Multistage ozone and biological treatment system for real wastewater containing antibiotics

Light-driven photocatalysis as an effective tool for degradation of antibiotics

Antibiotic contamination has become a severe issue and a dangerous concern to the environment because of large release of antibiotic effluent into terrestrial and aquatic ecosystems. To try and solve these issues, a plethora of research on antibiotic withdrawal has been carried out. Recently photocatalysis has received tremendous attention due to its ability to remove antibiotics from aqueous solutions in a cost-effective and environmentally friendly manner with few drawbacks compared to traditional photocatalysts. Considerable attention has been focused on developing advanced visible light-driven photocatalysts in order to address these problems. This review provides an overview of recent developments in the field of photocatalytic degradation of antibiotics, including the doping of metals and non-metals into ultraviolet light-driven photocatalysts, the formation of new semiconductor photocatalysts, the advancement of heterojunction photocatalysts, and the building of surface plasmon resonance-enhanced photocatalytic systems.

Fluoroquinolone antibiotics in the aquatic environment: environmental distribution, the research status and eco-toxicity

The increasing presence of fluoroquinolone (FQ) antibiotics in aquatic environments is a growing concern due to their widespread use, negatively impacting aquatic organisms. This paper provides an overview of the environmental distribution, sources, fate, and both single and mixed toxicity of FQ antibiotics in aquatic environments. It also examines the accumulation of FQ antibiotics in aquatic organisms and their transfer into the human body through the food chain. The study identifies critical factors such as metabolism characteristics, physiochemical characteristics, light, temperature, dissolved oxygen, and environmental compatibility that influence the presence of FQ antibiotics in aquatic environments. Mixed pollutants of FQ antibiotics pose significant risks to the ecological environment. Additionally, the paper critically discusses advanced treatment technologies designed to remove FQ antibiotics from wastewater, focusing on advanced oxidation processes (AOPs) and electrochemical advanced oxidation processes (EAOPs). The discussion also includes the benefits and limitations of these technologies in degrading FQ antibiotics in wastewater treatment plants. The paper concludes by proposing new approaches for regulating and controlling FQ antibiotics to aid in the development of ecological protection measures.

Degradation of veterinary antibiotics by the ozonation process: Product identification and ecotoxicity assessment

The purpose of the study was to evaluate the effects of using of ozonation to remove antibiotics used, among others, in veterinary medicine, from the aqueous environment. The effect of this process on the degradation, mineralisation and ecotoxicity of aqueous solutions of ampicillin, doxycycline, tylosin, and sulfathiazole was investigated. Microbiological MARA® bioassay and two in silico methods were used for the ecotoxicity assessment. Ozonation was an effective method for the degradation of the antibiotics studied and the reduction in ecotoxicity of the solutions. However, after ozonation, the solutions contained large amounts of organic products, including compounds much less susceptible to ozonation than the initial antibiotics. Structures of 14, 12, 40 and 10 degradation products for ampicillin, doxycycline, tylosin, and sulfathiazole, respectively, were proposed. It was confirmed that ozone plays a greater role than hydroxyl radicals in the degradation of these antibiotics, with the exception of TYL. The use of ozonation to obtain a high degree of mineralisation is unfavourable and it is suggested to combine ozonation with biodegradation. The pre-ozonation will cause decomposition of antibiotic pharmacophores, which significantly reduces the risk of spread of antimicrobial resistance in the active biocenosis of wastewater treatment plants.

Insight into typical photo-assisted AOPs for the degradation of antibiotic micropollutants: Mechanisms and research gaps

Due to the incomplete elimination by traditional wastewater treatment, antibiotics are becoming emerging contaminants, which are proved to be ubiquitous and promote bacterial resistance in the aquatic systems. Antibiotic pollution has raised particular concerns, calling for improved methods to clean wastewater and water. Photo-assisted advanced oxidation processes (AOPs) have attracted increasing attention because of the fast reaction rate, high oxidation capacity and low selectivity to remove antibiotics from wastewater. On the basis of latest literature, we found some new breakthroughs in the degradation mechanisms of antibiotic micropollutants with respect to the AOPs. Therefore, this paper summarizes and highlights the degradation kinetics, pathways and mechanisms of antibiotics degraded by the photo-assisted AOPs, including the UV/O3 process, photo-Fenton technology, and photocatalysis. In the processes, functional groups are attacked by hydroxyl radicals, and major structures are destroyed subsequently, which depends on the classes of antibiotics. Meanwhile, their basic principles, current applications and influencing factors are briefly discussed. The main challenges, prospects, and recommendations for the improvement of photo-assisted AOPs are proposed to better remove antibiotics from wastewater.

