Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 8 de 8
Filtrar
1.
Environ Pollut ; 327: 121631, 2023 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-37058862

RESUMO

Microplastic pollution is widespread in terrestrial and aquatic environments; however, a systematic assessment of the ecological risks of microplastics is lacking. This study collected research studies on microplastics in soil, aquatic and sediment environments, and screened 128 articles including 3459 sites to assess the ecological risks posed by microplastics in China following a literature quality assessment. We developed a systematic ecological risk assessment framework for microplastics in terms of spatial characterization, biotoxicity and anthropogenic impacts. The results of the pollution load index indicated that 74% and 47% of the soil and aquatic environments studied, respectively, faced a medium or higher level of pollution. Comparing predicted no effect concentrations (PNEC) and measured environmental concentrations (MECs), revealed that soil (97.70%) and aquatic (50.77%) environmental studies were at serious ecological risk from microplastics. The results of the pressure-state-response model showed that the microplastic pollution in Pearl River Delta was in a high-risk state. In addition, we found that ultraviolet radiation and rainfall exacerbate soil microplastic pollution, and higher river runoff may carry large amounts of microplastic from the source. The framework developed in this study will help assess the ecological risks of microplastics in the region to promote the mitigation of plastic pollution.


Assuntos
Microplásticos , Poluentes Químicos da Água , Plásticos , Raios Ultravioleta , Monitoramento Ambiental/métodos , Ecossistema , China , Medição de Risco , Solo , Poluentes Químicos da Água/toxicidade , Poluentes Químicos da Água/análise
2.
J Environ Manage ; 326(Pt A): 116653, 2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36410300

RESUMO

For the sake of exploring a new economical and low-carbon alternative for real nitrate-containing wastewater treatment, a new combined partial denitrification-anammox with urea hydrolysis (U-PD-Anammox) process was developed. The nitrogen removal performance of this process was investigated through long-term operation in a sequencing batch reactor (SBR) and two submerged anaerobic biological filters (SABF). Results showed that the average NO3--N to NO2-N transformation ratio improved to 82.6% with organic carbon source to NO3-N ratio of 1.8, and urea hydrolysis provided sufficient NH4+-N and inorganic carbon to anammox process for nitrogen removal. The influent NH4+-N/NO2--N ratio for subsequent anammox reactor could be adjacent to the optimal ratio of 1.32 during the whole operation. The combined process showed efficient nitrogen removal performance with 85% NO3--N removal, 93.8% total nitrogen removal and total nitrogen loading rate as 1.1 ± 0.5 kg N/(m3·d). High-throughput sequencing analysis results revealed that Genera Thauera, Hyphomicrobium and Candidatus Brocadia were the dominant species responsible for partial denitrification, urea hydrolysis and anammox, respectively. The proposed process was more economically and environmental-friendly than the traditional denitrification process with 51.7% operational cost reduction, 99.7% N2O and 60% CO2 emission decrement, facilitating the sustainable development of the nitrate-containing wastewater treatment industry in the future.


Assuntos
Nitratos , Purificação da Água , Carbono , Ureia , Desnitrificação , Hidrólise , Oxidação Anaeróbia da Amônia , Dióxido de Nitrogênio , Óxidos de Nitrogênio , Nitrogênio
3.
Chemosphere ; 298: 134302, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35304209

RESUMO

Pyrolysis combined with land application for dewatered municipal sludge disposal revealed advantages in heavy metals solidification and resource utilization compared with other disposal technologies. In this study, utilizing dewatered municipal sludge for calcium-containing porous adsorbent preparation via pyrolysis was proposed and verified. After pyrolyzing at 900 ° C (Ca-900), the dewatered sludge obtained maximum adsorption capacity (83.95 mg P⋅ g-1) and the adsorption process conformed to the pseudo-second-order model and double layer model. Characteristic analysis showed the predominant adsorption mechanism was precipitation. Continuous column bed experiment indicated 2 g adsorbent could remove 4.27 mg phosphorus from tail wastewater with the initial phosphorus concentration of 1.03 mg ⋅ L-1. No heavy metals leaching was observed from Ca-900 adsorbent with pH value exceeding 1.0, and merely 1% addition of Ca-900 adsorbent (after actual water phosphorus adsorption) with soil could extremely promote the early growth of seedlings. Economic estimates demonstrated that this cost-effective modification could generate the most add-on value production. Based on these results, the strategy of 'one treatment but two uses' was proposed in this study, converting the wastes to resource and providing a native strategy for sludge disposal and resource recovery.


