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

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

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

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

Physicochemical, structural and combustion analyses to estimate the solid fuel efficacy of hydrochar developed by co-hydrothermal carbonization of food and municipal wastes

The application of a char derived from fruit peel waste and other municipal wastes as solid fuel depends on its physico-chemical properties. In this work, fruit peel waste (FW) along their mixture with facial tissue waste (FT) and wrapping paper waste (WP) as well as their respective hydrochars (FWHC, FTHC, and WPHC) produced via hydrothermal carbonization (HTC) was characterized in detail to ascertain their applicability as solid fuel. Moreover, the elemental O contents for FTHC and WPHC were about 12.8 and 5.1% respectively higher than FWHC. Heating value analysis indicated that WPHC had the highest HHV of 5164 kcal/kg. Combustion kinetic studies, carried out by thermogravimetric technique, revealed that about 33.78 kJ/mol of energy was required to generate a combustion reaction for WP, higher than the energy required to ignite WPHC (28.2 kJ/mol). The regression coefficient (R2) values were higher than 0.94, indicating that the Arrhenius equation could be used to model the sample combustion process. Overall, the study showed that Co-HTC of FW with paper-based municipal waste such FT and WP is an effective method of converting FW to a cleaner hydrochar (HC) with high calorific value and less sulphur content. Graphical abstract: [Figure not available: see fulltext.].This research was funded by National Plan for Science, Technology and Innovation (MAARIFAH), King Abdulaziz City for Science and Technology and Kingdom of Saudi Arabia, Award Number 14-ENV665-02

Hydrothermal Conversion of Food Waste to Carbonaceous Solid Fuel—A Review of Recent Developments

This review critically discussed recent developments in hydrothermal carbonization (HTC) of food waste and its valorization to solid fuel. Food waste properties and fundamentals of the HTC reactor were also covered. The review further discussed the effect of temperature, contact time, pressure, water–biomass ratio, and heating rate on the HTC of food waste on the physiochemical properties of hydrochar. Literature review of the properties of the hydrochar produced from food waste in different studies shows that it possesses elemental, proximate, and energy properties that are comparable to sub-bituminous coal and may be used directly as fuel or co-combusted with coal. This work conclusively identified the existing research gaps and provided recommendation for future investigations

Towards superior permeability and antifouling performance of sulfonated polyethersulfone ultrafiltration membranes modified with sulfopropyl methacrylate functionalized SBA-15

A non-solvent induced phase separation (NIPS) process was used to fabricate a series of sulfonated polyethersulfone (SPES) membranes blending with different concentrations of SBA-15-g-PSPA with the applications in the ultrafiltration (UF) process. SBA-15 was modified with 3-methacrylate-propyltrimethoxysilane (MPS) to form SBA-15-g-MPS. It was further modified with the charge tailorable polymer chains by reacting with 3-sulfopropyl methacrylate potassium salt. The nanoparticles were uniformly dispersed and finger-like channels were developed within the membrane. The adding of surface modified SBA-15-g-PSPA nanoparticles has significantly improved membrane water permeability, hydrophilicity, and antifouling properties. The pure water fluxes of the composite SPES membranes were significantly higher than the pristine SPES membrane. For the membrane containing 5% (mass) of SBA-15-g-PSPA (MSSPA5), the pure water flux was increased dramatically to 402.15 L·m−2·h−1, which is ∼1.5 times that of MSSPA0 (268.0 L·m−2·h−1). The high flux rate was achieved with 3% (mass) of SBA-15 nanoparticles with retained high rejection ratio 98% for natural organic matter. The results indicate that the fashioned composite membrane comprising SBA-15-g-PSPA nanoparticles have a promising future in ultrafiltration applications

Integrated approach in treatment of solid olive residue and olive wastewater

Generally olive oil generated two forms of waste by-products: solid olive residue (SOR) and olive wastewater (OWW). In the present study a promising solution is given to treat both SOR and OWW waste by-products. The first process consists of converting the solid olive residue to activated carbon using pyrolysis process at 600 °C, followed by steam activation procedure at three different temperatures. The attained activated carbon was examined by different experimental techniques such as FTIR, SEM, BET and iodine number. The surface area was increased by increasing stream activation temperature (reach 1020 m ^2 g ^−1 BET). However, the steam activation at 700 °C was found to be ideal for environmental and economic performance. On the other hand, the activated carbon at 700 °C displayed high removal capacity of both polyphenolic compounds and COD from olive wastewater. In fact, after 2 h of treatment, 95.5% of COD and 84.2% of polyphenolic compounds were completely removed