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1.
Small ; 20(43): e2402649, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-38949403

RESUMO

The utilization of the organic-inorganic hybrid photocatalysts for water splitting has gained significant attention due to their ability to combine the advantages of both materials and generate synergistic effects. However, they are still far from practical application due to the limited understanding of the interactions between these two components and the complexity of their preparation process. Herein, a facial approach by combining a glycolated conjugated polymer with a TiO2-X mesoporous sphere to prepare high-efficiency hybrid photocatalysts is presented. The functionalization of conjugated polymers with hydrophilic oligo (ethylene glycol) side chains can not only facilitate the dispersion of conjugated polymers in water but also promote the interaction with TiO2-X forming stable heterojunction nanoparticles. An apparent quantum yield of 53.3% at 365 nm and a hydrogen evolution rate of 35.7 mmol h-1 g-1 is achieved by the photocatalyst in the presence of Pt co-catalyst. Advanced photophysical studies based on femtosecond transient absorption spectroscopy and in situ, XPS analyses reveal the charge transfer mechanism at type II heterojunction interfaces. This work shows the promising prospect of glycolated polymers in the construction of hybrid heterojunctions for photocatalytic hydrogen production and offers a deep understanding of high photocatalytic performance by such heterojunction photocatalysts.

2.
Environ Sci Technol ; 58(6): 2598-2614, 2024 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-38291652

RESUMO

The widespread application of nanotechnology inevitably leads to an increased release of engineered nanoparticles (ENPs) into the environment. Due to their specific physicochemical properties, ENPs may interact with other contaminants and exert combined effects on the microbial community and metabolism of anaerobic digestion (AD), an important process for organic waste reduction, stabilization, and bioenergy recovery. However, the complicated interactions between ENPs and other contaminants as well as their combined effects on AD are often overlooked. This review therefore focuses on the co-occurrence of ENPs and cocontaminants in the AD process. The key interactions between ENPs and cocontaminants and their combined influences on AD are summarized from the available literature, including the critical mechanisms and influencing factors. Some sulfides, coagulants, and chelating agents have a dramatic "detoxification" effect on the inhibition effect of ENPs on AD. However, some antibiotics and surfactants increase the inhibition of ENPs on AD. The reasons for these differences may be related to the interactive effects between ENPs and cocontaminants, changes of key enzyme activities, adenosine triphosphate (ATP) levels, reactive oxygen species (ROS) production, and microbial communities. New scientific opportunities for a better understanding of the coexistence in real world situations are converging on the scale of nanoparticles.


Assuntos
Nanopartículas , Anaerobiose , Nanopartículas/química , Nanotecnologia , Espécies Reativas de Oxigênio
3.
Environ Sci Technol ; 58(21): 9272-9282, 2024 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-38749055

RESUMO

Triclocarban (TCC), as a widely used antimicrobial agent, is accumulated in waste activated sludge at a high level and inhibits the subsequent anaerobic digestion of sludge. This study, for the first time, investigated the effectiveness of microbial electrolysis cell-assisted anaerobic digestion (MEC-AD) in mitigating the inhibition of TCC to methane production. Experimental results showed that 20 mg/L TCC inhibited sludge disintegration, hydrolysis, acidogenesis, and methanogenesis processes and finally reduced methane production from traditional sludge anaerobic digestion by 19.1%. Molecular docking revealed the potential inactivation of binding of TCC to key enzymes in these processes. However, MEC-AD with 0.6 and 0.8 V external voltages achieved much higher methane production and controlled the TCC inhibition to less than 5.8%. TCC in the MEC-AD systems was adsorbed by humic substances and degraded to dichlorocarbanilide, leading to a certain detoxification effect. Methanogenic activities were increased in MEC-AD systems, accompanied by complete VFA consumption. Moreover, the applied voltage promoted cell apoptosis and sludge disintegration to release biodegradable organics. Metagenomic analysis revealed that the applied voltage increased the resistance of electrode biofilms to TCC by enriching functional microorganisms (syntrophic VFA-oxidizing and electroactive bacteria and hydrogenotrophic methanogens), acidification and methanogenesis pathways, multidrug efflux pumps, and SOS response.