Application of Ozonation-Biodegradation Hybrid System for Polycyclic Aromatic Hydrocarbons Degradation

Creosote, a mixture of polycyclic aromatic hydrocarbons (PAHs), was and is a wood impregnate of widespread use. Over the years the accumulation of creosote PAHs in soils and freshwaters has increased, causing a threat to ecosystems. The combined ozonation-biodegradation process is proposed to improve the slow and inefficient biodegradation of creosote hydrocarbons. The impact of different ozonation methods on the biodegradation of model wastewater was evaluated. The biodegradation rate, the changes in chemical oxygen demand, and the total organic carbon concentration were measured in order to provide insight into the process. Moreover, the bacteria consortium activity was monitored during the biodegradation step of the process. The collected data confirmed the research hypothesis, which was that the hybrid method can improve biodegradation. The pre-ozonation followed by inoculation with a bacteria consortium resulted in a significant increase in the biodegradation rate. It allows for the shortening of the time required for the consortium to reach maximum degradation effectiveness and cell activity. Hence, the study gives an important and useful perspective for the decontamination of creosote-polluted ecosystems.

A critical review on retaining antibiotics in liquid digestate: Potential risk and removal technologies

Substantial levels of antibiotics remain in liquid digestate, posing a significant threat to human safety and the environment. A comprehensive assessment of residual antibiotics in liquid digestate and related removal technologies is required. To this end, this review first evaluates the potential risks of the residual antibiotics in liquid digestate by describing various anaerobic digestion processes and their half-lives in the environment. Next, emerging technologies for removing antibiotics in liquid digestate are summarized and discussed, including membrane separation, adsorption, and advanced oxidation processes. Finally, this study comprehensively and critically discusses these emerging technologies' prospects and challenges, including techno-economic feasibility and environmental impacts.

Production of forest seedlings using sewage sludge and automated irrigation with ozonated cattle wastewater

The large volume of effluents generated by intensive cattle production can become an environmental problem, requiring solutions that combine treatment and disposal of reuse water. The quality of cattle wastewater (CWW) treated by ozonation, the water requirement and its effect on the growth of seedlings of Dalbergia nigra cultivated with sewage sludge were determined under different light conditions. The study was carried out in a split plot scheme with 2 shading levels (0%—C₁, and 49.4% attenuation—C₂) and 3 types of irrigation water (control–T₁, 1 h ozonation–T₂, and 2 h–T₃), with 4 repetitions. Direct sowing was realized into 280 cm³ tubes which were irrigated by drip irrigation with automatic management. The height and collar diameter were measured every 21 days, and at the end of the nursery phase, and the Dickson quality index (DQI) and irrigation water productivity (WPir) were determined. In addition, seedlings were transplanted in a forest restauration area (FRA) of Atlantic Forest, with height and diameter monitoring for 200 days. With ozonation, there was an increase in pH and a reduction in electrical conductivity, total solids and turbidity in the CWW, allowing its use for irrigation of forest seedlings. The maximum volumes of water applied were 2.096 and 1.921 L plant^-1, with water supply T₂ and T₁, respectively, and coverages C₁ and C₂. In these conditions, the seedlings reached DQI of 0.47 and 0.17, and WPir of 2.35 and 1.48 g L^-1, respectively. The initial vegetative growth of the seedlings planted in the FRA was benefited by the nutrients provided by the CWW treated. Therefore, the use of sewage sludge and CWW treated has the potential to produce forest seedlings, reducing the release of waste and effluents into the environment.

A review toward contaminants of emerging concern in Brazil: Occurrence, impact and their degradation by advanced oxidation process in aquatic matrices

This work presents data regarding the occurrence and treatment of Contaminants of Emerging Concern (CECs) in Brazil in the past decade. The literature review (2011-2021) revealed the detection of 87 pharmaceutical drugs and personal care products, 58 pesticides, 8 hormones, 2 illicit drugs, caffeine and bisphenol A in distinct matrices (i.e.: wastewater, groundwater, sea water, rainwater, surface water, drinking water and hospital effluent). Concentrations of CECs varied from ng-μg L^-1 depending on the location, compound and matrix. The inefficiency of conventional wastewater treatment methods on the removal of CECs and lack of basic sanitation in some regions in the country aggravates contamination of Brazilian aquatic environments and poses potential environmental and health risks. Advanced oxidation processes (AOPs) are pointed out as viable and efficient alternatives to degrade CECs and prevent environmental contamination. A total of 375 studies involving the use of AOPs in Brazilian aqueous matrices were published in the last decade. Fenton and photo-Fenton processes, photo-peroxidation, ozonation, electrochemical advanced oxidation and heterogeneous photocatalysis are some of the AOPs applied by Brazilian research groups. Although many works discuss the importance of applying these technologies for CECs removal in real treatment plants, most of these studies assess the treatment of distilled water or simulated effluent. Therefore, the conduction of studies applying AOPs in real matrices are critical to drive the implementation of these processes coupled to conventional water and wastewater treatment in real plants in order to prevent the contamination of environmental matrices by CECs in Brazil.

