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1.
J Air Waste Manag Assoc ; 2023 Feb 01.
Article in English | MEDLINE | ID: mdl-36722606

ABSTRACT

It is generally believed that bio-waste is a suitable substrate for valorizations through fermentation with biogas production. An increasing number of municipalities in Poland implement selective collection of bio-waste. Limited qualitative and quantitative data are available on the composition of household bio-waste, including the contaminant content. This paper presents the adopted research method and the analysis results of the composition of household bio-waste segregated at source from 4 rural and 4 urban communes, from districts with single-family and multi-family housing. Household bio-waste is mostly food waste (43.9 to 56.0%), with a smaller percentage of garden waste (27.4 to 46.3%). According to data from other countries, in Poland, 'fruit and vegetable' waste constitutes the main part of household bio-waste (from 40.0 to 53.8%). The share of "contaminants" is relatively high. The most contaminated waste is that collected in containers in city districts with multi-family housing (16.6%). The share of contaminants in bio-waste collected in bags (rural areas and cities with single-family housing exceeded 10.0%). Implications: This article presents the results of an empirical analysis of the morphological composition, occurring contaminants and seasonal fluctuations in the stream of biodegradable waste delivered to the mechanical-biological treatment (MBT) installation in Marszow (Poland, Lubuskie province). This installation serves the area of 22 municipalities with more than 200.000 residents. Nearly 98% of households and housing estates are covered by regular waste collection. The study covered 12 streams of bio-waste delivered to the installation, divided into rural and urban areas with single-family and multi-family housing during the 2 seasons of autumn and winter. The importance of the conducted research is emphasized by the fact that the analysis of the morphological composition of bio-waste generated in households is rare, which is probably due to its labor- and time-consuming nature. The data obtained are a source of valuable information for both national and local governments, as well as can help meet the ambitious targets set for EU member states in terms of preparing for reuse and recycling of municipal waste, which are unlikely to be achieved without proper management of bio-waste. Another important argument is to reduce food waste in line with the sustainable development goal of reducing food waste by 50% by 2030.

2.
Environ Res ; : 115320, 2023 Jan 24.
Article in English | MEDLINE | ID: mdl-36706904

ABSTRACT

The present study examines food-waste (FW) and agriculture compost media (ACM) as cultivation media for D. armatus in conjunction with the bold basal medium (BBM). The microalgae cultivated in different dilutions of organic (FW or ACM) and inorganic (BBM) offered promising results at 3:1 (organic, FW or ACM: inorganic, BBM) dilution for one month. The 3:1 diluted mediums were further utilized for macromolecules production, which revealed the highest lipid (99,200 µg/ml), protein (112.5 µg/ml), and carbohydrate (8.75 µg/ml) with the ACM dilution, BBM, and FW dilution media, respectively. The fabricated growth kinetics and dynamics through "biofermentor" tool resulted in unstructured models of different growth phases of microalgae and algal growth kinetic parameters such as µmax, XLimst, and RFin. Overall, the study proposes a cleaner approach of utilizing the wastes as algal growth media through a circular economy approach which eventually reduces the algal growth media cost by environ-threat CO2 sequestration and biocommodities production capabilities.

