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In this work, the influence of bisphenol A (BPA) on biological wastewater treatment was studied. For it, two sequencing batch reactors (SBRs) were operated for three months. Both SBRs were fed with synthetic wastewater (SW), adding 1 mg·L -1 of BPA into the feed of reactor SBR-BPA, while the other one operated without BPA as a control reactor (SBR-B). In addition, batch experiments were performed with adapted and non-adapted activated sludge, simulating the reaction step of SBR-BPA, to determine the pathways for BPA removal. Results of batch experiments showed that adsorption and biodegradation were the only significant BPA removal routes. BPA removal by biodegradation was more efficient when adapted biomass was used in the tests (32.2% and 8.2% with adapted and non-adapted biomass, respectively), while BPA adsorption removal route was similar in both types of activated sludge (around 40%). Regarding the SBRs experiments, after 16 days no BPA concentration was detected in SBR-BPA effluent. In the adaptation process, SBR-BPA biomass was more sensitive to low temperatures resulting in higher effluent turbidity, COD and soluble microbial products concentrations than in SBR-B. However, once temperature increased, adapted biomass from SBR-BPA presented higher activity than SBR-B biomass, showing higher values of sludge production, microbial hydrolytic enzymatic activities and specific dynamic respiration rate. The bacterial community study revealed the increase of abundance of Proteobacteria (especially Thiothrix species) and Actinobacteria (especially Nocardioides species) phyla at the expense of Bacteroidetes and Chloroflexi phyla in SBR-BPA during its operation., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier B.V. All rights reserved.)

A complete study about the effects of 3,3',4',5-tetrachlorosalicylanilide (TCS) on organic matter elimination performance, sludge production and on the microbial community of a biological wastewater treatment process has been performed. For this purpose two sequencing batch reactors (SBR) worked in parallel for 43 days with 0.8 mg·L -1 of TCS (SBR-1) and without this metabolic uncoupler (SBR-2). Results indicated that 63.3% of sludge reduction was achieved in SBR-1. However, COD removal efficiency was maintained in similar values in both reactors (89.1% and 92.1% in SBR-1 and SBR-2, respectively). The exhaustive mixed liquor characterization led to know deeply the action mechanism of TCS. In this way, a 69% of adenosine triphosphate (ATP) reduction was observed in SBR-1 in comparison with values measured in SBR-2. On the contrary, an increase in soluble microbial products (SMP) and DNA concentrations occurred as a consequence of TCS addition. Thus, it could be concluded that sludge reduction due to TCS addition was due to both uncoupling effect and cellular lysis. Also, increase in all microbial hydrolytic enzymatic activities measured was observed, which explained the stable performance achieved in SBR-1 despite to the results explained above. It should be highlighted that this uncoupler should not be used in biological treatments that require nitrogen elimination because nitrifying bacteria were affected by its addition (Nitrosomonas and Nitrospira). Finally, the 16S rRNA gene amplicon sequencing informed that an important reduction of bacterial diversity resulted in SBR-1 due to TCS addition., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Ionic liquids are dual modifiers composed by a large anion and a large cation, which interact with both the hydrophobic alkyl-bonded phase and the anionic residual silanols in C18 columns. The deactivation of the silanol groups has important implications on the chromatographic analysis of basic drugs, being the improvement of peak profiles and shorter retention times the most noticeable features. However, other characteristics as selectivity or resolution are not usually considered, or are only examined for selected chromatographic conditions. In this work, the effect of the addition of the ionic liquid 1-hexyl-3-methyl imidazolium tetrafluoroborate to acetonitrile-water mixtures in a wide range of concentrations, using three C18 columns (Zorbax SB-C18, Nucleosil and Spherisorb) was studied for the separation of a group of β-adrenolytic drugs. The extremely poor chromatographic performance was highly improved in the presence of the ionic liquid, giving rise to shorter analysis times, smaller consumption of acetonitrile, significantly narrower and more symmetric peaks, and high resolution. The improvement was especially noteworthy for the Spherisorb column, which yielded the poorest results in the absence of additive., (Copyright © 2012 Elsevier B.V. All rights reserved.)

