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[Display omitted] • Molecularly imprinted magnetic biochar (MBC@MIPs) for oxytetracycline (OTC) was prepared. • MBC@MIPs had the ability to selectively remove OTC under the interference of various antibiotics. • MBC@MIPs had structural stability and recycling ability. Molecularly imprinted magnetic biochar (MBC@MIPs) was synthesized through molecular imprinting precipitation polymerization. This material demonstrated a selective adsorption capacity of oxytetracycline (OTC) from water samples. Upon characterization of MBC@MIPs, results revealed the formation of a memory cavity shell layer on the magnetic biochar's surface, exhibiting a distinctive recognition effect alongside commendable magnetic and thermal stability. Analysis of the adsorption kinetics indicated that the OTC adsorption process aligned well with the pseudo-second-order rate equation, with chemisorption acting as the predominant mechanism for antibiotic adsorption onto MBC@MIPs. The data could be well described by the Langmuir isotherm model. At 299 K, MBC@MIPs showed a maximum binding capacity of 67.89 mg·g−1, surpassing that of MBC (38.84 mg·g−1) by 1.77 times. MBC@MIPs exhibited the highest selectivity towards OTC, with an imprinting factor (IF) of 5.64. Even amidst interference from antibiotics, MBC@MIPs maintained a significant adsorption capacity for OTC (6.10 mg·g−1), with IF of 6.70. [ABSTRACT FROM AUTHOR]

[Display omitted] • Composting could decrease the abundance of iARGs and eARGs by 36.49% to 97.82%. • OTC enhanced the abundance of iARGs by 161 %–336 % after 38 days of composting. • The enhanced bacterial SOS response with OTC addition promoted the spread of ARGs. • The application of H-OTC compost product could increase the spread risk of ARGs. This research aimed to investigate the alterations in extracellular (eARGs) and intracellular (iARGs) antibiotic resistance genes in response to oxytetracycline (OTC), and unravel the dissemination mechanism of ARGs during composting. The findings revealed both low (L-OTC) and high contents (H-OTC) of OTC significantly enhanced absolute abundance (AA) of iARGs (p < 0.05), compared to CK (no OTC). Composting proved to be a proficient strategy for removing eARGs, while AA of eARGs was significantly enhanced in H-OTC (p < 0.05). OTC resulted in an increase in AA of mobile genetic elements (MGEs), ATP levels, antioxidant and DNA repair enzymes in bacteria in compost product. Structural equation model further demonstrated that OTC promoted bacterial DNA repair and antioxidant enzyme activities, altered bacterial community and enhanced MGEs abundance, thereby facilitating iARGs dissemination. This study highlights OTC can increase eARGs and iARGs abundance, underscoring the need for appropriate countermeasures to mitigate potential hazards. [ABSTRACT FROM AUTHOR]

In this study, a hybrid material, MIL-53(Al)@CBS, was synthesized via the solvothermal method, involving the growth of MIL-53(Al) crystals on cocoa bean shell residues (CBS). Physicochemical characterization techniques, including TGA, BET, FTIR, XRD, and SEM, confirmed successful hybridization. MIL-53(Al)@CBS was employed as an adsorbent for antibiotics (oxytetracycline, tetracycline, chlortetracycline) separation from aqueous solutions. Parameters like pH, adsorbent dose, concentration, time, and temperature were systematically evaluated. FTIR revealed π-π interactions and hydrogen bonds between tetracyclines and the adsorbent. MIL-53(Al)@CBS exhibited adsorption, with removal rates up to 98.92%, 99.04%, and 98.24% for OTC, TC, and CTC, respectively. Kinetics suggested adsorption depends on active site availability, with TC adsorbing fastest. Microscopic models showed adsorption on three distinct active site types with different affinities without competition or adherence to the Langmuir hypothesis. Importantly, MIL-53(Al)@CBS maintained high adsorption capacity even after ten washing cycles, highlighting its potential for water treatment., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

This study investigated the potential of micro-nano bubble (MNB) ozonation pretreatment to eliminate oxytetracycline (OTC) from wastewater and improve subsequent anaerobic digestion (AD) performance. The findings revealed that MNB ozonation achieved efficient OTC oxidation (>99 % in 60 min), and significantly enhanced methane production by 51 % compared to conventional ozonation (under 30 min of pretreatment). Additionally, MNB ozonation resulted in a decrease in the soluble chemical oxygen demand and reduced volatile fatty acid accumulation compared to conventional ozonation. Furthermore, the study sheds light on the profound impact of OTC and its oxidation by-products on the sludge microbiome. Exposure to OTC and its oxidation by-products resulted in alterations in extracellular polymeric substances composition and led to significant shifts in microbial community structure. This study highlights the promise of MNB ozonation as an effective approach for pharmaceutical pollutant removal and the optimization of AD performance in wastewater treatment, with implications for improved environmental sustainability., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