Assuntos
Eletrólise , Anaerobiose , Esgotos/microbiologia , Metano/metabolismo , Carbanilidas/farmacologia
4.
Environ Sci Technol ; 58(22): 9792-9803, 2024 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-38780952

RESUMO

Anaerobic fermentation is a crucial route to realize effective waste activated sludge (WAS) resource recovery and utilization, while the overall efficiency is commonly restrained by undesirable disruptors (i.e., chemical dewatering agents). This work unveiled the unexpectedly positive effects of biodewatering tannic acid (TA) on the volatile fatty acids (VFAs) biosynthesis during WAS anaerobic fermentation. The total VFAs yield was remarkably increased by 15.6 folds with enriched acetate and butyrate in TA-occurred systems. TA was capable to disintegrate extracellular polymeric substances to promote the overall organics release. However, TA further modulated the soluble proteins structure by hydrogen bonding and hydrophobic interactions, resulting in the decrease of proteins bioavailability and consequential alteration of metabolic substrate feature. These changes reshaped the microbial community and stimulated adaptive regulatory systems in hydrolytic-acidogenic bacteria. The keystone species for carbohydrate metabolism (i.e., Solobacterium and Erysipelotrichaceae) were preferentially enriched. Also, the typical quorum sensing (i.e., enhancing substrate transport) and two-component systems (i.e., sustaining high metabolic activity) were activated to promote the microbial networks connectivity and ecological cooperative behaviors in response to TA stress. Additionally, the metabolic functions responsible for carbohydrate hydrolysis, transmembrane transport, and intracellular metabolism as well as VFA biosynthesis showed increased relative abundance, which maintained high microbial activities for VFAs biosynthesis. This study underscored the advantages of biodewatering TA for WAS treatment in the context of resource recovery and deciphered the interactive mechanisms.


Assuntos
Ácidos Graxos Voláteis , Fermentação , Esgotos , Taninos , Ácidos Graxos Voláteis/metabolismo , Esgotos/microbiologia , Taninos/metabolismo , Anaerobiose , Microbiota
5.
Environ Sci Technol ; 58(40): 17959-17969, 2024 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-39322606

RESUMO

Triclocarban (TCC), as a typical antimicrobial agent, accumulates at substantial levels in natural environments and engineered systems. This work investigated the impact of TCC on anaerobic sulfur transformation, especially toxic H2S production. Experimental findings revealed that TCC facilitated sulfur flow from the sludge solid phase to liquid phase, promoted sulfate reduction and sulfur-containing amino acid degradation, and largely improved anaerobic H2S production, i.e., 50-600 mg/kg total suspended solids (TSS) TCC increased the cumulative H2S yields by 24.76-478.12%. Although TCC can be partially biodegraded in anaerobic systems, the increase in H2S production can be mainly attributed to the effect of TCC rather than its degradation products. TCC was spontaneously adsorbed by protein-like substances contained in microbe extracellular polymers (EPSs), and the adsorbed TCC increased the direct electron transfer ability of EPSs, possibly due to the increase in the content of electroactive polymer protein in EPSs, the polarization of the amide group C═O bond, and the increase of the α-helical peptide dipole moment, which might be one important reason for promoting sulfur bioconversion processes. Microbial analysis showed that the presence of TCC enriched the organic substrate-degrading bacteria and sulfate-reducing bacteria and increased the abundances of functional genes encoding sulfate transport and dissimilatory sulfate reduction.


