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1.
Artigo em Inglês | MEDLINE | ID: mdl-38580873

RESUMO

The emission reduction of atmospheric pollutants during the COVID-19 caused the change in aerosol concentration. However, there is a lack of research on the impact of changes in aerosol concentration on carbon sequestration potential. To reveal the impact mechanism of aerosols on rice carbon sequestration, the spatial differentiation characteristics of aerosol optical depth (AOD), gross primary productivity (GPP), net primary productivity (NPP), leaf area index (LAI), fraction of absorbed photosynthetically active radiation (FPAR), and meteorological factors were compared in the Sanjiang Plain. Pearson correlation analysis and geographic detector were used to analyze the main driving factors affecting the spatial heterogeneity of GPP and NPP. The study showed that the spatial distribution pattern of AOD in the rice-growing area during the epidemic was gradually decreasing from northeast to southwest with an overall decrease of 29.76%. Under the synergistic effect of multiple driving factors, both GPP and NPP increased by more than 5.0%, and the carbon sequestration capacity was improved. LAI and FPAR were the main driving factors for the spatial differentiation of rice GPP and NPP during the epidemic, followed by potential evapotranspiration and AOD. All interaction detection results showed a double-factor enhancement, which indicated that the effects of atmospheric environmental changes on rice primary productivity were the synergistic effect result of multiple factors, and AOD was the key factor that indirectly affected rice primary productivity. The synergistic effects between aerosol-radiation-meteorological factor-rice primary productivity in a typical temperate monsoon climate zone suitable for rice growth were studied, and the effects of changes in aerosol concentration on carbon sequestration potential were analyzed. The study can provide important references for the assessment of carbon sequestration potential in this climate zone.

2.
Environ Sci Pollut Res Int ; 30(54): 115556-115570, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37884719

RESUMO

The high value resource utilization of corn straw is a long-term problem at present and in the future. Biochar preparation is an important utilization way of corn straw. The research on city tail water treated by constructed wetland (CW) with biochar was carried out to further increase the wastewater treatment capacity of the CW. Surface characterization, structural characteristics, and adsorption of straw biochar modified by different acids were measured. The study found that the ability of H2SO4 to remove ash from biochar was stronger than other acids and H2SO4-biochar was easy to be cleaned without H2SO4 residue. The performance of biochar modified by H2SO4 was obviously better than other acids, and the biochar adsorption was enhanced. The modification of biochar substrate modified by H2SO4 in CW reduced the change of electrical conductivity (EC) and promoted denitrification. H2SO4-modified biochar promoted the absorption of N and P by Iris pseudacorus L. The compound modification effect of straw biochar was obvious. The results revealed the acid modification characteristics of straw biochar, which were beneficial for increasing the wastewater treatment rate by CW. This study will promote the sustainable development of CW.


Assuntos
Áreas Alagadas , Zea mays , Carvão Vegetal/química , Adsorção
3.
Environ Sci Pollut Res Int ; 30(50): 108582-108595, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37752393

RESUMO

Constructed wetland (CW) is an important method of ecological water treatment, and CW has obvious advantage in treating low-pollution water. In order to improve the treatment efficiency of CW, the first-order and second-order kinetics simulations of pollutant removal in CW were carried out to optimize operating conditions. The experimental study of city tail water treatment under unmodified biochar (different additions) or different modified biochar conditions showed that the first-order kinetic equation relatively accurately reflect the removal of pollutants by substrate. The relatively optimal range of biochar addition (2.21-3.79%) in the first-order kinetic analysis covered the relatively optimal mass ratio (2.95%). The first-order kinetic equation fitting showed that the half-life of ammonia nitrogen removal by NaOH (0.1 mol·L-1)-modified biochar was reduced by about 10% without plant. The half-life of total phosphorus removal by KMnO4 (0.1 mol·L-1) modified biochar was reduced by about 50%. The half-life of chemical oxygen demand removal by H2SO4 (0.75 mol·L-1) + 8 freeze-thaw cycles modified biochar was reduced by about 9.0%. When the half-life was small, the pollutant removal rate was high. The results of this study further confirmed the effectiveness of the simulation results of pollutant removal in CW with biochar by the first-order kinetic equation. This study further optimized the CW operating conditions and improved the treatment efficiency of nitrogen and phosphorus in the CW.


