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Lignocellulosic-based ethanol is a viable alternative to corn-based ethanol. However, the use of such feedstock is more complex than the use of sugar or starch due to the necessity for a pretreatment stage. Here we tested three pretreatment processes of oat straw: (1) submerged ozonation in water, (2) low temperature (40 °C) diluted sulphuric acid (DSA) and (3) room temperature diluted sulphuric acid/ozone mixture (SOM). A unique water/ozone reactor was designed and constructed to demonstrate the pretreatment processes. Results showed best lignin removal by the submerged ozonation pretreatment and consequently the highest sugar and ethanol yields. Despite the non-conventional low temperature, DSA pretreatment results had showed slight lower yields then ozonation, with degradation of hemicellulose to xylose, while SOM pretreatment showed the poorest results. DSA pretreatment would probably show industrial feasibility when pentoses fermenting abilities will be added.

In Niger, some localities in the Tahoua region, groundwater is the main source of drinking water for the population. However, these waters are very loaded with Fe (II) and Mn (II), respectively exceeding the standard set by the WHO (0.3 mg / L and 0.1 mg / L). When these waters are in contact with the oxygen in the air, this degrades their aesthetic and organoleptic quality, but also that of structures and pipes. The objective of this study is to take stock of the presence of iron and manganese in water and their impact on the structures, which may justify the need for the creation of a treatment unit for their removal. Sampling was carried out at the level of the four localities. The pH was measured at the sites, total iron and manganese (II) are measured in the laboratory by colorimetry using a DR3900. The results show that in all the boreholes sampled, the concentration of total Fe varies from 1.231 mg / L to 6.295 mg / L, and that of Mn (II) from 0 mg / L to 0.97 mg / L. All of the structures and pipes that carry this water are completely damaged or blocked by a ferric deposit, identified by the DRX as a very poorly crystallized 2-Line ferrihydrite.

Tertiary wastewater treatment could provide a reliable source of water for reuse. Amongst these types of wastewater treatment, deep-bed filtration of secondary effluents can effectively remove particles and organic matter, however, NH4+ and NO2&minus, are not easily removed. This study examined the feasibility of stimulating microbial activity using hydrogen peroxide (H2O2) as a bio-specific and clean oxygen source that leaves no residuals in the water and is advantageous upon aeration due to the solubility limitations of the oxygen. The performance of a pilot bio-filtration system at a filtration velocity of 5&ndash, 6 m/h, was enhanced by the addition of H2O2 for particle, organic matter, NH4+, and NO2&minus, removal. Hydrogen peroxide provided the oxygen demand for full nitrification. As a result, influent concentrations of 4.2 &plusmn, 2.5 mg/L N-NH4+ and 0.65 &plusmn, 0.4 mg/L N-NO2 were removed during the short hydraulic residence time (HRT). In comparison, filtration without H2O2 addition only removed up to 0.6 mg/L N-NH4+ and almost no N-NO2&minus, A DNA metagenome analysis of the functional genes of the media biomass reflected a significant potential for simultaneous nitrification and denitrification activity. It is hypothesized that the low biodegradability of the organic carbon and H2O2 addition stimulated oxygen utilization in favor of nitrification, followed by the enhancement of anoxic activity.

Ferrimagnetic materials such as natural magnetite are used for practical applications because of their electronic, magnetic and catalytic properties in the degradation of organic compounds. In order to determine its physicochemical properties in relation to its catalytic activity, the natural magnetite of Ofoud Mount (Niger) is characterized by X-ray florescence (XRF), X-ray diffraction (DRX), specific surface area (BET) and Fourier transformed infrared (FTIR). The result shows an iron content of 97.09% and a specific surface area of 69.742 m2/g. The crystal structure of magnetite is cubic with lattice parameters α = β = γ = 90°, a (A) = b (A) = c (A) = 8.3740. The results of this study suggest that the natural magnetite of Ofoud Mount can be used as iron source in various fields of science despite the presence of a few impurities that can improve its catalytic activity.

International audience; Uranium (U) deposits can undergo oxidizing events, subsequent to which the U may be redistributed or precipitated under distinct mineralogical forms. Occurrences of U6+ minerals can be the result of either (i) in situ oxidation and alteration of previous U4+ minerals or (ii) direct precipitation from U6+-rich solutions. Samples from Imouraren, the largest U6+ore deposit known in the world, located in the Tim Mersoï Basin, Northern Niger, have been studied to determine the nature, distribution, and timing of occurrences of U and related minerals. The host rock is composed of sandstones and analcime-rich siliciclastic rocks of Jurassic age. The U ore is largely dominated by acicular hexavalent U minerals and by a very small amount of uraninite. A comprehensive geochemical model that describes the origin and geochemical setting of this style of economically important mineralization has been developed. The petrographic and mineralogical studies show evidence of in situ uraninite alteration into uranophane and metatyuyamunite, documented by textural relationships and chemical analyses using SEM and electron microprobe. The textural relationship between the U4+ and U6+ minerals is supported by the near-identical REE signatures of the primary uraninite and related secondary U minerals. Ion microprobe U-Pb dating (from 21 to ~ 1 Ma) confirms that primary uraninites were altered to U6+ minerals under supergene conditions during Cenozoic oxidation events in western Africa, in relation with the well-known stages of intense continental weathering that have affected western Africa from the early Cenozoic to recent times.