Assuntos
Metais Pesados , Esgotos , Adsorção , Cálcio , Cálcio da Dieta , Carvão Vegetal , Fertilizantes , Fósforo
4.
Small Methods ; 5(3): e2001045, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-34927824

RESUMO

Nanosafety is a major concern for nanotechnology development. Evaluation of the transcriptome and the DNA methylome is proposed for nanosafety assessments. RNA m6A modification plays a crucial role in development, disease, and cell fate determination through regulating RNA stability and decay. Here, since black phosphorus quantum dots (BPQDs), among many other types of QDs, increase the global m6A level and decrease the demethylase ALKBH5 level in lung cells, the epitranscriptome is taken into consideration for the first time to evaluate nanosafety. Both the transcriptome and m6A epitranscriptome analyses show that BPQDs alter many biological processes, such as the response to selenium ions and the lipoxygenase pathway, indicating possible ferroptosis activation. The results further show that BPQDs cause lipid peroxidation, mitochondrial dysfunction, and iron overload. Recognition of these modified mRNAs by YTHDF2 leads to mRNAs' decay and eventually ferroptosis. This study shows that RNA m6A modification not only is a more sophisticated indicator for nanosafety assessment but also provides novel insight into the role of RNA m6A in regulating BPQD-induced ferroptosis, which may be broadly applicable to understanding the functions of RNA m6A under stress.


Assuntos
Ferroptose , Pontos Quânticos , Ferroptose/genética , Fósforo/metabolismo , Pontos Quânticos/toxicidade , RNA Mensageiro/metabolismo , Proteínas de Ligação a RNA/genética
5.
Respir Res ; 21(1): 189, 2020 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-32677946

RESUMO

BACKGROUND: Currently, the diagnosis of chronic obstructive pulmonary disease (COPD) is not uniform, COPD guidelines recommend fixed ratio (FR), whereas ATS and ERS define airflow obstruction based on lower limit of normal (LLN). We aim to determine if there is difference between the two diagnostic criteria for morbidity, mortality, exacerbation. METHODS: Four databases and all relevant studies from the references were searched from inception to June 25, 2019, to find studies that described the rate of comorbidity, the exacerbation rates, mortality in COPD patients. Data analysis was performed using STATA/SE 14.0 and followed the standard of Cochrane Collaboration. A sensitivity analysis was performed to find the source of heterogeneity. RESULTS: Thirteen studies and 154,447 participants were finally included in this meta-analysis. The 11 cohort studies and 2 cross-sectional studies were all high-quality. Patients with airflow limitation according to either FR or LLN had higher mortality (HRFR+/LLN- = 1.27, 95% CI = 1.14-1.42; HRFR-/LLN+ = 1.83, 95% CI = 1.17-2.86) than those who met neither criteria. When compared with the FR-/LLN- criteria, those who met the FR criteria were more likely to exacerbate (HR FR+/LLN- = 1.64, 95% CI = 1.09-2.46; HR FR-/LLN+ = 1.58, 95% CI = 0.70-3.55). The meta-analysis for comorbidities showed no significant difference between patients who met neither criteria and those who met LLN or FR criteria. CONCLUSION: The patients with airflow limitations according to FR were more likely to exacerbate than those with LLN only. Patients that met either FR or LLN were more likely to have higher mortality than FR-/LLN-. There was no difference between the FR+/LLN- and FR-/LLN+ groups for the occurrence of comorbidities.