Assuntos
Poluentes Ambientais , Purificação da Água , Áreas Alagadas , Cinética , Purificação da Água/métodos , Nitrogênio , Fósforo , Eliminação de Resíduos Líquidos/métodos
4.
J Hazard Mater ; 459: 132132, 2023 10 05.
Artigo em Inglês | MEDLINE | ID: mdl-37494794

RESUMO

Three novel neonicotinoids (cycloxaprid, flupyradifurone and sulfoxaflor) were designed to reduce the biotoxicity for non-target organisms. These neonicotinoids were photolyzed under light radiation, but it was unclear for the photo-enhanced toxicity and influences of the novel modifying group of the three neonicotinoids. The photolysis and photo-enhanced toxicity experiments were performed for the three neonicotinoids, coupled with quantum chemistry calculation, the mechanisms of photolysis, photo-enhanced toxicity and the influences of novel modifying groups were analyzed. The results showed the photolysis pathways were enriched as compared with previous neonicotinoids due to the composition of modifying groups, singlet oxygen and hydroxyl participated the photolysis of cycloxaprid and flupyradifurone. All tested neonicotinoids exhibited photo-enhanced toxicity to Vibrio fischeri. Due to the difference of photolysis mechanism and toxicity to V. fischeri, the photo-enhanced toxicity curves showed diverse variation when histidine, tert-butanol or dissolved organic matters was in presence of the test solutions. The impact of novel modifying groups over photolysis and photo-enhanced toxicity were analyzed based on the comparison with previous neonicotinoids, theoretically predicted UV-Vis spectra and photo-physical/chemical property descriptors. The data showed the composition of novel modifying group increased the light absorption and photo-chemical activities for the three neonicotinoids.


Assuntos
4-Butirolactona , Poluentes Químicos da Água , Fotólise , Neonicotinoides/química , Poluentes Químicos da Água/química , Aliivibrio fischeri
5.
J Phys Chem Lett ; 14(12): 2940-2949, 2023 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-36930804

RESUMO

The Schottky barrier (SB) in the ultraclean van der Waals contact between two-dimensional (2D) MoS2 and three-dimensional (3D) indium (In) strikingly deviates from the Schottky-Mott limit (SML). Herein, on the basis of first-principles calculation, the origin of the SB deviation is brought to bear, as well as a strategy for mitigating the SB deviation. In light of the good agreement between the SB and the corrected SB by interface potential difference (ΔV) and Fermi -level shift (ΔEF) based on the SML, the SB deviation is attributed to the combined effects of ΔV and ΔEF. Furthermore, when a Au, Sc, or Ti thin film is coated on the back side of In, the SB deviation and the sum of ΔV and ΔEF decrease similarly. Importantly, in the Ti coating situation, the SB is reduced to 0.12 eV, notably smaller than the value of 0.30 eV in the Au coating case. This interface engineering can be generalized to regulate the SB between a 2D semiconductor and a 3D alloy.

6.
Environ Sci Pollut Res Int ; 30(17): 49948-49962, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36787063

RESUMO

Biochar prepared from straw as constructed wetland (CW) substrate reduces straw pollution and simultaneously promotes the wastewater treatment efficiency of CW. In order to further analyze the pollutant removal mechanism of KMnO4-modified biochar substrate, the KMnO4-modified biochar was characterized. The experiment on city tail water treatment by CW with biochar was analyzed. The research showed that the surface property improvement on KMnO4 (0.1 mol/L)-modified biochar was the most obvious. The biochar modified by 0.1 mol/L KMnO4 increased the SSA and the number of oxygen functional groups and alcohol hydroxyl. KMnO4-modified biochar improved the removal efficiency of NO3--N in CW. KMnO4-modified biochar substrate with plants improved the TP removal efficiency (about 45%). KMnO4 as modifier reduced the influence of biochar on electrical conductivity tracing experiment. This study will improve the utilization value of straw and the removal efficiency of CW.


