Adsorption of tetracycline from contaminated water using ZnO, montmorillonite, and ZnO/montmorillonite composites: Adsorption kinetics and the role of pHzcp in adsorption capacity

Clay minerals in sediments have strong adsorption capacities for pollutants, but their role in the distribution of antibiotics in estuaries and nearby coastal areas is unclear. We evaluated the clay mineral montmorillonite (SWy-2) adsorption capacity for tetracycline (TC). We assessed the adsorption capacity of SWy-2 for TC by measuring the removal percentage of 30 mg/L TC over time. The effects of pH and ionic strength on the TC adsorption onto SWy-2 were investigated. We analyzed the kinetics of TC adsorption using a pseudo-second-order model and determined the adsorption isotherm using the Langmuir equation. SWy-2 particles were characterized using zeta potential, Fourier transform infrared (FTIR), and X-ray diffraction (XRD) analyses before and after TC adsorption. The removal percentage of 30 mg/L TC by SWy-2 reached 70.76% within 0.25 h and gradually increased to 78.64% at 6 h. TC adsorption was influenced by pH and ionic strength, where low pH enhanced and high ionic strength reduced the adsorption. The kinetics of TC adsorption followed a pseudo-second-order model, and the adsorption isotherm adhered to the Langmuir equation. The saturated adsorption capacity (qmax) of SWy-2 for TC was 227.27 mg/g. Zeta potential, FTIR, and XRD analyses confirmed that electrostatic interactions and chemical bonds played a significant role in the TC adsorption by SWy-2. SWy-2 clay mineral exhibits a substantial adsorption capacity for TC, indicating its potential as an effective sorbent to mitigate antibiotic contamination in estuaries and nearby coastal areas. The observed effects of pH and ionic strength on TC adsorption have implications for the environmental fate and transport of antibiotics. The pseudo-second-order kinetic model and Langmuir isotherm equation provide valuable insights into the adsorption behavior and capacity of TC on SWy-2. Characterization analyses support the involvement of electrostatic interactions and chemical bonds in the SWy-2-TC adsorption mechanism.

Numeric and nonnumeric information input to predict adsorption amount, capacity and kinetics of tetracyclines by biochar via machine learning

Pyrolysis temperature affects the physiochemical characteristics of lanthanum-modified biochar derived from orange peels: Insights into the mechanisms of tetracycline adsorption by spectroscopic analysis and theoretical calculations

In this study, the adsorption of the antibiotic compound tetracycline (TC) from aquaculture wastewater was investigated using lanthanum‐modified carbon nanotubes (La‐CNTs) prepared by impregnation method. The composition and morphology of La‐CNTs were characterized by EDS, XRD, and BET analysis. Single‐factor experiments were performed to investigate their effect on the adsorption of TC by La‐CNTs. The adsorption kinetics and adsorption isotherms indicated that the pseudo‐second‐order kinetic model and Langmuir adsorption isotherm equation adequately described the adsorption behavior of La‐CNTs. Moreover, the maximum adsorption capacity () was 93.46 mg/g. The thermodynamics studies indicated that adsorption of TC by La‐CNTs were endothermic and spontaneous respectively. Further, the adsorption force of La‐CNTs on TC could be attributed to van der Waals force, π–π adsorbate–adsorbent interaction and electrostatic interaction. Based on these experimental results, this novel composite material shows good potential application value for the removal of TC from aquaculture wastewater.

The adsorption and desorption behavior of tetracycline on an Alfisol and an Ultisol was investigated at varying soil/solution ratios (1:10, 1:50, and 1:100) and different cation types (CaCl 2 , KCl, and NaCl) and H 2 O using a batch equilibration experiment. Kinetic studies revealed that the adsorption of tetracycline on the two soils was rate limited, and the adsorption kinetics could be well described by the Elovich equation and exponent equation. Changes in the soil/solution ratio affected the relative equilibration time in the Ultisol, but there was no effect of the initial tetracycline concentration. The adsorption rate in the soils decreased as the soil/solution ratio increased from 1:50 to 1:10. The adsorption and desorption data on tetracycline in the two soils could be described by the Freundlich isotherm equation, with r values >0.952 under all experimental treatments. The Ultisol always had stronger adsorption (higher distribution coefficient [ K d ] value) than the Alfisol under all experimental conditions. The K d values decreased with increasing soil/solution ratios in the two tested soils at 1 or 1.25 mg L −1 of tetracycline; however, this trend did not occur at 25 mg L −1 of tetracycline. The adsorption isotherm had an S‐type curve that changed into an L‐type curve with decreasing soil/solution ratios from 1:10 to 1:100. The presence of cations in the soil solution, especially CaCl 2 , can significantly reduce the adsorption of tetracycline in soils. The presence of cations also significantly reduced the nonlinearity of the adsorption isotherms.