Assuntos
Enxofre , Enxofre/metabolismo , Anaerobiose , Biodegradação Ambiental , Carbanilidas/metabolismo
6.
Environ Sci Technol ; 58(18): 8043-8052, 2024 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-38648493

RESUMO

Bisphenol A (BPA), as a typical leachable additive from microplastics and one of the most productive bulk chemicals, is widely distributed in sediments, sewers, and wastewater treatment plants, where active sulfur cycling takes place. However, the effect of BPA on sulfur transformation, particularly toxic H2S production, has been previously overlooked. This work found that BPA at environmentally relevant levels (i.e., 50-200 mg/kg total suspended solids, TSS) promoted the release of soluble sulfur compounds and increased H2S gas production by 14.3-31.9%. The tryptophan-like proteins of microbe extracellular polymeric substances (EPSs) can spontaneously adsorb BPA, which is an enthalpy-driven reaction (ΔH = -513.5 kJ mol-1, ΔS = -1.60 kJ mol-1K -1, and ΔG = -19.52 kJ mol-1 at 35 °C). This binding changed the composition and structure of EPSs, which improved the direct electron transfer capacity of EPSs, thereby promoting the bioprocesses of organic sulfur hydrolysis and sulfate reduction. In addition, BPA presence enriched the functional microbes (e.g., Desulfovibrio and Desulfuromonas) responsible for organic sulfur mineralization and inorganic sulfate reduction and increased the abundance of related genes involved in ATP-binding cassette transporters and sulfur metabolism (e.g., Sat and AspB), which promoted anaerobic sulfur transformation. This work deepens our understanding of the interaction between BPA and sulfur transformation occurring in anaerobic environments.


Assuntos
Enxofre , Enxofre/metabolismo , Anaerobiose , Sulfeto de Hidrogênio/metabolismo , Fenóis/metabolismo , Compostos Benzidrílicos/metabolismo
7.
Environ Res ; 262(Pt 2): 119904, 2024 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-39270963

RESUMO

Global energy shortages and environmental crises underscore the imperative for a circular economy to tackle resource scarcity and waste management. The circular economy model encourages the recovery and reuse of valuable materials, reducing reliance on finite natural resources and lessening the environmental impact of waste disposal. Among urban organic solid wastes, waste activated sludge (WAS) emerges as a potent reservoir of untapped resources (including various inorganic and organic ones) offering significant potential for recovery. This review delves into a comprehensive analysis of directional valorization of WAS to recover high-valued products, including the inorganic matters (i.e. phosphorus, ammonia nitrogen, and heavy metals), organic resources (i.e. extracellular polymers like alginate and protein, volatile fatty acid, methane, hydrogen, and plant growth hormones) and reutilization of WAS residues for the preparation of adsorbent materials - the biochar. Moreover, the main recovery methodologies associated influencing parameters, product application, and attendant challenges for those diverse recovered resources are unveiled. Future research are encouraged to prioritize the development of integrated multi-resource recovery approaches, the establishment of regulatory frameworks to support resource recovery and product utilization, and the systematic evaluation of disposal strategies to foster a more sustainable and resource-efficient future. This work illuminates avenues for sustainable WAS management with high-valued resource recovery towards circular economy.

8.
BMC Geriatr ; 24(1): 471, 2024 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-38811904

RESUMO

BACKGROUND: In the current context of ageing, the field of smart elderly care has gradually developed, contributing to the promotion of health among older adults. While the positive impact on health has been established, there is a scarcity of research examining its impact on the quality of life (QoL). This study aims to investigate the mediating role of social support in the relationship between smart elderly care and QoL among older adults. METHODS: A total of 1313 older adults from Zhejiang Province, China, participated in the study. Questionnaires were used to collect data on participants' basic demographic information, smart elderly care, social support, and QoL. The descriptive analyses of the demographic characteristics and correlation analyses of the three variables were calculated. Indirect effects were tested using bootstrapped confidence intervals (CI). RESULTS: The analysis revealed a positive association between smart elderly care and social support (ß = 0.42, p < 0.01), as well as a positive correlation between social support and QoL (ß = 0.65, p < 0.01). Notably, social support emerged as an important independent mediator (effect size = 0.28, 95% bootstrap CI 0.24 to 0.32) in the relationship between smart elderly care and QoL. CONCLUSIONS: The results of this study underscore the importance of promoting the utilization of smart elderly care and improving multi-faceted social support for older adults, as these factors positively contribute to the overall QoL.