International audience; Chalcogen bonding results from non-covalent interactions occurring between electrodeficient chalcogen atoms and Lewis bases. Among the chalcogens, tellurium is the strongest Lewis acid, but Te-based compounds are scarcely used as organocatalysts. For the first time, telluronium cations demonstrated impressive catalytic properties at low loadings in three benchmark reactions: the Friedel–Crafts bromination of anisole, the bromolactonization of ω-unsaturated carboxylic acids and the aza-Diels–Alder between Danishefsky's diene and imines. The ability of telluronium cations to interact with a Lewis base through chalcogen bonding was demonstrated on the basis of multi-nuclear (17O, 31P, and 125Te) NMR analysis and DFT calculations.

BackgroundDietary supplements, like small-quantity lipid-based nutrient supplements (SQ-LNS), are used in intervention programs to prevent undernutrition among women and young children in low-income countries. An objective marker is needed to track consumption of supplements to evaluate the effectiveness of these programs.ObjectiveThe aim of this study was to evaluate saccharin and resveratrol as potential adherence markers for tracking recent consumption of a single serving of SQ-LNS in women.MethodsForty-seven healthy nonpregnant women 18-45 y of age were assigned to consume a single dose of SQ-LNS (20g) containing either 10mg sodium saccharin or 5mg trans-resveratrol, under supervision. On the day before and for 2 d following SQ-LNS consumption, urine samples were collected each day for 24 h as 3 consecutive 4-h collections and one 12-h overnight collection. Urinary concentrations of saccharin and trans-resveratrol-3-O-sulfate, a resveratrol metabolite, were measured by ultra-high-performance liquid chromatography interfaced to a mass spectrometer with electrospray ionization [UHPLC-(ESI-)MS/MS]. Urinary concentrations (μmol/L urine) of saccharin and trans-resveratrol-3-O-sulfate were plotted against time, and receiver operating characteristic (ROC) curves were used to determine the discriminative capacity of each compound, at each post-consumption time point compared with baseline, to detect recent consumption of SQ-LNS. Cutoff values to differentiate supplement consumption from nonconsumption of each marker were developed using the closest-to-(0,1)-corner cut-point approach.ResultsForty-five participants were included in the analysis. Urinary concentrations of saccharin and trans-resveratrol-3-O-sulfate increased within 4 h of SQ-LNS consumption. Urinary concentration cutoff values for saccharin (13.4µmol/L) and trans-resveratrol-3-O-sulfate (0.7µmol/L) allowed for 78% and 89% sensitivity, respectively, and 100% specificity in detecting consumption of SQ-LNS within the first 12h after consumption.ConclusionsUrinary concentrations of saccharin and trans-resveratrol-3-O-sulfate reflect consumption of SQ-LNS containing those compounds during the first 12h post-consumption with high sensitivity and specificity in healthy women and may be useful objective adherence markers for tracking consumption of SQ-LNS.

International audience; Non-symmetrical chiral 4,4′-bipyridines have recently found interest in organocatalysis and medicinal chemistry. In this regard, the development of efficient methods for their synthesis is highly desirable. Herein, a series of non-symmetrical atropisomeric polyhalogenated 4,4′-bipyridines were prepared and further functionalized by using cross-coupling reactions. The desymmetrization step is based on the N-oxidation of one of the two pyridine rings of the 4,4′-bipyridine skeleton. The main advantage of this methodology is the possible post-functionalization of the pyridine N-oxide, allowing selective introduction of chlorine, bromine or cyano groups in 2- and 2′-postions of the chiral atropisomeric 4,4′-bipyridines. The crystal packing in the solid state of some newly prepared derivatives was analyzed and revealed the importance of halogen bonds in intermolecular interactions

1,3-Enynes are important building blocks in organic synthesis and also constitute the key motif in various bioactive natural products and functional materials. However, synthetic approaches to stereodefined substituted 1,3-enynes remain a challenge, as they are limited to Wittig and cross-coupling reactions. Herein, stereodefined 1,3-enynes, including tetrasubstituted ones, were straightforwardly synthesized from cis or trans-alkynylated oxiranes in good to excellent yields by a one-pot cascade process. The procedure relies on oxirane deprotonation, borylation and a stereospecific rearrangement of the so-formed alkynyloxiranyl borates. This stereospecific process overall transfers the cis or trans-stereochemistry of the starting alkynyloxiranes to the resulting 1,3-enynes.

Lignocellulosic waste (here municipal trimmings) is a promising sustainable feedstock for ethanol production, but requires costly and polluting pretreatment, often resulting in toxic by-products. Ozonation, nonpolluting, effective pretreatment method, is not used commercially due to high energy requirements of ozone production at high ozone doses needed. Our results, however, demonstrated that low-dose ozonation (15 min, accumulated TOD = 318 mg L−1) of water-submerged waste resulted in improved enzymatic saccharification efficiency (31% of cellulose) compared to a non-ozonated sample (12%) although only 20% of the lignin was removed. Ozonation up to 90 min resulted in better conversion however exceptionally long ozonation (6 h and beyond) resulted in reduced conversion. These results suggest that contrary to common hypothesis, short ozonation could offer an effective and feasible pretreatment method for high sugar release without the need for delignification. In addition, the ozonation process was accompanied by changes in absorbance, mainly at 280 nm, making it a useful tool for process monitoring. Net calculated energy balance was positive for all ozonation regimes, with increased process efficiency at lower ozone doses. Furthermore, ozonation can be generated on-site and on demand, enabling decentralized pretreatment operated near the feed source, thus overcoming transportation costs.

