Proposal to optimize ecotoxicological evaluation of wastewater treated by conventional biological and ozonation processes

A mixture of urban and hospital effluents (50 % v/v) was evaluated for ecotoxicity with an advanced bioassay battery. Mixed effluents were tested before any treatment, after biological treatment alone, and after biological treatment followed by a tertiary ozonation (15 mg O₃/L). Laying a high value on the continuance of organisms’ fitness, essential to preserve a healthy receiving ecosystem, the main objective of this study was to combine normalized bioassays with newly developed in vivo and in vitro tests in order to assess alteration of embryo development, growth and reproduction, as well as genotoxic effects in aquatic organisms exposed to complex wastewater effluents. Comparison of the bioassays sensitivity was considered. Contrary to the lack of toxicity observed with normalized ecotoxicity tests, endpoints measured on zebrafish embryos such as developmental abnormalities and genotoxicity demonstrated a residual toxicity in wastewater both after a biological treatment followed or not by a tertiary O₃ treatment. However, the ozonation step allowed to alleviate the residual endocrine disrupting potential measure in the biologically treated effluent. This study shows that normalized bioassays are not sensitive enough for the ecotoxicological evaluation of wastewaters and that there is a great need for the development of suitable sensitive bioassays in order to characterize properly the possible residual toxicity of treated effluents.     

Survey regarding the occurrence of selected organic micropollutants in the groundwaters of overseas departments

To collect a complete dataset regarding the occurrence of organic substances in groundwater, this study presents the examination of 66 organic contaminants in the groundwater of overseas departments, including pesticides, pharmaceutical compounds, hormones and some industrial substances. The selective and sensitive analytical methods are described. These techniques begin with solid-phase extraction (SPE) followed by analysis using liquid chromatography–tandem mass spectrometry (LC-MS/MS) and gas chromatography–mass spectrometry (GC-ToF-MS). The paper summarises the analytical results from 40 sampling points collected during two campaigns in Guadeloupe, Martinique, Reunion, Mayotte and Guiana, representing 80 samples. Of the 66 target substances, 36 were determined at least once. Among the most frequently detected are bisphenol A (frequency, 96 %; max., 7,400 ng/L), caffeine (frequency, 91 %; max., 1,240 ng/L), pentachlorophenol (frequency, 55 %; max., 418 ng/L), and carbamazepine (frequency, 56 %; max., 22 ng/L). The results do not put in evidence that the origin of the sample or climatic characteristics of these regions influence the dilution and release of micropollutants.     

Insights on the solubilization products after combined alkaline and ultrasonic pre-treatment of sewage sludge

This work provides insights on the solubilization products after a simultaneous combination of alkaline and ultrasonic(ALK + ULS) pre-treatment of sewage sludge.Soluble chemical oxygen demand(SCOD) increased from 1200 to 11,000 mg/L after such treatment. Organics with molecular weight around 5.6 k Da were solubilized because of the synergistic effect of ultrasound and alkali. Organics with molecular weight larger than300 k Da increased from 7.8% to 60%, 16% and 42.3% after ULS, ALK and ALK + ULS treatment, respectively. Excitation emission matrix fluorescence spectroscopy analysis identified soluble microbial product-like and humic acid-like matters as the main solubilization products. Sludge anaerobic biodegradability was significantly enhanced with the simultaneous application of ALK + ULS pre-treatment. ALK + ULS pre-treatment resulted in 37.8% biodegradability increase compared to the untreated sludge. This value was higher compared to the biodegradability increase induced by individual ALK pre-treatment(5.7%) or individual ULS pre-treatment(20.7%) under the same conditions applied.     

Antibiotic removal from water: Elimination of amoxicillin and ampicillin by microscale and nanoscale iron particles

Zerovalent iron powder (ZVI or Fe⁰) and nanoparticulate ZVI (nZVI or nFe⁰) are proposed as cost-effective materials for the removal of aqueous antibiotics. Results showed complete removal of Amoxicillin (AMX) and Ampicillin (AMP) upon contact with Fe⁰ and nFe⁰. Antibiotics removal was attributed to three different mechanisms: (i) a rapid rupture of the β-lactam ring (reduction), (ii) an adsorption of AMX and AMP onto iron corrosion products and (iii) sequestration of AMX and AMP in the matrix of precipitating iron hydroxides (co-precipitation with iron corrosion products). Kinetic studies demonstrated that AMP and AMX (20 mg L⁻¹) undergo first-order decay with half-lives of about 60.3 ± 3.1 and 43.5 ± 2.1 min respectively after contact with ZVI under oxic conditions. In contrast, reactions under anoxic conditions demonstrated better degradation with t_1/2 of about 11.5 ± 0.6 and 11.2 ± 0.6 min for AMP and AMX respectively. NaCl additions accelerated Fe⁰ consumption, shortening the service life of Fe⁰ treatment systems.     

New remains of the enigmatic cetartiodactyl Bugtitherium grandincisivum Pilgrim, 1908, from the upper Oligocene of the Bugti Hills (Balochistan, Pakistan)

Newly discovered fossil material of the enigmatic cetartiodactyl Bugtitherium grandincisivum from the upper Oligocene of the Bugti Member of the Chitarwata Formation in the Bugti Hills (Balochistan, Pakistan) is reported. These new specimens consist of two fragmentary muzzles (one preserving the first incisors and belonging to a juvenile) and a fragmentary right mandible with m3. The morphologies of the anterior dentition and m3 provided by these new specimens confirm the validity of the genus Bugtitherium and advocate probable anthracotheriid affinity for the genus rather than entelodontid or suoid affinities, but do not definitively close the debate about Bugtitherium’s familial affinities within Cetartiodactyla. Although still poorly documented, this large-sized anthracotheriid-like cetartiodactyl is a possible key form for understanding the early evolution of hippos, and, in turn, the ancestry of whales, because of both its morphological similarities with hippos and primitive Paleogene whales and its Tethysian distribution.     

Continuous radioactivity monitoring systems. From the pre-history of radioprotection to the future of radioecology

The first significant quantities of artificial radioactivity appeared in the environment around the end of the 1940s. They were gigantic and their metrology very quickly seemed to be essential for sanitary and military reasons. In the 1950s, the first continuous monitoring systems of "fall out" were created. They were neither automatic nor sensitive and radioprotection of the environment was not a concern only for simple public information. Since then, radioecology, technology and evolution of our mentality have completely modified our way of thinking. Thus, from the 1980s up to the dawn of the new millennium, the gap between the performances of metrology laboratories and certain aspects of direct measurement has almost disappeared. 1986 certainly contributed a lot to the concept of surveillance networks and alarm systems, emphasising that the major advantage of these is the fact that they are operational, the minute before the accident.