Sonochemical degradation of PFAS in ion exchange regeneration wastes.

One of the primary technologies currently being deployed for the removal of per- and polyfluoroalkyl substances (PFAS) from water is ion exchange (IX). For regenerable IX resins, concentrated PFAS in the resulting spent brine and/or still bottoms requires further treatment. This research demonstrated that PFAS in spent brine and still bottoms can be effectively degraded sonochemically at 1000 kHz. Overall, PFAS degradation was negatively impacted by high total organic carbon (TOC) and residual methanol (MeOH) solvent (up to 50 g/kg; 5% w:w), but was enhanced by the high chloride. The addition of caustic (up to 1 N NaOH) partially mitigated the inhibition by TOC and MeOH. Sonochemical degradation of individual PFAS compounds resulted in significant mineralization to form inorganic fluoride, but small quantities of volatile organic fluorine species (VOF) were noted. This is believed to be the first report of sonochemical degradation of PFAS in ion exchange regeneration wastes, and indicates the possibility for the application of this technology as part of a complete PFAS capture and destruction treatment train.

Formation of volatile chlorinated and brominated products during low temperature thermal decomposition of the representative PFAS perfluorohexane sulfonate (PFHxS) in the presence of NaCl and NaBr.

Per- and polyfluoroalkyl substances (PFAS) are synthetic organofluorine compounds known for their chemical and physical stability as well as their wide range of uses. Some PFAS are widely distributed in the environment, leading to concerns related to both environmental and human health. High temperature thermal treatment (i.e., incineration) has been utilized for PFAS treatment, but this requires significant infrastructure and energy, prompting interest in lower temperature approaches that may still lead to efficient destruction. Lower treatment temperatures, however, increase the potential for incomplete PFAS mineralization and formation of volatile organofluorine (VOF) products. Herein, we report the formation of novel VOF products that include chlorinated and brominated compounds during the thermal treatment of potassium perfluorohexane sulfonate (PFHxS), a representative perfluoroalkyl acid (PFAA). By comparing the gas chromatography-mass spectrometry (GC-MS) results of known VOF stocks to evolved VOF during thermal treatment of PFAS, the formation of perfluorohexyl chloride and perfluorohexyl bromide was observed when PFHxS was heated at temperatures between 275 and 475 °C in the presence of NaCl and NaBr, respectively. To our knowledge, this is the first report of chlorinated or brominated VOF products during thermal treatment of a PFAA. These findings suggest that a range of mixed halogenated VOF may form during thermal treatment of PFAS at relatively low temperature (e.g., 500 °C) and that these can be a function of salts present in the matrix.

Biochemical and Nutritional Characterization of Edible Seaweeds from the Peruvian Coast.

In Peru, the number of species of edible seaweeds within the genera Chondracanthus, Porphyra (hereafter P.), Pyropia (hereafter Py.), and Ulva has not been fully established, nor is there a significant level of information available related to their chemical and nutritional composition. This study involved the biochemical analysis of species belonging to ten genera of macroalgae, known edible and some of which have the potential to be used as food, including six red (Callophyllis, Chondracanthus, Mazzaella, Porphyra, Pyropia, and Rhodymenia), two green (Ulva and Codium), and two brown (Eisenia and Lessonia) species collected along the Peruvian coast (6°-17° S). In the evaluation of 37 specimens, differences were found in the proximal composition, amino acid composition, and fatty acid profiles, which were specific to subgroups and supported their taxonomic classification, mainly at the order level. The red algae Porphyra/Pyropia (Bangiales) had the highest average percentage of protein (24.10%) and carbohydrates (59.85%) and the lowest percentage of ash (7.95%). Conversely, the brown alga Eisenia (Laminariales) had the lowest average percentage of protein, with different values related to the structure: 14.11% at the level of the frond and 9.46% at the level of the stipe. On the other hand, Bryopsidales green algae showed the highest average percentages of lipids (5.38%). The moisture percentages ranged from 4 to 16%, and no relevant significant differences were shown between the orders. The characteristic amino acids in all of the studied groups were glutamic acid, aspartic acid, alanine, and leucine. The highest average of the essential amino acids ratio was obtained for the Gigartinales red algae (48.65%), and the highest values of the essential amino acid index (EAAI) were obtained for the Ulvales, Laminariales, Gigartinales, and Rhodymeniales algae (EAAI > 0.92). The highest average relative percentage of fatty acids was obtained for polyunsaturated fatty acids, followed by saturated fatty acids. The major component of the ω6 fatty acids from red and brown algae was arachidonic acid (C20:4n - 6). The highest level of ω3 fatty acids was observed for the eicosapentaenoic acids (EPA) in red algae. The highest median ω6/ω3 ratio was displayed by the red alga Callophyllis variegata (Gigartinales). A detailed knowledge of edible seaweeds, and those considered potentially edible, would help to diversify the diet based on macroalgae in Peru.

