Abstract:Birnessite is one of the most common manganese oxides in the clay-sized fraction (\2 lm) of soils and has high cation exchange capacity and larger surface area. Birnessite was previously studied for decomposition of selected antibiotics from water. In this study, the removal of tetracycline (TC) by birnessite from aqueous solution was investigated as a function of initial tetracycline concentration, solution pH, temperature, and equilibrium time. Changes in solid phase after TC adsorption and desorption were c… Show more
“…All experiments were conducted at constant temperature using cooling water and temperature controller. At pre-specified time intervals, 2 mL sample was withdrawn, filtered through 0.22 μm syringe filter and mixed with the same volume of methanol to quench the reaction before analysis [ 3 ]. Fig 1 Schematic of the experimental used in this study; (1) temperature controller, (2) water-circulating (3) TC solution reactor (4) cooling water inlet, (5) cooling water outlet (6) sampling port …”
Section: Methodsmentioning
confidence: 99%
“…Tetracycline (TC) is extensively used for the prevention and treatment of infectious diseases in human and veterinary medicine and as feed additives for promote growth in agriculture [ 1 , 2 ]. Because of their extensive usage, their strongly hydrophilic feature, low volatility [ 2 ] and relatively long half-life [ 3 ], TC antibiotic has been frequently detected in different environmental matrices: surface waters (0.07-1.34 μg/L) [ 4 ], soils (86.2-198.7 μg/kg) [ 5 ], liquid manures (0.05-5.36 μg/kg) [ 5 ] and in 90 % of farm lagoon samples (>3 μg/L) [ 6 ]. In addition to environmental contamination, the occurrence of TC in the aquatic environments would also increase antibiotic resistance genes [ 7 ].…”
BackgroundIn this study, a central composite design (CCD) was used for modeling and optimizing the operation parameters such as pH, initial tetracycline and persulfate concentration and reaction time on the tetracycline degradation using sono-activated persulfate process. The effect of temperature, degradation kinetics and mineralization, were also investigated.ResultsThe results from CCD indicated that a quadratic model was appropriate to fit the experimental data (p < 0.0001) and maximum degradation of 95.01 % was predicted at pH = 10, persulfate concentration = 4 mM, initial tetracycline concentration = 30.05 mg/L, and reaction time = 119.99 min. Analysis of response surface plots revealed a significant positive effect of pH, persulfate concentration and reaction time, a negative effect of tetracycline concentration. The degradation process followed the pseudo-first-order kinetic. The activation energy value of 32.01 kJ/mol was obtained for US/S2O82- process. Under the optimum condition, the removal efficiency of COD and TOC reached to 72.8 % and 59.7 %, respectively. The changes of UV–Vis spectra during the process was investigated. The possible degradation pathway of tetracycline based on loses of N-methyl, hydroxyl, and amino groups was proposed.ConclusionsThis study indicated that sono-activated persulfate process was found to be a promising method for the degradation of tetracycline.
“…All experiments were conducted at constant temperature using cooling water and temperature controller. At pre-specified time intervals, 2 mL sample was withdrawn, filtered through 0.22 μm syringe filter and mixed with the same volume of methanol to quench the reaction before analysis [ 3 ]. Fig 1 Schematic of the experimental used in this study; (1) temperature controller, (2) water-circulating (3) TC solution reactor (4) cooling water inlet, (5) cooling water outlet (6) sampling port …”
Section: Methodsmentioning
confidence: 99%
“…Tetracycline (TC) is extensively used for the prevention and treatment of infectious diseases in human and veterinary medicine and as feed additives for promote growth in agriculture [ 1 , 2 ]. Because of their extensive usage, their strongly hydrophilic feature, low volatility [ 2 ] and relatively long half-life [ 3 ], TC antibiotic has been frequently detected in different environmental matrices: surface waters (0.07-1.34 μg/L) [ 4 ], soils (86.2-198.7 μg/kg) [ 5 ], liquid manures (0.05-5.36 μg/kg) [ 5 ] and in 90 % of farm lagoon samples (>3 μg/L) [ 6 ]. In addition to environmental contamination, the occurrence of TC in the aquatic environments would also increase antibiotic resistance genes [ 7 ].…”
BackgroundIn this study, a central composite design (CCD) was used for modeling and optimizing the operation parameters such as pH, initial tetracycline and persulfate concentration and reaction time on the tetracycline degradation using sono-activated persulfate process. The effect of temperature, degradation kinetics and mineralization, were also investigated.ResultsThe results from CCD indicated that a quadratic model was appropriate to fit the experimental data (p < 0.0001) and maximum degradation of 95.01 % was predicted at pH = 10, persulfate concentration = 4 mM, initial tetracycline concentration = 30.05 mg/L, and reaction time = 119.99 min. Analysis of response surface plots revealed a significant positive effect of pH, persulfate concentration and reaction time, a negative effect of tetracycline concentration. The degradation process followed the pseudo-first-order kinetic. The activation energy value of 32.01 kJ/mol was obtained for US/S2O82- process. Under the optimum condition, the removal efficiency of COD and TOC reached to 72.8 % and 59.7 %, respectively. The changes of UV–Vis spectra during the process was investigated. The possible degradation pathway of tetracycline based on loses of N-methyl, hydroxyl, and amino groups was proposed.ConclusionsThis study indicated that sono-activated persulfate process was found to be a promising method for the degradation of tetracycline.
