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1.
Antioxidants (Basel) ; 13(5)2024 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-38790627

RESUMO

This study aimed to assess the influence of varying dietary levels of astaxanthin (AST) on the growth, antioxidant capacity and lipid metabolism of juvenile swimming crabs. Six diets were formulated to contain different AST levels, and the analyzed concentration of AST in experimental diets were 0, 24.2, 45.8, 72.4, 94.2 and 195.0 mg kg-1, respectively. Juvenile swimming crabs (initial weight 8.20 ± 0.01 g) were fed these experimental diets for 56 days. The findings indicated that the color of the live crab shells and the cooked crab shells gradually became red with the increase of dietary AST levels. Dietary 24.2 mg kg-1 astaxanthin significantly improved the growth performance of swimming crab. the lowest activities of glutathione (GSH), total antioxidant capacity (T-AOC), superoxide dismutase (SOD) and peroxidase (POD) were found in crabs fed without AST supplementation diet. Crabs fed diet without AST supplementation showed lower lipid content and the activity of fatty acid synthetase (FAS) in hepatopancreas than those fed diets with AST supplementation, however, lipid content in muscle and the activity of carnitine palmitoyl transferase (CPT) in hepatopancreas were not significantly affected by dietary AST levels. And it can be found in oil red O staining that dietary 24.2 and 45.8 mg kg-1 astaxanthin significantly promoted the lipid accumulation of hepatopancreas. Crabs fed diet with 195.0 mg kg-1 AST exhibited lower expression of ampk, foxo, pi3k, akt and nadph in hepatopancreas than those fed the other diets, however, the expression of genes related to antioxidant such as cMn-sod, gsh-px, cat, trx and gst in hepatopancreas significantly down-regulated with the increase of dietary AST levels. In conclusion, dietary 24.2 and 45.8 mg kg-1 astaxanthin significantly promoted the lipid accumulation of hepatopancreas and im-proved the antioxidant and immune capacity of hemolymph.

2.
Artigo em Inglês | MEDLINE | ID: mdl-36231659

RESUMO

Mining activities are one of the main contamination sources of Cd in soil. However, the information about the influence of silver mining on Cd pollution in soil in mining-affected areas is limited. In the present study, sixteen paired soil and rice grain samples were collected from the farmland along the Luxi River nearby a silver mine in Yingtan City, Jiangxi Province, China. The total, bioavailable, and fraction of Cd in soil and Cd content in rice grain were determined by inductively coupled plasma mass spectrometry. The transformation of Cd in the soil-rice system and potential health risk via consumption of these rice grains were also estimated. The results showed that Cd concentration in these paddy soils ranged from 0.21 to 0.48 mg/kg, with the mean Cd concentration (0.36 mg/kg) exceeded the national limitation of China (0.3 mg/kg, GB 15618-2018). Fortunately, all these contaminated paddy soils were just slightly polluted, with the highest single-factor pollution index value of 1.59. The DTPA- and CaCl2-extractable Cd in these paddy soils ranged from 0.16 to 0.22 mg/kg and 0.06 to 0.11 mg/kg, respectively, and the acid-soluble Cd occupied 40.40% to 52.04% of the total Cd, which was the highest among different fractions. The concentration of Cd in rice grain ranged from 0.03 to 0.39 mg/kg, and the mean Cd concentration in rice grain (0.16 mg/kg) was within the national limitation of China (0.2 mg/kg, GB 2762-2017). The bioaccumulation factor of Cd in rice grain ranged from 0.09 to 1.18, and its correlation with various indicators was nonsignificant (p < 0.05). Health risk assessment indicated that the noncarcinogenic risk for local rice consumers was within the acceptable range, but the carcinogenic risk (CR) was ranging from 1.24 × 10-2 to 1.09 × 10-3 and higher than the acceptable range (1.0 × 10-4), indicating that the local rice consumers suffered serious risk for carcinogenic diseases. The results of the present study can provide reference for safety production of rice in silver mining-affected areas.


