Degradation of drugs in water with advanced oxidation processes and ozone

A critical review on ibuprofen removal from synthetic waters, natural waters, and real wastewaters by advanced oxidation processes

Ibuprofen (IBP) is one ubiquitous drug prescribed as anti-inflammatory, analgesic, and antipyretic. It has been detected in effluents of wastewater plant treatments, sewage sludge, hospital wastewaters, surface waters, and drinking water due to its continuous release to the environment, mainly from the excretion in the urine of animals and humans. IBP is a carcinogenic and non-steroidal endocrine disrupting drug with harmful effects over fungal, bacterial, algae, microorganisms, crustacean, and fish species, and can be potentially hazard for human health. Since conventional treatments remove inefficiently this drug, many advanced oxidation processes (AOPs) have been developed aiming their abatement from waters to avoid their harmful health problems. This paper presents an exhaustive and critical review on the application of AOPs to treat synthetic waters, natural waters, and real wastewaters polluted with IBP alone or mixed with other common drugs covering up to 2020. The characteristics and main results obtained for single, hybrid, and sequential treatments are described. Dielectric barrier or pulsed-corona discharges are detailed among the single processes. Hybrid processes such as photocatalysis (UV/H₂O₂, UV/chlorine, TiO₂/UV), hybrid ozonation (O₃/H₂O₂, electro-peroxone, catalytic ozonation), Fenton-based processes (photo-Fenton, electro-Fenton, photoelectro-Fenton), zero-valent iron, ultrasonic, peroxymonosulfate, and persulfate, are discussed. The effect of the kind of irradiation (UV, visible, solar) on photo-assisted processes is analyzed. Sequential processes with biological pre- or post-treatments using or not membranes for natural water and real wastewater remediation are described. Finally, 38 by-products detected during IBP removal by AOPs are reported, allowing envisaging three parallel pathways for its initial degradation.

Development of an Ozone-Assisted Sample Preparation Method for the Determination of Cu and Zn in Rice Samples

A green analytical method for the determination of Cu and Zn in rice samples was developed. This method was based on an ozone-assisted extraction (OAE) in diluted acid media. A novel closed system was designed for this purpose that allowed four simultaneous sample treatments being safe for the laboratory environment. The method consisted in 0.5 g of the sample, 15 minutes of ozonation, and 3 minutes of centrifugation. The obtained supernatant was ready for Cu and Zn determinations by flame atomic absorption spectrometry. Detection limits were 0.20 and 0.08 mg kg^-1 for Cu and Zn, respectively, with a precision (RSD) better than 5% for both elements. A certified reference material of rice flour was analyzed for trueness evaluation, and the mean recoveries (%) were 100.4 (Cu) and 95.9 (Zn). Several commercial rice samples were analyzed using this method, and the results were compared with those obtained using traditional microwave-assisted digestion (MAE). Both methods yielded comparable results. Cu and Zn levels were in accordance with reported values in other regions. The OAE resulted to be simple and economical and with results equivalent with those obtained using traditional sample preparation procedures as MAE with the advantage of being in good agreement with the principles of green analytical chemistry.

Removal of Tetracycline Oxidation Products in the Nanofiltration Process

The possibility of removing tetracycline (TRC) from water in an integrated advanced oxidation and membrane filtration process was investigated. Ozonation and UV/H2O2 photooxidation were applied for the destruction of TRC. Six oxidation products (OPs) retaining the structural core of TRC have been identified. One new TRC oxidation product, not reported so far in the literature, was identified—ethyl 4-ethoxybenzoate. All identified OPs were effectively retained on the membrane in the nanofiltration process. However, chemical oxygen demand (COD) measurements of the filtrates showed that in the case of UV/H2O2 oxidation, the OPs passed through the membrane into the filtrate. Various water matrices were used in the research, including the river water untreated and after ozone treatment. It has been shown that organic matter present in surface water can improve pharmaceutical retention, although it contributes to significant membrane fouling. Pre-ozonation of the river water reduced the membrane fouling. The XPS analysis was used to show ozone and H2O2 influence on the top polymer layer of the membrane. It was shown that the oxidants can damage the amide bond of the polyamide.