3.
Front Microbiol ; 13: 1095497, 2022.
Article in English | MEDLINE | ID: mdl-36699587

ABSTRACT

Background: Anaerobic digestion (AD) is important in treating of food waste, and thousands of metagenome-assembled genomes (MAGs) have been constructed for the microbiome in AD. However, due to the limitations of the short-read sequencing and assembly technologies, most of these MAGs are grouped from hundreds of short contigs by binning algorithms, and the errors are easily introduced. Results: In this study, we constructed a total of 60 non-redundant microbial genomes from 64.5 Gb of PacBio high-fidelity (HiFi) long reads, generated from the digestate samples of a full-scale biogas plant fed with food waste. Of the 60 microbial genomes, all genomes have at least one copy of rRNA operons (16S, 23S, and 5S rRNA), 54 have ≥18 types of standard tRNA genes, and 39 are circular complete genomes. In comparison with the published short-read derived MAGs for AD, we found 23 genomes with average nucleotide identity less than 95% to any known MAGs. Besides, our HiFi-derived genomes have much higher average contig N50 size, slightly higher average genome size and lower contamination. GTDB-Tk classification of these genomes revealed two genomes belonging to novel genus and four genomes belonging to novel species, since their 16S rRNA genes have identities lower than 95 and 97% to any known 16S rRNA genes, respectively. Microbial community analysis based on the these assembled genomes reveals the most predominant phylum was Thermotogae (70.5%), followed by Euryarchaeota (6.1%), and Bacteroidetes (4.7%), and the most predominant bacterial and archaeal genera were Defluviitoga (69.1%) and Methanothrix (5.4%), respectively. Analysis of the full-length 16S rRNA genes identified from the HiFi reads gave similar microbial compositions to that derived from the 60 assembled genomes. Conclusion: High-fidelity sequencing not only generated microbial genomes with obviously improved quality but also recovered a substantial portion of novel genomes missed in previous short-read based studies, and the novel genomes will deepen our understanding of the microbial composition in AD of food waste.

4.
Cities ; 135: 104199, 2023 Apr.
Article in English | MEDLINE | ID: mdl-36694707

ABSTRACT

Global food systems are broken and in need of profound change. These imbalances and vulnerabilities are particularly strong in cities, where most of the global population lives and that are at the core of the major challenges linked with food production and consumption. The food system transition needs cities as key game-changers towards more sustainable, equitable, healthier and fairer food systems. Against this backdrop, the present article analyses the role of food policies within urban policies, with a focus on Italian cities. In particular, the article discusses data collected from representatives of 100 municipalities across Northern, Central and Southern Italy. Moreover, it addresses the types of policies and initiatives adopted at the local level, the main obstacles encountered, the role of national and international city networks and the impact of Covid-19 on urban food security, with the aim to identify potential models of urban food policies as a structural component of a broader urban agenda. By doing this, the article aims at filling a research gap in current literature, as it is the first large-scale survey on urban food policies in Italy, identifying models of urban food policies that are already being developed within broader urban development agendas.

5.
Biomass Convers Biorefin ; : 1-17, 2023 Jan 17.
Article in English | MEDLINE | ID: mdl-36683845

ABSTRACT

The abundance of food waste across the globe has called for the mitigation and reduction of these discarded wastes. Herein, the potential of biochar derived from food waste is unquestionable as it provides a sustainable way of utilizing the abundance of available biomass, as well as an effective way of preserving the ecosystem through the reduction of concerning environmental issues. This review focuses on the food waste-based biochar as advanced electrode materials in the energy storage devices. Efforts have been made to present and discuss the current exploration of the food waste utilization, along with the biochar production technologies through thermochemical conversion, including combustion, gasification, and pyrolysis method. Finding its limitation in literatures, discussion on the food waste-based biochar fabrication method as the electrode materials is elaborated, alongside the current food waste-based biochar that has been explored in the energy application thus far. Towards the end, the outlook and perspective on the further development of food waste-based biochar have been outlined.

6.
Food Chem ; 411: 135486, 2023 Jan 16.
Article in English | MEDLINE | ID: mdl-36682163

ABSTRACT

The existing QuEChERS-combined analytical pretreatment methods are limited by large reagent consumption, high environmental burden, and mediocre effects. To provide an efficient and green pretreatment method, this study developed pH-responsive switchable deep eutectic solvents (SDESs) to extract triazole fungicides (TFs) from fruit peel wastes, which could enhance the preconcentration effect of target compounds in food waste samples with complex matrices. The mechanisms of pH-induced phase transition and hydrophobicity-hydrophilicity conversion of pH-responsive SDESs were investigated by pH phase diagrams and chemical characterization techniques, respectively. We validated the established method by high-performance liquid chromatography-diode array detector (HPLC-DAD), and lower LOD (0.089-0.351 ng mL-1), LOQ (0.297-1.172 ng mL-1), RSD (≤8.8 %) and satisfactory recoveries (90.6 %-110.9 %) and preconcentration factors (389-512) were obtained in rotting grape peel, watermelon peel, and orange peel samples. Our findings highlight the potential of pH-responsive SDESs in the extraction and analysis of various natural food products.