Evaluación del potencial de Desmodesmus asymmetricus y Chlorella vulgaris para la remoción de nitratos y fosfatos de aguas residuales / Potential assessment of Desmodesmus asymmetricus and Chlorella vulgaris for removal of nitrates and phosphates in wastewater

Resumen En este estudio evaluamos las microalgas Chlorella vulgaris y Demodesmus asymmetricus, con el fin de determinar la proporción de microalgas que remueven la mayor concentración de nitrógeno y fósforo en aguas residuales de una planta de tratamiento. Se realizó un diseño de mezclas de las microalgas con el agua residual durante 9 días, con fotoperiodo 12:12 h, en un invernadero. Las mayores eficiencias de remoción de nitrógeno (principalmente NO3 -N y NO2 -N) y fósforo (PO4 ) se observaron en los tratamientos con mayor proporción de D. asymmetricus, entre ellos sobresalió el tratamiento T3 (25% C. vulgaris / 75% D. asymmetricus) donde se removió el 100% de nitrógeno y 77.1% de fósforo. De igual manera con el oxígeno disuelto (OD), el T3 obtuvo el mejor resultado alcanzando una media de 25.50 ± 0.28 mg/L. Finalmente, de acuerdo con el análisis del diseño de mezclas, se determinó que la mezcla óptima de microalgas que logra la mayor producción de OD y la mayor remoción, fue la proporción de 6% de C. vulgaris y 94% de D. asymmetricus en un tiempo de cultivo de 9 días. En conclusión, las microalgas demuestran su capacidad de biorremediación de aguas residuales domésticas.

Abstract In this work, we evaluated the proportion Chlorella vulgaris and Demodesmus asymmetricus microalgae, that removes the highest concentration of nitrogen and phosphorus in wastewater from a treatment plant. A mixture design was employed in this study, for 9 days, with 12:12 h photoperiod, in a greenhouse. The highest nitrogen removal efficiencies (mainly NO3 -N and NO2 -N) and phosphorus (PO4 ) were observed in treatments with the highest proportion of D. asymmetricus, including T3 (25% C. vulgaris / 75 % D. asymmetricus), where 100.0% nitrogen and 77.1% phosphorus were removed. Likewise, T3 obtained the best result of dissolved oxygen (DO), achieving average of 25.50 ± 0.28 mg/L. Finally, according to the analysis of the mixture design, the optimal microalgae mixture was determinated that achieves the highest DO production, and the highest removal was the proportion of 6% of C. vulgaris and 94% of D. asymmetricus in 9 days cultivation time. In conclusion, microalgae have shown their capacity for bioremediation of domestic wastewater, which is an alternative to consider.

Technique for Intraoperative Neuromonitoring During Periacetabular Osteotomy After Concomitant Hip Arthroscopy.

Intraoperative neurologic injury during periacetabular osteotomy (PAO) for the treatment of symptomatic acetabular dysplasia is a major complication that can lead to permanent disability and limit the benefit of correcting the acetabular dysplasia. Current literature reflects the evolution of hip-preservation surgery for symptomatic acetabular dysplasia to include hip arthroscopy to address the intra-articular abnormalities, including labral tears, chondral lesions, and femoral cam morphology. A growing number of young hip surgeons and surgeon teams are subscribing to this approach and now performing concomitant hip arthroscopy and PAO. The value of intraoperative neuromonitoring cannot be understated, both in terms of surgeon confidence as well as patient safety, particularly during the learning curve of PAO, with or without hip arthroscopy. We present our current technique for the application of neuromonitoring to allow free mobility of the operative leg and continuous monitoring during PAO. This reproducible technique allows the use of nonsterile neuromonitoring to be used through a sterile conduit, positioned to allow free mobility of the operative extremity and performance of the PAO. We believe this technique provides additional safety benefit and increases awareness regarding neurologic compromise, particularly for the low-volume PAO surgeon or during the procedural learning curve.