Soil columns simulating soil aquifer treatment (SAT), fed with synthetic secondary effluent by intermittent infiltration of flooding/drying cycles, were characterized for nitrogen and organic carbon removal, and microbial ecology and biokinetics. The columns differed in the concentration ratio of chemical oxygen demand (COD) to the summed NH 4 + , NO 2 − and organic nitrogen—2 (C/N2) or 5 (C/N5). Chemical profiles along the column demonstrated a preference for COD oxidation over nitrification and coupled denitrification, with higher nitrogen loss (57% vs. 16%) in the C/N5 column. Unexpectedly, significant dominance of the genus Nitrospira over the genus Nitrobacter and ammonia-oxidizing bacteria (AOB) was strongly correlated at column depths where NH 4 + removal occurred. Moreover, the Nitrospira profile had the strongest correlation to the profile of NH 4 + (positive) and NO 3 − (negative), strongly indicating complete ammonia oxidation. 16S sequencing analysis of the topsoil in C/N2 vs. C/N5 columns revealed double the abundance of microbial aerobic potential (64% vs. 32%) vs. one-third the denitrification potential (13% vs. 31%). The concentrations and degradability levels of organic carbon were the most influential parameters shaping community structure. Niche differentiation within the biofilm attached to the soil is suggested to have an important role in the process's anoxic activity and nitrogen removal.

Actinometers are physical or chemical systems that can be employed to determine photon fluxes. Chemical actinometers are photochemical systems with known quantum yields that can be employed to determine accurate photon fluxes for specific photochemical reactions. This review explores in detail several practical chemical actinometers (ferrioxalate, iodide-iodate, uranyl oxalate, nitrate, uridine, hydrogen peroxide and several actinometers for the vacuum ultraviolet). Each actinometer is described with recommended conditions for its use.

Saccharin and trans-resveratrol were incorporated into small quantity lipid-based nutritional supplements (SQ-LNS) to be evaluated as the markers of consumption for nutritional intervention studies. Forty-seven healthy women consumed a single supplement with either 8.6 mg of saccharin or 5 mg of trans-resveratrol, and urine was collected for 4 h. A rapid 11 min method employing multiple reaction monitoring and ultrahigh performance liquid chromatography coupled to a triple quadrupole mass spectrometer was developed to measure saccharin and resveratrol metabolites in urine simultaneously. The linear dynamic range of the method was from 3 to 1000 ng mL-1, with the correlation coefficient of 0.999 and limits of quantification from 15.28 to 53.03 ng mL-1. Sample preparation was simple dilution with an average recovery of 97.8%. Ion suppression was observed with urine concentrations >10%. Mean levels of saccharin and resveratrol-3-O-sulfate in urine were 5.481 ± 4.359 and 3.440 ± 4.160 nmol L-1, respectively. We developed and validated a method to measure saccharin and trans-resveratrol metabolites in urine to objectively corroborate the consumption of SQ-LNS for the first time in nutrition intervention studies.

Commercial 4,4'-bipyridine is a popular scaffold that is primarily employed as a linker in 3D self-assembled architectures such as metallo-organic frameworks or as a connector in 2D networks. The introduction of alkyl substituents on the bipyridine skeleton is instrumental when 4,4'-bipyridines are used as linkers to form 2D self-assembled patterns on surfaces. Here, several synthetic strategies to access 4,4'-bipyridines functionalized at various positions are described. These easily scalable reactions have been used to introduce a range of alkyl substituents at positions 2 and 2' or 3 and 3' and at positions 2,2' and 6,6' in the case of tetra-functionalization. Scanning tunneling microscopy studies of molecular monolayers physisorbed at the graphite-solution interface revealed different supramolecular patterns whose motifs are primarily dictated by the nature and position of the alkyl chains.

The chalcogen bond (ChB) is a noncovalent interaction based on electrophilic features of regions of electron charge density depletion (&sigma, holes) located on bound atoms of group VI. The &sigma, holes of sulfur and heavy chalcogen atoms (Se, Te) (donors) can interact through their positive electrostatic potential (V) with nucleophilic partners such as lone pairs, &pi, clouds, and anions (acceptors). In the last few years, promising applications of ChBs in catalysis, crystal engineering, molecular biology, and supramolecular chemistry have been reported. Recently, we explored the high-performance liquid chromatography (HPLC) enantioseparation of fluorinated 3-arylthio-4,4&prime, bipyridines containing sulfur atoms as ChB donors. Following this study, herein we describe the comparative enantioseparation of three 5,5&prime, dibromo-2,2&prime, dichloro-3-selanyl-4,4&prime, bipyridines on polysaccharide-based chiral stationary phases (CSPs) aiming to understand function and potentialities of selenium &sigma, holes in the enantiodiscrimination process. The impact of the chalcogen substituent on enantioseparation was explored by using sulfur and non-chalcogen derivatives as reference substances for comparison. Our investigation also focused on the function of the perfluorinated aromatic ring as a &pi, hole donor recognition site. Thermodynamic quantities associated with the enantioseparation were derived from van&rsquo, t Hoff plots and local electron charge density of specific molecular regions of the interacting partners were inspected in terms of calculated V. On this basis, by correlating theoretical data and experimental results, the participation of ChBs and &pi, hole bonds in the enantiodiscrimination process was reasonably confirmed.