Assuntos
Oryza , Poluentes do Solo , Cádmio/análise , Cloreto de Cálcio , China , Grão Comestível/química , Oryza/química , Ácido Pentético , Medição de Risco , Prata/análise , Solo/química , Poluentes do Solo/análise
3.
Zhongguo Gu Shang ; 35(8): 736-9, 2022 Aug 25.
Artigo em Chinês | MEDLINE | ID: mdl-35979766

RESUMO

OBJECTIVE: To explore the effects of different administration methods of tranexamic acid(TXA) on the perioperative blood loss, hidden blood loss, transfusion rate and adverse reactions in lumbar spinal decompression and fusion. METHODS: Sixty patients who received lumbar spinal canal decompression and fusion from July 2019 to July 2020 were enrolled and divided into observation group and control group, with 30 cases in each group. The observation group was given 2 g TXA orally at 2 hours before operation, control group was given 1 g TXA for 5-10 min before skin incision and 6 hours after operation intravenously. The intraoperative blood loss, postoperative drainage, total blood loss, hidden blood loss, drainage tube removal time, blood transfusion rate, venous thrombosis rate, adverse event rate were recorded respectively. The changes of hemoglobin(Hb) and hematocrit (HCT) were observed before operation and 1, 3 days after operation. RESULTS: Hb and HCT at 1 and 3 days after operation were significantly improved compared with those before operation(P<0.01). However, there was no significant difference between the groups(P>0.05). There were no significant difference in amount of blood loss, postoperative drainage, total blood loss, intraoperative blood loss, hidden blood loss, postoperative drainage time, and blood transfusion rate between two groups (P>0.05). There were no venous thrombosis and adverse events occurred in both groups. CONCLUSION: During the perioperative period of lumbar spinal decompression and fusion, oral TXA and intravenous TXA have the same effect in reducing perioperative blood loss and are safe and reliable. It is recommended that oral TXA be used to save medical costs and convenience.


Assuntos
Antifibrinolíticos , Fusão Vertebral , Ácido Tranexâmico , Trombose Venosa , Antifibrinolíticos/uso terapêutico , Perda Sanguínea Cirúrgica/prevenção & controle , Descompressão , Humanos , Hemorragia Pós-Operatória , Canal Medular , Fusão Vertebral/métodos , Ácido Tranexâmico/uso terapêutico , Trombose Venosa/etiologia
4.
Toxics ; 10(6)2022 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-35736924

RESUMO

As an eco-friendly and efficient adsorbent for removal of potential toxic metals from aqueous solution, biochar has received widespread attention. In the present study, wheat straw biochar (BC) and corresponding modified biochar (HNC) were used to remove Cu2+, Cd2+ and Pb2+ from an aqueous solution. The influence of the environment factors on metals adsorption and adsorption mechanism were discussed in detail. The results showed that the HNC had porous structures and owned ample functional groups (-OH, -COOH and C-N groups) compared with the BC. In the single system, the adsorption capacities of HNC for Cu2+, Cd2+ and Pb2+ at a pH of 5.5 were 18.36, 22.83 and 49.38 mg/g, which were 76.89%, 164.36% and 22.75% higher than that of the BC, respectively. In addition, the adsorption process of Cu2+ and Cd2+ on BC and HNC fitted to the Langmuir isotherm model and pseudo-second-order kinetics, but the adsorption of Pb2+ on BC and HNC fitted to the Langmuir isotherm model and pseudo-first-order kinetics. Adsorption isotherms indicated that the adsorption of Cu2+, Cd2+ and Pb2+ by BC and HNC was a spontaneous endothermic process. The competitive adsorption of mixed metal ions (Cu2+, Cd2+ and Pb2+) revealed that HNC was more preferential to adsorb Cu2+ compared with Cd2+ and Pb2+. Furthermore, Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy analyses revealed that the main adsorption mechanisms were surface complexation and precipitation, and the adsorbed Cu2+, Cd2+ and Pb2+ on HNC mainly exist as CuO, Cd(OH)2, Pb3O4 and Pb(OH)2.