Assuntos
Áreas Alagadas , Zea mays , Nitrogênio , Carvão Vegetal/química
7.
Int Immunopharmacol ; 114: 109506, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36442284

RESUMO

Neuropathic pain is a growing concern in the medical community, and studies on new analgesic targets for neuropathic pain have become a new hot spot. Whether Connexin43 (Cx43) has a key role in neuropathic pain mediated by the purinergic 2X4 (P2X4) receptor in rats with chronic constriction injury (CCI) was explored in this study. Our experimental results show that blockade of Cx43 could attenuate neuropathic pain in rats suffering from CCI via the P2X4, p38, ERK, and NF-kB signalling pathways. These results suggest that Cx43 may be a promising therapeutic target for the development of novel pharmacological agents in the management of neuropathic pain.


Assuntos
Conexina 43 , Neuralgia , Ratos , Animais , Ratos Sprague-Dawley , Conexina 43/metabolismo , Constrição , Neuralgia/tratamento farmacológico , Neuralgia/metabolismo , Sistema de Sinalização das MAP Quinases
8.
World J Clin Cases ; 10(20): 6960-6965, 2022 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-36051135

RESUMO

BACKGROUND: This paper introduces a case of recurrent keratoacanthoma (KA). KA is a self-healing disease. Recurrence after surgical resection is rare. In this case, the local application of retinoic acid ointment after the second operation achieved a good prognosis after 2 years of follow-up. CASE SUMMARY: A 76-year-old male patient was admitted to the hospital for "lower lip rupture and scab for 3 mo". Treatment: A rectangular incision was made in the healthy tissue about 3 mm outside the periphery of the lower lip mass, and a modified Bernard sliding flap was designed to completely remove the mass. Pathology showed (lower lip) KA. When the patient returned 6 mo after surgery, the middle mucosa of the lower lip had a bulge with a diameter of about 0.5 cm. The boundary was still clear, the surface was ulcerated. A recurrence of lower lip KA was suspected and a fan-shaped incision was performed in the healthy tissue about 5 mm outside the lesion to completely resect. Pathological showed lower lip KA had recurred. Topical application of tretinoin cream was applied once a day for 3 mo. The lower lip wounds were clean at the 2-year postoperative follow-up and the mucosa was normal. CONCLUSION: Adjuvant retinoic acid treatment after KA surgical resection can achieve good results.

9.
Chemosphere ; 304: 135341, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35716708

RESUMO

Owing to their wide distribution, easy production, and resistance to degradation, microplastics (MPs) represent a globally emerging group of pollutants of concern. Furthermore, their decomposition can result in the generation of nanoplastics (NPs), which cause further environmental issues. Currently, the impact of the combination of these plastics with other organic pollutants on crop growth remains poorly investigated. In this study, a hydroponic experiment was conducted for seven days to evaluate the effects of 50 nm, 50 mg/L polystyrene (PS), and 1 mg/L phenanthrene (Phe) on the growth of rice plants. The results revealed that both Phe and PS inhibited growth and improved the antioxidant potential of rice. Relative to Phe alone, exposure to a combination of PS and Phe reduced Phe accumulation in the roots and shoots by 67.73% and 36.84%, respectively, and decreased the pressure on the antioxidant system. Exposure to Phe alone destroyed the photosynthetic system of rice plant leaves, whereas a combination of PS and Phe alleviated this damage. Gene Ontology (GO) analysis of the rice transcriptomes revealed that detoxification genes and phenylalanine metabolism were suppressed under exposure to Phe, which consequently diminished the antioxidant capacity and polysaccharide synthesis in rice plants. Kyoto Encyclopaedia of Genes and Genomes (KEGG) transcriptome analysis revealed that the combined presence of both PS and Phe improved photosynthesis and energy metabolism and alleviated the toxic effects of Phe by altering the carbon fixation pathway and hormone signal transduction in rice plants. The combination of PS and Phe also prevented Phe-associated damage to rice growth. These findings improve our understanding of the effects of MP/NPs and polycyclic aromatic hydrocarbons on crops.