• Achromobacter denitrificans OTC-F possessed high degradation efficiency to OTC. • Biochar increased the biodegradation rate of oxytetracycline by 15.13–26.78%. • Biochar reduced the biotoxicity of OTC to the strain. • Biochar increased the activity of antioxidant enzymes by 34.1–91.0%. • Biochar promoted the secretion of glutathione. Contamination of the environment with large amounts of residual oxytetracycline (OTC) and the corresponding resistance genes poses a potential threat to natural ecosystems and human health. In this study, an effective OTC-degrading strain, identified as Achromobacter denitrificans OTC-F, was isolated from activated sludge. In the degradation experiment, the degradation rates of OTC in the degradation systems with and without biochar addition were 95.01–100% and 73.72–99.66%, respectively. Biochar promotes the biodegradation of OTC, particularly under extreme environmental conditions. Toxicity evaluation experiments showed that biochar reduced biotoxicity and increased the proportion of living cells by 17.36%. Additionally, biochar increased the activity of antioxidant enzymes by 34.1–91.0%. Metabolomic analysis revealed that biochar promoted the secretion of antioxidant substances such as glutathione and tetrahydrofolate, which effectively reduced oxidative stress induced by OTC. This study revealed the mechanism at the molecular level and provided new strategies for the bioremediation of OTC in the environment. [ABSTRACT FROM AUTHOR]

[Display omitted] • The OTC residues may affect the transformation between DOM components in composting. • The transformation of DOM components was influenced indirectly under the OTC stress. • A significant positive correlation between OTC tolerant bacteria and humification. • The DOC, TN, and core OTC tolerant bacteria enhanced DOM component transformation. This study explored the interaction among the components of dissolved organic matter (DOM), environmental factors and oxytetracycline (OTC) tolerant bacteria during chicken manure composting using Parallel Factor Analysis (PARAFAC) and 16S rRNA sequencing analysis. The results revealed that the OTC residues in chicken manure may affect the transformation between the protein-like component (C1) and humus-like component (C2 and C3) during composting. The transformation of DOM components under the OTC stress was indirect by affecting the microbial community activity. The OTC tolerant bacteria that still exist after the high temperature period of composting had a significant positive correlation between the humification process. The correlations of the dissolved organic carbon (DOC), total nitrogen (TN), and core OTC tolerant bacteria with DOM components, which enhanced the cooperative function of DOM component transformation. To clarify the influence of OTC residue on the humification process can promote the composting carbon fixation and improve composting quality. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel nano Y 2 O 3 -modified biochar composite (Y 2 O 3 @BC600) was synthesized. • Y 2 O 3 @BC600 exhibited excellent adsorption for oxytetracycline of 223.46 mg/g. • Removal mechanisms of aqueous oxytetracycline by Y 2 O 3 @BC600 were clarified. • Y 2 O 3 @BC600 showed better anti-interference ability, stability, and reusability. Nano Y 2 O 3 -modified biochar composites (Y 2 O 3 @BC600) were fabricated successfully and exhibited great adsorption toward oxytetracycline (OTC). The Langmuir adsorption capacity of Y 2 O 3 @BC600-1:4 for OTC reached 223.46 mg/g, 10.52 times greater than that of BC600. The higher dispersion of Y 2 O 3 nanoparticles, increased surface area of 175.65 m2/g and expanded porosity of 0.27 cm3/g accounted for higher OTC adsorption by Y 2 O 3 @BC600-1:4. Y 2 O 3 @BC600-1:4 could resist the interference of co-existing cations (Na+, K+, Mg2+, Ca2+) and anions (Cl−, NO 3 −, SO 4 2−) on OTC removal. Y 2 O 3 coating changed surface charge property of BC600, favoring the contribution of electrostatic interaction. Synchrotron radiation-based Fourier transform infrared spectroscopy detected obvious peak shift and intensity change of surface –OH when OTC adsorption occurred. Accordingly, stronger H-bonding (charge-assisted hydrogen bond, OTC–H 2 N+···HO–Y 2 O 3 @BC600-1:4) was proposed for OTC adsorption. Y 2 O 3 @BC600 exhibited renewability and stability in the adsorptive removal of OTC. Therefore, Y 2 O 3 @BC600 may be a novel and suitable adsorbent for antibiotic removal. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • OTC was biodegradaded and electricity generation synchronously in OTC D-GM-BE MFC. • The OTC removal efficiency of O-GM-BC and O-GM-BA was 95.0% and 91.8% in eight days. • The maximum power density of O-D-GM-BE MFC was 2.1 times of O-C-BE MFC. • Exoelectrogens and bacteria of OTC degradation were enriched in O-GM-BA and O-GM-BC. • Mechanisms of biodegradation of OTC and EET process in D-GM-BE MFC were proposed. Abstract A three-step method to prepare dual graphene modified bioelectrode (D-GM-BE) in microbial fuel cell (MFC) in previous studies. This study explored the biodegradation of oxytetracycline (OTC) and electricity generation in O-D-GM-BE MFC. The OTC removal efficiency of graphene modified biocathode and bioanode (O-GM-BC, O-GM-BA) was 95.0% and 91.8% in eight days. The maximum power density generated by O-D-GM-BE MFC was 86.6 ± 5.1 mW m−2, which was 2.1 times of that in OTC control bioelectrode (O-C-BE) MFC. The Rct of O-GM-BA and O-GM-BC were decreased significantly by 78.3% and 76.3%. OTC was biodegraded to monocyclic benzene compounds by bacteria. O-GM-BA was affected strongly by OTC, and Salmonella and Trabulsiella were accounted for 83.0%, while typical exoelectrogens (Geobacter) were still enriched after the maturity of biofilm. In O-GM-BC, bacteria related with OTC biodegradation (Comamonas , Ensifer , Sphingopyxis , Pseudomonas , Dechloromonas , etc.) were enriched, which contributed to the high removal efficiency of OTC. [ABSTRACT FROM AUTHOR]

