Microplastics as an emerging hazard to terrestrial and marine ecosystems: Sources, Occurrence and Analytical Methods

Microplastics (MPs) with particles lower than 5mm in size, are crucial pollution of increasing ecotoxicological concern in the environments. Lately, studies on MPs have been documented globally due to increasing awareness of the potential risks for human health and for the environment. However due to limitations of different analytical methods and environmental assessment risk, MPs distribution and biological effects are still database topics. To clarify this gap, this study brings out a wide range of scientific literature related to MPs studies in different environmental compartments as well as sediments, oceans, coastlines, uptake and the health effect. The environmental and health risk related to microplastic contamination is still unclear

Removal of Pharmaceuticals from Water by Adsorption and Advanced Oxidation Processes: State of the Art and Trends

International audiencePharmaceutical products have become a necessary part of life. Several studies have demonstrated that indirect exposure of humans to pharmaceuticals through the water could cause negative effects. Raw sewage and wastewater effluents are the major sources of pharmaceuticals found in surface waters and drinking water. Therefore, it is important to consider and characterize the efficiency of pharmaceutical removal during wastewater and drinking-water treatment processes. Various treatment options have been investigated for the removal/reduction of drugs (e.g., antibiotics, NSAIDs, analgesics) using conventional or biological treatments, such as activated sludge processes or bio-filtration, respectively. The efficiency of these processes ranges from 20-90%. Comparatively, advanced wastewater treatment processes, such as reverse osmosis, ozonation and advanced oxidation technologies, can achieve higher removal rates for drugs. Pharmaceuticals and their metabolites undergo natural attenuation by adsorption and solar oxidation. Therefore, pharmaceuticals in water sources even at trace concentrations would have undergone removal through biological processes and, if applicable, combined adsorption and photocatalytic degradation wastewater treatment processes. This review provides an overview of the conventional and advanced technologies for the removal of pharmaceutical compounds from water sources. It also sheds light on the key points behind adsorption and photocatalysis

Application of Sequential Combination of Electro-Coagulation/Electro-Oxidation and Adsorption for the Treatment of Hemodialysis Wastewater for Possible Reuse

Reusing hemodialysis wastewater (HWW) is more difficult due to its higher conductivity (salinity) and the need for an iterative RO or adsorption process. It can therefore be challenging and technologically laborious. In this context, this study aimed to investigate the possibility of treating HWW by combining electro-coagulation (EC) and electro-oxidation (EO) processes and adsorption as the best technologies to achieve efficient removal of dissolved micropollutants. In this work, the application of electro-coagulation/electro-oxidation processes using, respectively, aluminum and platinum electrodes combined with adsorption onto active carbon to treat HWW was studied. In the EC process, high removal of phosphate ions and chemical oxygen demand (COD) was observed. In the EO process, the COD removal performance, total nitrogen, and Mg were significant and reached 100, 83, and 89%, respectively, after 100 min of treatment. The estimated energies required to treat HWW by EC and/or EO were approximately 0.7 kWh/m3 and 0.05 kWh/m3, respectively. While the EO and EC processes used for COD removal from HWW showed almost similar performances, the EO process seems to consume less energy. Therefore, electrochemical removal of HWW can be successfully performed using the EO process and activated carbon (AC) for the complete removal of COD and the mineralization of pharmaceutical residues. The experimental results showed that the coupling of the three processes (EC–EO–AC) provides treated water that can be reused in agriculture due to its less sodium absorption ratio (SAR) value and might be an alternative method of wastewater treatment responding to the concept of green dialysis

Soil contamination by microplastics in relation to local agricultural development as revealed by FTIR, ICP-MS and pyrolysis-GC/MS

Plastic film mulching and use of wastewaters for irrigation have been common agricultural practices for over half a century in Tunisia, especially in arid regions, resulting in the undesired creation of a pathway for microplastics (MPs) to enter farmland soil. In order to assess the extent and characteristics of soil contamination by MPs in the Moknine province, an area of intensive agricultural practices, 16 farmland soil samples were collected and characterized. The total concentration of targeted MPs was 50-880 items/kg; among them, the most common MPs type being polypropylene (PP), mainly occurring as white/transparent fibers with small size (cross section <0.3 mm). SEM images of MPs surfaces revealed multiple features related to environmental exposure and degradation. ATR-FTIR spectroscopy and pyrolysis-GC/MS analyses enabled the accurate identification of MPs separated from the embedding soil micro and macro-aggregates. Finally, contamination of the polymeric microparticles with a broad range of metals was found by ICP-MS analysis, suggesting that MPs can be5 vectors for transporting heavy metals in the soil and indicators of soil contamination as a result of mismanagement of industrial wastewaters