7.
Nutrients ; 15(2)2023 Jan 06.
Article in English | MEDLINE | ID: mdl-36678172

ABSTRACT

There is evidence that hospital waste is indisputably high, and various strategies have been used to reduce the hospital's rate of plate waste. This study aimed to map the currently implemented strategies in lowering the rate of plate waste in hospitals and categorize the different types of strategies used as interventions, as well as determine their impact based on specific parameters. The scoping review method included a search of three databases using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA-SCR). The duplicate articles (n = 80) were removed. A total of 441 articles remained for the title and abstract screening. After 400 were excluded, 41 articles were reviewed for eligibility. Thirty-two full articles were eliminated due to a lack of focus on plate waste evaluation. Finally, nine accepted studies were grouped into five categories: menu modification, room service implementation, menu presentation, meal-serving system, and dietary monitoring tool. In conclusion, results showed that the majority of the studies implemented either of the five strategies to reduce plate waste; however, the cook-freeze system and staff training for both kitchen and ward staff were not yet part of any intervention strategy. The potential of this method should be explored in future interventions.


Subject(s)
Diet , Meals , Humans , Hospitals
8.
Nutrients ; 15(2)2023 Jan 07.
Article in English | MEDLINE | ID: mdl-36678180

ABSTRACT

BACKGROUND AND AIMS: Patients' nutritional intake is a crucial issue in modern hospitals, where the high prevalence of disease-related malnutrition may worsen clinical outcomes. On the other hand, food waste raises concerns in terms of sustainability and environmental burden. We conducted a systematic review to ascertain which hospital services could overcome both issues. METHODS: A systematic literature search following PRISMA guidelines was conducted across MEDLINE, Web of Science, and Scopus for randomised controlled trials (RCTs) and observational studies comparing the effect of hospital strategies on energy intake, protein intake, and plate/food waste. The quality of included studies was assessed using the Newcastle-Ottawa Scale for cohort studies and the Cochrane Risk of Bias tool from the Cochrane Handbook for Systematic Reviews of Interventions for RCTs. RESULTS: Nineteen studies were included, assessing as many hospital strategies such as food service systems-including catering and room service-(n = 9), protected mealtimes and volunteer feeding assistance (n = 4), food presentation strategies (n = 3), nutritional counseling and education (n = 2), plant-based proteins meal (n = 1). Given the heterogeneity of the included studies, the results were narratively analysed. CONCLUSIONS: Although the results should be confirmed by prospective and large sample-size studies, the personalisation of the meal and efficient room service may improve nutritional intake while decreasing food waste. Clinical nutritionist staff-especially dietitians-may increase food intake reducing food waste through active monitoring of the patients' nutritional needs.


Subject(s)
Eating , Malnutrition , Humans , Energy Intake , Malnutrition/prevention & control , Meals/psychology , Hospitals
9.
Bioresour Technol ; 371: 128644, 2023 Mar.
Article in English | MEDLINE | ID: mdl-36681346

ABSTRACT

This study investigated the performance and mechanisms of intermittent aeration to regulate gaseous emission and humification during food waste digestate composting. In addition to continuous aeration, three intermittent aeration regimes were conducted with the on-off interval ratio at 3:1, 2:1, and 1:1 within each 30 min, respectively. Results showed that intermittent aeration regimes reduced gaseous emission and enhanced humification during composting. In particular, intermittent aeration with the on/off ratio of 1:1 was more effective to reduce organic mineralization than other regimes, which alleviated the emission of nitrous oxide and ammonia by 63.1% and 75.7% in comparison with continuous aeration, respectively. In addition, this aeration regime also enhanced the content of humic acid by 24.1%. Further analysis demonstrated that prolonging aeration-off intervals could enrich facultative bacteria (e.g. Atopobium and Clostridium) from digestate and inhibit the proliferation of several aerobic bacteria (e.g. Caldicoprobacter and Marinimicrobium) to retard organic mineralization for humification.


