Influence of sequential HTC pre-treatment and pyrolysis on wet food-industry wastes: Optimisation toward nitrogen-rich hierarchical carbonaceous materials intended for use in energy storage solutions.

Due to elevated protein content, the food-industry bio-wastes are promising feedstock to produce hierarchical (micro-mesoporous) carbonaceous materials with the intended use as electrodes in the energy storage solutions. However, the high initial water content, makes their direct activation through high-temperature processes costineffective due to significant heat requirements. In this study, the influence of pretreatment with hydrothermal carbonization (HTC) on wet food-industry bio-wastes, further pyrolysed, was investigated. Selected wastes (brewer's spent grains, spent coffee grains and spent sugar beets) were pre-treated by HTC at 180 °C or 240 °C, and then pyrolysed at 500 °C or 700 °C. Obtained materials were examined using elemental analysis, gas adsorption (N2 and CO2) and FT-IR. Besides minor differences caused by the bio-composition of wastes, the general trends were similar for feedstock. The pre-treatment had a beneficial influence on the properties of all wastes. The HTC at 180 °C and pyrolysis at 700 °C for all wastes show the most promising total specific surface area 560 ± 10 m2/g and accessible specific surface area 96 m2/g. Those conditions simultaneously did not reduce the total solid yield in comparison to the one-step process. The pre-treatment at 240 °C led to elevated nitrogen incorporation in the carbonaceous structure compared to HTC at 180 °C. However, it formed a hierarchical structure that was not stable for the thermal treatment. Study proves the HTC pre-treatment at 180 °C is beneficial for the conversion of food-industry bio-wastes into hierarchical carbonaceous material for their use in the energy storage systems application.

Valorization of the poultry litter through wet torrefaction and different activation treatments.

The increase in volume in bio-waste is inseparable from the production of biomass derived commodities. To reduce the use of conventional resources, the valorization of waste streams is gaining importance, and the valorisation of poultry litter fits perfectly into such scheme. This study shows a possible valorization of wet torrefied (300 °C) poultry litter (WTPL) through activation and its further use as a fertilizer, and as a wastewater micro-pollutant absorbent. The WTPL was activated thermally, physically (CO2) and chemically (KOH) at two different temperatures (600 °C and 800 °C) and 30 min residence time. The properties of ACs were evaluated based on results of the elemental and proximate analysis, suspension pH measurement, ICP-OES, FT-IR, N2 and CO2 adsorption and quantity of absorbed methylene blue (MB). The yields in thermal and physical ACs were comparable, but much higher than ACs from chemical activation (c.a. 50% and 15% at 600 °C and c.a. 47% and 6.5% at 800 °C). The thermal and physical ACs showed good suitability for application as a fertilizer due to their high macro- and micro-nutrients and low heavy metals concentration. Carbons activated with KOH proved their usefulness as wastewater pollutant absorbers through high MB's absorption (675.8 mg/g for 600 °C and 872.8 mg/g for 800 °C). Results state that the valorization of PL through activation is possible, and the selection of the activation method affects the final application of obtained material.

Effect of protein during hydrothermal carbonization of brewer's spent grain.

This study has two targets: Studying the extraction of the initial protein content from brewer's spent grain and the impact of protein's extraction on the chemical-physical properties of produced hydrochars. The protein was extracted from brewer's spent grains using the pH-shifting method. The extracted protein was quantified and characterized by their amino acid profile. The hydrothermal treatment was applied at 190 °C and 220 °C for 0.5 h, 1 h, 2 h, and 4 h. The hydrochars and process water were collected and assayed. The hydrochar after protein extraction reveals the lowest yield to hydrochars (67.10-45.14%), higher C/N ratio (19.66-21.33) and lower ash content (1.52-1.72 wt%) compared to the hydrochar without extraction.

[Heart arrest in cemented hip arthroplasty]. / Paro cardíaco en artroplastia de cadera cementada.

Hip arthroplasty is a common surgical intervention in our hospital practice, involving high perioperative risk related to patients age and multiple concomitant diseases. Hemodynamic complications described vary from slight hypotension during surgery to heart failure and sudden death, particularly if the operation involves a cemented femoral component. Because of the type of patients undergoing such operations (elderly patients, with osteoporosis and scarce cardiopulmonary reserve), the unclear origin of complications and the lack of consensus on what constitutes adequate monitoring during surgery, hip arthroplasty is problematic for the specialists involved. We report on five deaths during cemented hip arthroplasty; after reviewing the case history and autopsy report of one, we believe the events leading to death were triggered by massive pulmonary embolism.

Paro cardíaco en artroplastia de cadera cementada / Heart failure during cemented hip arthroplasty

La artroplastia de cadera es una intervención quirúrgica muy frecuente en nuestro medio hospitalario y que conlleva un riesgo perioperatorio elevado por la edad avanzada de los pacientes y la múltiple patología concomitante. Las complicaciones hemodinámicas descritas varían desde la leve hipotensión intraoperatoria hasta la parada cardíaca y la muerte súbita, sobre todo si se trata de artroplastia de cadera con componente femoral cementado.El tipo de pacientes sometidos a esta intervención (ancianos, con osteoporosis y escasa reserva cardiorrespiratoria), la etiología no aclarada de las complicaciones y la falta de consenso acerca de la monitorización intraoperatoria adecuada convierten la artroplastia de cadera en un problema para los especialistas implicados en la misma.Presentamos 5 casos de muerte intraoperatoria en pacientes sometidos a artroplastia de cadera cementada, en los que, a juzgar por la clínica y el estudio necrópsico en uno de ellos, creemos que el cuadro fue desencadenado por un embolismo pulmonar masivo (AU)