Simultaneous Removal Of Antibiotics Research Articles

Efficient elimination of antibiotics and antibiotic resistance genes in hyperthermophilic sludge composting

Composting is widely applied in recycling ever-increasing sewage sludge. However, the insufficient elimination of antibiotics and antibiotic resistance genes (ARGs) in conventional compost fertilizer poses considerable threat to agriculture safety and human health. Here we investigated the efficacy and potential mechanisms in the removal of antibiotics and ARGs from sludge in hyperthermophilic composting (HTC) plant. Our results demonstrated that the HTC product was of high maturity. HTC led to complete elimination of antibiotics and potential pathogens, as well as removal of 98.8 % of ARGs and 88.1 % of mobile genetic elements (MGEs). The enrichment of antibiotic-degrading candidates and related metabolic functions during HTC suggested that biodegradation played a crucial role in antibiotic removal. Redundancy analysis (RDA) and structural equation modelling (SEM) revealed that the reduction of ARGs was attributed to the decline of ARG-associated bacteria, mainly due to the high-temperature selection. These findings highlight the feasibility of HTC in sludge recycling and provide a deeper understanding of its mechanism in simultaneous removal of antibiotics and ARGs.

Superoxide radical induced redox processes for simultaneous reduction of Cr (VI) and oxidation of ciprofloxacin in wastewater

Simultaneous removal of antibiotics and heavy metals from the wastewater is still a sophisticated task with great challenge. Interestingly, •O2- as a long-lived and highly active specie can simultaneously remove antibiotics and heavy metals. Herein, we design a S-type heterojunction photocatalyst, which can efficiently generate •O2-. Characterizations and DFT calculation demonstrate that internal electric field provides powerful propulsion for migration of photo generated carriers between Zn0.78Cd0.22S and g-C3N4, effectively extends electronic life, thereby enhances the production of •O2-. Photocatalytic reaction rate constants under optimal composite ratio conditions were 3.1-times (ciprofloxacin) and 5.9-times (Cr (VI)) higher than Zn0.78Cd0.22S under the coexisting pollutant system. Benefiting from the inbuilt electric field to stimulate electron transfer and utilization as well as the dual function of •O2-, it reveals the possibility of practical wastewater treatment in the internal circulating fluidized bed reactor.

Simultaneous removal of antibiotics and metal oxoanions from aqueous solution by Ce-doped UiO-66: Removal mechanisms and solid phase extraction

Simultaneous removal of coexistent antibiotics and heavy metals from wastewater is crucial for the safety and quality of aquatic ecosystems. Metal-organic frameworks (MOFs) are promising candidates for wastewater remediation due to their robust and tailorable pore structure, but the removal mechanisms for the synchronous removal of multiple pollutants remain unclear. Herein, Ce-doped UiO-66 (Ce-UiO-66) was prepared and utilized to efficiently remove multiple pollutants from water under single and mixed pollutant systems. After Ce doping, the adsorption amounts of pefloxacin (PEF), tetracycline (TC) and Cr(VI) reached 476.3 mg/g, 368.6 mg/g and 58.3 mg/g, respectively, which were 5–10 times higher than those of pristine UiO-66. In the binary system, the presence of Cr(VI) broadened the optimal adsorption pH range of PEF, and Cr(VI) adsorption was enhanced in the presence of low concentrated PEF. Various interactions contributed together to the excellent adsorption ability of Ce-UiO-66. The contribution degree of some interactions was as follows: (1) for PEF adsorption, at 2.0 < pH < 5.0, complexation bonding (CB) accounted for 40–95% of the total uptake; at 5.0 < pH < 10.0, the contribution of electrostatic attraction (EA) increased to approximately 5–36% while CB decreased to 32–50%; (2) for TC adsorption, at 2.0 < pH < 7.0, CB accounted for 50–81% of the total uptake; at 7.0 < pH < 10.0, the contribution of CB increased to approximately 30% and EA at 2.0 < pH < 10.0 accounted for 5–14% of the total uptake; and (3) for Cr(VI) adsorption, at 2.0 < pH < 10.0, EA and CB dominated the adsorption, together accounting for 50–100% of the total uptake. More importantly, the order of functional groups participating in adsorption was revealed by 2D-FTIR-COS analysis. Ce-UiO-66 showed excellent recycling ability and was efficient in removing multiple pollutants from various actual water samples. Moreover, simple solid phase extraction (SPE) experiments revealed that Ce-UiO-66 obtained excellent adsorption capacities of 474.63 mg/g and 261.8 mg/g for PEF and TC, respectively. This study provides a new paradigm for devolving highly robust adsorbents for wastewater treatment.