Assuntos
Poluentes Ambientais , Oryza , Fenantrenos , Antioxidantes/metabolismo , Poluentes Ambientais/metabolismo , Microplásticos/toxicidade , Fenantrenos/metabolismo , Plásticos/metabolismo , Poliestirenos/metabolismo , Transcriptoma
10.
Ecotoxicol Environ Saf ; 238: 113597, 2022 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-35533448

RESUMO

The pollution of corn straw to the environment had attracted much attention. The preparation and alkali modification of corn straw biochar as the constructed wetland (CW) substrate was conducive to solving the environment pollution caused by straw and improving the purification effect of CW. The NaOH modification mechanism of corn straw biochar was analyzed by measuring the surface morphology, element content, specific surface area (SSA), pore volume, crystal structure, surface functional groups and CO2 adsorption. Biochar prepared under relatively optimal NaOH-modified conditions was used as the vertical flow CW substrate to treat city tail water. The results showed that controlling the modification condition of NaOH (< 1.0 mol·L-1, ≤ 24 h) was conducive to prevent the biochar structure destruction and C element reduction. The SSA and pore volume of NaOH (0.1 mol·L-1) modified biochar are 360 m2·g-1 and 0.109 cm3·g-1, respectively. The biochar adsorption for CO2 conformed to the Langmuir and Freundlich isothermal adsorption theoretical model (R2 > 0.9). The maximum adsorption capacity of CO2 by modified biochar with NaOH (0.1 mol·L-1) was 64.516 cm3·g-1 and increased by 10.3%. The city tail water treated by CW with plants showed that the removal rates of ammonia nitrogen, total nitrogen and nitrate nitrogen reached about 90%. The research results improved the utilization value of straw, realized straw carbon sequestration and promoted the progress of CW technology.


Assuntos
Purificação da Água , Áreas Alagadas , Adsorção , Dióxido de Carbono , Carvão Vegetal/química , Nitrogênio , Hidróxido de Sódio , Água , Purificação da Água/métodos , Zea mays
11.
Sci Total Environ ; 829: 154725, 2022 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-35331769

RESUMO

Permafrost peatlands, as large soil carbon pools, are sensitive to global warming. However, the effects of temperature, moisture, and their interactions on carbon emissions in the permafrost peatlands remain unclear, when considering the availability of soil matrixes. The permafrost peatland (0-50 cm soil) in the Great Xing'an Mountains was selected to explore the deficiency. The cumulative carbon dioxide (CO2) and methane (CH4) emissions from soil were measured under different temperatures (5 °C, 10 °C, and 15 °C) and moisture content (130%, 100%, and 70%) treatments by the indoor incubation. The results showed that the soil carbon and nitrogen matrix determined soil carbon emissions. Warming affected the availability of soil carbon and nitrogen substrates, thus stimulating microbial activity and increasing soil carbon emissions. With soil temperature increasing by 10 °C, soil CO2 and CH4 emission rates increased by 5.1-9.4 and 3.8-6.4 times respectively. Warming promoted soil carbon emissions, and the decrease of moisture content promoted CO2 emissions but inhibited CH4 emissions in the permafrost peatland. Soil moisture and the carbon and nitrogen matrix determined the intensity of CO2 and CH4 emissions. The results were important to assess soil carbon emissions from permafrost peatlands under the impact of future climate warming and to formulate carbon emission reduction policies.


Assuntos
Pergelissolo , Dióxido de Carbono/análise , Metano , Nitrogênio , Pergelissolo/química , Solo/química
12.
Environ Sci Pollut Res Int ; 29(36): 54234-54249, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35298804

RESUMO

The combined effects and respective advantages of using pyrite and alkali-modified rice husk (RH) were studied as substrates for nitrogen and phosphorus removal from constructed wetlands, and the effects of the carbon to nitrogen (C/N) ratio and the tidal flow mode on system performance were explored. The results showed that alkali-modified RH, which enhances heterotrophic denitrification, had far more advantages than pyrite, which enhances autotrophic denitrification, and alkali-modified RH can be used for the treatment of sewage containing low C/N ratios. At a C/N ratio of 1.5, the total nitrogen (TN) removal rates exceeded 95%. However, the removal efficiency of the system with only pyrite only reached 76.90% when the influent C/N ratio was 6. Pyrite achieved a total phosphorus (TP) removal 10-20% higher than that of the control group. The tidal flow CWs showed enhanced nitrification, and the NH4+-N removal rates increased by approximately 10%, but the increase in dissolved oxygen (DO) was still insufficient to meet the needs of the systems, leading to limited TP removal. The combination of pyrite and alkali-modified RH was optimal for improving the ability of constructed wetlands to treat wastewaters, simultaneously removing nitrogen and phosphorus from sewage containing low C/N ratios. Combined with the tidal flow mode strategy, the use of pyrite and alkali-modified RH as substrates showed substantial advantages for improving water quality.