Assuntos
Qualidade de Vida , Apoio Social , Humanos , Idoso , Qualidade de Vida/psicologia , Feminino , Masculino , Idoso de 80 Anos ou mais , China/epidemiologia , Inquéritos e Questionários , Pessoa de Meia-Idade , Estudos Transversais , Serviços de Saúde para Idosos
9.
J Environ Manage ; 365: 121522, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38909576

RESUMO

Ofloxacin (OFL) is a commonly used antibiotic that can enter wastewater treatment plants and be adsorbed by the sludge, resulting in a high OFL concentration in sludge and affecting the subsequent sludge anaerobic digestion process. However, the micro mechanisms involved in this process have not been thoroughly studied. Therefore, this study focuses on the effect of OFL on the sludge anaerobic digestion of sludge to provide such support. The experimental results showed that the maximal methane yield decreased from 277.7 to 164.7 mL/g VSS with the OFL concentration increased from 0 to 300 mg/L. Additionally, OFL hindered the intermediate biochemical processes of hydrolysis, acidogenesis, acetogenesis, and acetoclastic methanogenesis. However, it promoted hydrogenotrophic methanogenesis process, using H2 as substrate, with the concentration of 300 mg/L OFL was 5.54 fold methane production of that in the control. Further investigation revealed that the negative effect of OFL was likely due to the induction of reactive oxygen species, which led to a decrease in cell activity and interference with the activity of key enzymes. Microbiological analysis revealed that OFL reduced the relative abundance of hydrolysis and acidogenesis bacteria, and Methanosaeta archaea, while increasing the relative abundance of hydrogenotrophic methanogenesis microorganism from 36.54% to 51.48% as the OFL concentration increase from 0 to 300 mg/L.


Assuntos
Metano , Ofloxacino , Esgotos , Esgotos/microbiologia , Metano/metabolismo , Anaerobiose , Hidrogênio/metabolismo , Archaea/metabolismo , Reatores Biológicos , Águas Residuárias
10.
J Environ Manage ; 360: 121159, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38759549

RESUMO

Intimately coupled photocatalysis and biodegradation (ICPB) system is a potential wastewater treatment technology, of which TiO2-based ICPB system has been widely studied. There are many ways to improve the degradation efficiency of the ICPB process, but no crystal facet engineering method has been reported yet. In this work, a new ICPB system coated with NaF-TiO2 exposing high energy facets was designed to degrade biorecalcitrant psychotropic drug - venlafaxine (VNF). Initially, the TiO2 crystal surface was modified with NaF, resulting in the formation of NaF-TiO2 with a 14.4% increase in the exposure ratio of (001). The contribution rate of ·OH was increased by 9.5%, and the contribution rate of h+ was increased by 33.2%. Next, NaF-TiO2 was loaded onto the surface of the sponge carrier, and then the ICPB system was constructed after about 15 days of biofilm formation. After the ICPB system was acclimated with VNF, the removal rate of COD decreased significantly (the lowest was 62.7%), but that of ammonia nitrogen remained at 50.5 ± 6.0% and the extracellular polymeric substance (EPS) secretion increased by 84.1 mg/g VSS. According to the high throughput results, at the phylum level, Proteobacteria and Chloroflexi together maintain the nitrogen removal capability and structural stability of the ICPB system. The relative abundance of Bacteroidota was significantly increased by 14.2%, suggesting that there may be some correlation between Bacteroidota and certain metabolites of the anti-depressant active ingredients. At the genus level, the Thauera (3.1%∼11.5%) is the major bacterial group that secretes EPS, protecting biofilm against external influences. Most of the changes in microorganisms are consistent with the decontamination properties and macroscopic appearance of EPS in the ICPB system. Finally, the degradation efficiency of ICPB system for VNF was investigated (92.7 ± 3.8%) and it was mostly through hydroxylation and demethylation pathways, with more small molecular products detected, providing the basis for biological assimilation of VNF. Collectively, the NaF-TiO2 based ICPB system would be lucrative for the future degradation of venlafaxine.


