Comparative Investigation of the Physicochemical Properties of Chars Produced by Hydrothermal Carbonization, Pyrolysis, and Microwave-Induced Pyrolysis of Food Waste

This work presents a comparative study of the physicochemical properties of chars derived by three thermochemical pathways, namely: hydrothermal carbonization, HTC (at 180, 200 and 220 °C), pyrolysis, PY, (at 500, 600 and 700 °C) and microwave assisted pyrolysis, MW (at 300, 450 and 600 W). The mass yield of HTC samples showed a decrease (78.7 to 26.7%) as the HTC temperature increased from 180 to 220 °C. A similar decreasing trend in the mass yield was also observed after PY (28.45 to 26.67%) and MW (56.45 to 22.44%) of the food waste mixture from 500 to 700 °C and 300 to 600 W, respectively. The calorific value analysis shows that the best among the chars prepared by three different heating methods may be ranked according to the decreasing value of the heating value as: PY500, MW300, and HTC180. Similarly, a decreasing trend in H/C values was observed as: PY500 (0.887), MW300 (0.306), and HTC180 (0.013). The scanning electron microscope (SEM) analyses revealed that the structure of the three chars was distinct due to the different temperature gradients provided by the thermochemical processes. The results clearly show that the suitable temperature for the HTC and PY of food waste was 180 °C and 500 °C, respectively, while the suitable power for the MW of food waste was 300 WFunding: This research was funded by National Plan for Science, Technology and Innovation (MAAR-IFAH), King Abdulaziz City for Science and Technology, Kingdom of Saudi Arabia, Award Number 14-ENV665-02.Scopu

Physicochemical properties and combustion kinetics of food waste derived hydrochars

In this work, simulated food waste (15% white bread, 15% palm dates (without seeds), 5% boiled egg (without shells), 20% spent tea leaves, 20% spent coffee ground, and 25% banana peel in parts weight) was subjected to hydrothermal carbonization (HTC) at 180, 200 and 220 °C for 120 min. The mass yield and energy yield of the resultant hydrochars viz. HTC180, HTC200, and HTC220 were 69.46, 68.50, 65.35% and 88.91, 87.68, 84.30%, respectively. Among the hydrochars produced, HTC220 had the highest heating value (HHV: 23.61 MJ/kg), while the food waste had a HHV of 18.17 MJ/kg. Activation energy for the combustion of food waste and HTC220 was determined by modelling the thermogravimetric data using the Arrhenius equation and was found to be in the range of 29.98 to 33.51 kJ/mol and 16.52 to 25.47 kJ/mol, respectively. The densification ratio for the three hydrochar samples varied slightly (1.28–1.29). The results indicate that the hydrochar produced from food waste could be a potential to substitute coal combustion.King Abdulaziz City for Science and Technology - grant no. 14-ENV665-02

Photocatalytic degradation of methylene blue and antibacterial activity of mesoporous TiO2-SBA-15 nanocomposite based on rice husk

Concerns have been increased regarding the existence of pollutants in environmental water resources and their risks to the ecosystem and human society. TiO2 photocatalyst is considered as an effective photocatalyst to remove the pollutants. Herein, the mesoporous TiO2-SBA-15 was prepared using the rice husk extract as the silica source. The fabricated nanocomposites were characterized using FTIR, small and wide angle XRD, Raman spectroscopy, UV-vis, BET surface area analysis, and HRTEM. The photocatalytic efficiency of the composites for the degradation of methylene blue (MB) has been evaluated under UV irradiation. Interestingly, due to the excellent dispersion of TiO2 on the wall of SBA-15 and good hydrophilicity, the nanocomposites displayed a good catalytic activity. The higher photodegradation performance was achieved by the composite containing 10 wt% TiO2 by which the MB was fully degraded within 15-20 min of irradiation. Besides, TiO2-SBA-15 could effectively inhibit the growth of Gram-positive and Gram-negative bacteria. These results offer a practical and economic approach in the environmental management industries

High-Pressure Metal-Free Catalyzed One-Pot Two-Component Synthetic Approach for New 5-Arylazopyrazolo[3,4-b]Pyridine Derivatives

An appropriate and efficient Q-tube-assisted ammonium acetate-mediated protocol for the assembly of the hitherto unreported 5-arylazopyrazolo[3,4-b]pyridines was demonstrated. This methodology comprises the cyclocondensation reaction of 5-amino-2-phenyl-4H-pyrazol-3-one with an assortment of arylhydrazonals in an NH$_4$OAc/AcOH buffer solution operating a Q-tube reactor. This versatile protocol exhibited several outstanding merits: easy work-up, mild conditions, scalability, broad substrate scope, safety (the Q-tube kit is simply for pressing and sealing), and a high atom economy. Consequently, performing such reactions under elevated pressures and utilizing the Q-tube reactor seemed preferable for achieving the required products in comparison to the conventional conditions. Diverse spectroscopic methods and X-ray single-crystal techniques were applied to confirm the proposed structure of the targeted compounds

Flavoring and Coating Technologies for Processing Methods, Packaging Materials, and Preservation of Food