International audience; 2’-(4-Pyridyl)- and 2’-(4-hydroxyphenyl)-TCIBPs (TCIBP = 3,3’,5,5’-tetrachloro-2-iodo-4,4’-bipyridyl) are chiral compounds that showed interesting inhibition activity against transthyretin fibrillation in vitro. We became interested in their enantioseparation since we noticed that the M-stereoisomer is more effective than the P-enantiomer. Based thereon, we recently reported the enantioseparation of 2’-substituted TCIBP derivatives with amylose-based chiral columns. Following this study, herein we describe the comparative enantioseparation of both 2’-(4-pyridyl)- and 2’-(4-hydroxyphenyl)-TCIBPs on four cellulose phenylcarbamate-based chiral columns aiming to explore the effect of the polymer backbone, as well as the nature and position of substituents on the side groups on the enantioseparability of these compounds. In the frame of this project, the impact of subtle variations of analyte and polysaccharide structures, and mobile phase (MP) polarity on retention and selectivity was evaluated. The effect of temperature on retention and selectivity was also considered, and overall thermodynamic parameters associated with the analyte adsorption onto the CSP surface were derived from van ’t Hoff plots. Interesting cases of enantiomer elution order (EEO) reversal were observed. In particular, the EEO was shown to be dependent on polysaccharide backbone, the elution sequence of the two analytes being P-M and M-P on cellulose and amylose tris(3,5-dimethylphenylcarbamate), respectively. In this regard, a theoretical investigation based on molecular dynamics (MD) simulations was performed by using amylose and cellulose tris(3,5-dimethylphenylcarbamate) nonamers as virtual models of the polysaccharide-based selectors. This exploration at the molecular level shed light on the origin of the enantiodiscrimination processes.

Advanced technologies, such as reverse osmosis (RO), allow the reuse of treated wastewater for direct or indirect potable use. However, even highly efficient RO systems produce ~10&ndash, 15% highly contaminated concentrate as a byproduct. This wastewater RO concentrate (WWROC) is very rich in metal ions, nutrients, and hard-to-degrade trace organic compounds (TOrCs), such as pharmaceuticals, plasticizers, flame retardants, and detergents, which must be treated before disposal. WWROC could be up to 10 times more concentrated than secondary effluent. We examined the efficiency of several advanced oxidation processes (AOPs) on TOrC removal from a two-stage WWROC matrix in a pilot wastewater-treatment facility. WWROC ozonation or UV irradiation, with H2O2 addition, demonstrated efficient removal of TOrCs, varying between 21% and over 99% degradation, and indicating that radical oxidation (by HO&middot, ) is the dominant mechanism. However, AOPs are not sufficient to fully treat the WWROC, and thus, additional procedures are required to decrease metal ion and nutrient concentrations. Further biological treatment post-AOP is also highly important, to eliminate the degradable organic molecules obtained from the AOP.

The short treatment regimen (STR) achieves a >80% cure in rifampicin-resistant tuberculosis (RR-TB) patients. However, ototoxicity induced by the injectable is a concern. This is the first study to evaluate the replacement of injectables by linezolid in patients with audiometry abnormalities at baseline or during the treatment.We conducted a retrospective cohort study of all RR-TB patients started on the STR between 2016 and June, 2019, in Niger. Patients underwent audiometry every 2 months in 2016 and every month since 2017.Of 195 patients, 16.9% (33 out of 195) received linezolid from the start (n=17), or switched from injectables to linezolid during treatment (n=16), based on audiometry abnormalities. In 2016, two patients developed severe ototoxicity despite switching to linezolid. Since 2017, no patient developed severe hearing loss or complete deafness. Severe haematological toxicity was observed in 18.1% (six out of 33) of patients on linezolid, none of which was life threatening. The use of linezolid was associated with severe but manageable adverse events (hazard ratio 8.9, 95% CI 2.5–31.5; p=0.001). A total of 90.9% (30 out of 33) of patients on a linezolid-containing STR were cured, and none experienced treatment failure. Three died, but not due to adverse events.Baseline and monthly audiometry monitoring and using linezolid after detection of hearing abnormalities appears effective to prevent severe ototoxicity, while keeping high treatment success and manageable adverse events.

