Degradation Of Chlortetracycline Research Articles

Elucidating the Stimulatory and Inhibitory Effects of Dissolved Organic Matter from Poultry Litter on Photodegradation of Antibiotics.

This study examined the photolytic fate of the chlortetracycline (CTC), ciprofloxacin (CIP), roxarsone (ROX), and sulfamethoxazole (SMX) antibiotics in agriculturally relevant matrices. The observed photodegradation kinetics for antibiotics in solutions containing dissolved organic matter (DOM) from three poultry litter extracts was modeled to identify contributions from direct and indirect photolysis. Suwannee River natural organic matter (SRN) was used as a surrogate DOM standard. Poultry litter-derived DOM generated lower concentrations of reactive species compared to SRN. Direct photolysis was the dominant transformation mechanism for CIP, whereas CTC, ROX, and SMX were sensitized by 3DOM* and 1O2. The impacts of agricultural DOM on photodegradation of antibiotics were identified in terms of pseudo-first-order rate constants for formation of reactive species and second-order rate constants for reaction of reactive species with DOM. Solutions containing poultry litter-derived DOM generated similar levels of 3DOM* and 1O2, enhancing degradation of CTC, ROX, and SMX. The reactivity of SMX was markedly different in solutions containing poultry litter DOM compared to solutions with SRN, indicating that the photolytic fate of select antibiotics varies for agricultural and surface water matrices. As the majority of antibiotics are consumed by animals, these findings provide new insight into agriculturally relevant transformation mechanisms and kinetics.

Removal of Chlortetracycline and Morphological Changes in Heavy Metals in Swine Manure Using the Composting Process

The widespread use of antibiotics and heavy metals in livestock farms results in large residues of antibiotics and heavy metals in the livestock manure. Composting technology can biodegrade residual antibiotics and solidify heavy metals. A pilot composting reactor was used to analyze the characteristics of chlortetracycline (CTC) removal at different antibiotic concentrations[0 mg·kg-1 (CK), 10 mg·kg-1 (T1), and 50 mg·kg-1 (T2)]. Moreover, the morphological changes in heavy metals during the composting process were analyzed. After composting, no chlortetracycline was detected in the CK group and the antibiotics degradation rates of T1 and T2 groups reached 96.31% and 97.32%, respectively. The chlortetracycline degradation fits the pseudo-first-order kinetics model. Heavy metals can be solidified during the composting; thus, the bioavailable state of Cu and Zn (exchangeable state, reducible state) changed into the oxidation state and residues with apparent passivation formed. The correlation analysis showed that the removal of CTC showed strong positive correlations with the biological available Cu and Zn.

Degradation of chlortetracycline using immobilized laccase on Polyacrylonitrile-biochar composite nanofibrous membrane

The continuous release of antibiotic compounds through wastewater effluent into environment has raised concerns about their potential problems for different organisms. Enzymatic degradation with laccase is a green option for removal of pharmaceutical compounds from aqueous media. In this study, laccase was immobilized onto homemade Polyacrylonitrile-biochar composite nanofibrous membrane and the obtained biocatalyst was employed for removal of chlortetracycline, a widely used antibiotic, from aqueous media in continuous mode. The results showed that the immobilized laccase has improved storage, temperature and pH stability compared to free laccase. Also, it retained more than 50% of its initial activity after 7cycles of ABTS oxidation which indicated improved enzyme reusability. Finally, while using immobilized laccase for degradation of chlortetracycline in continuous mode exhibited 58.3%, 40.7% and 22.6% chlortetracycline removal efficiency at flux rates of 1, 2 and 3mL/h∙cm2.