Construction of integrated system for the treatment of Acid orange 7 dye from wastewater: Optimization and growth kinetic study

In this work, an effort has been made to develop an integrated system (ozonation followed by biodegradation) for the treatment of Acid orange 7 (AO 7) dye. The process parameters such as pH (3.0-11) and ozone dosage (5-25 mg/L) were optimized and obtained as 3.0 and 25 mg/L, respectively to treat the AO 7 by ozonation. Similarly, the process parameters, namely pH (5.0-9.0) and temperature (25-45 °C) were optimized and found to be 7.0 and 35 °C, respectively by biological treatment. Bacillus sp. was found to be the most effective bacteria to remove the AO 7. An integrated system obtained an overall 98.7% removal of AO 7 under optimum conditions. Andrews-Haldane model was best to predict the experimental data and the bio-kinetic constants; µ_max: 0.1875 day^-1; K_s: 49.53 mg/L; K_i: 133.32 mg/L were obtained. The developed integrated system can be a promising option for the treatment of azo dye containing-wastewaters.

Construction of biotreatment platforms for aromatic hydrocarbons and their future perspectives

Aromatic hydrocarbons (AHCs) are one of the major environmental pollutants introduced from both natural and anthropogenic sources. Many AHCs are well known for their toxic, carcinogenic, and mutagenic impact on human health and ecological systems. Biodegradation is an eco-friendly and cost-effective option as microorganisms (e.g., bacteria, fungi, and algae) can efficiently breakdown or transform such pollutants into less harmful and simple metabolites (e.g., carbon dioxide (aerobic), methane (anaerobic), water, and inorganic salts). This paper is organized to offer a state-of-the-art review on the biodegradation of AHCs (monocyclic aromatic hydrocarbons (MAHs) and polycyclic aromatic hydrocarbons (PAHs)) and associated mechanisms. The recent progress in biological treatment using suspended and attached growth bioreactors for the biodegradation of AHCs is also discussed. In addition, various substrate growth and inhibition models are introduced along with the key factors governing their biodegradation kinetics. The growth and inhibition models have helped gain a better understanding of substrate inhibition in biodegradation. Techno-economic analysis (TEA) and life cycle assessment (LCA) aspects are also described to assess the technical, economical, and environmental impacts of the biological treatment system.

Comparative overview of advanced oxidation processes and biological approaches for the removal pharmaceuticals

Nowadays, pharmaceuticals are the center of significant environmental research due to their complex and highly stable bioactivity, increasing concentration in the water streams and high persistence in aquatic environments. Conventional wastewater treatment techniques are generally inadequate to remove these pollutants. Aiming to tackle this issue effectively, various methods have been developed and investigated on the light of chemical, physical and biological procedures. Increasing attention has recently been paid to the advanced oxidation processes (AOPs) as efficient methods for the complete mineralization of pharmaceuticals. Their high operating costs compared to other processes, however, remain a challenge. Hence, this review summarizes the current and state of art related to AOPs, biological treatment and their effective exploitation for the degradation of various pharmaceuticals and other emerging molecules present in wastewater. The review covers the last decade with a particular focus on the previous five years. It is further envisioned that this review of advanced oxidation methods and biological treatments, discussed herein, will help readers to better understand the mechanisms and limitations of these methods for the removal of pharmaceuticals from the environment. In addition, we compared AOPs and biological treatments for the disposal of pharmaceuticals from the point of view of cost, effectiveness, and popularity of their use. The exploitation of coupling AOPs and biological procedures for the degradation of pharmaceuticals in wastewater was also presented. It is worthy of note that an integrated AOPs/biological system is essential to reach the complete degradation of pharmaceuticals; other advantages of this hybrid technique involve low energy cost, an efficient degradation process and generation of non-toxic by-products.