Pollution of water by single antibiotics has been investigated in depth. However, in reality, a wide range of different contaminants is often mixed in the aquatic environment (contaminant cocktail). Here, single and competitive sorption dynamics of ionizable norfloxacin (NOR), sulfamerazine (SMR) and oxytetracycline (OTC) by both pristine and modified biochars were investigated. Sorption kinetics of the three antibiotics was faster in ternary-solute than single-solute system. Sorption efficiency was enhanced in the competitive system for NOR by the pristine biochar, and for OTC by both the pristine biochar and the modified biochar, while SMR sorption by the pristine biochar and the KOH-modified biochar was inhibited. Sorption was governed by electrostatic interactions, π-π EDA and H-bonds for antibiotics sorption by biochar. SMR and OTC sorption by biochar was influenced by cation bridging and surface complexation, respectively. This research finding will guide the development of treatment procedures for water polluted by multiple antibiotics. [ABSTRACT FROM AUTHOR]

Anaerobic digestion (AD) has been applied to animal manure stabilization, and antibiotics is frequently found in animal manure. However, antibiotic degradation and microbial community structures during two-stage AD (acidification and methanogenesis) remain poorly understood. This experiments on two-stage anaerobic swine manure digesters were performed to investigate the degradation mechanisms and effects of chlortetracycline (CTC) and oxytetracycline (OTC) on microbial community structures. Results showed that acidification and methanogenesis showed good degradation performance for manure containing CTC and OTC at 60 and 40 mg/kg·TS, respectively. CTC and OTC were degraded by 59.8% and 41.3% in the acidogenic stage and by 76.3% and 78.3% in the methanogenic stage, respectively. CTC and OTC negatively affected bacterial community in methanogenic and acidogenic stages, respectively. They also adversely influenced the archaeal species in the methanogenic stage. Two-stage AD was proposed to treat manure containing antibiotics and to reduce the negative effects of antibiotics on AD. [ABSTRACT FROM AUTHOR]

[Display omitted] • Preparation of Fe-Mn lignin-based biochar (FMBC) by hydrothermal-pyrolysis method. • The degradation of oxytetracycline reached 90% within 30 min. • Oxygen-containing functional groups on industrial lignin biochar promote degradation. • The main reactive radicals generated in the FMBC-PDS system are SO 4 •– and •OH. • 38 degradation intermediates and 7 different degradation pathways were deduced. In this study, high-performance Fe-Mn-modified industrial lignin-based biochar (FMBC) was successfully prepared to facilitate the efficient degradation of oxytetracycline by its driven sulfate radical-based advanced oxidation process with 90% degradation within 30 min. The results showed that oxygenated functional groups (e. g. hydroxyl, carbonyl, etc.) in industrial lignin-based biochar, the synergistic effect of transition metals Fe and Mn, and defective structures were the active sites for activation of peroxy-disulfate. SO 4 ·− produced during the degradation process assumed a key function. Significantly, 38 intermediates were innovatively proposed for the first time in the system, and oxytetracycline was degraded in 7 ways, including deamidation, demethylation, hydroxylation, secondary alcohol oxidation, ring opening, dehydration, and carbonylation. A new perspective on the application of industrial lignin in the advanced oxidative degradation of organic pollutants was provided by this study. [ABSTRACT FROM AUTHOR]