Assuntos
Pulmão/fisiopatologia , Doença Pulmonar Obstrutiva Crônica/diagnóstico , Espirometria , Adulto , Idoso , Idoso de 80 Anos ou mais , Comorbidade , Progressão da Doença , Feminino , Volume Expiratório Forçado , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Prognóstico , Doença Pulmonar Obstrutiva Crônica/mortalidade , Doença Pulmonar Obstrutiva Crônica/fisiopatologia , Medição de Risco , Fatores de Risco , Capacidade Vital , Adulto Jovem
6.
Mar Pollut Bull ; 153: 110995, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32275544

RESUMO

Sediment and marine organism samples collected from Haizhou Bay and Lusi fishing ground in South Yellow Sea, China were analysed for polycyclic aromatic hydrocarbons (PAHs). The concentrations of 16 PAHs in marine organisms ranged from 127.43 to 350.53 ng/g dry weight (dw, Haizhou Bay fishing ground) and from 86.37 to 213.02 ng/g dw (Lusi fishing ground). The dominant compounds were 2- and 3-ring PAHs in marine organism tissues. The main PAH sources were found to be coal combustion. Specific habitat, feeding habit, trophic level and environmental differences may affect the PAH levels in marine organisms in our study area. The biota-sediment accumulation factor (BSAF) decreased with increasing PAH log Kow and BSAF values might differ in response to various environmental conditions and species. The excess cancer risk from PAH-contaminated seafood consumption was slightly higher than the guideline value (10-6), but much lower than the priority risk level (10-4).


Assuntos
Monitoramento Ambiental , Hidrocarbonetos Policíclicos Aromáticos , Poluentes Químicos da Água , Animais , Organismos Aquáticos , Bioacumulação , China , Sedimentos Geológicos , Humanos , Medição de Risco
7.
Water Res ; 162: 214-224, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31276985

RESUMO

Primary microplastics are mostly produced as part of the daily plastic product use. The emission process is often invisible but poses potential ecological hazards. Thus, primary microplastics deserve public attention. Due to China's huge population base and its rapid economic development, primary microplastics emissions are of both regional and global significance. This study is the first to establish the emission inventory of primary microplastics in mainland China. It was estimated that the primary microplastic waste from mainland China amounts to 737.29 Gg, and one-sixth of this amount entered the aquatic environment in 2015. The highest proportion of this waste was attributable to tire dust and synthetic fiber, accounting for 53.91% and 28.77% of the total respectively, in mainland China. The primary microplastics emissions mainly depend on the population, followed by the level of economic development. It was roughly estimated that 538 g of microplastics is produced by each person in China. At the grid scale, the spatial difference in the total primary microplastics emissions in mainland China primarily depends on the population density distribution and transportation network. We studied the entire life cycle of several sources of microplastics, from production to discharge into the aquatic environment. We suggested different control measures under different nodes. Increasing microplastics treatment in sewage treatment plants should be a short-term viable way to achieve some measure of reduction in their entry to the environment in mainland China. Our research can not only raise public awareness about primary microplastics, but can also guide the development of environmental policies to reduce plastic pollution.


Assuntos
Plásticos , Poluentes Químicos da Água , China , Monitoramento Ambiental , Poluição Ambiental
8.
Adv Mater ; 29(39)2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28833673

RESUMO

Flexible pressure sensors have many potential applications in wearable electronics, robotics, health monitoring, and more. In particular, liquid-metal-based sensors are especially promising as they can undergo strains of over 200% without failure. However, current liquid-metal-based strain sensors are incapable of resolving small pressure changes in the few kPa range, making them unsuitable for applications such as heart-rate monitoring, which require a much lower pressure detection resolution. In this paper, a microfluidic tactile diaphragm pressure sensor based on embedded Galinstan microchannels (70 µm width × 70 µm height) capable of resolving sub-50 Pa changes in pressure with sub-100 Pa detection limits and a response time of 90 ms is demonstrated. An embedded equivalent Wheatstone bridge circuit makes the most of tangential and radial strain fields, leading to high sensitivities of a 0.0835 kPa-1 change in output voltage. The Wheatstone bridge also provides temperature self-compensation, allowing for operation in the range of 20-50 °C. As examples of potential applications, a polydimethylsiloxane (PDMS) wristband with an embedded microfluidic diaphragm pressure sensor capable of real-time pulse monitoring and a PDMS glove with multiple embedded sensors to provide comprehensive tactile feedback of a human hand when touching or holding objects are demonstrated.


Assuntos
Diafragma , Humanos , Microfluídica , Pressão , Tato , Dispositivos Eletrônicos Vestíveis
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA