Removal of emerging pollutants by a 3-step system: Hybrid digester, vertical flow constructed wetland and photodegradation post-treatments

Simultaneous deep removal of nitrate and tetrabromobisphenol A in microbial electrochemical system-constructed wetland

Microbial electrochemical system-constructed wetland (MES-CW) is environmentally friendly in removing organic contaminants from wastewater. Tetrabromobisphenol A (TBBPA) is an emerging pollutant that is inefficiently removed in conventional wastewater treatment. The feasibility of deep removal of TBBPA and nitrate and the related mechanism in MES-CW remains unclear. This study demonstrated the enhanced TBBPA detoxification in MES-CW accompanied by nitrate removal. Nitrate significantly suppressed the TBBPA reductive debromination and methane generation. It altered the microbial community and enriched Acinetobacter in the electrode, stimulating the TBBPA hydrolytic debromination and metabolite oxidation. The biocathode supplied electrons for dehalogenators in TBBPA reductive debromination, while the anode served as the electron acceptor for function bacteria in TBBPA metabolite oxidation. Nitrate and anodic electricity optimized the microbial community and provided electron acceptors for TBBPA metabolites oxidation in MES-CW, guiding the deep removal of nitrate and emerging pollutants in wastewater.

New insight into the spatiotemporal distribution and ecological risk assessment of endocrine-disrupting chemicals in the Minjiang and Tuojiang rivers: perspective of watershed landscape patterns

This study evaluated the pollution characteristics, spatiotemporal distribution, and ecological risks of eight endocrine-disrupting chemicals (EDCs) in the Minjiang and Tuojiang rivers. Utilizing 3S technology (ArcGIS, remote sensing, GPS) and Fragstats, the research calculated eight landscape pattern indices related to land use types along the Minjiang river and established correlations between landscape factors and EDC distribution through stepwise multiple regression. The results indicated that bisphenol A (BPA) and nonylphenol (NP) were the most concerning EDCs, with detection frequencies of 97-100% and peak concentrations up to 63.35 ng L-1, primarily located in the middle and lower reaches of the Minjiang river and the upper reaches of the Tuojiang river. There was a significant correlation between the spatial distribution of pollutants and landscape patterns, where increased fragmentation, a higher number of patches, and complex patch shapes within a 10-kilometer buffer zone were associated with elevated levels of river pollution. By integrating four classical mathematical models to fit curves for acute and chronic toxicity data of BPA and NP, the findings suggested that BPA posed a higher ecological risk. This interdisciplinary research provided essential theoretical insights for investigating river pollution and its influencing factors, offering a new perspective on simultaneous river pollution control, urban functional zoning, and adjustment of watershed landscape spatial patterns from an urban planning standpoint.

Global insight into the occurrence, treatment technologies and ecological risk of emerging contaminants in sanitary sewers: Effects of the SARS-CoV-2 coronavirus pandemic

The SARS-CoV-2 pandemic caused changes in the consumption of prescribed/non-prescribed drugs and the population's habits, influencing the detection and concentration of emerging contaminants (ECs) in sanitary sewage and harming environmental and health risks. Therefore, the present work sought to discuss current literature data on the effects of the "COVID-19 pandemic factor" on the quality of raw sewage produced over a five-year period (2018-2019: pre-pandemic; 2020-2022: during the pandemic) and biological, physical, chemical and hybrid treatment technologies, influencing factors in the removal of ECs and potential ecological risks (RQs). Seven hundred thirty-one publications correlating sewage and COVID-19 were identified: 184 pre-pandemic and 547 during the pandemic. Eight classes and 37 ECs were detected in sewage between 2018 and 2022, with the "COVID-19 pandemic factor" promoting an increase in estrogens (+31,775 %), antibiotics (+19,544 %), antiepileptics and antipsychotics (+722 %), pesticides (+200 %), analgesics, anti-inflammatories and anticoagulants (+173 %), and stimulant medications (+157 %) in sanitary sewage. Among the treatment systems, aerated reactors integrated into biomembranes removed >90 % of cephalexin, clarithromycin, ibuprofen, estrone, and 17β-estradiol. The absorption, adsorption, and biodegradation mechanisms of planted wetland systems contributed to better cost-benefit in reducing the polluting load of sewage ECs in the COVID-19 pandemic, individually or integrated into the WWTP. The COVID-19 pandemic factor increased the potential ecological risks (RQs) for aquatic organisms by 40 %, with emphasis on clarithromycin and sulfamethoxazole, which changed from negligible risk and low risk to (very) high risk and caffeine with RQ > 2500. Therefore, it is possible to suggest that the COVID-19 pandemic intensified physiological, metabolic, and physical changes to different organisms in aquatic biota by ECs during 2020 and 2022.

Construction of type-II scheme SnO@HfC photocatalyst for bisphenol A degradation via peroxymonosulfate activation; DFT and self-cleaning analysis

In this study, novel stannous oxide@hafnium carbide (SnO@HfC) nanocomposite was successfully manufactured by an appropriate hydrothermal scheme which was utilized for the photocatalytic degradation of BPA by stimulation of peroxymonosulfate (PMS) and self-cleaning application. Numerous methods were applied for the characterization of photocatalyst and demonstrated the successful preparation of SnO@HfC nanocomposite. The crystal structures, band structures and density of states for SnO and HfC were explored by DFT analysis. The amazing PMS stimulation performance of SnO@HfC nanocomposite originated from the establishment of a heterojunction, which led to the enhancement of the light response aptitude and the electron conduction competence of the composite. BPA was degraded by 0.75 g/L PMS and SnO@HfC at neutral pH during the period of 60 min. In order to identify active groups in the reaction procedure, quenching experiments and electron paramagnetic resonance (EPR) approaches were also used. In the subsequent active species scavenging assays, where sulfate radicals, hydroxyl radicals, holes, and superoxide radicals were engaged in the degradation of BPA. While, liquid phase mass spectrometry (LC-MS) was used to pinpoint the intermediate metabolites in the course of degradation. SnO@HfC/PMS/light system delivered excellent TOC removal efficiency and less ions leaching. The SnO@HfC nanocomposite proved good durability and reusability in continuous cycle tests along with excellent self-cleaning function on the glass substrate. The SnO@HfC nanocomposite performs admirably in terms of self-cleaning application. The SnO@HfC nanocomposite is expected to be used in the future for the treatment of wastewater that contains pharmaceuticals due to its superior stability and reusability after five consecutive cycles.

Pharmaceutical residues in the ecosystem: Antibiotic resistance, health impacts, and removal techniques

Hospital wastewater has emerged as a major category of environmental pollutants over the past two decades, but its prevalence in freshwater is less well documented than other types of contaminants. Due to compound complexity and improper operations, conventional treatment is unable to remove pharmaceuticals from hospital wastewater. Advanced treatment technologies may eliminate pharmaceuticals, but there are still concerns about cost and energy use. There should be a legal and regulatory framework in place to control the flow of hospital wastewater. Here, we review the latest scientific knowledge regarding effective pharmaceutical cleanup strategies and treatment procedures to achieve that goal. Successful treatment techniques are also highlighted, such as pre-treatment or on-site facilities that control hospital wastewater where it is used in hospitals. Due to the prioritization, the regulatory agencies will be able to assess and monitor the concentration of pharmaceutical residues in groundwater, surface water, and drinking water. Based on the data obtained, the conventional WWTPs remove 10-60% of pharmaceutical residues. However, most PhACs are eliminated during the secondary or advanced therapy stages, and an overall elimination rate higher than 90% can be achieved. This review also highlights and compares the suitability of currently used treatment technologies and identifies the merits and demerits of each technology to upgrade the system to tackle future challenges. For this reason, pharmaceutical compound rankings in regulatory agencies should be the subject of prospective studies.