[Display omitted] • Long-term stress of OTC had obvious effects on AD reactor. • Biochar addition enhanced the metabolic activity of the AD bacteria. • Biochar addition improved the stability of sludge structure. • Biochar mitigated inhibition of OTC on AD bacteria. Reactors were established to study the feasibility of the direct addition of modified biochar to alleviate the long-term stress of oxytetracycline (OTC) on aerobic denitrification (AD) and improve the stability of the system. The results showed that OTC stimulated at μg/L, and inhibited at mg/L. The higher the concentration of OTC, the longer the system was affected. The addition of biochar, without immobilization, improved the tolerance of community, alleviated the irreversible inhibition effect of OTC, and maintained a high denitrification efficiency. Overall, the main mechanisms of AD enhancement by biochar under OTC stress were: enhancing the bacteria metabolic activity, strengthening sludge structure and substrate transport, and improving the community stability and diversity. This study confirmed that direct addition of biochar could effectively alleviate the negative effect of antibiotics on the microorganisms, strengthen the AD, which provided a new idea to broaden the application of AD technology in livestock wastewater. [ABSTRACT FROM AUTHOR]

[Display omitted] • The large fluctuation of OLR of swine wastewater was simulated. • 0.3 mg/L OTC boosted the biodegradability of the substrate. • 8.0 mg/L OTC stimulated four methanogenic pathways (especially CO 2 => CH 4). • 8.0 mg/L OTC reduced the metabolic functions of material swap on the cell membrane. • 8.0 mg/L OTC reduced the functions of information recognition on the cell membrane. High concentrations of antibiotics in swine wastewater raises concerns about the potential adverse effects of anaerobic digestion (AD). Current studies mainly focused on the effects of various antibiotic concentrations. However, these studies didn't take into account the fluctuation of swine wastewater quality and the change of reactor operating conditions in practical engineering applications. In this study, it was found that in the operating systems with COD of 3300 mg/L and hydraulic retention time (HRT) of 4.4 days, the continuous addition of oxytetracycline for 30 days had no effect on the AD performance. Nevertheless, when COD and HRT were changed to 4950 mg/L and 1.5 days respectively, oxytetracycline at 2 and 8 mg/L increased the cumulative methane yield by 27% and 38% at the cost of destroying cell membrane, respectively, while oxytetracycline at 0.3 mg/L improved the performance and stability of AD. These results could be referred for practical engineering applications. [ABSTRACT FROM AUTHOR]

In the present investigation, the adsorptive removal of the antibiotic drug oxytetracycline (OTC) and toxic heavy metal cadmium (Cd) from aqueous solution was carried out using forest and wood-processing residues. Numerous biochars were prepared using different chemical agents (H 3 PO 4 , H 2 SO 4 , NaOH and KOH) and pyrolysis times and temperatures. Several elemental, chemical and structural characterizations were performed. The optimum conditions for pyrolysis to enable the production of biochars with well-developed porosity was 600 °C for 1 h, for both residues. The adsorption process using selected activated biochars was optimized with respect to reaction time, pH, temperature and initial load of pollutants. Under optimized operating conditions, and based on equilibrium modelling data, the biochars which showed the highest removal efficiencies of OTC and cadmium were “5 M H 3 PO 4 forest” (263.8 mg/g) and “1 M NaOH forest” (79.30 mg/g), respectively. Compared to adsorbents reported in the literature, the efficiencies of those biochars are highly competitive. [ABSTRACT FROM AUTHOR]

[Display omitted] • Complete mineralization of oxytetracycline can be achieved within 1 min at 80 °C. • Both Cu-biochar and microwave are crucial to activate oxidants to generate free radicals. • Persulfate and hypochlorite are activated to reactive •SO 4 − and •ClO, respectively. • Alleviation of Cu leaching is attributed to stable Cu(I)–N–biochar structure. Microwave (MW)-assisted catalytic degradation of organic pollutants draws increasing attention owing to its high efficiency in wastewater treatment. This work developed Cu-loaded biochar (CuBC) catalysts for time-efficient mineralization of refractory and high-concentration oxytetracycline (OTC). With only 1 min at 80 °C, Na 2 S 2 O 8 achieved 100% total organic carbon (TOC) removal over the Cu5BC, while NaClO mineralized 73.3% TOC over the metal-free BC, in contrast to a relatively low mineralization efficiency (< 35%) achieved by H 2 O 2. The high efficiency in MW-assisted oxidation systems could be ascribed to reactive oxidizing species (•SO 4 − or •ClO), which otherwise were barely detectable in a conventional heating system. The interactions between CuBC and MW were revealed by correlating the physiochemical characteristics to the MW absorption ability. The proposed catalytic systems can contribute to the development of a high-throughput and low-carbon wastewater treatment technology. [ABSTRACT FROM AUTHOR]