Subject(s)
Composting , Refuse Disposal , Gases , Refuse Disposal/methods , Food , Soil
10.
Antioxidants (Basel) ; 12(1)2022 Dec 27.
Article in English | MEDLINE | ID: mdl-36670916

ABSTRACT

Ingredients rich in phenolic compounds and antioxidants of winemaking wastes, which play an important role in the prevention of various diseases and the control of viruses, are being explored. Currently, there is a concern about honeybee population loss, with deformed wing virus (DWV) being the most common virus infecting apiaries and one of the main causes of honeybee decline. Hence, the effect of grape pomace powder (GPP) as a dietary supplement to enhance the immune system of honeybees affected by DWV was evaluated. The characteristics of the ingredient GPP, obtained by spray-drying, revealed a high anthocyanin content (1102.45 mg 100 g-1), and it was applied at doses of 0.5, 1, 2.5 and 5% as a dietary supplement for bees infected by DWV. The results showed that the GPP treatments strengthened the immune response of honeybees against DWV. Moreover, the expression of the Relish gene was significantly higher in bees fed with GPP compared to the infected control. This study, which is framed in the search of food waste valorization for environmental sustainability, proves the feasibility of using grape wastes as dietary supplements for pollinators, and provides knowledge of the influence of polyphenols on the expression profiles of immune-related genes in honeybees.

11.
Antioxidants (Basel) ; 12(1)2023 Jan 09.
Article in English | MEDLINE | ID: mdl-36671016

ABSTRACT

Myrtle liqueur production generates high amounts of by-products that can be employed for the extraction of bioactive compounds. Bio-based, non-toxic and biodegradable solvents (ethyl acetate and 2-methyltetrahydrofuran), and a mechanical extraction were applied to myrtle seeds, by-products of the liqueur production, to extract oils rich in phenolic compounds. The oils obtained were characterized for yield, peroxide value (PV), lipid composition, and total phenolic concentration (TPC). The phenolic profile of the oils, determined by LC-MS, the antioxidant activity, and the oxidative stability were also analyzed. A validated UHPLC-ESI-QTRAP-MS/MS analytical method in multiple reaction monitoring (MRM) mode was applied to quantify myricetin and its main derivatives in myrtle oils. The results pointed out clear differences among extraction methods on myricetin concentration. The oxidative stability of myrtle oils was studied with electron paramagnetic resonance (EPR) spectroscopy highlighting the effect of the extraction method on the oxidation status of the oils and the role of phenolic compounds in the evolution of radical species over time. A principal component analysis applied to LC-MS data highlighted strong differences among phenolic profiles of the oils and highlighted the role of myricetin in the oxidative stability of myrtle oils. Myrtle oil, obtained from the by-products of myrtle liqueur processing industry, extracted with sustainable and green methods might have potential application in food or cosmetic industries.

12.
Environ Sci Pollut Res Int ; 2023 Jan 19.
Article in English | MEDLINE | ID: mdl-36656472

ABSTRACT

The present study used Chrysomya megacephala larvae (CML) to transform food waste into safe and high-quality fish feed to substitute fish meal as a source of protein for growing Oujiang color common carps followed by a human health risk assessment of polycyclic aromatic hydrocarbons (PAHs). The results showed the ∑PAH concentration in the CML fed with food waste ranged from 50 to 370 µg kg-1, and the most abundant PAH compound in the CML was BaP, contributing 59-84% of ∑PAHs. The Pearson correlation analysis results indicated no correlation between the ∑PAH concentrations and the culture substrate ratio (p > 0.05). Concentrations of BaP in the CML decreased with the increase of breeding density (p < 0.01). The residues as organic fertilizers have no potential ecological risk for PAHs. The biotransformed larva meal was used to partially or completely replace the fish meal as supplementary protein in the experimental feeds (T0, 0%; T50, 50%; T100, 100%). No significant difference (p < 0.05) of survival rate, lipid, and protein content in Oujiang color common carp was noted among T0, T50, and T100 fish feeds. Concentrations of ∑PAHs in Oujiang color common carp fed with the CML fish feeds all met the food safety standards in the European Union (EU). Furthermore, the consumption of Oujiang color common carps fed with the CML feed does not pose any health risks of PAHs for humans.

