The request for alternative sources of energy has led to evaluating untapped routes for energy production, such as using abundant and low-cost waste materials, e.g., lignocellulosic wastes, as the ...substrate for biological processes aimed at biofuel production. This study focused on peanut shells (PS) valorisation via anaerobic digestion (AD). Two emerging pretreatments, i.e., organosolv and ultrasounds, were investigated to unlock the full AD potential of PS. The impact of a substrate-to-solvent ratio in organosolv pretreatment was investigated (i.e., 1:5 vs. 1:10 vs. 1:20). Different exposure times were tested for ultrasound pretreatment, corresponding to applied energy densities of 30,000, 12,000, and 6000 kJ/kg VS, respectively. Organosolv pretreatment achieved the maximal polyphenol solubilisation, i.e., 4.90 mg/g TS, when increasing the substrate-to-solvent ratio, whereas methane production did not benefit from the pretreatment, being comparable with that of raw PS at most (i.e., 55.0 mL CH4/g VS). On the other hand, ultrasounds mainly affected sugar solubilisation (up to 37.90 mg/g TS), enhancing methane production up to an extra 64%, achieved with the highest energy density. The organosolv route would benefit from further downstream steps to recover the biomolecules released in the liquid fraction, whereas ultrasounds pretreatment provided a slurry suitable for direct AD.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
The need to ensure adequate levels of both human and environmental health protection calls for the identification of efficient wastewater treatment processes that target the removal of conventional ...pollutants as well as emerging contaminants, including synthetic dyes. This study explores the potential of ozone for use in the decolorization of both pretreated tannery wastewater and urban wastewater effluents. Different ozone contact times (15, 30, and 45 min) were applied to such wastewater samples at an uncontrolled (7.5–8.2) pH as well as at a pH adjusted to 10. The highest color removal efficiencies (REs) (>90%) were obtained with urban wastewater after a 45 min contact time and at pH 10. Under the same conditions, a COD RE from 31 to 51% was achieved. Even without pH adjustment, color and COD REs ranging from 81 to 92% and 39 to 41%, respectively, were obtained. A preliminary evaluation of the costs associated with the implementation of an ozonation stage within the wastewater treatment plant (WWTP) generating the urban wastewater used here was carried out. The energy cost of the ozone treatment would account for a 69% increase in the total energy cost of the WWTP, suggesting the need to identify proper strategies to enhance the cost-competitiveness of this technology.
The anaerobic digestion of sewage sludge is highly sensitive to high zinc concentrations. Although sulfate-reducing bacteria (SRB) activity can negatively affect methanogenesis, SRB-mediated metal ...sulfide precipitation can alleviate zinc toxicity. A series of mesophilic anaerobic batch experiments was performed for the biomethane potential of three different sewage sludge samples for 74 days using the background sludge zinc content, alone or in combination with the external addition of 200, 300 and 400 mg Zn/L. The highest biomethane production was 165 ± 1 mL CH4/g VS using activated sludge (AS) with a background concentration of 93 mg Zn/L. A slight decrease in the biomethane yield (i.e., 157 ± 1, 158 ± 1 and 159 ± 1 mL CH4/g VS) was obtained in the presence of 293, 393 and 493 mg Zn/L, respectively. The potential reason for the high methanogenic activity at high inlet Zn concentrations could be that the AS used in this study was already acclimated to those conditions. Zinc was likely removed from the system by sulfide precipitation, and a removal efficiency above 99% was achieved under all zinc concentrations. A sulfate reduction efficiency of 99% was also obtained. Overall, this study details the potential utilization of biogenic sulfide as a metal detoxifying agent without detrimental effects on methane production from sewage sludge.