[Display omitted] • Provides a new idea for the recycle and harmless treatment of AMD. • More than 99% terramycin was reduced after adding HCMI of compost. • By adding HCMI, Qac B and tet H decreased by 0.35, and 0.15%, respectively. • The succession of microorganism had greatly factor on the varies of ARG subtypes. • The HCMI improve the removal rate of ARG subtype to a certain extent. In order to tackle the issue of terramycin mycelial dreg (TMD) diagnosis and removal of terramycin and antibiotic resistance genes (ARGs), this study adopted aerobic composting (AC) technology and added homemade compound microbial inoculum (HCMI) to promote the AC of TMD and enhance the removal of terramycin and ARGs. The findings demonstrated that terramycin residue could be basically harmless after AC. Moreover, HCMI not only reduced Qac B and tet H but also increased the degradation rates of Van RA, Van T, and dfr A24 by 40.81%, 5.65%, and 54.18%, respectively. The HCMI improved the removal rate of ARG subtypes to a certain extent. According to redundancy analysis, during AC, the succession of the microbial community had a stronger influence on the variance of ARG subtype than the environmental conditions. Differences in the abundance of various bacteria due to changes in temperature may be an intrinsic mechanism for the variation of ARG subtypes. [ABSTRACT FROM AUTHOR]

The effects of Erythromycin (ERY) and oxytetracycline (OTC), including individual and combinative effect, on enhanced biological phosphorus removal (EBPR) system within a short-term (24 h) were evaluated in this study. Results showed that the P-removal efficiency decreased to 34.6% and 0.0% under the effect of ERY (10 mg/L) and OTC (10 mg/L) for 24 h. OTC concentration higher than 5 mg/L was sufficient to cause serious adverse impact on the EBPR performance. While the performance of EBPR system will be impacted by ERY above 10 mg/L. OTC, due to its special antibacterial action to the gram-negative bacteria which most PAOs belong to, has more serious negative effect on the EBPR performance than ERY does. Moreover, in the combined antibiotics test, neither synergistic nor antagonistic effect was detected between ERY and OTC. Finally, ERY (10 mg/L) and OTC (10 mg/L) could inhibit the microorganisms’ activity, while couldn’t induce serious microorganisms death within 24 h. [ABSTRACT FROM AUTHOR]

The effects of oxytetracycline (OTC) on nitrogen-fixing bacterial communities were investigated during cattle manure composting. The abundance and community structure of nitrogen-fixing bacteria were determined by qPCR and denaturing gradient gel electrophoresis (DGGE), respectively. The matrix was spiked with OTC at four levels: no OTC, 10 mg/kg dry weight (DW) OTC (L), 60 mg/kg DW OTC (M), and 200 mg/kg DW OTC (H). The high temperature period of composting was shorter with M and H, and the decline in temperature during the cooling stage was accelerated by OTC. OTC had a concentration-dependent inhibitory effect on the nitrogenase activity during early composting, and the nifH gene abundance declined significantly during the later composting stage. The DGGE profile and statistical analysis showed that OTC changed the nitrogen-fixing bacterial community succession and reduced the community richness and dominance. The nitrogen-fixing bacterial community structure was affected greatly by the high level of OTC. [ABSTRACT FROM AUTHOR]

This study aimed to determine the fate and effect of oxytetracycline (OTC) and its metabolites during thermophilic anaerobic digestion of cow manure. OTC-medicated and non-medicated digesters were operated at 55 °C with different volatile solids (VS) concentrations (4% and 6%) and mixing rates (90 and 120 rpm). OTC and its metabolites were measured by HPLC and LC/MS/MS, respectively. Microbial community dynamics were monitored by denaturing gradient gel electrophoresis (DGGE) and real-time PCR (qPCR). Approximately 2 mg/L initial OTC concentration caused 10–30% inhibition on biogas production and higher inhibition was observed as mixing rate increased. DGGE results indicated that OTC caused a shift in bacterial community structure and several species became dominant with time. Archaeal community decreased throughout the digestion period. RNA based qPCR analyses showed that gene copy numbers of bacteria and Methanomicrobiales declined in all digesters whereas gene copy numbers of Methanobacteriales and Methanosarcinales increased in high mixing rate digesters. [ABSTRACT FROM AUTHOR]