The 3,3&prime, 5,5&prime, tetrachloro-2-iodo-4,4&prime, bipyridine structure is proposed as a novel chemical scaffold for the design of new transthyretin (TTR) fibrillogenesis inhibitors. In the frame of a proof-of-principle exploration, four chiral 3,3&prime, tetrachloro-2-iodo-2&prime, substituted-4,4&prime, bipyridines were rationally designed and prepared from a simple trihalopyridine in three steps, including a Cu-catalysed Finkelstein reaction to introduce iodine atoms on the heteroaromatic scaffold, and a Pd-catalysed coupling reaction to install the 2&prime, substituent. The corresponding racemates, along with other five chiral 4,4&prime, bipyridines containing halogens as substituents, were enantioseparated by high-performance liquid chromatography in order to obtain pure enantiomer pairs. All stereoisomers were tested against the amyloid fibril formation (FF) of wild type (WT)-TTR and two mutant variants, V30M and Y78F, in acid mediated aggregation experiments. Among the 4,4&prime, bipyridine derivatives, interesting inhibition activity was obtained for both enantiomers of the 3,3&prime, tetrachloro-2&prime, (4-hydroxyphenyl)-2-iodo-4,4&prime, bipyridine. In silico docking studies were carried out in order to explore possible binding modes of the 4,4&prime, bipyridine derivatives into the TTR. The gained results point out the importance of the right combination of H-bond sites and the presence of iodine as halogen-bond donor. Both experimental and theoretical evidences pave the way for the utilization of the iodinated 4,4&prime, bipyridine core as template to design new promising inhibitors of TTR amyloidogenesis.

In this study, we present an innovative new bio-treatment approach for 17&alpha, ethynyestradiol (EE2). Our solution for EE2 decontamination was accomplished by using the SBP (Small Bioreactor Platform) macro-encapsulation method for the encapsulation of two bacterial cultures, Rhodococcus zopfii (R. zopfii ) and Pseudomonas putida F1 (P. putida). Our results show that the encapsulated R. zopffi presented better biodegradation capabilities than P. putida F1. After 24 h of incubation on minimal medium supplemented with EE2 as a sole carbon source, EE2 biodegradation efficacy was 73.8% and 86.5% in the presence of encapsulated P. putida and R. zopfii, respectively. In the presence of additional carbon sources, EE2 biodegradation efficacy was 75% and 56.1% by R. zopfii and P. putida, respectively, indicating that the presence of other viable carbon sources might slightly reduce the EE2 biodegradation efficiency. Nevertheless, in domestic secondary effluents, EE2 biodegradation efficacy was similar to the minimal medium, indicating good adaptation of the encapsulated cultures to sanitary effluents and lack of a significant effect of the presence of other viable carbon sources on the EE2 biodegradation by the two encapsulated cultures. Our findings demonstrate that SBP-encapsulated R. zopfii and P. putida might present a practical treatment for steroidal hormones removal in wastewater treatment processes.

International audience; The halogen bond (XB) is a noncovalent interaction involving a halogen acting as electrophile and a Lewis base. In the last decades XB has found practical application in several fields. Nevertheless, despite the pivotal role of noncovalent interactions in separation science, investigations of XB in this field are still in their infancy, and so far a limited number of studies focusing on solid phase extraction, liquid-liquid microextraction, liquid-phase chromatography, and gas chromatography separation have been published. In addition, in the last few years, our groups have been systematically studying the potentiality of XB for HPLC enantioseparations. On this basis, in the present paper up-to-date results emerging from focused experiments and theoretical analyses performed by our laboratories are integrated with a descriptive presentation of XB features and the few studies published until now in separation science. Then, the aim of this article is to provide a comprehensive and critical discussion of the topic, and account for some still open issues in the application of XB to separate chemical mixtures.

International audience; The chromatographic performances of four coated and immobilized amylose phenylcarbamate-based chiral columns were evaluated and compared under normal phase (NP) elution conditions by using chiral 4,4'-bipyri-dine derivatives as analytes. n-Hexane/2-propanol 90:10 and n-hexane/2-propanol/methanol 90:5:5 mixtures were employed as mobile phases (MPs), and the effect of adding methanol in the MP on retention and selectivity was considered. The effect of temperature on retention and selectivity was also evaluated, and overall thermo-dynamic parameters associated with the analyte adsorption onto the CSP surface were derived from van't Hoff plots. Interesting cases of enantiomer elution order (EEO) reversal, which are dependent on the nature of polar modifier, analyte structure, column-type, and temperature, were observed. The impact of substitution pattern and electronic properties of analytes and selectors on the separation behaviour was investigated by correlating chro-matographic parameters and molecular properties determined by using density functional theory (DFT) calculations. Both coated and immobilized amylose tris(3,5-dimethylphenylcarbamate) columns allowed for the baseline enantioseparation (2.0 ≤ R S ≤ 4.9) of all 4,4'-bipyridines considered in this study. These results appear particularly useful because both enantiomers of these 4,4'-bipyridine derivatives are currently under investigation as new inhibitors of transthyretin fibrillogenesis, a biochemical phenomenon which is implicated to cause amyloid diseases.

International audience; Designed more than thirty years ago in order to improve and maximize the discrimination capability of native polysaccharides, cellulose-and amylose-based selectors have shown excellent and unequalled performances for the enantioseparation of chiral compounds. The successful story of these chiral selectors relies on a multi-site high-ordered chiral platform which is held up by intramolecular hydrogen bonds (HBs), and makes the polymer able to host and discriminate enantiomers. In this environment, both achiral and stereoselective intermolecular noncovalent interactions play a pivotal role, and HBs, halogen bonds (XBs), dipole-dipole, π-π stacking, steric repulsive, and van der Waals interactions underlie adsorption process and formation of transient diastereomeric assemblies between the polymer and the enantiomer pair. In the last decades, advances in computational chemistry and spectroscopic techniques have improved knowledge of noncovalent interactions, contributing to decode their functions in chemical systems. Significantly, over time the growing interplay between experimental and theoretical approaches has contributed to unravel intermolecular forces underlying selector-selectand association and to understand recognition patterns. On this basis, this review summarizes seminal and representative studies dealing with noncovalent interactions that function in HPLC enantioseparations promoted by cellulose benzoates and phenylcarbamates of amylose and cellulose. The importance of integrating theoretical and experimental approaches to profile mechanisms and interaction patterns is highlighted by discussing focused case studies. In particular, the advantageous utilization of electrostatic potential (V) analysis and molecular dynamics (MD) simulations in this field is evidenced. A systematic compilation of all published literature has not been attempted.