The organic acids (OAs) market has been expanding due to their versatility and wide range of uses in several industrial applications, thus prompting a transition from chemical to biological ...approaches to generate such high-value products. Nevertheless, downstream processes to separate OAs from the fermentation broth represent, to date, the main cost in biological OAs manufacturing. With the goal of limiting this issue, the present study investigated OAs separation from a lactic acid (LA)-rich fermentation broth through physical, i.e., using ethyl acetate (EA), and physico-chemical, i.e., using tributyl phosphate (TBP), solvent extraction. In addition, the salting-out effect of different salts on OAs recovery was investigated. Among the investigated conditions, a combination of pure TBP and 40% ammonium sulfate ensured the highest LA extraction efficiency of 65%. Besides, mixing TBP with EA (50:50) enabled to maintain the same LA extraction efficiency while reducing the process costs, limiting the toxicity of the chemicals involved, and obtaining an extracted OAs mix with lower co-metabolites, i.e. volatile fatty acids, compared to using pure TBP. Overall, solvent extraction assisted by salting-out agents were shown to be a promising method to separate OAs from a fermentation broth in liquid form, especially for fermentation processes operated at low pH.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Anaerobic digestion is a promising alternative to valorize agrifood wastes, which is gaining interest under an environmental sustainability overview. The present research aimed to compare anaerobic ...digestion with olive pomace oil extraction, by using life cycle assessment, as alternatives for the valorization of the olive mill solid waste generated in the centrifugation process with a two-outlet decanter from oil mills. In the case of olive pomace oil extraction, two cases were defined depending on the type of fuel used for drying the wet pomace before the extraction: natural gas or a fraction of the generated extracted pomace. The anaerobic digestion alternative consisted of the production of biogas from the olive mill solid waste, heat and electricity cogeneration by the combustion of the generated biogas, and composting of the anaerobic digestate. The life cycle assessment showed that anaerobic digestion was the best alternative, with a global environmental impact reduction of 88.1 and 85.9% respect to crude olive pomace oil extraction using natural gas and extracted pomace, respectively, as fuel.
There is significant interest in the development of new drugs to treat vascular dementia. However, before US approval of new drugs for this entity is possible, certain issues with regulatory ...implications need to be addressed. Is vascular dementia a distinct clinical syndrome with valid diagnostic criteria? Can this entity be distinguished from Alzheimer's disease (AD) and other causes of dementia? What design features are important for clinical trials in this disorder? The US Food and Drug Administration (FDA) convened a special meeting of the Peripheral and Central Nervous System Advisory Committee in an attempt to answer these questions. The conclusions from this meeting indicate that vascular dementia (VaD) is a pathologically heterogeneous disorder but appears to be reasonably distinguishable from AD dementia. The NINDS-AIREN diagnostic criteria are suitable as entry criteria for vascular dementia trials. Trials should be similar in duration to AD dementia trials and should employ a dual outcome strategy (cognitive + global/functional measures). For drugs that are believed to have a disease-modifying effect, clinical trials should study specific vascular dementia subtypes and would need to employ substantially different designs from those used currently. The term “vascular dementia” may not be entirely appropriate to describe this population.
Transient visual disturbance following cardiac catheterization has been regarded as a benign and transient complication. We describe two cases of computed-tomography-documented occipital infarction ...after cardiac catheterization that emphasize a complication more serious than previously thought.
We used crossed polarized neutral density filters to quantitate relative afferent pupillary defects. To prove reproducibility, the relative afferent pupillary defects of 20 patients were measured ...with this technique by two independent observers. There was no statistically significant difference between the two measurements. Relative afferent pupillary defects as low as 0.03 log unit were easily measured. These filters offer a convenient and reproducible technique that is more sensitive than the use of neutral density filters.
We describe 17 patients with acquired convergence-evoked nystagmus (CEN). Vertical CEN was most common (82%), with upbeat much more frequent than downbeat. The most common diagnoses were multiple ...sclerosis (41%) and brainstem infarction (29%). CEN is an easily elicited bedside sign of posterior fossa dysfunction and can be a clinically useful manifestation. In cases of isolated optic neuritis, the presence of CEN may indicate dissemination of neurologic disease.
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