[Display omitted] • ZnFe-LDH loaded on MBC was prepared by co-precipitation method. • The composite exhibited outstanding adsorption capacity for OTC at 426.61 mg/g. • Multiple physical and chemical mechanisms were involved in OTC adsorption. • Plant invasion control and pollutants removal was accomplished simultaneously. Antibiotic contamination in water has been an increasing global concern, and how to effectively remove antibiotics (e.g., oxytetracycline [OTC] hydrochloride) from wastewater becomes imperative. In this study, the biochar derived from an invasive plant (Mikania micrantha Kunth) was synthesized with Zn/Fe- layered double hydroxide (LDH) by co-precipitation method (ZnFe-LDH/MBC) to remove OTC from water. ZnFe-LDH/MBC posed the highest OTC removal performance of 426.61 mg/g. ZnFe-LDH/MBC exhibited stability and efficiency in OTC adsorption at different pH levels and under interfering conditions with co-existing ions, as well as outstanding regeneration capabilities during adsorption–desorption cycles. Furthermore, the removal of OTC by ZnFe-LDH/MBC was mediated by several processes including pore filling, hydrogen bonding force, electrostatic interaction, π-π interaction, as well as complexation. Consequently, ZnFe-LDH/MBC has excellent potential for the purification of OTC pollutants that is low-cost, efficient, and environmentally friendly. [ABSTRACT FROM AUTHOR]

Highlights: [•] The role of bio-augmentation in assisting recovery of ANAMMOX from OS was studied. [•] The bio-augmentation time (BAT) was optimized. [•] The bio-augmentation dosage (BAD) was optimized. [•] The changes in sludge characteristics were monitored. [•] The mechanisms of bio-augmentation were discussed. [ABSTRACT FROM AUTHOR]

Highlights: [•] The ANAMMOX performance under transient OTC stress was investigated. [•] The factors influencing the stability were evaluated. [•] The changes in sludge characteristics were provided. [•] The indicators for robustness and recovery performance were addressed. [Copyright &y& Elsevier]

Highlights: [•] The adsorption process was highly pH-dependant. [•] Zwitterions are the most sorbed oxytetracycline species on activated sludge. [•] Different metal ions have different effects on the adsorption process. [•] Surface complexation are the main adsorption mechanism of OTC to activated sludge. [ABSTRACT FROM AUTHOR]

[Display omitted] In this study, sycamore flocs (SF), which caused environmental and health problems, were utilized to prepare biochar. SFB 2-900 obtained under the conditions of activation agent K 2 CO 3 , pyrolysis temperature 900℃ and m(K 2 CO 3):m(BC) 2 had the strongest adsorption capacity (730 mg/g) for oxytetracycline hydrochloride (OTC-HCl). The pseudo-second-order kinetic model and Langmuir model described the adsorption kinetics and isotherms best. SFB 2-900 exhibited high OTC-HCl adsorption capacity in both higher ionic strength and wide pH range. The theoretical simulation indicated that the closest interaction distance between OTC-HCl and SFB 2-900 was 2.44 Å via π-π stacking configuration. Pore filling, π-π electron donor acceptor (EDA) interaction, H-bonding and electrostatic interactions were also involved in the process of OTC-HCl removal. SFB 2-900 showed great removal efficiency for OTC-HCl in different water matrices and good regeneration ability. This study solved the problems caused by SF, realized waste biomass recycling, and achieved preparing high-efficient adsorbent for antibiotic. [ABSTRACT FROM AUTHOR]

Abstract: Biochars produced from biomass residues have been recognized as effective sorbents to hydrophobic compounds, but knowledge on sorption of antibiotics to biochar and its mechanisms are still inadequate. Sorption of oxytetracycline (OTC) in aqueous solution to maize-straw-derived biochar, and the effect of pH and metal ions, was investigated in batch experiments, and the main sorption mechanisms were elucidated using FTIR and zeta potential measurements. The results showed that sorption of OTC on biochar was highly pH-dependant. The amount of sorbed OTC first increased and then decreased with increasing pH, and maximum sorption was achieved at pH 5.5. Cu2+ enhanced the sorption of OTC, while Pb2+ slightly reduced the sorption under acidic conditions. Other metal ions had no significant effect on the sorption of OTC to biochar. Surface complexation, through π–π interaction and metal bridging, was the most important sorption mechanism although cation exchange might have played a role. [Copyright &y& Elsevier]

Abstract: The individual and combined effect of cefazolin (CFZ) and oxytetracycline (OTC) on thermophilic anaerobic digestion (55°C) of dairy manure in batch digesters was investigated. Methane productions from the concentrations tested (30, 60 and 90mgL−1) were compared with no-antibiotic control. CFZ concentrations showed no inhibition (P >0.05) for methane production. The individual OTC and combined CFZ and OTC at concentrations of 30, 60 and 90mgL−1 represented 79.1%, 70.3%, 68.6% (P <0.05) and 88.5%, 82.7%, 70.3% (P <0.05) respectively, of the control values. The high CH4 production, optimal pH and VFA data during digestion indicated the process stability and treatment efficiency. [Copyright &y& Elsevier]