Assuntos
Oryza , Áreas Alagadas , Álcalis , Carbono , Desnitrificação , Ferro , Nitrogênio , Fósforo , Esgotos , Sulfetos , Eliminação de Resíduos Líquidos
13.
J Environ Manage ; 310: 114758, 2022 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-35255381

RESUMO

Corn straw is rich in resources, and the preparation of biochar as the constructed wetland (CW) substrate is an effective measure to realize high-value resource utilization. The objective of this paper was to improve the treatment effect of CW on city tail water, the freeze-thaw cycles (FTCs) modification and chemical modification (KMnO4, NaOH and H2SO4) of straw biochar and the utilization of modified straw biochar in CW were studied. The modification characteristics of straw biochar were discussed through scanning electron microscope, element determination, pore structure determination, X-ray diffraction analysis, Fourier transform infrared reflection analysis, CO2 adsorption and desorption experiment and application experiment of CW (no plants and plants). The results show that under the influence of strong oxidation of KMnO4, the combination of KMnO4 and FTCs modification is easy to cause the destruction of biochar structure, and the content of carbon element is reduced. Except for the combined modification of NaOH and FTCs, other composite modifications have little effect on the crystal structure and functional groups of straw biochar. The adsorption capacity of CO2 by FTCs modified biochar increased by 20.4%, and the adsorption capacity of CO2 by H2SO4 and FTCs composite modified biochar increased by 23.0%. The effect of H2SO4 modification of straw biochar based on FTCs modification is obviously better than that of NaOH and KMnO4. The research results are of great significance to improve the material structure of biochar and the purification effect of CW on city tail water.


Assuntos
Água , Zea mays , Adsorção , Carvão Vegetal/química , Áreas Alagadas
14.
Environ Sci Pollut Res Int ; 29(21): 31700-31712, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35013975

RESUMO

Climate warming has intensified changes of permafrost freeze-thaw process and postponed the starting period of soil freezing, which significantly affected the processes of N2O production and emission from the soils. However, responses of soil N2O fluxes to freeze-thaw cycles (FTCS) during autumn freezing period in permafrost peatlands in field remain unclear. Therefore, the static chamber-GC techniques were used to explore the effects of autumn FTCS on N2O fluxes in the three permafrost peatlands [Calamagrostis angustifolia peatland (CA), Larix gmelini-Sphagnum swamp (LS), and Eriophorum vaginatum peatland (EV)] in Da Xing'an Mountains, Northeast China, from September to November 2019. The response peaks of N2O fluxes to autumn FTCS in CA (29.22 ± 14.90 µg m-2 h-1) and EV (19.70 ± 7.26 µg m-2 h-1) occurred in the autumn FTCS prophase, whereas LS (11.33 ± 0.90 µg m-2 h-1) appeared in the autumn FTCS metaphase. CA (394.90 µg m-2) and EV (497.82 µg m-2) acted as a N2O source, and LS (- 1321.43 µg m-2) was a N2O sink. The effects of autumn FTCS on N2O fluxes were significantly different (p < 0.001) in the three permafrost peatlands. N2O emissions during autumn FTCS were mainly driven by soil NH4+-N0-50 cm, DOC30-40 cm and 40-50 cm content and soil NO3--N0-50 cm content. The results implied that autumn FTCS could stimulate soil N2O emissions in permafrost peatlands and confirmed the important contribution of N2O emissions during autumn FTCS to annual nitrogen budget. This study could improve the accuracy of regional estimates of annual nitrogen budget.


Assuntos
Óxido Nitroso , Pergelissolo , China , Congelamento , Nitrogênio , Óxido Nitroso/análise , Poaceae , Solo
15.
ACS Appl Mater Interfaces ; 14(2): 2881-2892, 2022 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-34985854