Fe2+ and UV Catalytically Enhanced Ozonation of Selected Environmentally Persistent Antibiotics

The aim of the study was to determine oxidation potential of selected persistent, environmentally relevant antibiotics (Amoxicillin, Levofloxacin, and their mixture with Vancomycin) to reduce their environmental emissions. Ozonation (O3) and indirect ozonation at pH 9.5 (O3/pH9.5) were catalytically enhanced by addition of Fe2+ (O3/Fe2+) and photocatalytic ozonation in combination with Fe2+ and UV-A black light (O3/Fe2+/UV) at two temperatures using total organic carbon (TOC) and chemical oxygen demand (COD) to identify formation of by-products. Oxidative degradation followed pseudo-first order consecutive reactions. Initial phase of oxidation was more intensive than mineralisation at 21 and 40 °C: up to 57.3% and 69.2%, respectively. After 120 min mineralization at 21 °C was up to 64.9% while at 40 °C it was up to 84.6%. Oxidation reached up to 86.6% and 93.4% at 21 °C and 40 °C, respectively. The most efficient processes were indirect ozonation at pH 9.5 (O3/pH9.5) (up to 93.4%) and photocatalytic enhanced ozonation with Fe2+ and UV-A black light (O3/Fe2+/UV) (up to 89.8%). The lowest efficiency was determined in experiments with direct ozonation (up to 75.5%). Amoxicillin was the only one completely mineralised. Study confirmed that ozonation with addition of Fe2+ and UV radiation has the potential to improve efficiency of the antibiotic-removal processes. Further experiments varying amounts of Fe2+ and other experimental conditions should be accomplished to set up more general methodological approach for reduction of antibiotics emissions.

Recent advances in photodegradation of antibiotic residues in water

Antibiotics are widely present in the environment due to their extensive and long-term use in modern medicine. The presence and dispersal of these compounds in the environment lead to the dissemination of antibiotic residues, thereby seriously threatening human and ecosystem health. Thus, the effective management of antibiotic residues in water and the practical applications of the management methods are long-term matters of contention among academics. Particularly, photocatalysis has attracted extensive interest as it enables the treatment of antibiotic residues in an eco-friendly manner. Considerable progress has been achieved in the implementation of photocatalytic treatment of antibiotic residues in the past few years. Therefore, this review provides a comprehensive overview of the recent developments on this important topic. This review primarily focuses on the application of photocatalysis as a promising solution for the efficient decomposition of antibiotic residues in water. Particular emphasis was laid on improvement and modification strategies, such as augmented light harvesting, improved charge separation, and strengthened interface interaction, all of which enable the design of powerful photocatalysts to enhance the photocatalytic removal of antibiotics.

The hybrid system successfully to consisting of activated sludge and biofilter process from hospital wastewater: Ecotoxicological study

This article aimed to demonstrate solution hospital wastewater due to more consumption of antibiotics, public concern has been significantly increased for usage, fates and occurrences of these emerging compounds in the environments and biota. Therefore, it does need more discoveries about occurrences and new treatment methods. Since the conventional treatment methods are low efficient on antibiotics, integration and combination of biological systems together or with an additional process has been shown that provided a better result. However, here, the potential of a full scale combined treating system with activated sludge-scoria biofilter (ASSB) was investigated for removal of ceftriaxone (CEF) and amoxicillin (AMX). To determine the potential biodegradability of proposed system, the solid-water distribution coefficient (K_d) was calculated. Overally, 118 samples were collected from three points; wastewater entering, exiting the activated sludge, and exiting the biofilter. To determine the amount of CEF and AMX antibiotics, the samples were analyzed using HPLC-UV. The results showed that the activated sludge system were able to eliminate the AMX and CEF antibiotics about 70.36 and 84.49%, respectively. In compare to activated sludge, the average mean of ASSB system for the removal efficiency were 87.53% (for AMX) and 93.17% (for CEF), respectively. As a result, it can be found that the efficiency of the combined activated sludge-biofilter system in removing of the low levels of antibiotics was more than individual activated system. The result of K_d revealed that AMX (with a K_d about 0.172) has lower tendency to biomass rather than CEF (with a K_d about 0.512). The ecological toxicity assessment guaranteed there is no risk for fish and daphnia when the activated sludge and also ASSB effluents to be discharged into the environment even without any diluting.