Extracción e identificación de lípidos polares de las microalgas Nannochloropsis oceanica y Desmodesmus asymmetricus / Extraction and identification of polar lipids from microalgae Nannochloropsis oceanica and Desmodesmus asymmetricus / Extração e identificação os lipídios polares das microalgas Nannochloropsis ocean ca e Desmodesmus asymmetricus

Resumen Los lípidos polares de las microalgas sor de gran interés debido a su aplicación como ingredientes naturales novedosos para las industrias cosmética, nutricional y farmacéutica. Por ello, el presente trabajo buscó determinar el efecto de los principales factores en la extracción e identificación de los lípidos polares de las microalgas Nannochloropsis oceanica y Desmodesmus asymmetricus, mediante el diseño de superficie de respuesta de Box-Behnken y el diseño factorial completo, respectivamente. Estas cepas del Banco de Germoplasma de Organismos Acuáticos (BGOA - IMARPE) fueron cultivadas en un invernadero, en biorreactores de 30 litros, centrifugadas y liofilizadas. Los lípidos fueron extraídos con cloroformo-metanol, fraccionados y analizados con un espectrómetro de masas Waters Xevo G2-XS QTOF. La maximización de la extracción de los lípidos totales determinó un valor óptimo de la relación masa-solvente de 25mg/3 mL, una proporción 1:1 de cloroformo-metanol, aproximadamente, y un tiempo del baño de ultrasonido entre 10 y 30 min. Los principales lípidos polares identificados para N. oceanica fueron lisofosfatidilcolina (LPC), diacilgliceril-N,N,N-trimetilhomoserina (DGTS), digalactosil diacilglicerol (DGDG) y monogalactosil diacilglicerol (MGDG) y para D. asymmetricus fueron sulfoquinovosil diacilglicerol (SQDG), LDGTS, DGTS, DGDG y MGDG.

Abstract The microalgae polar lipids are of great interest due to their application as novel natural ingredients for the cosmetic, nutritional, and pharmaceutical industry. For this reason, the present work sought to determine the effect of the main factors in the extraction and identification of polar lipids from the microalgae Nannochloropsis oceanica and Desmodesmus asymmetricus, using Box-Behnken response surface methodology design and full factorial design, respectively. These strains from the Germplasm Bank of Aquatic Organisms (BGOA - IMARPE) were grown in a greenhouse, in 30 L bioreactors, centrifuged and lyophilized. The lipids were extracted with chloroform-methanol, fractionated and analyzed with the Waters Xevo G2-XS QTOF mass spectrometer. The maximization of total lipid extraction determined an optimal value of the mass-solvent ratio of 25 mg / 3 mL, an approximate ratio of chloroform-methanol 1:1 and an ultrasound bath time between 10 and 30 min. The main polar lipids identified for the N. oceanica microalgae were lysophophatidylcholine (LPC), diacylglyceryl-N,N,N-trimethylhomoserine (DGTS), digalactosyldiacylglycerol (DGDG), and monogalactosyldiacylglycerol (MGDG) and for D. asymmetricus were sulfoquinovosyl diacylglycerol (SQDG), LDGTS, DGTS, DGDG, and MGDG.

Resumo Os lipídios polares das microalgas possuem grande interesse em sua aplicação como novos ingredientes naturais na indústria cosmética, nutricional e farmacêutica. A presente pesquisa procura determinar o efeito dos principais fatores na extração e identificação dos lipídios polares das microalgas Nannochloropsis oceanica e Desmodesmus asymmetricus, por meio do um experimento de Box-Behnken e um experimento fatorial completo, respectivamente. As cepas do Banco do Germoplasma do Organismos Aquáticos (BGOA - IMARPE), foram cultivadas em casa de vegetação, em biorreatores do 30 L, centrifugadas e liofilizadas. Os lipídios foram extraídos com clorofórmio-metanol, fracionados e analisados com o espectrómetro do massa Waters Xevo G2-XS QTOF. A maximização da extração lipídica determinou um valor ótimo da razão massa-solvente de 25 mg / 3 mL, uma proporção aproximadamente clorofórmio-metanol de 1:1 e no tempo do banho de ultrassom entre 10 e 30 minutos. Os principais lipídios polares identificados para das microalgas N. oceanica foram lisofosfatidilcolina (LPC), diacilgliceril-N,N,N-trimetil-homoserina (DGTS), digalactosil diacilglicerol (DGDG) e monogalactosil diacilglicerol (MGDG), e para D. asymmetricus foram sulfoquinovosil diacilglicerol (SQDG), LDGTS, DGTS, DGDG e MGDG.