Preparation of porous CuO nanosheet-liked structure (CuO-NS) using C 3 N 4 template with enhanced visible-light photoactivity in degradation of chlortetracycline

Abstract After applying for many years, antibiotics, such as chlortetracycline (CTC), have been widely detected in aquatic environment. The persistence and toxicity effect of them ungently calling for better solution. In this study, CuO nanosheet-liked structure has been successfully synthesized through a C 3 N 4 templating method with the presence of benzyl alcohol and sodium citrate by assembling small CuO nanoparticles onto the surface of C 3 N 4 nanosheet. Because of the C 3 N 4 -liked structure, narrowing band gap, enhanced visible light absorption and decreased recombination rate of photogenerated electron-hole pairs, the as-prepared CuO nanosheet-liked structure exhibits an enhanced visible-light photocatalytic activity in the degradation of CTC. Furthermore, Pt nanoparticles with a dimension around 10 nm have been loaded onto the surface of CuO nanosheet-liked structure to enhance the visible-light photoactivity of the photocatalyst. For the first time, the CuO-based photocatalyst can be applied in the photocatalytic degradation of CTC and displays an improved performance while comparing to TiO 2 -based photocatalysts. In particular, nearly 50% concentration of CTC in the solution can be degraded with the presence of Pt/CuO-NS-2 in 120 min. With the synergy effect between H 2 O 2 and Pt/CuO-NS-2, the degradation efficiency and ability of CTC has been further improved. Around 80% of CTC in the solution was degraded in 60 min.

Synthesis and characterization of porous TiO 2 -NS/Pt/GO aerogel: A novel three-dimensional composite with enhanced visible-light photoactivity in degradation of chlortetracycline

Abstract Chlortetracycline (CTC) has been widely applied as antibiotic for years and frequently detected in water. The presence of CTC not only leading inhibition of growth and toxic effect to specific species, but also raising concern for their potential influences of human health. In order to decline the negative effect and water pollution causing by the chlortetracycline (CTC), a novel aerogel named TPGA with 3D structure has been successfully fabricated using graphene oxide (GO), titanium dioxide nanosheets and platinum nanoparticles as raw materials. The structures and properties of this composite are carefully characterized by multiple methods, including TEM, SEM, SRD, EDS, FTIR, DRS and PL. Because of the increased separation and transfer of photogenerated electron-hole pairs, enlarged surface area and improved utilization of visible light, the TPGA composite exhibits an improved photocatalytic activity in the degradation of CTC under visible-light irradiation. In particular, while the mTiO2-NS/Pt: mGO = 0.5, around 45% of CTC in the solution can be degraded in 90 min.

Biodegradation of chlortetracycline by acclimated microbiota

Abstract The wide presence of antibiotic chlortetracycline in the environment has aroused increasing ecological and human health concerns. Biodegradation can be a promising strategy to dissipate chlortetracycline. However, there is a paucity of knowledge on the biodegradation of chlortetracycline. The present study investigated the biodegradation of chlortetracycline by a microbial community in liquid culture, the potential intermediates, the influences of temperature, external carbon and nitrogen sources, and the composition of chlortetracycline-degrading microbial community. At the initial chlortetracycline level of 100 μg l−1, the average removal rates of 48.7% and 84.9% were achieved by acclimated microbial populations in one and four weeks, respectively. Four potential intermediates were identified using LC/MS/MS analysis. Moreover, microbial growth was observed with chlortetracycline biodegradation. Chlortetracycline could be used as sole carbon and nitrogen sources by the microbial community, while temperature rise and addition of external nitrogen source favored chlortetracycline biodegradation. Illumina MiSeq high-throughput sequencing analysis indicated that bacterial community structure considerably changed with the degradation of chlortetracycline. Firmicutes, Proteobacteria and Bacteroidetes were the dominant phylum groups in chlortetracycline-degrading bacterial community.

Chlortetracycline removal by using hydrogen based membrane biofilm reactor

In the last years, increasing attention has been paid on the presence of antibiotics in aqueous environments due to their ecological damage and potential adverse effects on organisms. Membrane biofilm reactors (MBfR) have been gained a significant popularity as an advanced wastewater treatment technology in removing of organic micro-pollutants. In this study, the performance of H2-MBfR for simultaneous removal of nitrate and chlortetracycline, formation of transformation products and community analysis of the biofilm grown on the gas permeable hollow fiber membranes was evaluated by considering effect of the hydraulic retention time, surface loadings of target pollutants and H2 pressure. The results showed that the simultaneous chlortetracycline (96%) and nitrate removal (99%) took placed successfully under the conditions of 5h HRT and 2psi H2 pressure. It has been determined that the main elimination process was biodegradation and Betaproteobacteria species was responsible for chlortetracycline degradation.