The difference between bioelectricity and direct current on the simultaneous removal of antibiotics and nitrogen in constructed wetlands

Given its advantages in terms of high efficiency and low energy consumption, bioelectrochemistry - integrated constructed wetlands (BEC-CWs) have been applied widely in the various pollutant removal. However, the study on the synchronous removal performance, difference and molecular mechanism of various pollutants in different BEC-CWs is limited. This study explored the difference of performance and mechanisms on the antibiotics and nitrogen simultaneous removal by microbial fuel cell - integrated CW (MFC-CW) and direct current - integrated CW (EC-CW). Results showed that MFC-CW and EC-CW were all performed better ofloxacin (OFLO) removal (>99 %), where the biodegradation was the key contributor (91.00–94.70 %). The MFC can better promote the substrate adsorption, while EC was more conducive to improve plant uptake for OFLO removal in CWs. MFC-CW (78.86 ± 11.61 %) performed better total nitrogen removal than EC-CW (58.84 ± 12.86 %). The anammox gene (107 ∼ 108 copies·g−1) played an important role in the nitrogen removal. The denitrification performance of BEC-CWs was inhibited due to OFLO addition, especially in EC-CW. MFC-CW inhibited the quinolone resistance genes generation and improved nitrogen removal efficiency by increasing the abundances of related microorganisms. The bioelectricity can improve the microbial diversity in CWs compared to direct current. The OFLO degradation in EC-CW were initiated with defluorination, dealkylation, decarboxylation, and opening of piperazinyl ring, while it was defluorination, dealkylation, and decarboxylation in MFC-CW. EC-CW tended to increase the membrane transport and signal transduction, while MFC tended to improve organic compound metabolism and nitrogen transformation. These findings provide new insights into the difference between bioelectricity and direct current on the synchronous removal of various pollutants in the constructed wetlands.

Simultaneous antibiotic removal and mitigation of resistance induction by manganese bio-oxidation process

Microbial degradation to remove residual antibiotics in wastewater is of growing interest. However, biological treatment of antibiotics may cause resistance dissemination by mutations and horizontal gene transfer (HGT) of antibiotic resistance genes (ARGs). In this study, a Mn(Ⅱ)-oxidizing bacterium (MnOB), Pseudomonas aeruginosa MQ2, simultaneously degraded antibiotics, decreased HGT, and mitigated antibiotic resistance mutation. Intracellular Mn(II) levels increased during manganese oxidation, and biogenic manganese oxides (BioMnOx, including Mn(II), Mn(III) and Mn(IV)) tightly coated the cell surface. Mn(II) bio-oxidation mitigated antibiotic resistance acquisition from an E. coli ARG donor and mitigated antibiotic resistance inducement by decreasing conjugative transfer and mutation, respectively. BioMnOx also oxidized ciprofloxacin (1 mg/L) and tetracycline (5 mg/L), respectively removing 93% and 96% within 24 h. Transcriptomic analysis revealed that two new multicopper oxidase and one peroxidase genes are involved in Mn(II) oxidation. Downregulation of SOS response, multidrug resistance and type Ⅳ secretion system related genes explained that Mn(II) and BioMnOx decreased HGT and mitigated resistance mutation by alleviating oxidative stress, which makes recipient cells more vulnerable to ARG acquisition and mutation. A manganese bio-oxidation based reactor was constructed and completely removed tetracycline with environmental concentration within 4-hour hydraulic retention time. Overall, this study suggests that Mn (II) bio-oxidation process could be exploited to control antibiotic contamination and mitigate resistance propagation during water treatment.