5.
Water Res ; 221: 118741, 2022 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-35752094

RESUMO

Seasonal temperature changes significantly affect microbial community diversity, composition, and performance in wastewater treatment plants. However, the community assembly mechanisms under seasonal temperature variations remain unclear. Here, we carried out temperature cycling experiments (30 °C, 35 °C, 37 °C, 40 °C, 42 °C, 45 °C, 40 °C, and 30 °C) to investigate how temperature impacts microbial performance and co-occurrence network and how assembly processes determine the structure and function of microbial communities during treating aniline wastewater. During the 195-day operation, the system achieved an efficient and stable aniline removal of 99%. Interestingly, α-diversity and network complexity were negatively correlated with temperature but could be recovered when the temperature was returned to 30 °C. The results showed that functional redundancy was probably responsible for the excellent microbial performance during the whole process. Null model analyses presented that deterministic process dominated the community when the temperature was 30 °C, and stochasticity dominated the assembly process when the temperature was over 30 °C. Overall, the balance between stochastic and deterministic processes in the treatment of aniline wastewater mediated the reoccurrence of microbial community and co-occurrence network at different temperatures. This study provides new insights into microbial community reoccurrence under seasonal temperature changes and a theoretical basis for regulating microbial communities in wastewater treatment plants.


Assuntos
Microbiota , Purificação da Água , Compostos de Anilina , Processos Estocásticos , Temperatura , Águas Residuárias
6.
J Aquat Anim Health ; 34(4): 159-166, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-35262205

RESUMO

Vibrio parahaemolyticus is an important pathogen causing pandemic diseases in marine animals and brings about severe economic losses in aquaculture worldwide. The emergence of multi-drug-resistant V. parahaemolyticus and the prohibition of antibiotics both require the development of new therapeutic agents with alternative action. In this study, the effect of gallnut Galla chinensis water extract (GWE) on V. parahaemolyticus growth and virulence was investigated to determine the potential for its use in disease prevention and treatment in aquaculture. The minimum inhibitory concentration and minimum bactericidal concentration of GWE against V. parahaemolyticus were identified as 0.49 and 0.98 mg/mL, respectively. Membrane damage in V. parahaemolyticus was further verified through the increase of conductivity and leakage of nucleic acids and proteins. Moreover, GWE caused membrane invaginations and damage in V. parahaemolyticus as observed via scanning electron microscopy. After treatment with GWE, the biofilm formation and the activities of respiratory chain dehydrogenase, lactate dehydrogenase, and succinate dehydrogenase of V. parahaemolyticus were all significantly inhibited. These findings suggest that GWE has the potential to be developed as a supplemental agent to mitigate the infections caused by V. parahaemolyticus in aquaculture.


Assuntos
Vibrio parahaemolyticus , Animais , Antibacterianos/farmacologia , Virulência
7.
Artigo em Inglês | MEDLINE | ID: mdl-35270219

RESUMO

To understand the influence of Pb/Zn smelter on surrounding environment, 110 soil and 62 wheat grain samples (62 paired samples) were collected nearby a Pb/Zn smelter in Jiaozuo City, Henan Province, China. The content and spatial distribution of metal(loid)s in the soil-wheat system, and the potential health risk via consumption of wheat grains were determined. Results showed that the average content of Pb, Cd, As, Cu, Zn, and Ni in soil were 129.16, 4.28, 17.95, 20.43, 79.36, and 9.42 mg/kg, respectively. The content of Cd in almost all soil samples (99.1%) exceeded the national limitation of China (0.6 mg/kg). Spatial distribution analysis indicated that atmospheric deposition might be the main pollution source of Pb, Cd, As, and Zn in soil. In addition, the average content of Pb, Cd, As, Cu, Zn, and Ni in wheat grain were 0.62, 0.35, 0.10, 3.7, 35.77, and 0.15 mg/kg, respectively, with the average Pb and Cd content exceeding the national limitation of China. The average bioaccumulation factor of these metal(loid)s followed the following order: Zn (0.507) > Cu (0.239) > Cd (0.134) > Ni (0.024) > Pb (0.007) > As (0.006). Health risk assessment indicated that the average noncarcinogenic risk of children (6.78) was much higher than that of adults (2.83), and the carcinogenic risk of almost all wheat grain is higher than the acceptable range, with an average value of 2.43 × 10−2. These results indicated that humans who regularly consume these wheat grains might have a serious risk of noncarcinogenic and carcinogenic diseases.