Hierarchical La0.7Ce0.3FeO3/halloysite nanocomposite for photocatalytic degradation of antibiotics

The hierarchical La0.7Ce0.3FeO3/halloysite nanotubes (HNTs) composites have been successfully prepared via sol–gel method. XRD and TEM characterizations indicated that the sheet-like La0.7Ce0.3FeO3 coupled with the co-precipitated CeO2 were evenly deposited onto the surface of halloysite. The photocatalytic degradation of chlortetracycline under visible light irradiation using La0.7Ce0.3FeO3/HNTs as catalyst was evaluated by high-performance liquid chromatography, which exhibited remarkable photocatalytic activity with the removal rate up to 99 % in 90 min, due to the formation of “solid solution/co-precipitation” heterostructure as well as the excellent adsorptive capability of halloysite for antibiotics.

Degradation of chlortetracycline in wastewater sludge by ultrasonication, Fenton oxidation, and ferro-sonication

Residual emerging contaminants in wastewater sludge remain an obstacle for its wide and safe applications such as landfilling and bio-fertilizer. In this study, the feasibility of individual ultrasonication (UlS) and Fenton oxidation (FO) and combined, Ferro-sonication processes (FO) on the degradation of chlortetracycline (CTC) in wastewater sludge was investigated. UlS parameters such as amplitude and sonication time were optimized by response surface methodology (RSM) for further optimization of FS process. Generation of highly reactive hydroxyl radicals in FO and FS processes were compared to evaluate the degradation efficiency of CTC. Increasing in the ratio of hydrogen peroxide and iron concentration showed increased CTC degradation in FO process; whereas in FS, an increase in iron concentration did not show any significant effect (p>0.05) on CTC degradation in sludge. The estimated iron concentration in sludge (115mg/kg) was enough to degrade CTC without the addition of external iron. The only adjustment of sludge pH to 3 was enough to generate in-situ hydroxyl radicals by utilizing iron which is already present in the sludge. This observation was further supported by hydroxyl radical estimation with adjustment of water pH to 3 and with and without the addition of iron. The optimum operating UlS conditions were found to be 60% amplitude for 106min by using RSM. Compared to standalone UlS and FO at 1:1 ratio, FS showed 15% and 8% increased CTC degradation respectively. In addition, UlS of sludge increased estrogenic activity 1.5 times higher compared to FO. FS treated samples did not show any estrogenic activity.

Electrooxidation–Ultrasonication Hybrid Process for Antibiotic Chlortetracycline Treatment

AbstractThis study investigated the electrochemical oxidation of chlortetracycline in aqueous solution using a Ti/PbO2 anode under ultrasound irradiations. The influence of various parameters such as electric current applied, power of ultrasound, and treatment time were evaluated and optimization process was investigated by using factorial design and central composite design methodology. The results indicated that the chlortetracycline degradation rate was greatly influenced by the current and the treatment time. A current intensity of 3.92 A under ultrasound irradiation of 20 W (at 500 kHz) for a period of treatment of 95 min were found to be the best conditions for chlortetracycline oxidation in term of cost-effectiveness. The initial concentration (10 mg/L) could be optimally diminished up to 73.3% while using a Ti/PbO2 anode. Under these conditions, a relatively high mineralization of chlortetracycline (61.4% of total organic carbon removal) was recorded. Then, the optimal conditions were applied on ...

One-pot solvothermal synthesis of magnetic SnFe2O4 nanoparticles and their performance in the photocatalytic degradation of chlortetracycline with visible light radiation

Highly crystalline SnFe2O4 nanoparticles with high saturation magnetization and superior chlortetracycline degradation efficiency was developed using a one-pot solvothermal method.