International audience; Asymmetric catalysis based on halogen and chalcogen bonds (XB and ChB) is in its infancy and the search for new chiral XB and ChB donors represents a crucial step towards its development. In this context, we designed and prepared new motifs containing three key substructures, namely regions of electron charge density depletion centred on iodine and chalcogen atoms, the ethynyl functionality and the planar chiral ferrocenyl platform. Nine ferrocenyl iodoalkynes were prepared as pure enantiomers by asymmetric synthesis. The XB donor property of racemic ferrocenyl iodoalkynes was demonstrated in solution in two benchmark reactions: the Ritter reaction and the benzoxazole synthesis from thioamides. In contrast, the ferrocenyl chalcogenoalkynes were far less active in these reactions. The potential of racemic and enantiopure ferrocenyl iodoalkynes as XB donors were also confirmed by X-ray diffraction analysis observing I···C contacts between the electropositive σ-hole of the iodine atom and electron rich π clouds for all crystal structures studied in the solid state.

Cellulose nanocrystals (CNCs) have gained increased interest worldwide for their unique properties. CNC production by acid hydrolysis of cellulose-rich biomass is well established, but its' quantification is still complicated. In this study, a rapid method for the determination of CNC concentration using Calcofluor White (CW) fluorescence dye is demonstrated for both purified and homemade CNCs recovered from Whatman filter paper. The method is robust, selective for crystalline cellulose, suitable for routine measurement in CNC production and that the pH must be basic for staining using CW.

Herein, we demonstrate the fabrication of Bi(0)-doped bismuth oxyhalide solid solution films for the removal of trace organic pollutants (TrOPs) in water. With the advantage of a viscous AlOOH sol, very high loadings (75 wt %) of bismuth oxyhalides were embedded within the thin films and calcined at 500 °C to develop porous alumina composite coatings. Various concentrations of Bi(0) doping were tested for their photocatalytic activity. Seven TrOPs including iopromide (IPRM), iohexol (IHX), iopamidol (IPMD), sulfamethoxazole (SMX), carbamazepine, venlafaxine, and bezafibrate (BZF) were selected for this study based on their occurrence and detection in effluents and surface waters worldwide. In all tests, with the exception of IPRM, 3% Bi(0)-doped BiOCl0.875Br0.125 showed highest activity, which can be attributed to its unique, highly organized, and compact morphology besides its well-matched energy band positions. Although IPMD, IHX, IPRM, and SMX are susceptible to photolysis, still the photocatalytic activity significantly augmented the removal of all tested compounds. In addition, analysis of the surface charge excluded electrostatic interactions and confirmed the ion-exchange adsorption mechanism for the high degradation rate of BZF in the presence of bismuth oxyhalides.

A successful attempt to degrade synthetic estrogen 17&alpha, ethynylestradiol (EE2) is demonstrated via combining photocatalysis employing magnesium peroxide (MgO2)/low-pressure ultraviolet (LP-UV) treatment followed by biological treatment using small bioreactor platform (SBP) capsules. Reusable MgO2 was synthesized through wet chemical synthesis and extensively characterized by X-ray diffraction (XRD) for phase confirmation, X-ray photoelectron spectroscopy (XPS) for elemental composition, Brunauer-Emmett-Teller (BET) to explain a specific surface area, scanning electron microscopy (SEM) imaging surface morphology, and UV-visible (Vis) spectrophotometry. The degradation mechanism of EE2 by MgO2/LP-UV consisted of LP-UV photolysis of H2O2 in situ (produced by the catalyst under ambient conditions) to generate hydroxyl radicals, and the degradation extent depended on both MgO2 and UV dose. Moreover, the catalyst was successfully reusable for the removal of EE2. Photocatalytic treatment by MgO2 alone required 60 min (~1700 mJ/cm2) to remove 99% of the EE2, whereas biodegradation by SBP capsules alone required 24 h to remove 86% of the EE2, and complete removal was not reached. The sequential treatment of photocatalysis and SBP biodegradation to achieve complete removal required only 25 min of UV (~700 mJ/cm2) and 4 h of biodegradation (instead of &gt, 24 h). The combination of UV photocatalysis and biodegradation produced a greater level of EE2 degradation at a lower LP-UV dose and at less biodegradation time than either treatment used separately, proving that synergetic photocatalysis and biodegradation are effective treatments for degrading EE2.

