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Liquid-liquid partition coefficient is a useful tool to predict biological and environmental fate of organic compounds, for example bioaccumulation or toxicity of lipophilic contaminants. Conversely, the partitioning of ionizable compounds is poorly studied in contrast to that of neutral compounds. Yet, such topic deserves attention, since numerous organic contaminants are ionizable as well as their degradation products. Hence, the contribution of charged species has to be considered in order to model accurately the mass balance or partition of ionizable compounds. In this context, we investigated the liquid-liquid partition of 13 ionizable compounds (oxalic acid, histidine, benzimidazole, etc.), covering various classes of compounds (carboxylic acids, amino-acids, etc.). The n-octanol/water partition coefficient was measured from pH 1 up to 13, in order to fully gather the distribution of both neutral and charged species. Empirical models describing these results are reviewed and partition parameters adjusted for charged species. The study of benzoic acid derivatives (benzoic, salicylic, ortho- and iso-phthalic acids) provides insights on the influence of chemical groups on the partitioning. In the case of tryptophan, the use of acid/base microconstants allowed to estimate the partition of both the zwitterion and its neutral tautomer. Despite a major zwitterionic form (log P Z (tryptophan) = -1.58 ± 0.30), the minor but neutral tautomer (log P N (tryptophan) = +0.03 ± 0.30) drives the partition equilibrium. Overall, the provided data may be useful to assess the retention of contaminants, its dependency on pH and salinity variations, and thus understanding their environmental fate. Such data may also be useful as well for molecular simulation involving solvation of organic ions in aqueous and non-aqueous solvents., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

An artificial neural network model is proposed for the surface tension of liquid organic fatty acids covering a wide temperature range. A set of 2051 data collected for 98 acids (including carboxylic, aliphatic, and polyfunctional) was considered for the training, testing, and prediction of the resulting network model. Different architectures were explored, with the final choice giving the best results, in which the input layer has the reduced temperature (temperature divided by the critical point temperature), boiling temperature, and acentric factor as an independent variable, a 41-neuron hidden layer, and an output layer consisting of one neuron. The overall absolute percentage deviation is 1.33%, and the maximum percentage deviation is 14.53%. These results constitute a major improvement over the accuracy obtained using corresponding-states correlations from the literature.

The process of surface mining and extracting bitumen from oil sand produces large quantities of tailings and oil sands process-affected water (OSPW). The industry is currently storing OSPW on-site while investigating strategies for their detoxification. One such strategy relies on the biodegradation of organic compounds by indigenous microbes, resulting in aged tailings waters with reduced toxicity. This study assessed the toxicity of OSPW aged statically for approximately 18 years. Dissolved organics in aged OSPW were fractionated using a preparative solid-phase extraction method that generated three organic fractions (F1-F3) of increasing polarity. Eight aquatic species from different trophic levels were exposed to whole OSPW (WW) and the derived OSPW organic fractions to assess toxicity: Pimephales promelas, Oryzias latipes, Vibrio fischeri, Daphnia magna, Lampsilis cardium, Hyalella azteca, Ceriodaphnia dubia, and Hexagenia spp. Broad comparisons revealed that P. promelas and H. azteca were most sensitive to dissolved organics within aged OSPW, while WW was most toxic to L. cardium and H. azteca. Three cases of possible contaminant interactions occurred within whole OSPW treatments, as toxicity was higher than organic fractions for H. azteca and L. cardium, and lower for P. promelas. As such, the drivers of toxicity appeared to be dependent on the species exposed. Of the organic fractions assessed, F3 (most polar) was the most toxic overall while F2 (intermediate polarity) displayed little toxicity to all species evaluated. This presents strong evidence that classical mono-carboxylic naphthenic acids, mostly present in F1 (least polar), are not primarily responsible for the toxicity in aged tailings. The current study indicates that although the aged tailings source (≥18 years) did not display acute toxicity to the majority of organisms assessed, inorganic components and polyoxygenated organics may pose a persistent concern to some aquatic organisms., (Crown Copyright © 2019. Published by Elsevier B.V. All rights reserved.)