Role of 1[O2]∗ in chlortetracycline degradation by solar radiation assisted by ruthenium metal complexes

This study was aimed at the degradation of chlortetracycline (CTC) in aqueous solution by direct and indirect photooxidation employing a solar simulator. Ruthenium complexes, tris-(2,2′-bipyridine) ruthenium(II) chloride (Ru3B), and tris-(1,10-phenanthroline) ruthenium(II) chloride (Ru3P) were used as photosensitizers to promote singlet oxygen (1[O2]∗) formation in indirect photooxidation. The degradation kinetics of CTC followed a first-order kinetic, and the rate constant and the maximum percentage of degradation decreased by raising the concentration of CTC. This effect was attributed to that the amount of radiant energy absorbed by each CTC molecule decreased by raising the concentration of CTC. Addition of Ru3B produced a 6.98-fold increase in the degradation rate and 3-fold increment in the maximum percentage of degradation in comparison to direct photolysis. This is due to the formation of 1[O2]∗ in the aqueous medium, as corroborated by the finding that a reduction in the level of dissolved oxygen produces a proportional decrease in the removal rate of CTC. High-resolution mass spectrometry studies demonstrated that degradation byproducts result from reduction–oxidation processes and the loss of functional groups, highlighting the hydrolysis and reduction of the primary amide, the formation of double bonds, and the addition of 1[O2]∗ to the aromatic ring of CTC. The presence of humic acid in the solution favored direct photolysis but inhibited the action of photosensitizers.

Effects of straw addition on increased greenhouse vegetable yield and reduced antibiotic residue in fluvo-aquic soil

Organic manure application is an important measure for high yield and good quality vegetable production, whereas organic manure is also a main source of residual antibiotic in soils. A 3-yr experiment was conducted on a fluvo-aguic soil in Tianjin of northern China. The objective of this study was to investigate the effects of different fertilization patterns on yield of six-season vegetables with celery and tomato rotation, and dynamic change of tetracyclines residues in the soil during the sixth growing season (tomato season). The field experiment comprised six treatments depending on the proportion of nitrogen of each type of fertilizer: 4/4 CN (CN, nitrogen in chemical fertilizer), ¾ CN+¼ MN (MN, nitrogen in pig manure), 2/4 CN+2/4 MN, ¼ CN+¾ MN, 2/4 CN+¼ MN+¼ SN (SN, nitrogen in corn straw), and CF (conventional fertilization, the amounts of nitrogen application were 943 and 912 kg N ha−1 for celery and tomato season, respectively). In addition to CF treatment, the amount of nitrogen application in other treatments was greatly reduced and equal (450 and 450 kg N ha−1 for celery and tomato season, respectively). Results showed that the combined application of ¾ CN+¼ MN achieved the highest yield and economic benefit in the first four seasons, but addition of straw (2/4 CN+¼ MN+¼ SN treatment) performed better in the subsequent two seasons, and the average yields of 2/4 CN+¼ MN+¼ SN treatment were respectively higher by 9.9 and 12.8% than those of 4/4 CN treatment, and by 5.6 and 10.5% than those of CF treatment. The residual chlortetracycline (CTC) in manure-amended soil for three consecutive years increased along with the increase of applied amount of pig manure. Under the same amount of pig manure application, content of CTC in straw-amended soil was obviously decreased compared with no straw-amended soil (¾ CN+¼ MN treatment), and averagely decreased by 41.9% for four sampling periods in the sixth season. Addition of crop straw facilitated the degradation of CTC in manure-amended soil. As a whole, the conventional fertilization was not the desirable pattern based on yield, economic benefit and environment, the optimal fertilization pattern with the highest yield and profit and the least soil chlortetracycline residue was the treatment of 2/4 CN+¼ MN+¼ SN under this experimental condition.

Effect of the chlortetracycline addition method on methane production from the anaerobic digestion of swine wastewater

Effects of antibiotic residues on methane production in anaerobic digestion are commonly studied using the following two antibiotic addition methods: (1) adding manure from animals that consume a diet containing antibiotics, and (2) adding antibiotic-free animal manure spiked with antibiotics. This study used chlortetracycline (CTC) as a model antibiotic to examine the effects of the antibiotic addition method on methane production in anaerobic digestion under two different swine wastewater concentrations (0.55 and 0.22mg CTC/g dry manure). The results showed that CTC degradation rate in which manure was directly added at 0.55mg CTC/g (HSPIKE treatment) was lower than the control values and the rest of the treatment groups. Methane production from the HSPIKE treatment was reduced (p<0.05) by 12% during the whole experimental period and 15% during the first 7days. The treatments had no significant effect on the pH and chemical oxygen demand value of the digesters, and the total nitrogen of the 0.55mg CTC/kg manure collected from mediated swine was significantly higher than the other values. Therefore, different methane production under different antibiotic addition methods might be explained by the microbial activity and the concentrations of antibiotic intermediate products and metabolites. Because the primary entry route of veterinary antibiotics into an anaerobic digester is by contaminated animal manure, the most appropriate method for studying antibiotic residue effects on methane production may be using manure from animals that are given a particular antibiotic, rather than adding the antibiotic directly to the anaerobic digester.

