Occurrence and levels of selected compounds in European compost and digestate samples

This report describes work conducted by the European Commission’s Joint Research Centre (JRC) in the context of an Administrative Arrangement between DG Environment and the JRC. This work aimed at the generation, within a limited timeframe, of a large amount of analytical data, with high scientific and statistical value, for a number of compost and digestate types (afterwards referred to as COMDIG samples), to help provide a general overview and estimation of that possible variability within and between different COMDIG materials. The report includes the results of a targeted and independent screening of typical European situations of COMDIG materials with regard to the occurrence and levels of compounds of concern, many of which have never been assessed at a pan-European level. In total, 139 samples, mostly taken as grab samples and originating from 15 countries, were assessed for 22 minor and trace elements and 92 organic compounds including ingredients of personal care products and pharmaceuticals. The underlying analytical methods are carefully documented with regard to their performance characteristics. Where available, the so-called “horizontal” standards were followed. The results obtained are assessed statistically. Although the analysed single samples are insufficient to make any statement on the performance of the treatment processes leading to COMDIG samples, this collective of data provide a glimpse of the pan-European situation as regards the studied compounds.JRC.H.1-Water Resource

Dioxins and dioxin-like compounds in composts and digestates from European countries as determined by the in vitro bioassay and chemical analysis

Aerobic composting and anaerobic digestion plays an important role in reduction of organic waste by transforming the waste into humus, which is an excellent soil conditioner. However, applications of chem- ical-contaminated composts on soils may have unwanted consequences such as accumulation of persistent compounds and their transfer into food chains. The present study investigated burden of composts and dig- estates collected in 16 European countries (88 samples) by the compounds causing dioxin-like effects as determined by use of an in vitro transactivation assay to quantify total concentrations of aryl hydrocarbon receptor-(AhR) mediated potency. Measured concentrations of 2,3,7,8-Tetrachlorodibeno-p-dioxin (2,3,7,8-TCDD) equivalents (TEQbio) were compared to concentrations of polycyclic aromatic hydrocarbons (PAHs) and selected chlorinated compounds, including polychlorinated dibenzo-p-dioxins/furans (PCDD/ Fs), co-planar polychlorinated biphenyls (PCBs), indicator PCB congeners and organochlorine pesticides (OCPs). Median concentrations of TEQbio (dioxin-like compounds) determined by the in vitro assay in crude extracts of various types of composts ranged from 0.05 to 1.2 with a maximum 8.22 lg (TEQbio) kg1 dry mass. Potencies were mostly associated with less persistent compounds such as PAHs because treatment with sulfuric acid removed bioactivity from most samples. The pan-European investigation of contamina- tion by organic contaminants showed generally good quality of the composts, the majority of which were in compliance with conservative limits applied in some countries. Results demonstrate performance and added value of rapid, inexpensive, effect-based monitoring, and points out the need to derive correspond- ing effect-based trigger values for the risk assessment of complex contaminated matrices such as composts.JRC.H.1-Water Resource

Arrhenius Behavior of the Bulk Na-Ion Conductivity in Na 3 Sc 2 (PO 4 ) 3 Single Crystals Observed by Microcontact Impedance Spectroscopy

NASICON-based solid electrolytes with exceptionally high Na-ion conductivities are considered to enable future all solid-state Na-ion battery technologies. Despite 40 years of research the interrelation between crystal structure and Na-ion conduction is still controversially discussed and far from being fully understood. In this study, microcontact impedance spectroscopy combined with single crystal X-ray diffraction, and differential scanning calorimetry is applied to tackle the question how bulk Na-ion conductivity σbulk of sub-mm-sized flux grown Na3Sc2(PO4)3 (NSP) single crystals is influenced by supposed phase changes (α, β, and γ phase) discussed in literature. Although we found a smooth structural change at around 140 °C, which we assign to the β → γ phase transition, our conductivity data follow a single Arrhenius law from room temperature (RT) up to 220 °C. Obviously, the structural change, being mainly related to decreasing Na-ion ordering with increasing temperature, does not cause any jumps in Na-ion conductivity or any discontinuities in activation energies Ea. Bulk ion dynamics in NSP have so far rarely been documented; here, under ambient conditions, σbulk turned out to be as high as 3 × 10–4 S cm–1 at RT (Ea, bulk = 0.39 eV) when directly measured with microcontacts for individual small single crystals

EU wide campaign exercise on bioassays and chemical mixture effects

Thousands different chemicals are discharged into the environment from agriculture, industry, medical facilities, house-holds. Currently, there is an increasing concern for the environmental impact of mixture of compounds since the additive and eventual synergistic effects are unknown and could produce serious adverse effects. Recently, a document from the European Commission on combination effects of chemicals highlighted the need to ensure that risks associated with chemical mixtures are properly understood and assessed. To address this issue, a joint-effort of 16 European and associated research groups participated to an exercise to test a synthetic reference chemical mixture on the own routine bioassays to investigate the chemical mixtures effects. The reference material included class of pesticides, pharmaceuticals, industrial products, heavy metals and polyaromatic hydrocarbons. The mixures were prepared, each compound at Equivalent Quality Standard (EQS) value, the safety limit concentration allowed by the European Water Framework Directive, (WFD).The bioassays proposed by the groups could cover the entire ecosystem from bacteria to fish as well in vitro assays providing an unique scenario from ecological risk assessment perspective. The results showed that effects were observed at very low concentration on algal-bacteria composition in a marine microcosm, immobilization in crustacean, fish embryo toxicity and frog embryo development. We conclude that some precaution on the chemical mixture assessment should be taken even in case the individual compounds are present at EQS, the safety limit concentration under European legislation