“…One of the ways of removing TCs or other pharmaceutical compounds is adsorption on clays, biochar, activated carbon, iron and manganese oxides or ion exchange resins (Ahmed et al, 2015;Jiang et al, 2015;Liu et al, 2017;Mohd Amin et al, 2016;Zhao et al, 2014). Table 1 shows a relation of TCs adsorption capacity of various materials.…”
Tetracyclines are one of the most widely used class of veterinary and human antibiotics. The conventional treatment of wastewater based on activated sludge is not effective to remove antibiotics and their residues are still biologically active, which represents a problem in terms of bacterial resistance. The main objective of this work is to assess ability of stevensite and two biochars to adsorb three tetracycline antibiotics from water. Batch adsorption experiments were carried out to test the ability of these materials to adsorb tetracyclines. Then desorption experiments were performed to determine the adsorption strength on stevensite. In order to elucidate the adsorption mechanism of tetracyclines on stevensite, cation exchange analysis and spectroscopic analyses by IR and XRD were performed. The adsorption of tetracyclines on stevensite was tested on continuous system with water artificially contaminated. Finally, the designed filter was validated with tetracyclines spiked wastewater. The two biochars and stevensite were able to adsorb between 60 and 100% of the tetracyclines present in the batch system. Stevensite was the material with the highest tetracyclines removal capacity (around 100% at low concentrations of tetracyclines). Biochars showed less affinity for tetracyclines adsorption (70%). Tetracyclines desorption from stevensite reached values lower than 10% for low tetracyclines concentrations. The IR spectroscopy suggested that cation exchange is the main mechanism of tetracyclines adsorption on clay and also proved the role of amide and amine groups in this adsorption. The cation exchange mechanism was confirmed by displacement of Ca and Mg from stevensite. A continuous wastewater flow through a system composed by stevensite leaved this system with no tetracyclines, indicating water purification by tetracyclines adsorption in clay.
“…Because of its high efficiency, lack of byproducts and other characteristics, adsorption methods have been widely used in the removal of TCs from water [ 8 , 12 , 13 , 14 ]. Adsorbent materials currently being studied include graphene oxide (GO) [ 15 ], magnetite [ 9 , 12 , 13 ], goethite [ 16 ], birnessite [ 17 ], and chitosan [ 18 ]. GO is a two-dimensional material consisting of a single layer of carbon atoms arranged in six-membered rings and is one of the thinnest known 2-D materials [ 19 ].…”
A readily separated composite was prepared via direct assembly of Fe3O4 magnetic nanoparticles onto the surface of graphene oxide (GO) (labeled as Fe3O4@GO) and used as an adsorbent for the removal of tetracycline (TC) from wastewater. The effects of external environmental conditions, such as pH, ionic strength, humic acid (HA), TC concentration, and temperature, on the adsorption process were studied. The adsorption data were analyzed by kinetics and isothermal models. The results show that the Fe3O4@GO composite has excellent sorptive properties and can efficiently remove TC. At low pH, the adsorption capacity of Fe3O4@GO toward TC decreases slowly with increasing pH value, while the adsorption capacity decreases rapidly at higher pH values. The ionic strength has insignificant effect on TC adsorption. The presence of HA affects the affinity of Fe3O4@GO to TC. The pseudo-second-order kinetics model and Langmuir model fit the adsorption data well. When the initial concentration of TC is 100 mg/L, a slow adsorption process dominates. Film diffusion is the rate limiting step of the adsorption. Importantly, Fe3O4@GO has good regeneration performance. The above results are of great significance to promote the application of Fe3O4@GO in the treatment of antibiotic wastewater.
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