Despite the ubiquity of microbial extracellular polymeric substances (EPS) in soils and aquatic environments, the roles played by EPS in the nonreductive transformation of toxic and degradation-resistant oxoanions are poorly understood. Here, we used perchlorate, which is ubiquitous in surface environments, as an initiator to study the spontaneous assembly of EPS into microcapsules involved in trapping and immobilizing oxoanions. The results confirmed that ClO4- oxoanions could be rapidly trapped in 20 min by EPS extracted from a common Bacillus subtilis, whereas no chemical reduction of ClO4- occurred in 48 h. Integrated spectroscopic analyses with florescence quenching microtitration and theoretical models showed that amino functionalities of EPS are responsible for sequestering ClO4-, with lower pH values being more favorable to formation of EPS-ClO4- micelles. Combined molecular dynamics scheme with wave function analyses showed that besides amino residues, the protonated side-chain amino groups in the basic proteins have a greater capacity for sequestering ClO4- through a noncovalent H-bonding mechanism in which dissociable protons serve as the nodes to bridge ClO4-. https://www.selleckchem.com/products/kn-93.html A quantitative association between the number of hydrogen bonds and bioavailability revealed that immobilization by EPS mitigates the uptake of toxic oxoanions by forage ryegrass, reducing their risk exposure to edible produce. MAIN FINDING OF THE WORK Micelles formed by freely dissolved EPS mitigate the uptake of toxic oxoanions by forage ryegrass.One of the main requirements of any sound biological monitoring is the availability of long term and, possibly, temporal data with a high resolution. This is often difficult to be achieved, especially in Antarctica, due to a variety of logistic constraints, which make continuous sampling and monitoring activities generally unfeasible. Here we focus on the 5 μm filters used in the desalination plant of the Italian research base "Mario Zucchelli" in the Terra Nova Bay area (Ross Sea, Antarctica) to evaluate intra-annual coastal nanoplankton dynamics. These filters, together with others of larger mesh sizes, are used to decrease the amount of organisms and debris in the input seawater before the desalination processes take place, hence automatically collect the plankton present in the water column around the desalination system intake. We have used a DNA metabarcoding approach to characterize the communities retained by filters' sets collected in January 2012 and 2013. Intra-annual dynamics were disclosed with an unprecedented detail, that would not have been possible by using standard sampling approaches, and highlighted the importance of extreme, stochastic events such as katabatic wind pulses, which triggered dramatic, short-term shifts in coastal nanoplankton composition. This method, by combining a cost-effective sampling and molecular techniques, may represent a viable solution for long-term monitoring programs focusing on Antarctic coastal communities.The biogeochemical behavior of Cd, Co, Cr, Cu, Ni and Pb along the historically polluted Scheldt estuary (Belgium - The Netherlands) was investigated in this study. As never studied before in this area, labile trace metals were measured using the passive sampling technique of Diffusive Gradients in Thin-films (DGT), while total dissolved and particulate trace metal concentrations were assessed using classic active sampling techniques. This dual approach allowed us to highlight the variations of trace metal speciation and distribution in the estuarine surface waters, considering environmental and physicochemical gradients along the transect. The large data set obtained was then compared with literature data of historical measurements along the Scheldt (from 1980 until now), but also from other estuaries. As emphasized by our results, trace metal mobility and partitioning along the Scheldt estuary was mainly driven by biogeochemical reactions which were strongly influenced by gradients of specific estuarine physico-chemical parameters, such as salinity, turbidity, temperature and so on. Hence, all species of trace metals displayed a non-conservative behavior. More precisely, dissolved labile fractions of trace metals showed higher levels in the middle estuary, where many solubilization and remobilization processes occurred due to turbulent mixing mechanisms and an increasing salinity. Our study confirmed the decreasing trend historically observed for particulate metals along the Scheldt, as well as the rising concentrations recorded for dissolved trace metals which might also lead to an increase of their labile fraction measured by the DGT. Finally, these preliminary results suggested that a more regular monitoring of labile metal along the Scheldt estuary is essential to have an in-depth understanding of trace metal speciation and to review bioavailability of trace metals within estuarine ecosystems.The decomposition of long-chain perfluorocarboxylic acids (PFCAs), including perfluorononanoic acid (PFNA) and perfluorodecanoic acid (PFDA), were investigated by electrochemical activation of peroxymonosulfate (PMS) on porous Ti/SnO2-Sb membrane anode. The results indicated that PMS activation could efficiently promote PFNA/PFDA decomposition, with pseudo-first-order rate constants about 3.12/2.06 times as compared with that of direct electro-oxidations. The energy consumptions of PFNA and PFDA decomposition were 36.31 and 37.46 kWh·m-3·order-1, respectively. The quantitative detection results of •OH with electron paramagnetic resonance (EPR) demonstrated that PMS activation promoted •OH formation. The inhibited performance in radical scavengers indicated both •OH and SO4•- might be mainly involved in PFNA decomposition, while SO4•- might be mainly involved in PFDA decomposition during PMS activation process. The mineralization mechanism for long-chain PFCAs decomposition which was mainly by repeating CF2-unzipping cycle via radical reaction based on the intermediates verification and mass balance of C and F, was proposed. These results suggested that electrochemical activation of PMS on porous Ti/SnO2-Sb membrane anode exhibited high efficiency in mineralizing PFNA and PFDA under mild conditions. This work might provide an efficient way for persistent organic pollutants, including, but not limited to long-chain PFCAs elimination from wastewater.