Homogeneously catalytic oxidation of phenanthrene by the reaction of extracellular secretions of pyocyanin and Nicotinamide Adenine Dinucleotide

Application of biological methods on polycyclic aromatic hydrocarbons (PAHs) treatment is always limited by its low degradation efficiency. In this work, a catalytic oxidation pathway of phenanthrene resulted by extracellular secretions of P. aeruginosa NY3 was proposed. Results of the in vitro experiments showed that, the extracellular secretions of Pyocyanin (Pyo) and Nicotinamide Adenine Dinucleotide (NADH) acted as homogeneous catalysts because which produced H₂O₂, hydroxyl free radical and superoxide anion radical continuously under aerobic conditions. These produced reactive oxygen species oxidized the phenanthrene in aqueous solution, leading to the cleavage of the phenanthrene ring and the formation of phthalates products and low molecular weight metabolites (such as alkanoic acids). The ratio of BOD₅/COD of phenanthrene-containing wastewaters was greatly improved after treating with Pyo and NADH. Results of the in vivo experiments showed that, pre-degradation of phenanthrene by extracellular fluid simultaneously containing Pyo and NADH, promoted cell growth of P. aeruginosa NY3, which confirmed the improvement of bioavalability of phenanthrene-containing wastewaters by the catalytic oxidation of Pyo and NADH. Further details of the free radical detection indicated that, the increase in secretion of Pyo by a bacterium was favorable to the production of H₂O₂ in the extracellular fluid.

Investigation of catalytic self-cleaning process of multiple active species decorated macroporous PVDF membranes through peroxymonosulfate activation

Currently, carbon-based catalysts integrated with macroporous catalytic membrane have aroused considerable attention for environmental remediation because of its practicability and high efficiency. Herein, nitrogen doped carbon nanotube hybrids (Fe-Co@NC-CNTs) decorated with multiple active species (Fe₃Co₇/CoFe₂O₄@Fe/CoNC) were designed through N-molecule assisted pyrolysis of bimetallic (Fe/Co) metal-organic frameworks, and then immobilized on poly(vinylidene fluoride) (PVDF) membrane to construct macroporous Fe-Co@NC-CNTs/PVDF catalytic membrane via directional freezing technique, where active sites were efficiently exposed for oxidants and target pollutants. As expected, Fe-Co@NC-CNTs/PVDF membrane successfully achieved almost 100% bisphenol A (BPA) degradation after 40 min via PMS activation, which was significantly overperformed the majority of conventional carbon-based catalysts. Besides, we found that Fe-Co@NC-CNTs/PVDF membrane not only exhibited ideal catalytic and self-cleaning property in humic acid (HA)-BPA coexistence system, but also maintained the excellent reusability and ultrahigh water flux (10464.45 L m^-2 h^-1) even after 5 cycles. Notably, in EPR analysis and quenching experiments, it was found that sulfate radicals (SO₄·^- and ·OH) and singlet oxygen (¹O₂) participated the degradation process while ¹O₂ made a major contribution. More significantly, this study is very meaningful for the development of novel catalytic self-cleaning membranes with PMS activation.

Adsorptive removal of apramycin antibiotic from aqueous solutions using Tween 80-and Triton X-100 modified clinoptilolite: experimental and fixed-bed modeling investigations

This study examined the performance of natural clinoptilolite (NC) modified with two surfactants of Triton X-100 (NC-Triton) and Tween 80 (NC-Tween) on apramycin (APR) adsorption from wastewater in batch and continues systems. The optimum pH, contact time, adsorbent dosage, and temperature were achieved. The findings revealed that the sorption was best described using the Langmuir isotherm compared to other isotherms. The maximum adsorption capacity of NC-Triton was greater than NC and NC-Tween. The lumped method was applied to solve the fixed-bed equations; predict breakthrough curve; determine axial dispersion coefficient and overall mass transfer coefficient parameters; and compare theoretical results with experimental results. Good fitness of experimental data with kinetic models of intra-particle diffusion, pseudo-first-order/liquid film diffusion and pseudo-second-order for NC, NC-Tween and NC-Triton, respectively, indicated that they were more suitable than the other models. Endothermic and spontaneous processes were resulted from positive enthalpy and negative Gibbs free energy changes, respectively.

Degradation of antibiotics by advanced oxidation processes: An overview

Antibiotics are becoming emerging contaminants due to their extensive production and consumption, which have caused hazards to the ecological environment and human health. Various techniques have been studied to remove antibiotics from water and wastewater, including biological, physical and chemical methods. Among them, advanced oxidation processes (AOPs) have received increasing attention due to their fast reaction rate and strong oxidation capability, which are effective for the degradation of antibiotics in aquatic environments. In this review paper, a variety of AOPs, such as Fenton or Fenton-like reaction, ozonation or catalytic ozonation, photocatalytic oxidation, electrochemical oxidation, and ionizing radiation were briefly introduced, including their principles, characteristics, main influencing factors and applications. The current applications of AOPs for the degradation of antibiotics in water and wastewater were analyzed and summarized, the concluding remarks were given and their future perspectives and challenges were discussed.