The development of biodegradation treatment processes for oil sands process-affected water (OSPW) has been progressing in recent years with the promising potential of biofilm reactors. Previously, the granular activated carbon (GAC) biofilm process was successfully employed for treatment of a large variety of recalcitrant organic compounds in domestic and industrial wastewaters. In this study, GAC biofilm microbial development and degradation efficiency were investigated for OSPW treatment by monitoring the biofilm growth on the GAC surface in raw and ozonated OSPW in batch bioreactors. The GAC biofilm community was characterized using a next-generation 16S rRNA gene pyrosequencing technique that revealed that the phylum Proteobacteria was dominant in both OSPW and biofilms, with further in-depth analysis showing higher abundances of Alpha- and Gammaproteobacteria sequences. Interestingly, many known polyaromatic hydrocarbon degraders, namely, Burkholderiales, Pseudomonadales, Bdellovibrionales, and Sphingomonadales, were observed in the GAC biofilm. Ozonation decreased the microbial diversity in planktonic OSPW but increased the microbial diversity in the GAC biofilms. Quantitative real-time PCR revealed similar bacterial gene copy numbers (>10(9) gene copies/g of GAC) for both raw and ozonated OSPW GAC biofilms. The observed rates of removal of naphthenic acids (NAs) over the 2-day experiments for the GAC biofilm treatments of raw and ozonated OSPW were 31% and 66%, respectively. Overall, a relatively low ozone dose (30 mg of O3/liter utilized) combined with GAC biofilm treatment significantly increased NA removal rates. The treatment of OSPW in bioreactors using GAC biofilms is a promising technology for the reduction of recalcitrant OSPW organic compounds., (Copyright © 2015, American Society for Microbiology. All Rights Reserved.)

The hospital records of 548 consecutive patients undergoing midtrimester pregnancy termination by the local administration of prostaglandins (PGs) have been reviewed. Most women (352 or 64%) were single and 322 (59%) were pregnant for the 1st time. 2/3 of the patients (361 or 66%) were between 12-16 weeks pregnant, whereas 7 (1%) were considered to be more than 20 weeks pregnant. In 401 cases (92%), abortion was performed under Item 2 of the 1967 Abortion Act, although Item 4 was cited in 34 (81%) of those individuals with a pregnancy of greater than 17 weeks duration. Apart from 10 women (2%) in whom severe hemorrhage was documented, the major complication rate was less than 1%. The use of local PGs provides a safe, effective treatment method for therapeutic abortion in the 2nd trimester.

Vaginal pessaries, up to a maximum of 5, each containing 1 mg of 16,16-dimethyl-trans-delta squared-prostaglandin E1, ester (Gemeprost) were inserted as high as possible into the posterior fornix of the vagina at 3 hourly intervals in 459 women with abnormal intrauterine pregnancies presenting for termination of the pregnancy. There were 145 missed abortions (31.6%), 207 intrauterine fetal deaths (45.1%), 86 molar pregnancies (18.7%), 5 anencephalics (1.1%), and 16 others (3.5%). The study was conducted from July 1981-March 1982. 402 women (87.6%) underwent abortion within the 30 hour observation period, including 139 women (30.3%) who required additional procedures to complete evacuation of the uterus. Expulsion of the uterine contents failed to occur within 30 hours in 57 women (12.4%) and alternative procedures were employed. These failures consisted of 37 missed abortions, 17 intrauterine fetal deaths, 2 molar pregnancies, and 1 pregnancy with an IUD in situ. Side effects caused by the drug were basically tolerable. 234 women (51.0%) had 1 or more side effects, gastrointestinal tract disturbances (nausea, vomiting, and diarrhea) being the most frequently observed, and moderate fever the next most frequent. There was 1 ruptured uterus.

The influence of naproxen (a typical prostaglandin [PG] synthetase inhibitor) and arachidonic acid (AA) on the isolated uterus in estrus cycle (day 14) in guinea pigs was investigated. The results show that AA could increase the contractions of the uterus. Naproxen could inhibit the contractility caused by AA. The potency of inhibition was dose-dependent. The inhibition of tonus was quite obvious. The animal model is considered the suitable one for investigating the effect of PG synthetase inhibitor on myometrium.