Adsorption of anti-inflammatory and analgesic drugs traces in water on clay minerals

International audienc

Effects of microplastics’ physical and chemical properties on aquatic organisms: State-of-the-art and future research trends

Microplastics (MPs) pose a global threat to marine ecosystems, little is known about the factors that influence their bioavailability. Microplastics have the ability to adsorb contaminants from the environment, as well as to act as vectors for toxicants and pathogens. This is why addressing MPs' physicochemical properties, as well as toxicological concerns, bioavailability, and environmental impact, is critical. Furthermore, the biological response to MPs is difficult to interpret and is yet to be successfully related to MPs inherent physical and chemical characteristics, including shape, size, and chemical structure. Thus, ecotoxicological effects on (marine) organisms, both by themselves and when associated with other pollutants, should be studied not only at individual but also at the populational and community levels.Herein, we summarize the current research on the interactions of MPs with aquatic organisms and related chemicals, such as additives and heavy metals. Additionally, knowledge gaps, and future research opportunities, are highlighted.Khawla Chouchene acknowledges financial support from the Sfax Center of Biotechnology through a Postdoctoral contract. JPC thanks the financial support from the Portuguese Foundation for Science and Technology (FCT) under contract 2021.00909.CEECIND. The financial support to CESAM by FCT/MCTES (UIDP/50017/2020+UIDB/50017/2020+LA/P/0094/2020), through national funds, is also acknowledged, as well as funding for BioPlasMar (PTDC/CTA-AMB/0934/2021)

Development of Novel Peptide-Based Michael Acceptors Targeting Rhodesain and Falcipain-2 for the Treatment of Neglected Tropical Diseases (NTDs)

This paper describes the development of a class of peptide-based inhibitors as novel antitrypanosomal and antimalarial agents. The inhibitors are based on a characteristic peptide sequence for the inhibition of the cysteine proteases rhodesain of Trypanosoma brucei rhodesiense and falcipain-2 of Plasmodium falciparum. We exploited the reactivity of novel unsaturated electrophilic functions such as vinyl-sulfones, -ketones, -esters, and -nitriles. The Michael acceptors inhibited both rhodesain and falcipain-2, at nanomolar and micromolar levels, respectively. In particular, the vinyl ketone 3b has emerged as a potent rhodesain inhibitor (k2nd = 67 × 106 M-1 min-1), endowed with a picomolar binding affinity (Ki = 38 pM), coupled with a single-digit micromolar activity against Trypanosoma brucei brucei (EC50 = 2.97 μM), thus being considered as a novel lead compound for the discovery of novel effective antitrypanosomal agents

Development of Novel Peptide-Based Michael Acceptors Targeting Rhodesain and Falcipain‑2 for the Treatment of Neglected Tropical Diseases (NTDs)

This paper describes the development of a class of peptide-based inhibitors as novel antitrypanosomal and antimalarial agents. The inhibitors are based on a characteristic peptide sequence for the inhibition of the cysteine proteases rhodesain of Trypanosoma brucei rhodesiense and falcipain-2 of Plasmodium falciparum. We exploited the reactivity of novel unsaturated electrophilic functions such as vinyl-sulfones, -ketones, -esters, and -nitriles. The Michael acceptors inhibited both rhodesain and falcipain-2, at nanomolar and micromolar levels, respectively. In particular, the vinyl ketone <b>3b</b> has emerged as a potent rhodesain inhibitor (<i>k</i>_2nd = 67 × 10⁶ M^–1 min^–1), endowed with a picomolar binding affinity (<i>K</i>_i = 38 pM), coupled with a single-digit micromolar activity against Trypanosoma brucei brucei (EC₅₀ = 2.97 μM), thus being considered as a novel lead compound for the discovery of novel effective antitrypanosomal agents