Recent development of advanced biotechnology for wastewater treatment

The importance of highly efficient wastewater treatment is evident from aggravated water crises. With the development of green technology, wastewater treatment is required in an eco-friendly manner. Biotechnology is a promising solution to address this problem, including treatment and monitoring processes. The main directions and differences in biotreatment process are related to the surrounding environmental conditions, biological processes, and the type of microorganisms. It is significant to find suitable biotreatment methods to meet the specific requirements for practical situations. In this review, we first provide a comprehensive overview of optimized biotreatment processes for treating wastewater during different conditions. Both the advantages and disadvantages of these biotechnologies are discussed at length, along with their application scope. Then, we elaborated on recent developments of advanced biosensors (i.e. optical, electrochemical, and other biosensors) for monitoring processes. Finally, we discuss the limitations and perspectives of biological methods and biosensors applied in wastewater treatment. Overall, this review aims to project a rapid developmental path showing a broad vision of recent biotechnologies, applications, challenges, and opportunities for scholars in biotechnological fields for "green" wastewater treatment.

Antibiotics mineralization by electrochemical and UV-based hybrid processes: evaluation of the synergistic effect

Antibiotics are not efficiently removed in conventional wastewater treatments. In fact, different advanced oxidation process (AOPs), including ozone, peroxide, UV radiation, among others, are being investigated in the elimination of microcontaminants. Most of AOPs proved to be efficient on the degradation of antibiotics, but the mineralization is on the one hand not evaluated or on the other hand not high. At this work, the UV-based hybrid process, namely Photo-assisted electrochemical oxidation (PEO), was applied, aiming the mineralization of microcontaminants such as the antibiotics Amoxicillin (AMX), Norfloxacin (NOR) and Azithromycin (AZI). The influence of the individual contributions of electrochemical oxidation (EO) and the UV-base processes on the hybrid process (PEO) was analysed. Results showed that AMX and NOR presented higher mineralization rate under direct photolysis than AZI due to the high absorption of UV radiation. For the EO processes, a low mineralization was found for all antibiotics, what was associated to a mass-transport limitation related to the low concentration of contaminants (200 µg/L). Besides that, an increase in mineralization was found, when heterogeneous photocatalysis and EO are compared, due to the influence of UV radiation, which overcomes the mass-transport limitations. Although the UV-based processes control the reaction pathway that leads to mineralization, the best results to mineralize the antibiotics were achieved by PEO hybrid process. This can be explained by the synergistic effect of the processes that constitute them. A higher mineralization was achieved, which is an important and useful finding to avoid the discharge of microcontaminants in the environment.

Removal of antibiotics from aqueous solution by using magnetic Fe3O4/red mud-nanoparticles

In this study, the availability of magnetically separable Fe₃O₄-red mud nanoparticles (Fe₃O₄-RM-NPs) for the removal of antibiotics from wastewater was investigated. Disadvantages of red mud and Fe₃O₄ because of difficult separation from aqueous media, agglomeration, and iron leaching were overcome by combining these two materials. After examinating adsorption capability of magnetic Fe₃O₄-RM-NPs for all studied antibiotic compounds, the experiments were performed by using Ciprofloxacin (CIPRO) as a model compound. Batch experiments were performed to determine the effect of red mud content of synthesized Fe₃O₄-RM-NPs, pH, reaction time and temperature on the proposed method. The surface morphology, magnetic properties, crystalline structure, thermal stability and Brunauer-Emmet-Teller surface area of the synthesized Fe₃O₄-RM-NPs were determined. The saturation magnetization of Fe₃O₄-RM-NPs was determined to be 12.2 emu/g, which is efficient to separate adsorbent from water by using a conventional magnet. For the efficient removal of CIPRO from aqueous media optimum conditions were determined to be 1.5 g red mud for Fe₃O₄-RM-NPs synthesize, pH 6.0, reaction time 60 min, 3 g/L Fe₃O₄-RM-NPs dosage at 25 °C. Adsorption was fitted well with pseudo-second-order kinetic model. Equilibrium data were found to be better represented by Freundlich isotherm. n value was 4.32, and K_F value was 110.15 mg/g for Freundlich isotherm. No important matrix effect was determined for removal of CIPRO from wastewater sample. Film diffusion mechanism controlled adsorption. Magnetically separable Fe₃O₄-RM-NPs are proposed to be used as efficient adsorbent to remove antibiotics from wastewater sources. Since red mud is a process waste, proposed nanomaterial is a good alternative to commercial adsorbents.