Assuntos
Metais Pesados , Poluentes do Solo , Adulto , Cádmio/análise , Criança , China , Grão Comestível/química , Monitoramento Ambiental , Humanos , Chumbo/análise , Metais Pesados/análise , Medição de Risco , Solo , Poluentes do Solo/análise , Triticum , Zinco/análise
8.
Environ Technol ; 43(17): 2604-2611, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33577396

RESUMO

A previous isolated Gordonia sp. (Lff) was used to degrade di-n-octyl phthalate (DOP) contamination in both aqueous solution and soil. The influence of temperature, pH, inoculum size, salt content and initial concentration of DOP on DOP degradation by Lff were analysed. The response of soil bacterial community to DOP and Lff was also analysed by Illumina MiSeq sequence method. Results showed that the optimal temperature, pH, inoculum size and salt content were 35oC, 8.0, 5% and <5%, respectively. Under the optimal condition, more than 91.25% of DOP with different initial concentrations (100-2000 mg/L) could be degraded by Lff. Kinetics analysis indicated that biodegradation of DOP by Lff could be described by first-order kinetics (R2 > 0.917) with the half-life (t1/2) changing irregularly between 0.58 and 0.83 d. In addition, Lff enhanced the removal of DOP in soil and alleviated the toxicity of DOP on soil microorganisms. Furthermore, its influence on soil bacterial community is not obvious. These results suggested that Lff was effective in remediating DOP contamination in different environments.


Assuntos
Bactéria Gordonia , Ácidos Ftálicos , Biodegradação Ambiental , Bactéria Gordonia/metabolismo , Ácidos Ftálicos/química , Ácidos Ftálicos/metabolismo , Solo
9.
Ecotoxicol Environ Saf ; 220: 112370, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-34058673

RESUMO

A 6 weeks pot culture experiment was carried out to investigate the stabilization effects of a modified biochar (BCM) on metals in contaminated soil and the uptake of these metals by wheat seedlings. The results showed that the application of BCM significantly increased the soil fertility, the biomass of wheat seedling roots increased by more than 50%, and soil dehydrogenase (DHA) and catalase (CAT) activities increased by 369.23% and 12.61%, respectively. In addition, with the application of BCM, the diethylenetriaminepentaacetic acid extractable (DTPA-extractable) Cd, Pb, Cu and Zn in soil were reduced from 2.34 to 0.38 mg/kg, from 49.27 to 25.65 mg/kg, from 3.55 mg/kg to below the detection limit and from 4.05 to 3.55 mg/kg, respectively. Correspondingly, the uptake of these metals in wheat roots and shoots decreased by 62.43% and 79.83% for Cd, 73.21% and 66.32% for Pb, 57.98% and 68.92% for Cu, and 40.42% and 43.66% for Zn. Furthermore, BCM application decreased the abundance and alpha diversity of soil bacteria and changed the soil bacterial community structure dramatically. Overall, BCM has great potential for the remediation of metal-contaminated soils, but its long-term impact on soil metals and biota need further research.