The environmental impacts caused by Olive Mill Wastewater (OMWW) are a concern for both developing and developed countries. In this study, an ozone pretreatment combined with a fixed biomass bio-treatment using the Small Bioreactor Platform (SBP) capsules technology encasing a pure culture of a phenol-degrading OMWW isolate named Delftia EROSY was implemented to reduce phenolic compounds and organic matter in OMWW. Up to 90% of tannic acid (TA), a synthetic phenol model, was removed after the ozonation and biological stages. Ozone pretreatment of TA expedites the biological process by decreasing the time needed for the biodegradation of phenols. Ozonation (ozone dose = 765 mg L−1 O3) of OMWW demonstrated 20% COD and 61% total phenol removal, with an additional 36% increase in COD removal after the biological step (48 h). Interestingly, our results also showed that spectral absorbance can be used as a tool for monitoring ozonation followed by bio-treatment of OMWW. Absorbance results clearly demonstrate that bio-treatment is necessary for degrading not only phenolic compounds, but also phenol transformation products and the high organic load of the OMWW, following the ozonation step.

Ultraviolet (UV) irradiation is an emerging strategy for controlling the formation of undesired biofilms in water desalination facilities using reverse osmosis (RO). However, most studies examining these pretreatments are limited as they have been conducted on single-species cultures, while biofilms are composed of multiple-species communities. The goal of this study was to investigate the effect of UV-C irradiation on a model community composed of six environmental isolates from a marine biofilm formed in RO seawater desalination plant. There was a high variance in the susceptibility of the single-isolate cultures to UV-C, from no response (isolate Eryth23) to complete inactivation (isolate Vib3). The most active wavelength was around 260 nm, resulting in a loss of viability of single-isolate cultures and loss of vitality of the mixed-isolate cultures. With respect to biofilm formation, the activity of this wavelength was completely different compared to its activity on planktonic suspension. Irradiation with 260 nm did not inhibit the total biofilm formation by the six-isolate culture; moreover, isolates such as the resistant Eryth23 or the susceptible Pseudoalt17, even gained abundance in the mixed isolate biofilm. The only decrease in total biofilm was obtained from irradiation at 280 nm, which was less active against the planktonic culture. These results indicate that the complexity of the biofilm-forming microbial community may contribute to its resistance to UV-C irradiation. Significance and impact of the study This study examined the resistance of a multiple-isolate native marine culture to UV-C irradiation, in terms of viability, vitality and the ability to form biofilm. Results of this study showed that even though most of the cells were inactivated both in single-isolate and in multiple-isolate cultures, still the multiple-isolate cultures manages to form biofilms, surprisingly with higher biomass than without irradiation. The significance of the study is in its conclusion that studies on UV-C irradiation of biofilm-forming model micro-organisms are not always applicable to natural multiple-species communities.

Recent studies have shown the efficiency of hydroxyl radicals generated via ultraviolet (UV)-based advanced oxidation processes (AOPs) combined with hydrogen peroxide (UV/H2O2) as a treatment process in water. The effects of AOP treatments on bacterial gene expression was examined using Pseudomonas aeruginosa strain PAO1 as a model-organism bacterium. Many bacterial genes are not expressed all the time, but their expression is regulated. The regulation is at the beginning of the gene, in a genetic region called “promoter” and affects the level of transcription (synthesis of messenger RNA) and translation (synthesis of protein). The level of expression of the regulated genes can change as a function of environmental conditions, and they can be expressed more (induced, upregulated) or less (downregulated). Exposure of strain PAO1 to UV/H2O2 treatment resulted in a major change in gene expression, including elevated expression of several genes. One interesting gene is PA3237, which was significantly upregulated under UV/H2O2 as compared to UV or H2O2 treatments alone. The induction of this gene is probably due to formation of radicals, as it is abolished in the presence of the radical scavenger tert-butanol (TBA) and is seen even when the bacteria are added after the treatment (post-treatment exposure). Upregulation of the PA3237 promoter could also be detected using a reporter gene, suggesting the use of such genetic constructs to develop biosensors for monitoring AOPs in water-treatment plants. Currently biosensors for AOPs do not exist, consequently impairing the ability to monitor these processes on-line according to radical exposure in natural waters.

UV applied with H2O2 is a well-known advanced oxidation process (AOP) for degradation of trace organic compounds. However, the UV/H2O2 process has scarcely been documented as a disinfection method for brackish or seawater applications or particularly as a potential reverse osmosis (RO) biofouling control tool in varied treatment scenarios. The objective of this paper is to evaluate the potential of medium-pressure (MP)-UV/H2O2 as a pretreatment step to control brackish water RO (BWRO) biofouling caused by indigenous microorganisms. UV/H2O2 pretreatment significantly reduced total heterotrophic counts. Consequently, the quantity of biofilm cells and extracellular polymeric substances (EPS) following UV/H2O2 pretreatment was significantly lower than that obtained after the control and the singular UV pretreatment steps. This is attributed to the additive or synergistic effect of MP UV light, H2O2 and ˙OH radicals. Hence, UV/H2O2 has a high potential as a biofouling control tool in BWRO desalination systems. Higher H2O2 concentrations may achieve improved biofouling control due to enhanced radical formation and higher H2O2 residual effect.