13.
Bioresour Technol ; 371: 128633, 2023 Mar.
Article in English | MEDLINE | ID: mdl-36657585

ABSTRACT

The effects of zero-valent iron (ZVI) and iron oxides nanoparticles on anaerobic digestion (AD) performance of food waste (FW) were comparably clarified in this study. Results indicated that the nanoparticles supplement effectively enhanced the methane yields. As observed, these nanoparticles accelerated organics transformation and alleviated acidification process. Also, the enriched total methanogens and functional bacteria (e.g., Proteiniphilum) were consistent with the promotion of oxidative phosphorylation, citrate cycle, coenzymes biosynthesis and the metabolisms of amino acid, carbohydrate, methane. Additionally, these nanoparticles stimulated electron transfer potential via enriching syntrophic genera (e.g., Geobacter, Syntrophomonas), primary acetate-dependent methanogens (Methanosaeta, Methanosarcina) and related functions (pilus assembly protein, ferredoxins). By comparison, ZVI nanoparticle presented the excellent performance on methanogenesis. This study provides comprehensive understanding of the methanogenesis facilitated by ZVI and iron oxides nanoparticles through the enhancement of key microbes and microbial metabolisms, while ZVI is an excellent option for promoting the methane production.


Subject(s)
Microbiota , Refuse Disposal , Iron/chemistry , Anaerobiosis , Bioreactors , Sewage/microbiology , Methane/metabolism , Dietary Supplements , Oxides
14.
Sci Total Environ ; 868: 161645, 2023 Jan 16.
Article in English | MEDLINE | ID: mdl-36657683

ABSTRACT

Empirical research is required to identify psychological and psychographic factors which can activate or amplify norms of foodservice customers towards food waste reduction. By surveying 446 foodservice customers in Poland, a country with a large population of religion followers, this study examines the influence of religious values on personal norms and explores the moderating effect of social distance on injunctive norms. The results indicate that religious values do not activate personal norms directly but affect them indirectly via such mediating factors as the feeling of compassion and family upbringing. Close encounters, such as family and friends, amplify the effect of injunctive norms while distant encounters, such as fellow countrymen, do not. This suggests that measures for food waste reduction should be designed to appeal to the foodservice customers' feeling of compassion. The measures should also remind foodservice customers that their (grand)parents and friends would disprove food waste.

15.
Sci Total Environ ; : 161550, 2023 Jan 15.
Article in English | MEDLINE | ID: mdl-36652966

ABSTRACT

Valorization and utilization of industrial food processing waste as value added products, platform chemicals and biofuels, are needed to improve sustainability and reduce waste management costs. Various industrial food waste stream samples were characterized with respect to their physico-chemical characteristics and elemental composition. A subset of starchy food wastes and milk dust powder were evaluated in batch fermentation to acetone, a useful platform chemical. Production levels were similar to acetone produced from glucose but were achieved more quickly. Lactose concentration negatively affected fermentation and led to 50 % lower acetone concentration from milk dust powder than from starchy wastes. Uncooked starch waste can produce 20 % more acetone than cooked and modified starch waste. Fatty waste and mineral waste can be digested anaerobically generating biogas. Calorific value of soybean waste was 40 MJ/kg sufficiently high for biodiesel production. Low C/N ratios of wastewater and solids from food processing waste makes them unsuitable for anaerobic digestion but these waste types can be converted thermochemically to hydrochar and used as soil amendments. Low calorific content (10-15 MJ/kg) vegetable wastes also are not ideal for energy production, but are rich in flavonoids, antioxidants and pigments which can be extracted as valuable products. A model mapping food waste characteristics to best valorization pathway was developed to guide waste management and future cost and environmental impact analyses. These findings will help advance food industry knowledge and improve sustainable food production through valorized processing waste management.