Simultaneous removal of antibiotics and nitrogen by microbial fuel cell-constructed wetlands: Microbial response and carbon–nitrogen metabolism pathways

Microbial fuel cell-constructed wetlands (MFC-CWs) are attracted extensive attention due to their simultaneous removal performance during the co-occurrence of various pollutants in wastewater. This study explored the performance and mechanisms on the simultaneous removal of antibiotics and nitrogen from MFC-CWs which packed with coke (MFC-CW (C)) and quartz sand (MFC-CW (Q)) substrate. Results showed that removal of sulfamethoxazole (93.60 %), COD (77.94 %), NH4+-N (79.89 %), NO3−- N (82.67 %), and TN (70.29 %) significantly enhanced by MFC-CW (C) due to the enhancement of relative abundance of membrane transport, amino acid metabolism and carbohydrate metabolism pathways. The results indicated that coke substrate can generate more electric energy in MFC-CW. Firmicutes (18.56–30.82 %), Proteobacteria (23.33–45.76 %), and Bacteroidetes (17.1–27.85 %) were dominant phyla in the MFC-CWs. MFC-CW (C) posed significant effects on the microbial diversity and structure, which motivated the functional microbes involved in the transformation of antibiotics and nitrogen and bioelectricity generation. Given the overall performance of MFC-CW, packing with cost-effective substrate to electrode region of MFC-CWs was found to be an effective strategy for simultaneously removing antibiotics and nitrogen in the wastewater treatment.

Simultaneous removal of antibiotics and antibiotic resistance genes in wastewater by a novel nonthermal plasma/peracetic acid combination system: Synergistic performance and mechanism

In this study, a novel and green method combining plasma with peracetic acid (plasma/PAA) was developed to simultaneously remove antibiotics and antibiotic resistance genes (ARGs) in wastewater, which achieves significant synergistic effects in the removal efficiencies and energy yield. At a plasma current of 2.6 A and PAA dosage of 10 mg/L, the removal efficiencies of most detected antibiotics in real wastewater exceeded 90 % in 2 min, with the ARG removal efficiencies ranging from 6.3 % to 75.2 %. The synergistic effects of plasma and PAA could be associated with the motivated production of reactive species (including •OH, •CH3, 1O2, ONOO-, •O2- and NO•), which decomposed antibiotics, killed host bacteria, and inhibited ARG conjugative transfer. In addition, plasma/PAA also changed the contributions and abundances of ARG host bacteria and downregulated the corresponding genes of two-component regulatory systems, thus reducing ARG propagation. Moreover, the weak correlations between the removal of antibiotics and ARGs highlights the commendable performance of plasma/PAA in the simultaneous removal of antibiotics and ARGs. Therefore, this study affords an innovative and effective avenue to remove antibiotics and ARGs, which relies on the synergistic mechanisms of plasma and PAA and the simultaneous removal mechanisms of antibiotics and ARGs in wastewater.

Simultaneous removal of triclosan and nitrate by a stable denitrifying microbial consortium

The co-existence of antibiotics and nitrate in common in the aquatic environment, so the simultaneous removal of antibiotics and nitrate is necessary, but still challenge. In this study, a stable denitrifying microbial consortium capable of degrading triclosan was isolated from a long-term operated denitrifying bioreactor used for biological nitrate removal. The microbial consortium consisted of Pseudomonas (93.47 %), Burkholderia (1.56 %) and Cupriavidus (1.17 %) based on high-throughout sequencing analysis. The denitrification efficiency was higher under anoxic condition than that under aerobic condition. However, the accumulation of nitrite was observed under anoxic condition, with maximal concentration of 10.2 mg/L. Triclosan had negative impact on denitrification under both aerobic and anoxic conditions. The pseudo first-order kinetic constant of denitrification was 0.0303 h−1 and 0.0468 h−1 under aerobic and anoxic conditions, respectively. Dechlorination of triclosan was observed under aerobic condition but not under anoxic condition. Hydroxylated-triclosan, 2,4-dichlorophenol and phenol were identified as intermediate products of triclosan degradation.

Efficient adsorption of antibiotics and heavy metals from aqueous solution by structural designed PSSMA-functionalized-chitosan magnetic composite

