR). Produced TAB cryogels have thin polymeric walls and interconnected large pores. The TAB cryogels are elastic and sponge like; its water content can easily be removed by only compressed with hand. The TAB cryogels restore their original shape and size within seconds after soaked in water. On the other, elasticity of blank CRG is lower. The Freundlich and Langmuir adsorption isotherms were conducted to deduce the mechanism of the process. The kinetics of TC adsorption was moderately fast and almost reached equilibrium in 150min and the results followed pseudo-second-order kinetic model.

Efficient removal of tetracycline by reusable magnetic microspheres with a high surface area

A novel hypercrosslinked magnetic resin Q100 with a high surface area of 1153.8m2/g was prepared and characterized. Another magnetic resin (Q80) and two non-magnetic commercial resins (NDA150 and XAD-4) were selected as adsorbents for comparison to investigate the adsorption behavior and predominant factors controlling the adsorption of tetracycline (TC) onto the adsorbents. The adsorption kinetics of TC onto all resins followed a pseudo-second-order equation. Q100 exhibited much faster kinetics (k2=0.18) than the commercial resins XAD-4 (k2=0.031) and NDA150 (k2=0.021) because of the much smaller particle size of Q100. Moreover, Q100 also had the largest adsorption of the four resins due to its high surface area and abundant mesopore structure. For all of the adsorbents used in the present work, pH 5–6 was suitable for TC adsorption, whereas pH>12 could be used for regeneration. An increased ionic concentration could enhance the adsorption of TC on the four resins for the salting out effect. The recyclabilities of the four resins were also evaluated, and Q100 was found to be more reusable for TC removal than the other three resins.

Adsorption of tetracycline on 2:1 layered non-swelling clay mineral illite

The removal of tetracycline (TC) from aqueous environment by illite (IMt-2) was studied in a batch system at different pH and ionic strength conditions. Adsorbent characterizations were determined by XRD and FTIR. The TC adsorption capacity on IMt-2 was 32mg/g at pH 5–6 and the adsorption equilibrium data obeyed the Freundlich isotherm. The kinetics of TC adsorption was moderately fast and almost reached equilibrium in 8h and the results followed pseudo-second-order kinetic model and Elovich model. The X-ray diffraction patterns before and after TC adsorption revealed no changes in basal spacing and intensity under two kinetic adsorption and a few initial TC concentration conditions, indicating that the adsorbed TC molecules were on the external surface of the mineral in contrast to intercalation of TC into swelling clay minerals, such as montmorillonite and rectorite. In spite of its low TC adsorption capacity, the results suggested that IMt-2 could be a good candidate to remove TC from wastewater containing higher amounts of TC and illite would be an important environmental sink for the fate and transport of TC in soils.

Adsorption characteristics of tetracycline by two soils: assessing role of soil organic matter

The adsorption characteristics of tetracycline by 2 soils including a clay-rich soil (cinnamon soil) and an iron oxide-rich soil (red soil) were investigated as a function of soil organic matter (SOM). SOM is the main adsorbent for tetracycline in the soil environment. The results indicated that the adsorption kinetics of tetracycline by the different soils with or without organic matter was described by the Elovich equation and the exponent equation. The adsorption of tetracycline on red soil was quite rapid and equilibrium could be reached after 5 h. In contrast, the concentration of tetracycline in cinnamon soil reached equilibrium after 11 h. The difference in equilibrium time in cinnamon soil and red soil was caused by their dominant components for adsorption, including clays, organic matter, and Al/Fe hydrous oxides. It took longer for the penetration of tetracycline into the interlayers between clays and organic matter in cinnamon soil, but tetracycline needed less time for adsorption through surface complexation on oxide surfaces of red soil. Removing SOM from soil markedly shortened the equilibrium time (7 h) of adsorption and reduced the equilibrium concentration (Cs) in cinnamon soil, but not in red soil, because of different dominant components for adsorption in the 2 natural soils. In natural and SOM-free soils, >98% of tetracycline in solution could be sorbed. The adsorption of tetracycline on natural and SOM-free soils was well described by Freundlich adsorption isotherms. Batch adsorption experiments showed that the adsorption of tetracycline on natural red soil was stronger than that on natural cinnamon soil. Adsorption capacity (KF) decreased with an increase in SOM removed from soil, which is attributed to the effect of tetracycline sorbed by SOM in different soils. However, SOM affected the adsorption intensity (n) of different soils diversely; there was a decrease for red soil and an increase for cinnamon soil. In particular, red soil with high Al/Fe hydrous oxides had higher adsorption affinities than cinnamon soil.