A persistent antibiotic partitioning and co-relation with metals in wastewater treatment plant—Chlortetracycline

The addition of high concentration of chlortetracycline (CTC) antibiotic to livestock feed and its resistance toward degradation results in accumulation of CTC in the environment. The strong chelation activity of CTC with metal ions has impact on numerous factors, such as solubility, stability, degradation, and antibacterial activity of CTC in wastewater treatment plant (WWTP). Further, no studies have been carried out on the chelation behavior of CTC with metal ions and its effect on removal efficiency from WWTP. This study attempts to provide the information about CTC distribution in wastewater (WW) and wastewater sludge (WWS) and the role of CTC–metals complexation on this behavior. The analytical method developed in this study combines an existing pre-treatment technique of solid-phase extraction (SPE) with laser diode thermal desorption (LDTD) coupled with tandem mass spectrometry (MS/MS). LDTD–MS/MS analysis has been recently developed to enhance the high throughput capacity in MS by reducing LC–MS/MS runs of 5–30min to 10–30s in LDTD–MS/MS run. This study considered the most common, polluting and efficient metal ions (Al(III), Ca(II), Co(II), Cu(II), Fe(III), Mg(II), Ni(II) and Zn(II)) which have a tendency to complex with CTC in WW. Chlortetracycline–metal complex and its mobility in WWTP were well-correlated which showed that CTC concentration in WWS was higher than the WW. These results showed that the water soluble CTC became insoluble and/or relatively less soluble after chelation with metal ions. Furthermore, the results signify the importance of chelation property of CTC and serve as a tool in determining the wastewater treatment plant matrix to be treated and also the type of treatment method to be used.

Electrochemical degradation of chlortetracycline using N-doped Ti/TiO2 photoanode under sunlight irradiations

The appearance and the persistence of pharmaceutical products in the aquatic environment urgently call for the development of an innovative and practical water treatment technology. This study deals with the development of nanostructured nitrogen-doped TiO2 photoanodes and their subsequent use for chlortetracycline (CTC) photoelectrocatalytic oxidation under visible light. The N-doped TiO2 photoanodes with different nitrogen contents were prepared by means of a radiofrequency magnetron sputtering (RF-MS) process, with the objective to tune shift their optical absorption from the UV towards the visible. The N-doped TiO2 consist of nanostructured anatase phase with average TiO2 nanocrystallite size of 29 nm. The nitrogen doping is clearly shown to produce the desired red shift of the absorption onset of the TiO2 coatings (from ∼380 nm to ∼550 nm). Likewise, the N-doped TiO2 are found to be highly photo-electroactive not only under the UV light but most interestingly under the visible light as well. Using the optimal N-doped photoanodes, 99.6% of CTC (100 μg/L) was successfully degraded after 180 min of treatment time with a current intensity of 0.6 A. Under these conditions, a relatively high mineralization of CTC (92.5% ± 0.26% of TOC removal and 90.3% ± 1.1% of TN removal) was achieved.

Removal of chlortetracycline from spiked municipal wastewater using a photoelectrocatalytic process operated under sunlight irradiations

The degradation of chlortetracycline in synthetic solution and in municipal effluent was investigated using a photoelectrocatalytic oxidation process under visible irradiation. The N-doped TiO2 used as photoanode with 3.4 at.% of nitrogen content was prepared by means of a radiofrequency magnetron sputtering (RF-MS) process. Under visible irradiation, higher photoelectrocatalytic removal efficiency of CTC was recorded using N-doped TiO2 compared to the conventional electrochemical oxidation, direct photolysis and photocatalysis processes. The photoelectrocatalytic process operated at 0.6A of current intensity during 180min of treatment time promotes the degradation of 99.1±0.1% of CTC. Under these conditions, removal rates of 85.4±3.6%, 87.4±3.1% and 55.7±2.9% of TOC, TN and NH4+ have been recorded. During the treatment, CTC was mainly transformed into CO2 and H2O. The process was also found to be effective in removing indicator of pathogens such as fecal coliform (log-inactivation was higher than 1.2 units).

