A Review: Per- and Polyfluoroalkyl Substances-Biological Degradation.

Per- and polyfluoroalkyl substances (PFASs), highly stable synthetic organic compounds with multiple carbon-fluorine bonds, are emerging as environmental contaminants, toxic, bioaccumulative, and environmentally persistent. PFASs are strongly resistant to biological and chemical degradation, and therefore PFASs present a challenge to researchers and scientists for a better understanding and application of remediation methods and biodegradation of PFASs and have become subject to strict government regulations. The review summarizes the recent knowledge of bacterial and fungal degradation of PFASs, as well as the enzymes involved in the processes of transformation/degradation of PFASs.

Xenobiotics-Division and Methods of Detection: A Review.

Xenobiotics are compounds of synthetic origin, usually used for domestic, agricultural, and industrial purposes; in the environment, they are present in micropollutant concentrations and high concentrations (using ng/L to µg/L units). Xenobiotics can be categorized according to different criteria, including their nature, uses, physical state, and pathophysiological effects. Their impacts on humans and the environment are non-negligible. Prolonged exposure to even low concentrations may have toxic, mutagenic, or teratogenic effects. Wastewater treatment plants that are ineffective at minimizing the release of xenobiotic compounds are one of the main sources of xenobiotics in the environment (e.g., xenobiotic compounds reach the environment, affecting both humans and animals). In order to minimize the negative impacts, various laws and regulations have been adopted in the EU and across the globe, with an emphasis on xenobiotics removal from the environment, in a way that is economically, environmentally, and socially acceptable, and will not result in their accumulation, or creation of compounds that are more harmful. Detection methods allow detecting even small concentrations of xenobiotics in samples, but the problem is the diversity and mix of compounds present in the environment, in which it is not known what their effects are). In this review, the division of xenobiotics and their detection methods will be presented.

Assessment of PCB and chlorinated pesticide accumulation in mussels at Kastela Bay (Eastern Adriatic).

The biological response of mussels Mytilus galloprovincialis, resident and transplanted to cages, to contamination with anthropogenic pollutants from Kastela Bay, located in the central part of the eastern Adriatic coast, was investigated. The main purpose of this paper is to trace the accumulation of PCBs and chlorinated pesticides (HCB, lindane, heptachlor, aldrin, p,p'-DDTs) as a direct measure of potential contaminant availability to organisms, in a period from 2000 to 2011. In order to do so, cultured mussels (Mytilus galloprovincialis) of the same size and age were transplanted from the unpolluted Mali Ston Bay to the Kastela Bay. Sampling was performed bimonthly, and the level of target contaminants in whole soft tissue was determined. After two months of exposure, the concentration of PCBs in transplanted mussels increased on average 6.5-times, and of DDTs 2-times, while the intensity of changes for HCB, lindane, heptachlor and aldrin was negligible. Seasonal variation of pesticide content was similar without a significant change throughout the experimental period, while that of PCBs was somewhat different showing increased accumulation in summer. Seasonal and spatial variation of organochlorines in the Kastela Bay was likely the result of prevailing environmental rather than biological parameters. In accordance with prevailing hydrodynamic cycling, contaminant concentration decreased in acyclonic direction towards the exit of the Bay. Measurement of target contaminants in resident mussels sampled from the most contaminated area of the Bay exhibited decreasing concentrations of lindane, aldrin and p,p'-DDTs. However, PCBs exhibited statistically significant increasing concentrations in relation to the slightly increasing concentrations of HCB. With regard to human health, organochlorine (OC) levels in the mussel tissue were below prescribed limits for human consumption.

Evaluation of toxicity and biodegradability of choline chloride based deep eutectic solvents.

Deep eutectic solvents (DESs) have been dramatically expanding in popularity as a new generation of environmentally friendly solvents with possible applications in various industrial fields, but their ecological footprint has not yet been thoroughly investigated. In the present study, three choline chloride-based DESs with glucose, glycerol and oxalic acid as hydrogen bond donors were evaluated for in vitro toxicity using fish and human cell line, phytotoxicity using wheat and biodegradability using wastewater microorganisms through closed bottle test. Obtained in vitro toxicity data on cell lines indicate that choline chloride: glucose and choline chloride:glycerol possess low cytotoxicity (EC50>10 mM for both cell lines) while choline chloride:oxalic acid possess moderate cytotoxicity (EC50 value 1.64 mM and 4.19 mM for fish and human cell line, respectively). Results on phytotoxicity imply that tested DESs are non-toxic with seed germination EC50 values higher than 5000 mg L(-1). All tested DESs were classified as'readily biodegradable' based on their high levels of mineralization (68-96%). These findings indicate that DESs have a green profile and a good prospect for a wider use in the field of green technologies.