Ketoprofen as an emerging contaminant: occurrence, ecotoxicity and (bio)removal

Ketoprofen, a bicyclic non-steroidal anti-inflammatory drug commonly used in human and veterinary medicine, has recently been cited as an environmental contaminant that raises concerns for ecological well-being. It poses a growing threat due to its racemic mixture, enantiomers, and transformation products, which have ecotoxicological effects on various organisms, including invertebrates, vertebrates, plants, and microorganisms. Furthermore, ketoprofen is bioaccumulated and biomagnified throughout the food chain, threatening the ecosystem function. Surprisingly, despite these concerns, ketoprofen is not currently considered a priority substance. While targeted eco-pharmacovigilance for ketoprofen has been proposed, data on ketoprofen as a pharmaceutical contaminant are limited and incomplete. This review aims to provide a comprehensive summary of the most recent findings (from 2017 to March 2023) regarding the global distribution of ketoprofen in the environment, its ecotoxicity towards aquatic animals and plants, and available removal methods. Special emphasis is placed on understanding how ketoprofen affects microorganisms that play a pivotal role in Earth's ecosystems. The review broadly covers various approaches to ketoprofen biodegradation, including whole-cell fungal and bacterial systems as well as enzyme biocatalysts. Additionally, it explores the potential of adsorption by algae and phytoremediation for removing ketoprofen. This review will be of interest to a wide range of readers, including ecologists, microbiologists, policymakers, and those concerned about pharmaceutical pollution.

A review of hybrid enzymatic-chemical treatment for wastewater containing antiepileptic drugs

Epilepsy is one of the most common neurological diseases worldwide and requires treatment with antiepileptic drugs for many years or for life. This fact leads to the need for constant production and use of these compounds, placing them among the four pharmaceutical classes most found in wastewater. Even at low concentrations, antiepileptics pose risks to human and environmental health and are considered organic contaminants of emerging concern. Conventional treatments have shown low removal of these drugs, requiring advanced and innovative approaches. In this context, this review covers the results and perspectives on (1) consumption and occurrence of antiepileptics in water, (2) toxicological effects in aquatic ecosystems, (3) enzymatic and advanced oxidation processes for degrading antiepileptics drugs from a molecular point of view (biochemical and chemical phenomena), (4) improvements in treatment efficiency by hybridization, and (5) technical aspects of the enzymatic-AOP reactors.

Recent advances in carbon-based nanomaterials for the treatment of toxic inorganic pollutants in wastewater

Wastewater contains inorganic pollutants, generated by industrial and domestic sources, such as heavy metals, antibiotics, and chemical pesticides, and these pollutants cause many environmental problems.

Biochar-mediated removal of pharmaceutical compounds from aqueous matrices via adsorption

Pharmaceutical is one of the noteworthy classes of emerging contaminants. These biologically active compounds pose a range of deleterious impacts on human health and the environment. This is attributed to their refractory behavior, poor biodegradability, and pseudopersistent nature. Their large-scale production by pharmaceutical industries and subsequent widespread utilization in hospitals, community health centers, and veterinary facilities, among others, have significantly increased the occurrence of pharmaceutical residues in various environmental compartments. Several technologies are currently being evaluated to eliminate pharmaceutical compounds (PCs) from aqueous environments. Among them, adsorption appears as the most viable treatment option because of its operational simplicity and low cost. Intensive research and development efforts are, therefore, currently underway to develop inexpensive adsorbents for the effective abatement of PCs. Although numerous adsorbents have been investigated for the removal of PCs in recent years, biochar-based adsorbents have garnered tremendous scientific attention to eliminate PCs from aqueous matrices because of their decent specific surface area, tunable surface chemistry, scalable production, and environmentally benign nature. This review, therefore, attempts to provide an overview of the latest progress in the application of biochar for the removal of PCs from wastewater. Additionally, the fundamental knowledge gaps in the domain knowledge are identified and novel strategic research guidelines are laid out to make further advances in this promising approach towards sustainable development.