RESUMO

Cascade catalysis that combines chemical catalysis and biocatalysis has received extensive attention in recent years, especially the integration of metal nanoparticles (MNPs) with enzymes. However, the compatibility between MNPs and enzymes, and the stability of the integrated nanocatalyst should be improved to promote the application. Therefore, in this study, we proposed a strategy to space-separately co-immobilize MNPs and enzymes to the pores and surface of a highly stable covalent organic framework (COF), respectively. Typically, Pd NPs that were prepared by in situ reduction with triazinyl as the nucleation site were distributed in COF (Tz-Da), and organophosphorus hydrolase (OPH) was immobilized on the surface of Tz-Da by a covalent method to improve its stability. The obtained integrated nanocatalyst Pd@Tz-Da@OPH showed high catalytic efficiency and reusability in the cascade degradation of organophosphate nerve agents. Furthermore, the versatility of the preparation strategy of COF-based integrated nanocatalyst has been preliminarily expanded: (1) Pd NPs and OPH were immobilized in the triazinyl COF (TTB-DHBD) with different pore sizes for cascade degradation of organophosphate nerve agent and the particle size of MNPs can be regulated. (2) Pt NPs and glucose oxidase were immobilized in COF (Tz-Da) to obtain an integrated nanocatalyst for efficient colorimetric detection of phenol.


Assuntos
Arildialquilfosfatase/metabolismo , Materiais Biocompatíveis/metabolismo , Nanopartículas Metálicas/química , Estruturas Metalorgânicas/metabolismo , Agentes Neurotóxicos/metabolismo , Organofosfatos/metabolismo , Arildialquilfosfatase/química , Biocatálise , Materiais Biocompatíveis/química , Teste de Materiais , Estruturas Metalorgânicas/química , Estrutura Molecular , Agentes Neurotóxicos/química , Organofosfatos/química , Paládio/química , Paládio/metabolismo
16.
Ecotoxicol Environ Saf ; 226: 112881, 2021 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-34634737

RESUMO

Geological disasters seriously threaten the safety of human life, property, ecological resources, and the environment. Effective control of geological disasters is the focus of achieving sustainable social development. The Helong City (Jilin Province, China) was selected as the case study. Combined with GIS technology, a new integrated prediction model of geological disaster susceptibility was developed to improve the accuracy of geological disaster assessment, reduce the cost of geological disaster treatment, and ensure the sustainable development of ecological environment. The research results showed that elevation and normalized difference vegetation index (NDVI) were the key factors affecting susceptibility. Compared with the conventional model, the accuracy of the developing integrated model FR-DT and FR-RF was improved by more than 6%, and the disaster points were more concentrated in the high susceptibility zone. Statistical results of disaster treatment cost estimation and gross domestic product (GDP) value showed that the integrated model can save about 10% of treatment cost, and the ratio of total GDP/disaster governance cost was higher. The performance of the integrated model FR-DT and FR-RF had obvious advantages over the conventional model in terms of prediction accuracy, prevention pertinence, and prevention cost. These research results promote the advancement of geological disaster prevention and control technology, ensure the safety of the geological environment, and are of great significance to the sustainable development of the regional economy.


Assuntos
Desastres , Sistemas de Informação Geográfica , China , Cidades , Meio Ambiente , Humanos , Desenvolvimento Sustentável
17.
Environ Sci Pollut Res Int ; 28(44): 63237-63249, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34227002

RESUMO

Water pollution control is the focus of environmental pollution control. Ecological water treatment is widely used because of its low cost and landscape effect, and has no pollution. Aquatic plants have attracted wide attention because of their low cost and high level of resource utilization. In order to study the effects of emergent and submerged plants on the removal of different concentrations of wastewater, and the effect of pollutants on plant growth, two common aquatic plants found in Northeast China (Iris ensata Thunb. and Potamogeton malaianus Miq.) were selected. Under static conditions, the removal efficiency of nitrogen and phosphorus in wastewater with different concentrations by two kinds of plants was studied. The results showed that the removal rate of total nitrogen (TN) in medium- and high-pollutant concentration water samples and total phosphorus (TP) in medium- and low-pollutant concentration water with I. ensata reached more than 75%. The removal rate of TN in the medium-pollutant concentration water with P. malaianus reached 71.4%, while the removal efficiency of TN and TP in the low-pollutant concentration water was higher than 80%. In the Nanhu Park Lake samples, I. ensata had the highest removal rates of TN (80.38%) and TP (85.62%). This study shows that both I. ensata and P. malaianus can be used as aquatic plants to restore the water quality of urban lakes. This research provides an important basis for the phytoremediation and treatment of urban domestic wastewater and urban surface water bodies in Northern China.