Sulfur-doped zero-valent iron supported on biochar for tetracycline adsorption and removal

Molecularly imprinted particle embedded composite cryogel for selective tetracycline adsorption

Hierarchical tannin-derived carbons as efficient tetracycline adsorbents

Antibiotic pollution poses a serious environmental concern worldwide, posing risks to ecosystems and human well-being. Transforming waste activated sludge into adsorbents for antibiotic removal aligns with the concept of utilizing waste to treat waste. However, the adsorption efficiency of these adsorbents is currently limited. This study identified KOH modification as the most effective method for enhancing tetracycline (TC) adsorption by sludge biochar through a comparative analysis of acid, alkali, and oxidant modifications. The adsorption characteristics of TC upon unmodified sludge biochar (BC) as well as KOH-modified sludge biochar (BC-KOH) were investigated in terms of equilibrium, kinetics, and thermodynamics. BC-KOH exhibited higher porosity, greater specific surface area, and increased abundance of oxygen-based functional groups compared to BC. The TC adsorption on BC-KOH conformed the Elovich and Langmuir models, with a maximum adsorption capacity of 243.3 mg/g at 298 K. The adsorption mechanisms included ion exchange, hydrogen bonding, pore filling, and electrostatic adsorption, as well as π-π interactions. Interference with TC adsorption on BC-KOH was observed with HCO3−, PO43−, Ca2+, and Mg2+, whereas Cl−, NO3−, and SO42− ions exhibited minimal impact on the adsorption process. Following three cycles of utilization, there was a slight 5.94% reduction in the equilibrium adsorption capacity, yet the adsorption capacity remained 4.5 times greater than that of unmodified sludge BC, underscoring its significant potential for practical applications. This research provided new insights to the production and application of sludge biochar for treating antibiotic-contaminated wastewater.

Effects of environmental aging on the adsorption behavior of antibiotics from aqueous solutions in microplastic-graphene coexisting systems

Removal of tetracycline antibiotic from contaminated water media by multi-walled carbon nanotubes: operational variables, kinetics, and equilibrium studies.

The disposal and treatment of antibiotic residues is a recognized challenge due to the huge production, high moisture content, high processing costs, and residual antibiotics, which caused environmental pollution. Antibiotic residues contained valuable components and could be recycled. Using a one-step controllable pyrolysis technique in a tubular furnace, biochar (OSOBs) was produced without the preliminary carbonization step, which was innovative and time- and cost-saving compared to traditional methods. The main aim of this study was to explore the adsorption and removal efficiency of tetracycline (TC) in water using porous biochar prepared from oxytetracycline fermentation residues in one step. A series of characterizations were conducted on the prepared biochar materials, and the effects of biochar dosage, initial tetracycline concentration, reaction time, and reaction temperature on the adsorption capacity were studied. The experimental results showed that at 298 K, the maximum adsorption capacity of OSOB-3-700 calculated by the Langmuir model reached 1096.871 mg/g. The adsorption kinetics fitting results indicated that the adsorption of tetracycline on biochar was more consistent with the pseudo-second-order kinetic model, which was a chemical adsorption. The adsorption isotherm fitting results showed that the Langmuir model better described the adsorption process of tetracycline on biochar, indicating that tetracycline was adsorbed in a monolayer on specific homogeneous active sites through chemical adsorption, consistent with the kinetic conclusions. The adsorption process occurred on the surface of the biochar containing rich active sites, and the chemical actions such as electron exchange promoted the adsorption process.

Exploiting effective sorbents for antibiotic adsorption is highly desirable for the elimination of ecological risks from antibiotic contamination. In this study, MgAl-CO(3)(2-) hydrotalcites with different Mg/Al molar ratios were prepared and tetracycline (TC) adsorption to the hydrotalcites and calcined hydrotalcites was investigated by batch experiments. Calcined hydrotalcites had higher adsorption capacities compared to MgAl-CO(3)(2-) hydrotalcites. At low TC equilibrium concentrations, calcined hydrotalcites with differing Mg/Al ratios showed approximately identical TC uptakes. However, at high tetracycline concentration, greater TC adsorption capacity was observed for calcined hydrotalcite having a high Mg/Al ratio (i.e., 4.4). X-ray diffraction (XRD) characterization showed the presence of Mg-Al oxide solid solution in TC -loaded calcined hydrotalcite, suggesting that suspension of the calcined product in water and adsorption of TC had led to only partial reconstruction of the layered structure. We hypothesize that TC was adsorbed on the MgO surface at high equilibrium concentrations. The behavior of TC adsorption on the calcined hydrotalcite was well described by a dual adsorption model. Kinetic analysis suggested that at low adsorption levels, TC adsorption by calcined hydrotalcite could be modeled by both a pseudo second-order kinetics model and a nucleation-growth model. The present work demonstrates that calcined hydrotalcites may be promising adsorbents for effective removal of TC from water resources.

Adsorption of tetracycline and Cd(II) on polystyrene and polyethylene terephthalate microplastics with ultraviolet and hydrogen peroxide aging treatment

Experimental data and model prediction of tetracycline adsorption and desorption in agricultural soils