Abstract: The short- and long-term effects of oxytetracycline (OTC) on the anaerobic ammonium oxidation (Anammox) process were evaluated. The OTC inhibition of Anammox was substrate-, and especially nitrite-, dependent. The IC50 of OTC in the batch tests on an Anammox mixed culture was calculated to be 517.5mgL−1. The long-term effects of OTC on the Anammox process were examined in a continuous-flow upflow anaerobic sludge blanket reactor. Fifty milligrams per liter of OTC significantly decreased the nitrogen removal rate from 12.4 to 2kgNm−3 d−1 within 26days. The recovery of Anammox performance after OTC inhibition was accelerated by adding biocatalyst. In contrast to the modified Stover–Kincannon model, the modified Boltzmann model accurately simulated the recovery of Anammox performance. OTC presented in the influent led to sludge hardening and cell lysis. A poor settling property of Anammox sludge was also observed. [Copyright &y& Elsevier]

A batch test was employed to analyze the joint toxicity of copper (II) and oxytetracycline (OTC), OTC and sulfide, phenol and sulfide (S 2− ), phenol and copper (II), and OTC, copper (II) and substrate on an Anammox mixed culture. The joint toxicity of OTC and copper (II) on the Anammox mixed culture was antagonistic, whereas the interaction between OTC and S 2− and between phenol and S 2− was generally synergistic. The joint toxicity of phenol and copper (II) was dependent on the level of phenol: the joint toxicity was antagonistic at a high phenol level of 300 mg L −1 , whereas the joint toxicity was synergistic at a low phenol level of 75 mg L −1 . The joint toxic effect of OTC, copper (II) and NO 2 − –N on the Anammox activity can be ranked in the following order: NO 2 − –N > copper (II) > OTC. [ABSTRACT FROM AUTHOR]

Abstract: An anaerobic multichamber bed reactor (AMCBR) was effective in removing both molasses-chemical oxygen demand (COD), and the antibiotic oxytetracycline (OTC). The maximum COD and OTC removals were 99% in sequential AMCBR/completely stirred tank reactor (CSTR) at an OTC concentration of 300mgL−1. 51%, 29% and 9% of the total volatile fatty acid (TVFA) was composed of acetic, propionic acid and butyric acids, respectively. The OTC loading rates at between 22.22 and 133.33gOTCm−3 d−1 improved the hydrolysis of molasses-COD (k), the maximum specific utilization of molasses-COD (kmh ) and the maximum specific utilization rate of TVFA (kTVFA ). The direct effect of high OTC loadings (155.56 and −177.78gOTCm−3 d−1) on acidogens and methanogens were evaluated with Haldane inhibition kinetic. A significant decrease of the Haldane inhibition constant was indicative of increases in toxicity at increasing loading rates. [Copyright &y& Elsevier]

Abstract: This work studies the inhibitory effects and fate of the antibiotics oxytetracycline (OTC) and chlortetracycline (CTC) during the anaerobic digestion of pig manure. Both substances were added together in batch assays at concentrations of 10, 50 and 100mgL−1. Control assays only with antibiotics (abiotic) as well as without antibiotics (biotic) were also conducted. Methane production was reduced by 56%, 60% and 62% at OTC and CTC concentrations of 10, 50 and 100mgL−1, respectively. The IC50 level calculated from these experiments was estimated to be around 9mgL−1, a significant value considering the reported concentrations of these compounds in pig manure samples (up to 136mgL−1). Strong adsorption to solid matter was observed, which increased the stability of both substances. Antibiotic degradation was thus much higher in control assays, without solids, than those determined from assays including inoculum and manure substrate. [ABSTRACT FROM AUTHOR]

Abstract: Oxytetracycline (OTC) and chlortetracycline (CTC) are broad-spectrum antibiotics used in livestock production. Although laboratory-scale studies have shown that extractable concentrations of these compounds decrease over time within treated and untreated manures and soils, there is relatively little information from farm-scale experiments. The objective of this study was to determine the effect of different levels of management on manure pile temperature profiles and on the fate of OTC and CTC in manure from therapeutically treated calves. Four treatments were designed to span a range of management options – from simply piling up the manure to amending it with straw to increase aeration and adding insulating layers of straw. Replicate samples of antibiotic-containing calf manure were held at ambient temperature or placed in three locations within replicate 3m3 piles of beef manure. During the 28-day incubation period, concentrations of buffer-extractable OTC and CTC/ECTC (the summed concentrations of CTC and its epimer 4-epi-chlortetracycline (ECTC)) in manure samples incubated at ambient temperature (11–24°C) decreased 75% (from 18 to 4.6mgkg−1 dry weight (DW)) and 90% (from 192 to 16mgkg−1 DW), respectively. Concentrations of the CTC metabolite iso-chlortetracycline (ICTC) decreased 90% (from 37 to 3mgkg−1 DW). OTC and CTC/ECTC concentrations in samples incubated for 28days within a non-amended manure pile decreased 91% and >99%, respectively. During that period, the manure pile temperature ranged from 36°C to 45°C. Manure piles insulated with a blanket of straw and/or amended with straw (3:1, v/v) attained temperatures up to 70°C and contained very low levels of OTC, CTC/ECTC, and ICTC (ranging from <0.1 to 0.4mgkg−1 DW) after 28days. [Copyright &y& Elsevier]