The food sector addresses perhaps the main business with regard to degree, speculation, and variety. In a forever-evolving society, dietary requirements and inclinations are broadly factors. Alongside offering extraordinary mechanical help for inventive and valued items, the ongoing food industry ought to likewise cover the essential necessities of a consistently expanding populace. Active food packaging strategies have experienced a tremendous push forward in the last two decades. It is a great opportunity to decide which bioactive component will be more appropriate for each specific application once the microbiological hazards for each type of food item are recognized and the microbial targets are clearly differentiated. In order to improve Flavor delivery and preservation, the food industry and the science of Flavor are constantly creating new ingredients, processing techniques, and packaging materials. This improves the quality and acceptability of food by boosting Flavor stability. As most Flavors can be influenced by interactions with other food ingredients in addition to being volatile and chemically unstable to air, light, moisture, and high temperatures. The food sector will succeed in the long run if new technologies are quickly adopted and effectively used to meet both current and future consumer expectations

Fabrication of sulfonated polyethersulfone ultrafiltration membranes with an excellent antifouling performance by impregnating with polysulfopropyl acrylate coated ZnO nanoparticles

Sulfonated polyethersulfone/sulfopropyl methacrylate membranes impregnated with the polysulfopropyl acrylate coated ZnO nanoparticles were developed using a non-solvent-induced phase separation recipe. The composite membranes offered much-enhanced hydrophilicity and improved porosity, which are critical for the excellent antifouling performance and high permeate flux. By adding polysulfopropyl acrylate modified ZnO, it achieved the maximum water flux of 420 Lm−2h−1 while maintained the natural organic matter rejection rate of 99% with an excellent flux recovery ratio up to 99% in the antifouling measurement. The results display that the impregnation of ZnO nanoparticles in the sulfonated polyethersulfone membrane can effectively increase the surface hydrophilicity which is essential for reducing the irreversible fouling with improved long-term performance and excellent recyclability

Method for the fast determination of bromate, nitrate and nitrite by ultra performance liquid chromatography–mass spectrometry and their monitoring in Saudi Arabian drinking water with chemometric data treatment

A rapid, sensitive and precise method for the determination of bromate (BrO3(-)), nitrate (NO3(-)) and nitrite (NO2(-)) in drinking water was developed with Ultra performance Liquid Chromatography-Mass Spectrometry (UPLC-ESI/MS). The elution of BrO3(-), NO3(-) and NO2(-) was attained in less than two minutes in a reverse phase column. Quality parameters of the method were established; run-to-run and day-to-day precisions were <3% when analysing standards at 10µgL(-1). The limit of detection was 0.04µg NO2(-)L(-1) and 0.03µgL(-1) for both NO3(-)and BrO3(-). The developed UPLC-ESI/MS method was used to quantify these anions in metropolitan water from Saudi Arabia (Jeddah, Dammam and Riyadh areas) and commercial bottled water (from well or unknown source) after mere filtration steps. The quantified levels of NO3(-) were not found to pose a risk. In contrast, BrO3(-) was found above the maximum contaminant level established by the US Environmental Protection Agency in 25% and 33% of the bottled and metropolitan waters, respectively. NO2(-) was found at higher concentrations than the aforementioned limits in 70% and 92% of the bottled and metropolitan water samples, respectively. Therefore, remediation measures or improvements in the disinfection treatments are required. The concentrations of BrO3(-), NO3(-) and NO2(-) were mapped with Principal Component analysis (PCA), which differentiated metropolitan water from bottled water through the concentrations of BrO3(-) and NO3(-) mainly. Furthermore, it was possible to discriminate between well water; blend of well water and desalinated water; and desalinated water. The point or source (region) was found to not be distinctive

Cutaneous Leishmaniasis: Treatment Options and Possibilities for Drug Repurposing: Submitted: Jul 21, 2019 Accepted: Oct 25, 2019 Published online: Nov 12, 2019

Leishmaniasis is a tropical disease caused by aprotozoan which is obligate intracellular parasite belongs to the genus Leishmania. There are 3 forms of the disease: visceral leishmaniasis, cutaneous leishmaniasis which is the most common, and mucocutaneous leishmaniasis. The most important compounds used to treat leishmaniasis were meglumine antimoniate (e.g. glucantime), sodium stibogluconate (e.g. pentostam) and pentavalent antimonials. There are other drugs that may be used such as pentamidine and amphotericin B. Until now, the pentavalent antimonial compounds remain the corner stone in the treatment of cutaneous leishmaniasis although this group possesses high degree of toxicity. Other treatment options include the pentamidines and liposomal amphotericin B (AmBisome). Combination therapies using AmBisome and miltefosine are another effective alternative to antimonial compounds. Other latest therapeutic options include photodynamic therapy, tamoxifen and imiquimod. The proper choice of antileishmanial therapy depends on the geographic location, host immune status, availability of the drug, and expertise of the treating physician. The present review summarizes the current treatment options available for cutaneous leishmaniasis as well as some drugs on the horizon that show promising results in the treatment of cutaneous leishmaniasis