Ibuprofen as an emerging organic contaminant in environment, distribution and remediation

Pharmaceutical and personal care products (PPCPs) are the one of sub-class under emerging organic contaminants (EOCs). Ibuprofen is the world's third most consumable drug. This drug enters into our water system through human pharmaceutical use. It attracts the attention of environmentalist on the basis of risk associated, presence and transformation in the environment. The detection and removal are the two key area where we need to focus. The concentration of such compounds in waterbodies detected through conventional and also by the advanced methods. This review we described the available technologies including chemical, physical and biological methods, etc used the for removal of Ibuprofen. The pure culture based method, mixed culture approach and activated sludge culture approach focused and pathway of degradation of ibuprofen was deciphered by using the various methods of structure determination. The various degradation methods used for Ibuprofen are discussed. The advanced methods coupled with physical, chemical, biological, chemical methods like ozonolysis, oxidation and adsorption, nanotechnology based methods, nanocatalysis and use of nonosensors to detect the presence of small amount in waterbodies can enhance the future degradation of this drug. It is necessary to develop the new detection methods to enhance the detection of such pollutants. With the developments in new detection methods based on GC-MS//MS, HPLC, LC/MS and nanotechnology based sensors makes easier detection of these compounds which can detect even very minute amount with great sensitivity and in less time. Also, the isolation and characterization of more potent microbial strains and nano-photocatalysis will significantly increase the future degradation of such harmful compounds from the environment.

Recent Progress on Titanium Dioxide Nanomaterials for Photocatalytic Applications

Environmental and energy problems have drawn much attention owing to rapid population growth and accelerated economic development. For instance, photocatalysis, "a green technology", plays an important role in solar-energy conversion owing to its potential to solve energy and environmental problems. Recently, many efforts have been devoted to improving visible-light photocatalytic activity by using titanium dioxide as a photocatalyst as a result of its wide range of applications in the energy and environment fields. However, fast charge recombination and an absorption edge in the UV range limit the photocatalytic efficiency of TiO₂ under visible-light irradiation. Many investigations have been undertaken to overcome the limitations of TiO₂ and, therefore, to enhance its photocatalytic activity under visible light. The present literature review focuses on different strategies used to promote the separation efficiency of electron-hole pairs and to shift the absorption edge of TiO₂ to the visible region. Current synthesis techniques used to elaborate several nanostructures of TiO₂ -based materials, recent progress in enhancing visible photocatalytic activity, and different photocatalysis applications will be discussed. On the basis of the studies reported in the literature, we believe that this review will help in the development of new strategies to improve the visible-light photocatalytic performance of TiO₂ -based materials further.

Normal boundary intersection applied as multivariate and multiobjective optimization in the treatment of amoxicillin synthetic solution

Amoxicillin is a useful antibiotic to combat bacterial infections. However, this drug can cause serious problems when discarded in waterways due to its great bioaccumulation potential. This compound can be treated via advanced oxidation processes (AOPs), which are capable of converting amoxicillin into carbon dioxide and water. In this context, the use of ozone as an oxidizer has excelled in amoxicillin degradation. This paper aims at treating a synthetic solution of amoxicillin (0.1 g L^-1) in a reactor with ozone bubbling. A Design of Experiment (DoE) with a response surface known as Central Composite Design (CCD) was used to optimize the treatment process. In addition, a Normal Boundary Intersection (NBI) method was used in the construction of a Pareto boundary chart. Results after 1-h treatment showed a reduction of 53% of the initial organic matter from a designed model using factors, such as pH, ozone generator power, and O₃ flow. A model was built from the CCD with score of 0.9929. Thus, the model was able to represent the real scenario with confidence.

Consumption-based approach for pharmaceutical compounds in a large hospital

Hospital wastewater contains a great variety of pharmaceutical compounds (PhCs), mainly due to excretion by patients. These PhCs, called emerging pollutants, are not fully eliminated in treatment plants, and are consequently detected in various environmental matrices, contributing to bacterial resistance and adverse environmental impacts on water resources. This study explores a consumption-based approach to predict the contribution of PhCs to a Brazilian hospital's wastewater. This approach identifies the consumption of major pharmaceutical classes in the studied hospital. Overall, this approach demonstrates a unique opportunity to screen PhCs used in hospitals and identify priority pollutants in hospital wastewater.

Improving degradation of paracetamol by integrating gamma radiation and Fenton processes

Degradation of paracetamol (N-(4-hydroxiphenyl)acetamide) in aqueous solution by gamma radiation, gamma radiation/H2O2 and gamma radiation/Fenton processes was studied. Parameters affecting the radiolysis of paracetamol such as radiation dose, initial concentration of pollutant, pH and initial oxidant concentration were investigated. Gamma radiation was performed using a (60)Co source irradiator. Paracetamol degradation and mineralization increased with increasing absorbed radiation dose, but decreased with increasing initial concentration of the drug in aqueous solution. The addition of H2O2 resulted in an increased effect on irradiation-driven paracetamol degradation in comparison with the performance of the irradiation-driven process alone: paracetamol removal increased from 48.9% in the absence of H2O2 to 95.2% for H2O2 concentration of 41.7 mmol/L. However, the best results were obtained with gamma radiation/Fenton process with 100% of the drug removal at 5 kGy, for optimal H2O2 and Fe(2+) concentrations at 13.9 and 2.3 mmol/L, respectively, with a high mineralization of 63.7%. These results suggest gamma radiation/H2O2 and gamma radiation/Fenton processes as promising methods for paracetamol degradation in polluted wastewaters.