Residual silanols on C18 columns yield undesirable slow-kinetics ion-exchange interactions with positively charged basic compounds that result in asymmetrical peaks, low efficiencies and long retention times. The purity of the silica employed as supporting material, and the technique used to form the bonded phase, which varies with the brand and manufacturer, give rise to different amounts of residual silanols in the packings, and consequently, different chromatographic performance. One of the most efficient and widespread strategies to reduce or even eliminate the different performance among columns is the addition of a reagent to the mobile phase to block the silanol sites. However, the intrinsic nature of both stationary phase and additive leads to particular results. In this work, a group of basic compounds were analysed using six C18 stationary phases (Zorbax SB-C18, X-Terra MS C18, Kromasil, Lichrospher, Nucleosil, and Spherisorb) and acetonitrile-water mixtures. Two ionic liquids (ILs), 1-butyl- and 1-hexyl-3-methyl-imidazolium tetrafluoroborates, were added to the mobile phases to evaluate their silanol suppressing potency, based on the decreased retention of the basic compounds when the silanols are blocked (described by the Horváth equation), and the improvement in peak profile (described by the plots of the peak half-widths at diverse retention times). The suppressing potency based on the retention can be misleading when the adsorption of the IL anion is not negligible, since the anion attracts the cationic basic compounds increasing the retention. However, the accessibility of basic compounds to the silanols is prevented by both IL cation and anion, improving the peak profiles for all stationary phases. This was especially remarkable for Spherisorb, which in the absence of additive yielded by far the worst performance. 1-Hexyl-3-methyl-imidazolium tetrafluoroborate was the best additive in terms of retention and peak profile (width and asymmetry)., (Copyright © 2011 Elsevier B.V. All rights reserved.)

The cationic nature of basic drugs gives rise to broad asymmetrical chromatographic peaks with conventional C18 columns and hydro-organic mixtures, due to the ionic interaction of the positively charged solutes with the free silanol groups on the alkyl-bonded reversed-phase packing. Ionic liquids (ILs) have recently attracted some attention to reduce this undesirable silanol activity. ILs are dual modifiers (with a cationic and anionic character), which means that both cation and anion can be adsorbed on the stationary phase, giving rise to interesting interactions with the anionic free silanols and the cationic basic drugs. A comparative study of the performance of four imidazolium-based ILs as modifiers of the chromatographic behaviour of a group of β-blockers is shown. The ILs differed in the adsorption capability of the cation and anion on C18 columns. Mobile phases without additive and containing a cationic (triethylamine, TEA) or anionic (sodium dodecyl sulphate, SDS) additive were used as references for the interpretation of the behaviours. The changes in the nature of the chromatographic system, at increasing concentration of the additives, were followed based on the changes in retention and peak shape of the β-blockers. The silanol suppressing potency of the additives, and the association constants between the solutes and modified stationary phase or additive in the mobile phase, were estimated. The study revealed that SDS and the ionic liquid 1-hexyl-3-methylimidazolium tetrafluoroborate are the best enhancers of chromatographic peak shape among those studied., (Copyright © 2010 Elsevier B.V. All rights reserved.)

Dietary fish oil has a beneficial effect on heart and some bacterial diseases and apart from other effects, some studies have revealed their ability to modulate the course of inflammatory and autoimmune diseases. The study here reported was designed to evaluate the possible influence of a fish oil supplement on the course of a Trichinella infection. Nutritional, parasitological and immunological parameters were analyzed. Two groups of 20 Wistar rats, one fed a standard diet and the other one a standard diet supplemented with fish oil, were infected with 1000 L1 larvae. Other two uninfected groups served as control. Results were as follows: fish oil diet intake and infection have, respectively, a positive and a negative effect on growth and food utilization. The negative effect is detected later in animals fed the fish oil diet. A reduction of 30.9 and 36.6% in the number of adult worms and L1 larvae, respectively, was observed in the fish oil group as compared to the standard diet group. Production of IFNgamma (Th1 response) and IL4 (Th2) response was measured in stimulated splenic cells. The fish oil diet increased both IFNgamma and IL4 levels. At 6 days after infection both IFNgamma and IL4 responses were detected, but at 36 days after infection only IL4 was detected in the standard group. The level of somatic and cuticular antibodies was not affected by the diet.