[Display omitted] • The impact of different antibiotics against anammox granules was investigated. • The Ki values of oxytetracycline and polymyxin sulfate were 188.5 and 17.7 mg/L. • The short-run inhibition of penicillin upon anammox granules was negligible. • Impact of oxytetracycline was studied in anammox coupled denitrifying reactor. • Denitrifying bacteria had higher long-run tolerance than anammox bacteria. The anaerobic ammonium oxidation (anammox) based technology has been considered as an economic and efficient way to remove nitrogen. However, the anammox bacteria could be strongly inhibited by antibiotics. In present research, inhibiting properties of oxytetracycline, penicillin and polymyxin sulfate upon the anammox activity were investigated through batch experiment. The results implied that anammox activity was significantly inhibited by oxytetracycline and polymyxin sulfate. The non-competitive inhibiting model showed that the inhibiting constants (Ki) of oxytetracycline and polymyxin sulfate were 188.5 and 17.7 mg/L, respectively. Meanwhile, the anammox process was not suppressed while the concentration of penicillin reached 3000 mg/L. In long-run experiment, the influent oxytetracycline concentration of the anammox coupled denitrifying reactor was operated at 20 mg/L. It was observed that the anammox performance completely deteriorated, while the NO 2 –-N removing efficiency reached 15.8%. The obtained findings could provide important instruction for the treatment of antibiotic contaminated wastewater. [ABSTRACT FROM AUTHOR]

• Combined stress inhibited more heavily on NH 3 -N removal and biomass growth. • There existed optimal concentrations of Zn(II) and OTC for TP removal. • Exposure to OTC and 5.0 mg/L of Zn(II) increased TP removal via microalgae. • High concentrations of Zn(II) and OTC decreased unsaturation degree of fatty acids. • Nutrient removal mechanisms under stress of OTC and Zn(II) were elucidated. Removal of nutrients from swine wastewater digester effluent (SWDE) by microalgae Coelastrella sp. and production of Coelastrella sp. were investigated at the presence of oxytetracycline (OTC) and Zn(II). Mechanisms of stress of OTC and Zn(II) on microalgae were discussed via analyzing the removal performance of SWDE and biochemical characteristics of microalgae. Results showed that removal efficiency of ammonia nitrogen and biomass yield of microalgae at the presence of 5000 μg/L of OTC decreased by 13.1% − 50.1% and 28.2% −71.5%, respectively, when Zn concentration was increased from 0.50 mg/L to 5.0 mg/L. The presence of 5.0 mg/L Zn(II) promoted the accumulation of lipids in microalgae, and the presence of 50 μg/L OTC increased unsaturation of fatty acid methyl ester. Content of glutathione and activity of both glutamine synthetase and superoxide dismutase decreased with the increase of OTC concentration, while content of adenosine triphosphatase increased when Zn(II) concentration was also increased. [ABSTRACT FROM AUTHOR]

Abstract: Oxytetracycline (OTC) is a broad-spectrum antibiotic used in livestock production. The widespread use and relative persistence of OTC may encourage development of antibiotic-resistant bacteria. The objective of this study was to determine whether composting would substantially reduce the concentration of OTC found in manure from medicated animals. The effect of OTC on composting was also investigated. Five beef calves were medicated for 5 days with 22mg/kg/day of OTC. Approximately 23% of the OTC fed to the calves was recovered in the manure. Manure samples collected from calves prior to and after medication were mixed with straw and woodchips, and aliquots of the subsequent mixtures were treated in laboratory composters for 35 days. In addition, aliquots of the OTC-containing mixture were incubated at 25°C or sterilized followed by incubation at 25°C. The presence of OTC did not appear to affect composting processes. Within the first six days of composting, levels of extractable OTC in the compost mixture decreased from 115±8μg/g dry weight to less than 6±1μg/g dry weight (a 95% reduction). In contrast, levels of extractable OTC in room temperature incubated and sterilized mixtures decreased only 12–25% after 37 and 35 days, respectively. Levels of total heterotrophic bacteria and OTC-resistant bacteria in the finished compost mixture were roughly 30-fold higher and 10-fold lower, respectively, than levels in the mixture prior to composting. Although the basis of the OTC disappearance during composting is not known, the preponderence of OTC-sensitive bacteria and the decrease of OTC-resistant bacteria in the finished compost suggests that OTC residues have been rendered biologically inactive or unavailable. [Copyright &y& Elsevier]