Wastewater is major source of contaminants originating from the production, usage, and disposal of plastic materials. Due to their poor biodegradability of these contaminants in municipal wastewater treatment plants, additional advanced oxidation processes such as electrochemical treatments have been developed to improve the standard biological treatment. Here we review the applications of electrochemical treatments of wastewater for the removal of the following plastic contaminants: bisphenol A, phthalic acid esters, and benzotriazoles. We present the effectiveness of treatment in terms of contaminant removal and mineralization; the identification of transformation products; toxicity assessment; and process energy requirements. In the present review, we have focused on the applications of electrochemical treatments of wastewater for the removal of three important groups of contaminants originating mainly from plastics: bisphenol A, phthalic acid esters, and benzotriazoles. The review focuses on the research of electrochemical treatments for these contaminants from the last five years. The papers are assessed from the point of i) effectiveness of treatment in terms of contaminant removal and mineralization; ii) identification of transformation products; iii) toxicity assessment; iv) processes’ energy requirements. Electrochemical treatments were confirmed to be a viable option for the removal of selected contaminants from wastewater.

Micropollutants and emerging substances pose a serious problem to environmental sustainability and remediation, due to their widespread use and applications in everyday life. This group of chemicals is diverse but with common toxic and harmful properties. Their concentration in the environment is often very low; however, due to their recalcitrant nature, they are persistent in air, water, and soil. From an engineering point of view, the challenge is not straightforward. It is difficult to remove these contaminants from complex mixtures of substances by conventional methods used in wastewater and drinking water treatment. Ozonation and ozone-based AOPs are accepted processes of degradation of resistant substances or at least enhancement of their biodegradability. The aim of this review paper is to present research trends aimed at solving problems in the research and application of ozone-based processes in the removal of micropollutants from wastewater, thus preventing leakage of harmful substances into surface water, soil, and groundwater and facilitating the reuse of wastewater. Priority substances, micropollutants and emerging pollutants, as well as processes and technologies for their transformation and elimination, are briefly specified. Results obtained by the authors in solving research projects that were aimed at eliminating selected micropollutants by ozonation and ozone-based AOPs are also presented. This review focuses on selected alkylphenols, petroleum substances, and organochlorine pesticides.

Amoxicillin (AMX) and Ciprofloxacin (CIP) are antibiotics commonly used in human medicine with high environmental toxicity and poor biodegradability. They have been found in various hospital effluents and groundwater, and their environmental impact is still not fully understood. In this work, we investigated the possibility of treating model wastewaters containing the antibiotics AMX and CIP using ozonation, with the addition of H₂O₂ under various conditions, including different pH values, H₂O₂, and ozone dosages. The quantification of and treatment efficacy for antibiotic removal were determined via solid phase extraction followed by chromatographic separation by liquid chromatography coupled with tandem triple quadrupole mass spectrometry (LC/MS/MS). This analytical system is quite efficient for the detection of all major antibiotic classes, even if they are present at very low concentrations. The efficiency of ozonation was determined by measuring the TOC (Total Organic Carbon) changes after ozonation of the model wastewater and by measuring the concentration of the two antibiotics. In a sequential activated sludge process of ozone-treated model wastewater, almost complete TOC removal and an overwhelming decrease in antibiotic concentrations (up to 99%) were observed. Ozonation resulted in complete removal of AMX and CIP in less than 30 and 120 min, respectively. The results of this work indicate that ozonation could be a suitable pretreatment method to reduce the toxicity of contaminants (AMX and CIP) and improve the biodegradability of hospital wastewater.

The European Parliament adopted a legislative resolution of 10 April 2024 on the proposal for a directive of the European Parliament and of the Council concerning urban wastewater treatment. The reduction in pollution in discharged treated wastewater in the parameters of BOD₅, total nitrogen, and total phosphorus was emphasized. Based on these results, it stated that the impacts on the quality of lakes, rivers, and seas in the EU are visible and tangible. At the same time, it was emphasized that the sector of urban wastewater removal and treatment is responsible for 0.8% of total electricity consumption and about 0.86% of all greenhouse gas emissions in the entire EU. Almost a third of these emissions could be prevented by improving the treatment process, better use of sewage sludge, and increasing energy efficiency, as well as a higher rate of use of renewable resource technologies. It is also necessary to integrate treatment processes into the circular economy. Sludge management and water reuse are suboptimal as too many valuable resources are still being wasted. This article focuses on sustainable municipal wastewater treatment, innovative and new wastewater treatment processes and technologies (combined and hybrid processes, ANAMMOX, etc.) and their use in practice with the aim of increasing environmental and energy efficiency and reducing the carbon footprint. The research is focused on the possibilities of increasing the efficiency of energy processing of sludge, reuse of nitrogen and phosphorus, sludge, and reuse of treated wastewater.