The simultaneous removal of antibiotics and heavy metals is of great importance due to their harmful effects on the ecosystem and human health. In this work, a novel PSSMA-modified magnetic adsorbent (FO@CC-PM) with permanent porosity was designed and fabricated through polymer grafting and using freshwater snail shell as a pore-forming agent. FO@CC-PM was demonstrated to possess broad pH adaptability and excellent sorption capacities of 412.63, 214.07, 141.70, and 113.07 mg·g−1 for norfloxacin (NOR), sulfadiazine (SD), Cu(II), and Ni(II), respectively. They were significantly higher than other reported adsorbents due to the increased porosity, specific surface area, and functionalized sites. The adsorption process could be well described via the pseudo-second-order model and Langmuir isotherm. Besides, FO@CC-PM displayed satisfactory reusability in synthetic and model wastewater. In binary systems, the coexistence of Cu(II) and NOR promoted the sorption of each other, whereas no significant synergy was observed among Ni(II) and SD. This divergence was originated from the different coordination intensity between diverse co-existing contaminants. As demonstrated by FTIR and XPS analyses, electrostatic interaction, coordination, π-π stacking, hydrogen bonding, and hydrophobic effect were mainly involved in the adsorption mechanisms. This work provides an effective strategy for the custom design of novel adsorbents that can efficiently adsorb both heavy metals and antibiotics over a wide pH range.

Simultaneous Removal of Antibiotics and Heavy Metals with Poly(Aspartic Acid)-Based Fenton Micromotors.

The discharge of diverse pollutants has led to a complex water environment and posed a huge health threat to humans and animals. Self-propelled micromotors have recently attracted considerable attention for efficient water remediation due to their strong localized mass transfer effect. However, a single functionalized component is difficult to tackle with multiple contaminants and requires to combine different decontamination effects together. Here, we introduced a multifunctional micromotor to implement the adsorption and degradation roles simultaneously by integrating the poly(aspartic acid) (PASP) adsorbent with a MnO2 -based catalyst. The as-prepared micromotors are well propelled in contaminated waters by MnO2 catalyzing hydrogen peroxide. In addition, the catalytic ramsdellite MnO2 (R-MnO2 ) inner layer is decorated with Fe2 O3 nanoparticles to improve their catalytic performance, contributing to an excellent degradation ability with 90% tetracycline (TC) removal in 50 minutes by enhanced Fenton-like reactions. Combining the attractive adsorption capability of poly (aspartic acid) (PASP), the composite micromotors offer an efficient removal of heavy metal ions in short time. Moreover, the designed micromotors are able to simultaneously remove antibiotic and heavy metals in mixed contaminants circumstance just in single treatment. This multifunctional micromotor with distinctive decontamination ability exhibits a promising prospective in treating multiple pollutants in the future.

Mechanistic insight of simultaneous removal of tetracycline and its related antibiotic resistance bacteria and genes by ferrate(VI)

The emergence of antibiotics and their corresponding antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) have posed great challenges to the public health. The paper demonstrates the removal of co-existing tetracycline (TC), its resistant Escherichia coli (E. coli), and ARGs (tetA and tetR) in a mixed system by applying ferrate(VI) (FeVIO42−, Fe(VI)) at pH 7.0. TC was efficiently degraded by Fe(VI), and the rapid inactivation of the resistant E. coli was found with the complete loss of culturability. The results of flow cytometry suggested that the damage of membrane integrity and respiratory activity were highly correlated with the Fe(VI) dosages. Moreover, high-dose Fe(VI) eliminates 6 log10 viable but non-culturable (VBNC) cells and even breaks the cells into fragments. ARGs in extracellular form (e-ARGs) exhibited a high sensitivity of 4.44 log10 removal to Fe(VI). Comparatively, no removal of intracellular ARGs (i-ARGs) was observed due to the multi-protection of cellular structure and rapid decay of Fe(VI). The oxidized products of TC were assessed to be less toxic than the parent compound. Overall, this study demonstrated the superior efficiency and great promise of Fe(VI) on simultaneous removal of antibiotics and their related ARB and ARGs in water.

Tailoring aromatic ring-terminated edges of g-C3N4 nanosheets for efficient photocatalytic hydrogen evolution with simultaneous antibiotic removal

A promising “one stone three birds” route to enhance photocatalytic H2 production with simultaneous organic pollutant removal activity.