Assuntos
Bactérias/efeitos dos fármacos , Carvão Vegetal/farmacologia , Metais Pesados/metabolismo , Plântula/metabolismo , Poluentes do Solo/metabolismo , Solo/química , Triticum/efeitos dos fármacos , Disponibilidade Biológica , Biomassa , Cádmio/metabolismo , Poluição Ambiental , Raízes de Plantas/metabolismo , Plântula/efeitos dos fármacos , Plântula/crescimento & desenvolvimento , Microbiologia do Solo , Triticum/crescimento & desenvolvimento , Triticum/metabolismo
10.
Environ Sci Pollut Res Int ; 28(29): 38466-38475, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33733407

RESUMO

How to recycle metals from the waste resources becomes a hotspot all around the world. Non-ferrous residues, which was produced by non-ferrous melting industry, and various of Cu and Co compounds exist in the residues in the form of CuxOy, CuxSy, CoxSy. In order to efficiently extract valuable metals from the non-ferrous residues, this study investigated the bioleaching behavior of Cu and Co from non-ferrous residues, using iron-oxidizing bacteria (IOB, Leptospirillum ferriphilum CS13) and sulfur-oxidizing bacteria (SOB, Acidithiobacillus caldus S2) by controlling the microbial composition, initial pH, and initial ferrous ion concentration. The results showed that IOB had a better performance on extracting Cu and Co than that of SOB, especially for Cu. Furthermore, 77.7 and 79.8% of Cu and Co were extracted under the optimal ratio of the initial number of IOB and SOB (1:1) after bioleaching, which was more than that when bioleaching by any one of these two kinds of bacteria. However, the changes of initial pH and ferrous ion concentration could not significantly enhance bioleaching performance. The results indicated that bioleaching had a good performance on recovering of metals from non-ferrous residues and excellent application prospect for the cleaner resource recycling.


Assuntos
Cobre , Ferro , Acidithiobacillus , Bactérias , Cobalto , Oxirredução , Enxofre
11.
J Hazard Mater ; 406: 124641, 2021 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-33321321

RESUMO

It is important to obtain bacteria with the ability for reduction of dyes and Cr(Ⅵ) since dyes and Cr(Ⅵ) are often co-exist in textile wastewater. In this study, a new strain belonging to Ochrobactrum anthropi was isolated from textile wastewater, and could efficiently reduce Reactive Black 5 (RB 5) and Cr(Ⅵ). The results showed the degradation efficiency of RB 5 could achieve 100% and reduction efficiency of Cr(Ⅵ) was up to 80% within 3 days at initial RB 5 and Cr(Ⅵ) concentration of 400 mg/L and 20 mg/L. Mn2+ and Cu2+ could enhance the removal of RB 5 and Cr(Ⅵ), respectively. Glycerin, as electron donor, improved reduction efficiencies of RB 5 and Cr(Ⅵ). In addition, reduction mechanisms were further investigated. The results demonstrated that decreasing of RB 5 and Cr(Ⅵ) concentration were mainly through extracellular bioreduction rather than by adsorption. The FTIR and XPS analyses revealed that the O‒H, C‒C and C‒H groups on the cell surface might be involved in the reduction of RB 5 and Cr(Ⅵ). The information gives useful insights into understanding of how the bacterium reduce RB 5 and Cr(Ⅵ). The results indicated that the strain had excellent application prospect for treating industrial wastewater.


Assuntos
Ochrobactrum anthropi , Cromo , Naftalenossulfonatos
12.
Ecotoxicol Environ Saf ; 207: 111294, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-32931971

RESUMO

Heavy metal contamination in soil has attracted great attention worldwide. In situ stabilization has been considered an effective way to remediate soils contaminated by heavy metals. In the present research, a multiple-modified biochar (BCM) was prepared to stabilize Cd and Cu contamination in two different soils: a farmland soil (JYS) and a vegetable soil (ZZS). The results showed that BCM was a porous-like flake material and that modification increased its specific surface area and surface functional groups. The incubation experiment indicated that BCM decreased diethylenetriaminepentaacetic (DTPA)-extractable Cd and Cu by 92.02% and 100.00% for JYS and 90.27% and 100.00% for ZZS, respectively. The toxicity characteristic leaching procedure (TCLP)-extractable Cd and Cu decreased 66.46% and 100.00% for JYS and 46.33% and 100.00% for ZZS, respectively. BCM also reduced the mobility of Cd and Cu in soil and transformed them to more stable fractions. In addition, the application of BCM significantly increased the soil dehydrogenase, organic matter content and available K (p < 0.05). These results indicate that BCM has great potential in the remediation of Cd- and Cu-contaminated soil.