Benzimidazoles in wastewater: Analytical method development, monitoring and degradation by photolysis and ozonation

Pharmaceutical residues are constantly released into natural waters, mainly from wastewater treatment plants (WWTPs) whose processes are unable to completely eliminate them. Among these drugs, the occurrence of benzimidazoles, a class of antiparasitics for human and veterinary use, has been reported in WWTP effluents and surface waters. In this study, an SPE-UHPLC-MS/MS method was developed and optimized for extraction and quantitation of benzimidazoles in influents and effluents of a local WWTP and in hospital wastewater. The extraction procedure was optimized using response surface methodology (Box-Behnken design) and the optimal parameters were as follows: 2.0 mL of loading solvent consisting of a mixture of water:methanol (95:5, v/v) and temperature at 43 °C. In hospital wastewater, albendazole (ABZ) and its principal metabolite ricobendazole (RBZ) were the main benzimidazole-related contaminants and were found at concentrations of up to 3810 and 3894 ng L^-1, respectively. The WWTP system was able to remove from 46% to 95% of the ABZ quantified in the influent, discharging an effluent with 16-441 ng L^-1 of ABZ. The concentrations of other benzimidazoles and metabolites in the WWTP effluents remained below 350 ng L^-1. WWTP effluents fortified with 50 μg L^-1 of ABZ required 26.7 mg_O3 L^-1 to remove ABZ and RBZ. After ozonation, the COD and BOD₅ of the effluents were reduced by 27%. Photolysis by UVA radiation was not effective to remove ABZ and FBZ from the effluent samples.

Different Uses of Ozone: Environmental and Corporate Sustainability. Literature Review and Case Study

An extensive and interdisciplinary literature review was carried out to evaluate the uses of synthetically produced ozone in many different application areas. The objective of the study was to investigate the disinfectant and purifying effectiveness of this natural compound and evaluate its use as an economically and environmentally sustainable alternative to treatments that often involve the adoption of pharmaceutical agents. Being a natural substance, the potential environmental sustainability of the use of ozone in areas such as water disinfectant; pesticide action in agriculture; and antibiotic, anti-inflammatory and antiviral actions in animal husbandry and fish farming are of interest. In addition to environmental sustainability, economic sustainability is also important for companies employing ozone in their processes. Thus, a case study was proposed that represents the use of ozone in a pilot swine farm located in Northern Italy, both as an alternative to pharmaceutical drugs for the animals and as an air and water purifier. The case study demonstrates the economic sustainability of ozone use, especially in the medium run, along with its ability to reduce animal mortality (by about 2%), as well as decrease use of pharmaceutical antibiotics.

Sorption of norfloxacin, sulfamerazine and oxytetracycline by KOH-modified biochar under single and ternary systems

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.

A novel Z-scheme sonocatalyst system, Er3+:Y3Al5O12@Ni(Fe0.05Ga0.95)2O4-Au-BiVO4, and application in sonocatalytic degradation of sulfanilamide

A novel Z-scheme coated composite, Er³⁺:Y₃Al₅O₁₂@Ni(Fe_0.05Ga_0.95)₂O₄-Au-BiVO₄, was designed for sonocatalytic degradation of sulfanilamide and fabricated by sol-hydrothermal and calcination methods. The prepared sample was characterized by X-ray diffractometer (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), energy dispersive X-ray spectroscopy (EDX), UV-vis diffuse reflectance spectra (DRS), fourier transform infrared (FT-IR) spectra, Raman spectra and photoluminescence (PL) spectra. In Er³⁺:Y₃Al₅O₁₂@Ni(Fe_0.05Ga_0.95)₂O₄-Au-BiVO₄, Ni(Fe_0.05Ga_0.95)₂O₄ and BiVO₄ form a Z-scheme sonocatalytic system, Er³⁺:Y₃Al₅O₁₂ as an up-conversion luminescence agent (from visible-light to ultraviolet-light) provides the ultraviolet-light for satisfying the energy demand of wide band-gap Ni(Fe_0.05Ga_0.95)₂O₄ and Au nanoparticles as co-catalyst forms more active sites to enrich electrons. Also, Au nanoparticles as conductive channels promotes the electrons (e^-) from conduction band of BiVO₄ to transfer to valence band of Ni(Fe_0.05Ga_0.95)₂O₄. Due to the characteristics of valence state diversity, the Fe³⁺ and V⁵⁺ constitute a redox reaction recombination system, which can also push electrons (e^-) on conduction band of BiVO₄ to quickly transfer to valence band of Ni(Fe_0.05Ga_0.95)₂O₄. The sonocatalytic activity of Er³⁺:Y₃Al₅O₁₂@Ni(Fe_0.05Ga_0.95)₂O₄-Au-BiVO₄ nanocomposite was detected through degradation of sulfanilamide under ultrasonic irradiation. A high sonocatalytic degradation ratio (95.64%) of sulfanilamide can be obtained when the conditions of 10.00 mg/L sulfanilamide, 1.00 g/L Er³⁺:Y₃Al₅O₁₂@Ni(Fe_0.05Ga_0.95)₂O₄-Au-BiVO₄, 300 min ultrasonic irradiation and 100 mL total volume were adopted. Some factors such as ultrasonic irradiation time and cycle number on the sonocatalytic degradation efficiency are also investigated by using TOC and UV-vis spectroscopy. Subsequently, the effects of hydroxyl radicals (OH) and hole scavengers were investigated to elaborate the mechanism. The researches show that the prepared Z-scheme Er³⁺:Y₃Al₅O₁₂@Ni(Fe_0.05Ga_0.95)₂O₄-Au-BiVO₄ coated composite displayed an excellent sonocatalytic activity in degradation of sulfanilamide under ultrasonic irradiation.