Chlortetracycline degradation by photocatalytic ozonation in the aqueous phase: mineralization and the effects on biodegradability

Chlortetracycline (CTC) is a hazardous material in aquatic environments. This study was focused on optimization of photocatalytic ozonation processes for removal of CTC from wastewater at pH 2.2 and 7.0. In this study, the tested processes for CTC removal were arranged from the least efficient to the most efficient as: UV, UV/TiO2, O3, O3/UV and O3/UV/TiO2. Ozonation efficiency was due to ozone affinity for electron-rich sites on the CTC molecule. In the O3/UV and O3/UV/TiO2 processes, efficiency was increased by the photolysis of CTC and generation of •OH. At pH 7.0, all the processes were more efficient for CTC degradation than at pH 2.2 due to CTC speciation, ozone decay to •OH and the attractions between ionized CTC and TiO2 particles. UV/O3 at pH 7.0 showed an additive effect while other combination processes showed a synergistic effect that resulted in higher rates of reactions than the sums of individual reaction rates. The TOC removal ranged from 8% to 41% after one hour of reaction, with the above-mentioned order of efficiency. The biodegradability increased rapidly during the early minutes of the reaction. A reaction time of 10–15 min was sufficient for near maximum biodegradability, making these processes good pretreatments for the biological processes.

Electrochemical Oxidation of Chlortetracycline Using Ti/IrO2 and Ti/PbO2 Anode Electrodes: Application of Experimental Design Methodology

AbstractThe degradation of chlortetracycline hydrochloride in aqueous medium (initial concentration of 10 mg/L) has been studied by electrooxidation process using Ti/PbO2 and Ti/IrO2 anode electrodes. The performance of the electrolytic cell resulted from its capability of reacting on pollutants by using both effects of electrolysis. Indeed, the organic pollutants can be destroyed at the electrode surface where hydroxyl radicals are generated (direct effect), and they can be simultaneously oxidized in solution by means of active chlorine (indirect effect). Different operating parameters, such as current density, reaction time, and temperature, were investigated. The optimal experimental parameters for chlortetracycline degradation have been investigated by using a central composite design (CCD) methodology. It has been demonstrated that under the optimal conditions determined by this method, electrooxidation can economically be applied to oxidize chlortetracycline (96% of degradation for a total cost of ...

Photoelectrocatalytic oxidation of chlortetracycline using Ti/TiO2 photo-anode with simultaneous H2O2 production

This study investigated the photoelectrocatalytic oxidation (PECO) of chlortetracycline (CTC) in aqueous solution using a Ti/TiO2 photocatalyst. The Ti/TiO2 used as photo-anode was prepared by a pulsed laser deposition (PLD) method. The PLD TiO2 coatings were found to have rutile and anatase structures consisting of nano-crystallites of approximately 10nm and 15nm in diameter, respectively. The influence of various parameters such as crystallographic structure of Ti/TiO2, cathode material and pH were evaluated. Experimental results revealed that a current intensity of 0.39A under UV irradiation (245nm) for a period of treatment of 120min was beneficial for CTC oxidation. The initial CTC concentration (25μg/L) could be optimally diminished up to 98.0±0.2% while using a Ti/TiO2 photo-anode having a crystallographic structure of anatase and using vitreous carbon as cathode. Under these conditions, a relatively high mineralization of CTC (67.3±2.15% of TOC removal and 69.3±3.10% of TN removal) was recorded. The initial rate of photoelectrocatalytic degradation of CTC can be well described by the Langmuir–Hinshelwood (L–H) kinetic model (R2=0.9996) with a reaction rate constant of 17.3μg/Lmin. Likewise, microtox (Vibrio fisheri), microalga (Pseudokirchneriella Subcapitata) and Daphnia (Daphnia magna) biotests revealed that the treated – effluent was not toxic compared to the untreated effluent.