Assuntos
Cádmio/análise , Carvão Vegetal/química , Cobre/análise , Recuperação e Remediação Ambiental/métodos , Poluentes do Solo/análise , Solo/química , Adsorção , China , Propriedades de Superfície
13.
Environ Technol ; 42(17): 2749-2756, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31961776

RESUMO

Di-n-octyl phthalate (DOP), a plasticizer used in many different industrial products, is a frequently observed pollutant in the environment. Biodegradation by microorganisms is considered to be a realistic choice for the remediation of DOP contamination. In the present research, the halotolerant bacterial consortium (LF) enriched in our previous research was used to degrade DOP. It was found that the optimal conditions for LF to degrade DOP was temperature 30oC, pH 6.0, inoculum size >5%, and salt content <3%. LF could degrade a high concentration of DOP (2000 mg/L) with the removal efficiency of 96.33%. Substrate inhibition analyses indicated that the inhibition constant, maximum specific degradation rate and half-saturation constant were 2544.6 mg/L, 0.7 d-1 and 59.1 mg/L, respectively. Based on the analysis of the gas chromatography-mass spectrometry (GC-MS), the biodegradation pathway for DOP by LF was proposed. Furthermore, LF could degrade DOP in soil (100 mg/kg) with the highest removal efficiency of 89.3%. This study is the first report on DOP biodegradation by bacterial consortium. These results suggest that LF can be used to remediate DOP-contaminated environment.


Assuntos
Ácidos Ftálicos , Solo , Biodegradação Ambiental , Temperatura
14.
Environ Sci Pollut Res Int ; 27(36): 45581-45590, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32803576

RESUMO

Heavy metal-contaminated sediment is a common environmental problem. In situ stabilization is an effective and low-cost method to remediate heavy metal-contaminated sediment. In this study, a red mud-based low-cost composite (RMM) was used to stabilize heavy metal-contaminated sediment. RMM was mixed with heavy metal-contaminated sediment at the doses of 0%, 1%, 3% and 5%. The CaCl2-extractable, DTPA-extractable, leachability (TCLP) and heavy metal fractions were analysed to evaluate the stabilization efficiency of RMM for heavy metals. The selected properties and microbial activities of the sediment were analysed to verify the safety of RMM to sediment. The results showed that RMM reduced the DTPA-, CaCl2- and TCLP-extractable heavy metals in sediment. At an RMM dose of 5%, DTPA-, CaCl2- and TCLP- extractable heavy metals were reduced by 7.60%, 72.34% and 69.24% for Pb; 18.20%, 76.7% and 23.57% for Cd; 32.7%, 96.50% and 49.64% for Zn; and 35.0%, 61.20% and 55.27% for Ni, respectively. TCLP- and DTPA-extractable Cu was reduced by 71.15% and 12.90%, respectively. In contrast, CaCl2-extractable Cu increased obviously after the application of RMM. RMM reduced the acid-soluble fraction of Zn by 6.99% and increased the residual fraction of Ni by 4.28%. However, the influence of RMM on the fractions of Pb, Cd and Cu was nonsignificant. In addition, the application of RMM increased the pH values of the sediment, and the microbial activity in the sediment was also obviously enhanced. These results indicated that RMM has great potential in the remediation of heavy metal-contaminated sediment.


Assuntos
Metais Pesados , Poluentes do Solo , Disponibilidade Biológica , Poluentes do Solo/análise
15.
Huan Jing Ke Xue ; 41(5): 2381-2389, 2020 May 08.
Artigo em Chinês | MEDLINE | ID: mdl-32608857