Preparation of Ce4+-doped BaZrO3 by hydrothermal method and application in dual-frequent sonocatalytic degradation of norfloxacin in aqueous solution

In this paper, the dual-frequent sonocatalytic degradation of norfloxacin (NOR), an antibiotic, caused by Ce⁴⁺-doped BaZrO₃ is studied. The used Ce⁴⁺-doped BaZrO₃ as a novel sonocatalyst with highly efficient and stable sonocatalytic activity is prepared via hydrothermal method. The prepared sample is characterized by X-ray diffractometer (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflectance spectra (DRS) and Fourier transform infrared spectra (FT-IR) in order to investigate the structure, morphology and chemical composition. The dual-frequent sonocatalytic activity of prepared Ce⁴⁺-doped BaZrO₃ powder is evaluated through sonocatalytic degradation of norfloxacin (NOR) as a model organic pollutant. Some influencing factors such as single/dual-frequent ultrasonic frequent, cerium and zirconium molar proportions, ultrasonic irradiation time and used times are studied in detail by using UV-vis spectra. The generated reactive oxygen species (ROS) during the dual-frequent sonocatalytic degradation process of norfloxacin (NOR) are confirmed by using two different trapping agents. The holes (h⁺) and hydroxyl radicals (OH) are identified and the holes plays a major role during the oxidation process. Finally, the possible mechanism for the dual-frequent sonocatalytic degradation of norfloxacin (NOR) caused by Ce⁴⁺-doped BaZrO₃ is proposed. The experimental results show that the Ce⁴⁺-doped BaZrO₃ displays a good sonocatalytic activity under dual-frequent ultrasonic irradiation. Under optimal conditions, the most of norfloxacin (NOR) can be removed under dual-frequent ultrasonic irradiation for 150 min.

Surface restructuring of red mud to produce FeO x (OH) y sites and mesopores for the efficient complexation/adsorption of β-lactam antibiotics

In this work, iron oxide in the red mud (RM) waste was restructured to produce mesopores with surface [FeO _x (OH) _y ] sites for the efficient complexation/adsorption of β-lactam antibiotics. Red mud composed mainly by hematite was restructured by an acid/base process followed by a thermal treatment at 150-450 °C (MRM150, MRM200, MRM300, and MRM450) and fully characterized by Mössbauer, XRD, FTIR, BET, SEM, CHN, and thermogravimetric analyses. The characterization data showed a highly dispersed Fe³⁺ oxyhydroxy phase, which was thermally dehydrated to a mesoporous α-Fe₂O₃ with surface areas in the range of 141-206 m² g^-1. These materials showed high efficiencies (21-29 mg g^-1) for the adsorption of β-lactam antibiotics, amoxicillin, cephalexin, and ceftriaxone, and the data was better fitted by the Langmuir model isotherm (R ² = 0.9993) with monolayer adsorption capacity of ca. 39 mg g^-1 for amoxicillin. Experiments such as competitive adsorption in the presence of phosphate and H₂O₂ decomposition suggested that the β-lactamic antibiotics might be interacting with surface [FeO _x (OH) _y ] species by a complexation process. Moreover, the OH/Fe ratio, BET surface area and porosity indicated that this complexation is occurring especially on [FeO _x (OH) _y ]_surf sites contained in the mesopore space.