Ammonia-rich sediment: Practical issues about embryotoxicity as endpoint supporting challenges in dredging activities.

Regulations for dredging and sediment management often require the use of toxicity tests to support sediment classification, together with chemical characterization; among available bioassays, embryotoxicity tests (conducted on aqueous phase prepared from sediment) are commonly applied to evaluate sub-chronic toxicity, as in the case of Italian legislation. However, toxicity tests can be influenced by several confounding factors, such as ammonia that, in the context of sediment management, generally is not considered as a "traditional" contaminant of concern due to its low persistence. In order to better address and optimize sediment management, it is therefore essential to understand the influence of ammonia on the observed sediment toxicity.

Percarbonate mediated advanced oxidation of irbesartan: A suitable alternative to chlorination?

This study aims to investigate the environmental fate of irbesartan when subjected to activated percarbonate treatment. The investigation delves into the formation of disinfection byproducts (DBPs) and evaluates their toxicity, and it seeks to draw comparisons with outcomes from treatment with sodium hypochlorite, already characterized in previous findings. The proposed treatment indicates the formation of at least 11 DBPs - eight identified for the first time - which have been isolated by various chromatographic techniques, identified by Nuclear Magnetic Resonance and Mass Spectrometry studies and for which a mechanism has been proposed to elucidate their formation.

Ecotoxicological assessment of cyclic peptides produced by a Planktothrix rubescens bloom: Impact on aquatic model organisms.

Cyanobacterial blooms, a natural phenomenon in freshwater ecosystems, have increased in frequency and severity due to climate change and eutrophication. Some cyanobacteria are able to produce harmful substances called cyanotoxins. These metabolites possess different chemical structures and action mechanisms representing a serious concern for human health and the environment.

Levels of rare earth elements on three abandoned mining sites of bauxite in southern Italy: A comparison between TXRF and ICP-MS.

The essential utilization of rare earth elements (REEs) for the production of several electronic devices is making the demand for them being increased all the time. This extensive use of these elements has also increased concern about human and environmental health. Previous studies have shown that REE levels are higher in environmental samples near mining sites, and they are highly possible to be transferred to biota.

Octocrylene: From Sunscreens to the Degradation Pathway during Chlorination Processes: Formation of Byproducts and Their Ecotoxicity Assessment.

Octocrylene is an organic sunscreen whose main action is to absorb UVB radiation and short UVA wavelengths; it is used in various cosmetic products in order to provide an adequate sun-protection factor or to protect the cosmetic formulations themselves from UV radiation. This filter is believed to be a possible endocrine disruptor and is also questioned due to its allergic and/or photoallergic potential. However, it continues to be widely used, and it has been found in various environments, not least those of swimming pools, where it is evidently released by consumers, to the point that it is now considered an emerging micropollutant.

Secondary Effects of Hypochlorite Treatment on the Emerging Pollutant Candesartan: The Formation of Degradation Byproducts and Their Toxicological Profiles.

In recent years, many studies have reported the frequent detection of antihypertensive agents such as sartans (olmesartan, valsartan, irbesartan and candesartan) in the influents and effluents of wastewater treatment plants (WWTPs) and in the superficial waters of rivers and lakes in both Europe and North America. In this paper, the degradation pathway for candesartan (CAN) was investigated by simulating the chlorination process that is normally used to reduce microbial contamination in a WWTP. Twelve isolated degradation byproducts (DPs), four of which were isolated for the first time, were separated on a C-18 column by employing a gradient HPLC method, and their structures were identified by combining nuclear magnetic resonance and mass spectrometry and comparing the results with commercial standards.

LC and NMR Studies for Identification and Characterization of Degradation Byproducts of Olmesartan Acid, Elucidation of Their Degradation Pathway and Ecotoxicity Assessment.

The discovery of various sartans, which are among the most used antihypertensive drugs in the world, is increasingly frequent not only in wastewater but also in surface water and, in some cases, even in drinking or groundwater. In this paper, the degradation pathway of olmesartan acid, one of the most used sartans, was investigated by simulating the chlorination process normally used in a wastewater treatment plant to reduce similar emerging pollutants. The structures of nine isolated degradation byproducts (DPs), eight of which were isolated for the first time, were separated via chromatography column and HPLC methods, identified by combining nuclear magnetic resonance and mass spectrometry, and justified by a proposed mechanism of formation beginning from the parent drug.

Oxidation of diclofenac in water by sodium hypochlorite: Identification of new degradation by-products and their ecotoxicological evaluation.

Diclofenac (DCF) is the most widely prescribed non-steroidal anti-inflammatory drug in the world and it has been detected in drinking and surface waters. In this paper, the effect of chlorination process on DCF in aqueous solutions was investigated and the structures of 14 isolated degradation by-products (DPs), of which nine are new, have been determined from combining mass spectrometry and nuclear magnetic resonance data and justified by a proposed mechanism of formation beginning from the parent drug. Some degradation by-products show only one phenyl, others are dimers or trimers of the parental compound, which has undergone oxidative decarboxylation of the side chain and/or chlorination of this or one or both aromatic rings.

Disinfection by-products and ecotoxic risk associated with hypochlorite treatment of irbesartan.

Recently, many studies highlighted the consistent finding of irbesartan in effluents from wastewater treatment plants (WWTPs) and in some rivers and lakes in both Europe and North America, suggesting that no >80% can be removed by specific treatments. The present investigation attempts to study the chemical fate of irbesartan in a simulated chlorination step, mimicking the conditions of a WWTP. A total of six disinfection by-products were identified, five were completely new, and separated on a C-18 column by employing a gradient HPLC method.