Assuntos
Biodegradação Ambiental , Biofilmes , Titânio , Cloridrato de Venlafaxina , Biofilmes/efeitos dos fármacos , Titânio/química , Cinética , Poluentes Químicos da Água/metabolismo , Poluentes Químicos da Água/química , Águas Residuárias/química , Catálise
11.
J Environ Manage ; 353: 120156, 2024 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-38281426

RESUMO

The construction and precise synthesis of materials based on functional and structural orientations have emerged as a pivotal platform in the field of environmental management. In this paper, an efficient and stable catalyst (RuLDH) was constructed to achieve this goal. RuLDH comprises individual Ru atoms that are uniformly dispersed on ZnAl-LDH, achieved by room temperature stirring. Remarkably, RuLDH exhibits exceptional performance under visible light, effectively triggering the photocatalytic degradation of tetracycline hydrochloride (TC) via peroxymonosulfate (PMS) with a remarkable efficiency of 100%, all while avoiding the generation of highly toxic intermediates. In addition, RuLDH0.2 demonstrated its utility in fluorescence detection of TC, showcasing commendable analytical performance characterized by rapid response, low detection limit, and robust resistance to environmental interferences (with a detection limit of 1.0 mg/L). Notably, the RuLDH0.2/PMS/Vis system exhibited remarkable efficacy in treating actual pesticide wastewater, effectively exerting bactericidal and disinfectant effects. This study serves as a source of inspiration for the design of multifunctional single-atom catalysts, thereby pushing the boundaries of "integration of diagnosis and treatment" in environmental management and control.


Assuntos
Desinfetantes , Rutênio , Antibacterianos/farmacologia , Tetraciclina , Peróxidos
12.
Molecules ; 29(13)2024 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-38999048

RESUMO

Self-powered photoelectrochemical (PEC) ultraviolet photodetectors (UVPDs) are promising for next-generation energy-saving and highly integrated optoelectronic systems. Constructing a heterojunction is an effective strategy to increase the photodetection performance of PEC UVPDs because it can promote the separation and transfer of photogenerated carriers. However, both crystal defects and lattice mismatch lead to deteriorated device performance. Here, we introduce a structural regulation strategy to prepare TiO2 anatase-rutile heterophase homojunctions (A-R HHs) with oxygen vacancies (OVs) photoanodes through an in situ topological transformation of titanium metal-organic framework (Ti-MOF) by pyrolysis treatment. The cooperative interaction between A-R HHs and OVs suppresses carrier recombination and accelerates carrier transport, thereby significantly enhancing the photodetection performance of PEC UVPDs. The obtained device realizes a high on/off ratio of 10,752, a remarkable responsivity of 24.15 mA W-1, an impressive detectivity of 3.28 × 1011 Jones, and excellent cycling stability. More importantly, under 365 nm light illumination, a high-resolution image of "HUST" (the abbreviation of Harbin University of Science and Technology) was obtained perfectly, confirming the excellent optical imaging capability of the device. This research not only presents an advanced methodology for constructing TiO2-based PEC UVPDs, but also provides strategic guidance for enhancing their performance and practical applications.