Numerous aerogels are available in the scientific literature, however very few of them are in the market. Silicon, polymer, and carbon-based aerogels are commercially applied in various applications as construction, transportation, coating, day-lightning, oil, and gas. For water remediation purposes, very few materials are commercially available as aerogel blankets used for oil adsorption. We present the use of aerogels as a platform to support a wide range of novel materials, such as metals, semiconductors, oxides, polymers, biopolymers, hybrids and carbon. Aerogels are porous, consisting of 90–99% air, and are assembled into nanostructured materials. The discussed topics include synthesis (sol–gel process, aging, drying [ambient pressure, freeze, supercritical]), aerogel-based materials for water treatment, water-purification applications for aerogels (oil and toxic organic pollutant cleanup, heavy metal ion removal), reactor design in a pilot-scale application, conclusions and outlook. Although the use of aerogels in point-of-use applications for water treatment is promising, there are gaps in the cost and implementation of these new materials. Improvement in manufacturing and reduction in production costs is required to enhance market availability. Hence, we emphasized reactor design for bulk synthesis purposes. This review critically discusses the scientific, technical, and common barriers to commercialization of these novel materials.

Wastewater treatment (WWT) process is used to prevent pollution of water sources, improves sanitation condition, and reuse the water (mostly for agricultural purposes). One of the main goals of wastewater treatment is removal of nutrients, such as nitrogen which exists in the form of ammonia in the sewage. Excessive nitrogen concentration in the effluent is well known for eutrophication in aquatic environments and may cause a decrease of groundwater quality as a result of irrigation. However, it is not uncommon that the biological process results with undesirably high concentrations of nutrients, and therefore Wastewater Treatment Plants (WWTP) monitor nutrients to alert operators of this problem. It is desirable to identify WWT problems in the process ahead in order to achieve a better treatment. Thus, we suggest a novel machine learning method, based on Long-Short Term Memory (LSTM) architecture, that is able to predict effluent concentration of ammonia NH 4 + and nitrate NO 3 − a few hours ahead. We used measurements from the biological reactors sampled every minute, and combine it, for the first time in the literature, with climate measurements for improved prediction accuracy. Our proposed method showed an accuracy rate of 99% and F1-Scoreof 88% when predicting ammonia concentrations and an accuracy rate of 90% and F1-Scoreof 93% when predicting nitrate concentrations.

OBJECTIVES: An objective adherence marker is needed to track consumption of nutrient supplements in nutrition intervention trials and programs targeted to young children and women of reproductive age in low-income countries. Here, resveratrol and saccharin are evaluated as adherence markers for tracking short-term intermittent or daily consumption of a small-quantity lipid-based nutrient supplement (SQ-LNS) in US women in a ten-day controlled feeding study. METHODS: Sixty-three women were randomly assigned to receive daily for 10 d either: SQ-LNS containing trans-resveratrol (10 mg) and sodium saccharin (10 mg) (SQ-LNS/RS); 2) control SQ-LNS without the markers (SQ-LNS/C); or 3) alternating SQ-LNS/RS or SQ-LNS/C to simulate intermittent consumption. Urine concentrations of saccharin and trans-resveratrol-3-O-sulfate were measured in pooled urine samples collected 0–4 h post-consumption of the assigned SQ-LNS product on study days 4, 5, 9 and 10. Cutoff values were determined for urinary concentrations of each compound for classifying participants as consumers or non-consumers of SQ-LNS/RS. Then, participants were classified as daily, intermittent or non-consumers of SQ-LNS/RS based on their overall consumption pattern (number of days classified as a consumer during the 10-d period). RESULTS: The cutoff value for urinary trans-resveratrol-3-O-sulfate (0.80 µmol/L) classified participants correctly as consumers or non-consumers in 97% of samples; the cutoff value for urinary saccharin (6.92 µmol/L) classified participants correctly in 93% of samples. Overall, 95% of daily, 95% of intermittent, and 100% of control group participants were classified correctly into their consumption pattern based on urinary trans-resveratrol-3-O-sulfate concentrations during the 10-d period; and 75% of daily, 95% of intermittent, and 100% of control participants were classified correctly based on urinary saccharin concentrations. CONCLUSIONS: The results suggest that urinary concentrations of saccharin and trans-resveratrol-3-O-sulfate may be useful for qualitative assessment of daily vs. intermittent vs. non-consumption of SQ-LNS; further work is needed to assess the usefulness of the markers in the intended target populations. FUNDING SOURCES: Bill & Melinda Gates Foundation

In view of water-resource depletion, treated wastewater can serve as an alternative source for crop irrigation. However, conventional wastewater-treatment plants are energy-intensive and costly to construct and operate, especially for lower middle-income countries. The present study focused on improving the quality of wastewater by incorporating a coupled microalgal–bacterial biofilm (CMBB) treatment in wastewater ponds. Standard polyether sponges were dipped in raw wastewater samples to enhance biofilm development on them. The enriched sponges were used to treat wastewater, with or without external energy for aeration. Wastewater parameters were analyzed during the enrichment and treatment processes. The CMBB technology and aeration resulted in similar improvement of effluent quality, but the former saved on energy costs, and reduced total chemical oxygen demand (COD) by 36 % within 24 h and 71 % within 4 days; the values of biochemical oxygen demand (BOD), ammonium and phosphates decreased by 80 %, 64 % and 95 %, respectively, within 7 days. The resultant COD and BOD values were below the maximum allowed for reuse and discharge.