16.
Chemosphere ; 317: 137822, 2023 Jan 14.
Article in English | MEDLINE | ID: mdl-36649897

ABSTRACT

Food demand is expected to increase globally by 60-110% from 2005 to 2050 due to diet shifts and population growth. This growth in food demand leads to the generation of enormous agri-food wastes (AFWs), which could be classified into pre-consumption and post-consumption. The AFW represents economic losses for all stakeholders along food supply chains, including consumers. It is reported that the direct financial, social, and environmental costs of food waste are 1, 0.9, and 0.7 trillion USD/year, respectively. Diverse conventional AFW management approaches are employed at the different life cycle levels (entre supply chain). The review indicates that inadequate transportation, erroneous packaging, improper storage, losses during processing, contamination, issues with handling, and expiry dates are the main reason for the generation of AFWs in the supply chain. Further, various variables such as cultural, societal, personal, and behavioral factors contribute to the AFW generation. The selection of a specific valorization technology is based on multiple physicochemical and biological parameters. Furthermore, other factors like heterogeneity of the AFWs, preferable energy carriers, by-products management, cost, end-usage applications, and environmental legislative and disposal processes also play a crucial role in adopting suitable technology. Valorization of AFW could significantly impact both economy and the environment. AFWs have been widely investigated for the development of engineered added-value biomaterials and renewable energy production. Considering this, this study has been carried out to highlight the significance of AFW cost, aggregation, quantification, and membrane-based strategies for its management. The study also explored the satellite remote sensing data for Spatio-temporal monitoring, mapping, optimization, and management of AFW management. Along with this, the study also explained the most recent strategies for AFW valorization and outlined the detailed policy recommendation along with opportunities and challenges. The review suggested that AFW should be managed using a triple-bottom-line strategy (economic, social, and environmental sustainability).

17.
Int J Food Microbiol ; 388: 110069, 2022 Dec 31.
Article in English | MEDLINE | ID: mdl-36640563

ABSTRACT

Microorganisms have been extensively studied and used to produce a wide range of enzymes and bioactive substances for a number of uses. Cellulases have also been widely used for a variety of bioprocessing and biotransformation purposes and are acknowledged as the essential enzymes for industrial applications. Broad industrial applications and huge demand essentially require mass-scale and low-cost production of cellulase enzyme. Nevertheless, low-cost production of cellulase enzyme at industrial-level finds certain issues, and this may be mainly associated with the unavailability of cheap and effective substrate to be utilized in fermentation process. In this context, cellulosic wastes are counted as one of the suitable bioresources and have been well explored for low-cost and highly efficient cellulase enzyme productions. Further, banana peels waste is considered as the high cellulose & sugar containing food wastes which is renewable and hugely available worldwide. Therefore, the present review explores the possible utilizations of banana peels as a potential food waste to be employed as substrate to produce cellulase enzymes. Availability and compositional analysis of banana peels has been explored for the microbial cellulase production based on reported studies. Further, this review explores the applications of cellulase enzymes as antimicrobial agents. Based on the available studies and their evaluation, potential limitations and future suggestions for the production of cellulase enzymes and their applications as antibacterial agents have been provided, which have a high potential for numerous biomedical applications and may offer a new opportunity for industrial utility.