RESUMO

To improve the stabilization efficiency of biochar on heavy metals in soil, the magnetic material was synthesized by a mild liquid-phase reduction and oxidation method. A soil incubation experiment[0%, 0.3%, 0.6%, and 1.0% (ω)] was carried out to verify the stabilization efficiency of magnetic biochar on heavy metals in soil and its influence on soil properties. The potential stabilization mechanism of magnetic biochar on heavy metals was also analyzed. The results showed that the application of magnetic biochar decreased the bioavailable Cd, Cu, Ni, Pb, and Zn in soil, and the decrease ratio was positively correlated with the application rate of the magnetic biochar. After 24 days incubation, the content of bioavailable Cd, Cu, Ni, Pb, and Zn in soil decreased by 27.52%, 49.55%, 55.83%, 27.33%, and 26.01%, respectively[application rate (ω)at 1%]. However, the fraction of heavy metals in the soil did not change significantly, which may mainly be attributed to the relatively weak bonding mechanisms between the metals and the biochar. The application of magnetic biochar also improved soil properties. The pH of the soil increased by 0.7 units; dehydrogenase activity increased by six times; and catalase activity and organic matter increased by 37.06% and 22.11%, respectively.

16.
Sci Total Environ ; 729: 139060, 2020 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-32498182

RESUMO

Various types of biochar have been widely used to remediate soil contamination from heavy metals (HMs) and to reduce HM mobility and bioavailability in soils in recent years. Most researchers have paid attention to the beneficial effects of biochar during the remediation process, but few have emphasized their negative effects and the challenges for their application. In this review, the negative effects and challenges of applying biochar for the remediation of HM-contaminated soils are thoroughly summarized and discussed, including the changeable characteristics of biochar, biochar over-application, toxic substances in biochar, activation of some HMs in soils by biochar, nonspecific adsorption, and the negative influences of biochar on soil microorganisms and plants. In addition, further research directions and several recommendations (standardization, long-term field experiments, mechanisms research and designer biochars) were also proposed to enable the large-scale application of biochar for the remediation of HM-contaminated soils.


Assuntos
Solo , Carvão Vegetal , Recuperação e Remediação Ambiental , Metais Pesados , Poluentes do Solo
17.
Ecotoxicol Environ Saf ; 197: 110600, 2020 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-32289632

RESUMO

Cadmium (Cd) contamination in agricultural soil is a worldwide environmental problem. In situ stabilization has been considered an effective approach for the remediation of Cd-contaminated agricultural soil. However, information about the long-term effects of amendment on soil properties and stabilization efficiency remains limited. In the present study, mercapto-functionalized nano-silica (MPTS/nano-silica) was used to stabilize Cd in contaminated agricultural soil under field conditions for three years (with application rates of 0%, 0.2%, 0.4%, 0.6%, 0.8% and 1.0%). The application of MPTS/nano-silica reduced the soil aggregate stability (PDA0.25) (14.8%) and available K (24.9%) and significantly increased the soil dehydrogenase (DHA) (43.4%), yield of wheat grains (33.5%) and Si content in wheat tissues (55.2% in leaf, 50.4% in stem, and 37.7% in husk) (p < 0.05). More importantly, MPTS/nano-silica decreased the leachability (36.0%) and bioavailability (54.3%) of Cd in the soil and transformed Cd into a more stable fraction. The content of Cd in wheat grains decreased by 53.9%, 61.9% and 54.1% in 2017, 2018 and 2019, respectively, in comparison with the control. These results indicated that MPTS/nano-silica has long-term stabilization effects on Cd in agricultural soil and is a potential amendment for the remediation of Cd-contaminated agricultural soils.


Assuntos
Cádmio/análise , Dióxido de Silício/química , Poluentes do Solo/análise , Agricultura , Biodegradação Ambiental , Cádmio/farmacocinética , Nanopartículas/química , Solo/química , Poluentes do Solo/farmacocinética , Triticum/química , Triticum/metabolismo
18.
Bull Environ Contam Toxicol ; 103(6): 860-864, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31605159