Assuntos
Potamogetonaceae , Poluentes Químicos da Água , Purificação da Água , China , Nitrogênio/análise , Fósforo/análise , Águas Residuárias , Poluentes Químicos da Água/análise
18.
J Environ Manage ; 296: 113181, 2021 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-34243090

RESUMO

The co-combustion characteristics and kinetics of Fenton/CaO conditioned MSS, and biomass rice husk (RH) are studied by thermogravimetry, and the condition optimization was carried out by response surface methodology (RSM). The results show that the mixed fuel with RH is helpful to decrease Ti and Tb values and increase combustion characteristic index (CCI). The CCI of MSS after conditioning is 0.59-0.88 times lower than that of the pure MSS. In addition, the total Em of S2, MSS/RH mixed combustion after Fenton/CaO conditioning is lower, the combustion reactivity is stronger. According to RSM, the optimum conditions are considered to be: RH mixing ratio 56%, Fenton/CaO conditioner dosage 147 mg g-1 dry solids, heating rate 30 K min-1, the maximum CCI 25.3305 × 10-7%2 °C-3 min-2, and the minimum Em 10.6403 kJ min-1. This study supplies new insights into combustion technology of sludge.


Assuntos
Oryza , Esgotos , Biomassa , Cinética , Termogravimetria
19.
J Environ Manage ; 292: 112813, 2021 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-34030018

RESUMO

Constructed wetland (CW) has obvious advantages in wastewater treatment of medium and small towns. However, there is a lack of health monitoring research on CW system clogging. The electrical conductivity (EC) of wastewater purified by CW is related to the concentration of pollutants, which can reflect the CW clogging. The objectives of this study are to reveal the mechanisms of CWs substrate clogging from the perspective of wastewater EC changes, and provide an important reference for the health evaluation of CWs. The EC changes of nine CWs substrates (quartz sand, zeolite, gravel, coarse sand, straw biochar, sludge biochar, clay ceramsite, fly ash ceramsite and shale ceramsite) under different conditions (purified water, wastewater and wastewater + NaCl) were tested, and comparative analysis was used to reveal the influence of different substrate materials on the change of wastewater EC. The results show that the adsorption ability of substrate material isn't the main factor affecting the EC of wastewater, and the soluble component in the material is the important factor to cause the difference of EC increment. Under the condition of 0.4-1.0 g L-1 NaCl concentration, the adsorption of substrate materials had little effect on the EC of wastewater, and the effect of NaCl used in CW tracer experiment was good. Quartz sand, coarse sand, gravel and sludge biochar have little influence on the change of wastewater EC. Other materials that have great influence on the change of wastewater EC can be treated by modifying or controlling the mixing ratio. The results are of great significance to reveal the clogging state of CW system and to carry out health assessment research.


Assuntos
Águas Residuárias , Áreas Alagadas , Condutividade Elétrica , Esgotos , Eliminação de Resíduos Líquidos
20.
Environ Pollut ; 281: 117018, 2021 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-33813198

RESUMO

Sludge incineration technology is facing the problem of gaseous pollutant discharge. The control of NOx emissions is the key to reducing the impact of sludge combustion on environmental pollution. In this study, Fenton/CaO was used to condition municipal sludge, which was subsequently mixed with rice husk to fabricate briquette fuel for combustion experiments. The effects of the conditioner dosages, mass ratios of the rice hull to sludge, and the combustion temperatures on NOx emissions from briquette combustion were studied. The results showed that the NOx emissions decreased with increasing doses of conditioned sludge. In addition, with an increase in the rice husk ratio in the briquette, the NOx emissions decreased and the conversion rate increased. Additionally, with an increasing combustion temperature, the combustion of molded fuel became more complete. The NOx emission of conditioned sludge combustion was reduced by approximately 1.3 times compared with that of the sludge alone. Using the response surface methodology, the optimized conditions were obtained as follows: the rice husk mixing ratio is 43.8%, the Fenton/CaO conditioner dosage is 220 mg/g, and the temperature is 829 °C. The minimum NOx emission concentration was predicted to be 0.845 mg/g. The NOx emission laws observed from the combustion of mixed fuel pellets are believed to provide basic data for a new sludge treatment method.


Assuntos
Poluentes Atmosféricos , Oryza , Poluentes Atmosféricos/análise , Gases , Incineração , Esgotos
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