13.
Environ Sci Technol ; 57(16): 6387-6402, 2023 04 25.
Artigo em Inglês | MEDLINE | ID: mdl-37052478

RESUMO

Water-soluble synthetic polymers (WSPs) are distinct from insoluble plastic particles, which are both critical components of synthetic polymers. In the history of human-made macromolecules, WSPs have consistently portrayed a crucial role and served as the ingredients of a variety of products (e.g., flocculants, thickeners, solubilizers, surfactants, etc.) commonly used in human society. However, the environmental exposures and risks of WSPs with different functions remain poorly understood. This paper provides a critical review of the usage, environmental fate, environmental persistence, and biological consequences of multiple types of WSPs in commercial and industrial production. Investigations have identified a wide market of applications and potential environmental threats of various types of WSPs, but we still lack the suitable assessment tools. The effects of physicochemical properties and environmental factors on the environmental distribution as well as the transport and transformation of WSPs are further summarized. Evidence regarding the degradation of WSPs, including mechanical, thermal, hydrolytic, photoinduced, and biological degradation is summarized, and their environmental persistence is discussed. The toxicity data show that some WSPs can cause adverse effects on aquatic species and microbial communities through intrinsic toxicity and physical hazards. This review may serve as a guide for environmental risk assessment to help develop a sustainable path for WSP management.


Assuntos
Purificação da Água , Água , Humanos , Abastecimento de Água , Polímeros , Plásticos
14.
Environ Sci Technol ; 57(8): 3145-3155, 2023 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-36795785

RESUMO

1-Butyl-3-methylimidazolium chloride (BmimCl), an imidazolium-based ionic liquid, is considered the representative emerging persistent aquatic pollutant, and its environmental toxicity has attracted a growing concern. However, most of the investigations focused on monocultures or a single organism, with little information available on the complex syntrophic consortium that dominates the complex and successional biochemical processes, such as anaerobic digestion. In this study, the effect of BmimCl at environmentally relevant levels on glucose anaerobic digestion was therefore investigated in several laboratory-scale mesophilic anaerobic digesters to provide such support. Experimental results showed that BmimCl at 1-20 mg/L inhibited the methane production rate by 3.50-31.03%, and 20 mg/L BmimCl inhibited butyrate, hydrogen, and acetate biotransformation by 14.29%, 36.36%, and 11.57%, respectively. Toxicological mechanism studies revealed that extracellular polymeric substances (EPSs) adsorbed and accumulated BmimCl through carboxyl, amino, and hydroxyl groups, which destroyed the EPSs' conformational structure, thereby leading to the inactivation of microbial cells. MiSeq sequencing data indicated that the abundance of Clostridium_sensu_stricto_1, Bacteroides, and Methanothrix decreased by 6.01%, 7.02%, and 18.45%, respectively, in response to 20 mg/L BmimCl. Molecular ecological network analysis showed that compared with the control, the lower network complexity, fewer keystone taxa, and fewer associations among microbial taxa were found in the BmimCl-present digester, indicating the reduced stability of the microbial community.


Assuntos
Microbiota , Anaerobiose , Sobrevivência Celular , Imidazóis/química , Reatores Biológicos , Metano , Esgotos/química
15.
Environ Sci Technol ; 57(43): 16673-16684, 2023 10 31.
Artigo em Inglês | MEDLINE | ID: mdl-37862695

RESUMO

Nitrite (NO2-) accumulation caused by nitrite-oxidizing bacteria (NOB) inhibition in nitrification is a double-edged sword, i.e., a disaster in aquatic environments but a hope for innovating nitrogen removal technology in wastewater treatment. However, little information is available regarding the molecular mechanism of NOB inhibition at the cellular level. Herein, we investigate the response of NOB inhibition on NO2- accumulation established by a side-stream free ammonia treatment unit in a nitrifying reactor using integrated metagenomics and metaproteomics. Results showed that compared with the baseline, the relative abundance and activity of NOB in the experimental stage decreased by 91.64 and 68.66%, respectively, directly resulting in a NO2- accumulation rate of 88%. Moreover, RNA polymerase, translation factors, and aa-tRNA ligase were significantly downregulated, indicating that protein synthesis in NOB was interfered during NO2- accumulation. Further investigations showed that ribosomal proteins and GTPases, responsible for bindings between either ribosomal proteins and rRNA or ribosome subunits, were remarkably downregulated. This suggests that ribosome biogenesis was severely disrupted, which might be the key reason for the inhibited protein synthesis. Our findings fill a knowledge gap regarding the underlying mechanisms of NO2- accumulation, which would be beneficial for regulating the accumulation of NO2- in aquatic environments and engineered systems.


Assuntos
Nitritos , Dióxido de Nitrogênio , Nitritos/metabolismo , Reatores Biológicos/microbiologia , Nitrificação , Bactérias/genética , Bactérias/metabolismo , Amônia/metabolismo , Nitrogênio/metabolismo , Oxirredução , Proteínas Ribossômicas/metabolismo , Ribossomos/metabolismo , Esgotos/microbiologia
16.
Environ Sci Technol ; 57(17): 6761-6775, 2023 05 02.
Artigo em Inglês | MEDLINE | ID: mdl-37070716

RESUMO

The recovery of biomass energy from food waste through anaerobic digestion as an alternative to fossil energy is of great significance for the development of environmental sustainability and the circular economy. However, a substantial number of food additives (e.g., salt, allicin, capsaicin, allyl isothiocyanate, monosodium glutamate, and nonnutritive sweeteners) are present in food waste, and their interactions with anaerobic digestion might affect energy recovery, which is typically overlooked. This work describes the current understanding of the occurrence and fate of food additives in anaerobic digestion of food waste. The biotransformation pathways of food additives during anaerobic digestion are well discussed. In addition, important discoveries in the effects and underlying mechanisms of food additives on anaerobic digestion are reviewed. The results showed that most of the food additives had negative effects on anaerobic digestion by deactivating functional enzymes, thus inhibiting methane production. By reviewing the response of microbial communities to food additives, we can further improve our understanding of the impact of food additives on anaerobic digestion. Intriguingly, the possibility that food additives may promote the spread of antibiotic resistance genes, and thus threaten ecology and public health, is highlighted. Furthermore, strategies for mitigating the effects of food additives on anaerobic digestion are outlined in terms of optimal operation conditions, effectiveness, and reaction mechanisms, among which chemical methods have been widely used and are effective in promoting the degradation of food additives and increasing methane production. This review aims to advance our understanding of the fate and impact of food additives in anaerobic digestion and to spark novel research ideas for optimizing anaerobic digestion of organic solid waste.


Assuntos
Alimentos , Eliminação de Resíduos , Esgotos , Aditivos Alimentares , Anaerobiose , Reatores Biológicos , Metano
17.
J Environ Manage ; 343: 118203, 2023 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-37235988

RESUMO

Quaternary ammonium compounds (QACs) was frequently detected in wastewater treatment plants and leads to potential toxicity to the related biological processes. In this study, the effect of benzalkonium bromide (BK) on anaerobic sludge fermentation process for short chain fatty acid (SCFAs) production was investigated. Batch experiments indicated that BK exposure significantly enhanced the SCFAs production from anaerobic fermentation sludge and the maximum concentration of total SCFAs increased from 474.40 ± 12.35 mg/L to 916.42 ± 20.35 mg/L with BK increasing from 0 to 8.69 mg/g VSS. Mechanism exploration exhibited that the presence of BK enhanced much more bioavailable organic matters release, little affected on hydrolysis, acidification, but seriously inhibited methanogenesis. Microbial community investigation revealed that BK exposure importantly enhanced the relative abundances of hydrolytic-acidifying bacteria and also improved the metabolic pathways and functional genes for sludge lysis. This work further supplement the information for environmental toxicity of emerging pollutants.


Assuntos
Compostos de Benzalcônio , Esgotos , Fermentação , Anaerobiose , Brometos , Ácidos Graxos Voláteis/metabolismo , Concentração de Íons de Hidrogênio
18.
J Environ Manage ; 333: 117439, 2023 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-36758406

RESUMO

Infection of antibiotic-resistant pathogens mostly occurs in rural areas. In this paper, the dissemination of antibiotic resistance genes (ARGs) through fecal sewage treatment facilities to the ecosystem in a typical rural area is investigated. Household three-chamber septic tanks (TCs), household biogas digesters (BDs), wastewater treatment plants (WWTPs), vegetable plots, water ponds, etc. Are taken into account. The relative abundance of ARGs in fecal sewage can be reduced by BDs and WWTPs by 80% and 60%, respectively. While TCs show no reduction ability for ARGs. Fast expectation-maximization microbial source tracking (FEAST) analysis revealed that TCs and BDs contribute a considerable percentage (15-22%) of ARGs to the surface water bodies (water ponds) in the rural area. Most ARGs tend to precipitate in the sediments of water bodies and stop moving downstream. Meanwhile, the immigration of microorganisms is more active than that of ARGs. The results provide scientific basic data for the management of fecal sewage and the controlling of ARGs in rural areas.


Assuntos
Antibacterianos , Esgotos , Antibacterianos/farmacologia , Águas Residuárias , Genes Bacterianos , Ecossistema , Resistência Microbiana a Medicamentos/genética
19.
J Environ Manage ; 336: 117659, 2023 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-36893544

RESUMO

The growing increasing occurrence of perfluorooctanoic acid (PFOA) in wastewater has raised concerns about its potential impact on the environment. Nevertheless, the impact of PFOA at environmentally relevant level on the formation of aerobic granular sludge (AGS) is still a 'black box'. This study thus aims to fill this gap by comprehensive investigation of sludge properties, reactor performance and microbial community during the formation of AGS. It was found that 0.1 mg/L PFOA delayed the formation of AGS, causing relatively lower proportion of large size AGS at the end of operation process. Interestingly, the microorganisms contribute to the reactor's tolerance to PFOA by secreting more extracellular polymeric substances (EPS) to slow or block the entry of toxic substances into the cells. During the granule maturation period, the reactor nutrient removal especially chemical oxygen demand (COD) and total nitrogen (TN) were affected by PFOA, decreasing the corresponding removal efficiencies to ∼81.2% and ∼69.8%, respectively. Microbial analysis further revealed that PFOA decreased the abundances of Plasticicumulans, Thauera, Flavobacterium and Cytophagaceae_uncultured, but it has promoted Zoogloea and Betaproteobacteria_unclassified growth, which maintained the structures and functions of AGS. The above results revealed that the intrinsic mechanism of PFOA on the macroscopic representation of sludge granulation process was revealed, and it is expected to provide theoretical insights and practical support for direct adoption of municipal or industrial wastewater containing perfluorinated compounds to cultivate AGS.


Assuntos
Esgotos , Águas Residuárias , Esgotos/química , Eliminação de Resíduos Líquidos/métodos , Aerobiose , Reatores Biológicos/microbiologia , Nitrogênio
20.
Opt Express ; 30(22): 39329-39339, 2022 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-36298887

RESUMO

In this work, we demonstrate for the first time a narrow-linewidth III-V-on-Si double laser structure with more than a 110 nm wavelength tuning range realized using micro-transfer printing (µTP) technology. Two types of pre-fabricated III-V semiconductor optical amplifiers (SOAs) with a photoluminescence (PL) peak around 1500 nm and 1550 nm are micro-transfer printed on two silicon laser cavities. The laser cavities are fabricated in imec's silicon photonics (SiPh) pilot line on 200 mm silicon-on-insulator (SOI) wafers with a 400 nm thick silicon device layer. By combining the outputs of the two laser cavities on chip, wavelength tunability over S+C+L-bands is achieved.

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