Enhanced oxytetracycline removal coupling with increased power generation using a self-sustained photo-bioelectrochemical fuel cell

Photo-bioelectrochemical fuel cell (PBFC) represents a promising technology for enhancing removal of antibiotic pollutants while simultaneously sustainable transformation of organic wastes and solar energy into electricity. In this study, simultaneous antibiotic removal and bioelectricity generation were investigated in a PBFC with daily light/dark cycle using oxytetracycline (OTC) as a model compound of antibiotic. The specific OTC removal rate increased by 61% at an external resistance of 50 Ω compared to that in the open-circuit control, which was attributed to bioelectrochemically enhanced co-metabolic degradation in the presence of the bioanode. The OTC removal was obviously accelerated during illumination of cathode in contrast with a dark cathode due to the higher driving force for anodic bioelectrochemical reaction by using photosynthetic oxygen as cathodic electron acceptor during illumination than that using nitrate in dark. The bioelectrocatalytic activity of anodic biofilm was continuously enhanced even at an initial OTC concentration of up to 50 mg L−1. The degradation products of OTC can function as mediators to facilitate the electron transfer from bacteria to the anode, resulting in 1.2, 1.76 and 1.8 fold increase in maximum power output when 10, 30 and 50 mg L−1 OTC was fed to the bioanode, compared to the OTC-free bioanode, respectively. The OTC feeding selective enriched OTC-tolerant bacterial community capable of degrading complex organic compounds and producing electricity. The occurrence of ARGs during bioelectrochemical degradation of OTC was affected more greatly by the succession of the anodic bacterial community than the initial OTC concentration.

Removal of antibiotic resistance genes and control of horizontal transfer risk by UV, chlorination and UV/chlorination treatments of drinking water

This study investigated the reduction of one antibiotic resistance gene (ARG, sul1) and one integron (intI1) within a multiple-antibiotic-resistant bacterium (ARB), Pseudomonas. HLS-6, during UV, chlorination and UV/chlorination. This bacterial strain was easily inactivated by these three methods, but its gene inactivation was not so easy. Two short target gene sequences (sul1-qPCR and intI1-qPCR) were selected for quantitative analysis, and another two longer ones (sul1-PCR and intI1-PCR) were used for qualitative identification. During the initial reaction time (<20 min), the degradation rate order of sul1-qPCR and intI1-qPCR was as follows: UV/chlorination>chlorination>UV. The log reduction of sul1-qPCR and intI1-qPCR in UV/chlorination achieved >3.50 and 4.00 log, respectively. The removal efficiency of sul1-PCR and intI1-PCR was also identified by gel electrophoresis analysis, which further confirmed the advantage of UV/chlorination treatment on DNA damage. Among the radicals produced in UV/chlorination, only the reactive chlorine species (Cl⋅, Cl2⋅− and ClO⋅) can degrade the target genes. Under the condition of low chlorine dosage, sul1-qPCR was easier to be removed than intI1-qPCR by UV/chlorination. The log reduction of both sul1-qPCR and intI1-qPCR decreased with pH increasing during UV/chlorination. In the presence of sulfamethoxazole, UV/chlorination showed more advantages than direct UV and chlorination in the simultaneous removal of antibiotics, ARBs and ARGs.

Degradation of chlorotetracycline and bacterial disinfection in livestock wastewater by ozone-based advanced oxidation

The simultaneous removal of antibiotics and antibiotic-resistant bacteria by ozone-based advanced oxidation technology (AOT) was investigated for the treatment of anaerobic digestion effluent of piggery wastewater. Chlorotetracycline (CTC) and CTC-resistant bacteria were selected as targets since CTC has been the most used antibiotics in livestock industries in Korea. The performance of four different combinations of oxidation agents was investigated, showing the order of removal rate as O 3 < O 3/H 2O 2 < O 3/UV < O 3/UV/H 2O 2 for wastewater. Applications of O 3/UV/H 2O 2 and O 3/UV degraded almost all CTC within 15 and 20 min, respectively. Only 30% of CTC was degraded even in 40 min by O 3 alone and O 3/H 2O 2 degraded 65% of CTC in 40 min. The combination of ozone/H 2O 2 did not contribute significantly to CTC degradation, but the influence of UV was substantial when coupled with ozone. CTC was partially degraded during oxidation although main HPLC peak was completely vanished. The resulting intermediates of partially oxidized CTC possessed no more antibiotic capability, suggesting that CTC transformed into nontoxic organic constituents. For disinfection, ozone alone was not effective for disinfection; less than 2-log reduction was achieved in 1 h. UV was more superior in reducing bacterial population, showing more than 4-log reduction in 20 min and 5-log reduction in 40 min. UV was also effective in reducing both total and CTC-resistant bacterial population, and the contribution ratio of UV to ozone was about 3:1 in logarithmic scale. The application of O 3/UV together further enhanced the disinfection performance compared to UV alone.