18.
Chemosphere ; 316: 137786, 2023 Mar.
Article in English | MEDLINE | ID: mdl-36634716

ABSTRACT

The by-product from the anaerobic digestion of food waste (FW) called the digestate (DFW) needs proper disposal because of its high environmental burden. Composting can transform DFW into a nutrient-containing soil improver via a series of microbial metabolic activities. However, the long composting time and high amount of ammonia emission are the key concerns of DFW composting. In the present study, the effect of DFW-derived biochar (BC-DFW) on microbial succession and its involvement in nitrogen transformation and humification during DFW composting were investigated. The results indicated that the BC-DFW accelerated bacterial and fungal evolution, and the bacterial diversity was augmented by increasing the amount of BC-DFW. In particular, Cryomorpha, Castellaniella, Aequorivita, and Moheibacter were enriched by the addition of BC-DFW, thereby enhancing the degradation of organic matter and nitrogen transformation and increasing the germination index. The group with 25% BC-DFW contained a higher relative abundance of Cryomorpha (2.08%, 2.47%) than the control (0.39%, 1.72%) on days 19 and 35 which benefited the degradation of organic matter. The group with 25% BC-DFW quickly enhanced the growth of Nitrosomonas, thereby accelerating the conversion of ammonium-nitrogen to nitrate-nitrogen and reducing the phytotoxicity of the composting product.


Subject(s)
Composting , Microbiota , Refuse Disposal , Food , Soil , Nitrogen , Manure
19.
Bioresour Technol ; 371: 128601, 2023 Mar.
Article in English | MEDLINE | ID: mdl-36632852

ABSTRACT

The aim of this study was to remove the refractory organics from high-temperature anaerobic digestate food waste effluent by the coupling system of hydrolysis-acidification and denitrification. Iron-based materials (magnetite, zero-valent iron, and iron-carbon) were used to enhance the performance of thermophilic hydrolysis-acidification. Compared with the control group, magnetite had the best strengthening effect, increasing volatile fatty acids concentration and fluorescence intensity of easily biodegradable organics in the effluent by 47.6 % and 108.4 %, respectively. The coupling system of magnetite-enhanced thermophilic hydrolysis-acidification and denitrification achieved a nitrate removal efficiency of 91.2 % (influent NO3--N was 150 mg L-1), and reduced the fluorescence intensity of refractory organics by 33.8 %, compared with influent. Microbiological analysis indicated that magnetite increased the relative abundance of thermophilic hydrolytic acidifying bacteria, and coupling system enriched some genera simultaneously removing nitrate and refractory organics. This study provided fresh information on refractory organics and nitrogen removal of thermophilic wastewater biologically.


Subject(s)
Refuse Disposal , Waste Disposal, Fluid , Denitrification , Ferrosoferric Oxide , Food , Hydrolysis , Anaerobiosis , Nitrates , Bioreactors , Nitrogen , Iron , Hydrogen-Ion Concentration , Sewage/microbiology
20.
Waste Manag ; 158: 23-36, 2023 Jan 08.
Article in English | MEDLINE | ID: mdl-36628813

ABSTRACT

Bio-oil was generated from slow pyrolysis of cooked food waste (CFW) at various temperatures (300-500 °C). Then NMR analysis was used as a qualitative means to characterize the bio-oil for its nature (aliphatic or aromatic), and then the compounds were confirmed and quantified using the GC-MS. This analysis indicated that the pyrolysis at low temperature (300 °C) mainly generated carbonyl compounds (Aldehydes, Ketones, Esters, and Oxo groups), Levoglucosans, and Furans (17%, 24%, and 38%, respectively) considered as typical pyrolysis chemicals. Similarly, the pyrolysis at medium temperature (400 °C) generated other compounds that were present in significant quantity, including sugars, aliphatic compounds, nitrogen compounds, acids, phenolic compounds, and alcohols. However, their fraction decreased with an increase in pyrolysis temperature to 500 °C and the fraction of aromatics increased significantly (>60%). This aromatics fraction was much more than that in a bio-oil from typical biomass which can be attributed to distinctively different chemical characteristics of CFW due to presence of additional compounds such as starch, proteins, waxes and oils in CFW. Moreover, the composition of aromatic fraction was better because a very high percentage of aromatic ethers (>58%) e.g. Benzene, 1,3-bis (3-phenoxyphenoxy), was found at 500 °C which can be converted into aliphatic alkanes, aliphatic alcohols, aromatic derivatives and platform chemicals by means of catalyst addition.

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