RESUMO

In the present study, a pot-culture experiment was conducted to investigate the influences of mercapto-functionalized nanosilica (MPTS/nano-silica) on Cd stabilization and uptake by wheat seedling. Four different dosages of MPTS/nano-silica were applied: 0%, 0.3%, 0.6% and 1% (w/w), and the changes of DTPA-extractable Cd in soil, soil properties, wheat biomass, and uptake of Cd to wheat tissues (shoots and roots) were measured throughout the experiment. The results showed that the application of MPTS/nano-silica (at dose of 1%) reduced the DTPA-extractable Cd from 4.21 to 1.45 mg/kg in the soil. Whereas the addition of MPTS/nano-silica hardly changed soil properties and slightly decreased the biomass of wheat seedling. In addition, Cd concentration in wheat tissues decreased from 6.388 to 2.625 mg/kg for shoot, and from 18.622 to 6.368 mg/kg for root. These results indicated that MPTS/nano-silica is an ideal candidate for remediation of Cd contaminated agricultural soil.


Assuntos
Cádmio/análise , Recuperação e Remediação Ambiental/métodos , Nanopartículas/química , Dióxido de Silício/química , Poluentes do Solo/análise , Compostos de Sulfidrila/química , Triticum/efeitos dos fármacos , Agricultura , Biomassa , Plântula/química , Plântula/efeitos dos fármacos , Plântula/crescimento & desenvolvimento , Solo/química , Triticum/química , Triticum/crescimento & desenvolvimento
19.
Sci Total Environ ; 689: 645-651, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31279210

RESUMO

A bacterial strain (Gordonia sp. Lff) capable of efficiently degrading di-(2-ethylhexyl) phthalate (DEHP) was isolated from river sludge. The optimal pH and temperature for the degradation of DEHP by Lff were 7.0 and 35 °C, respectively. Lff could degrade high concentrations of DEHP (100-2000 mg/L) with a degradation efficiency of over 91.43%. The DEHP degradation curves fit well with first-order kinetics, with a half-life ranging from 0.598 to 0.746 d. Substrate inhibition analyses showed that the maximum specific degradation rate, half-saturation constant and inhibition constant were 0.8 d-1, 45.8 mg/L and 462.18 mg/L, respectively. A detailed biodegradation pathway of DEHP was proposed based on GC-MS analysis. Furthermore, Lff could also efficiently degrade DEHP in soils. DEHP or DEHP plus Lff changed the bacterial community in soils, and Lff accelerated the shaping of the bacterial community. To the best of our knowledge, this study is the first to perform a detailed investigation into the biodegradation of DEHP in soil by Gordonia sp. and its effect on the soil bacterial community. These results suggest that Lff is an ideal candidate for the bioremediation of DEHP-contaminated environments.


Assuntos
Dietilexilftalato/metabolismo , Poluição Ambiental/prevenção & controle , Recuperação e Remediação Ambiental/métodos , Bactéria Gordonia/metabolismo , Poluentes do Solo/metabolismo , Biodegradação Ambiental , Cromatografia Gasosa-Espectrometria de Massas , Solo/química
20.
Front Behav Neurosci ; 13: 277, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31920583

RESUMO

Few studies exist regarding the mechanism prior to response by which cognitive impairment may induce error in a single long-lasting task. The present study intends to clarify the changes in cognition at the electrophysiological level. Changes in amplitude and latency of N1, P2, N2, and P3 components of event-related potentials (ERPs) were analyzed for error and correct trials during normal and fatigue. Twenty-nine participants had to perform a 2-back working memory (WM) task for 100 min. The first 10 min and the last 10 min of the task were used as the normal state and fatigue state of the participant, respectively. EEG data were obtained from the first 10-min period and the final 10-min period. The results revealed smaller P3 and P2 amplitudes and longer P2 and N2 latency in the final 10-min which was after a long-lasting time task. Moreover, smaller P3 and P2 amplitudes but larger N2 amplitudes were observed in error trials for both states. Our results indicated that: (1) long lasting involvement in a cognitive task had a detrimental effect on attention, memory updating and cognitive control; and (2) impaired attention, impairments in memory updating and cognitive control were related to task errors. Our results imply that several impaired cognitive processes were consistently associated with the error and the altered ERP represents the neural patterns prior to error response in mental fatigue state.

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