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BACKGROUND: E1A-associated 300-kDa protein (P300), an endogenous histone acetyltransferase, contributes to modifications of the chromatin landscape of genes involved in multiple cardiovascular diseases. Ferroptosis of vascular smooth muscle cells (VSMCs) is a novel pathological mechanism of aortic dissection. However, whether P300 regulates VSMC ferroptosis remains unknown. METHODS: Cystine deprivation (CD) and imidazole ketone erastin (IKE) were used to induce VSMC ferroptosis. Two different knockdown plasmids targeting P300 and A-485 (a specific inhibitor of P300) were used to investigate the function of P300 in the ferroptosis of human aortic smooth muscle cells (HASMCs). Cell counting kit-8, lactate dehydrogenase and flow cytometry with propidium iodide staining were performed to assess the cell viability and death under the treatment of CD and IKE. BODIPY-C11 assay, immunofluorescence staining of 4-hydroxynonenal and malondialdehyde assay were conducted to detect the level of lipid peroxidation. Furthermore, co-immunoprecipitation was utilized to explore the interaction between P300 and HIF-1α, HIF-1α and P53. RESULTS: Compared with normal control, the protein level of P300 was significantly decreased in HASMCs treated with CD and IKE, which was largely nullified by the ferroptosis inhibitor ferrostatin-1 but not by the autophagy inhibitor or apoptosis inhibitor. Knockdown of P300 by short-hairpin RNA or inhibition of P300 activity by A-485 promoted CD- and IKE-induced HASMC ferroptosis, as evidenced by a reduction in cell viability and aggravation of lipid peroxidation of HASMCs. Furthermore, we found that hypoxia-inducible factor-1α (HIF-1α)/heme oxygenase 1 (HMOX1) pathway was responsible for the impacts of P300 on ferroptosis of HASMCs. The results of co-immunoprecipitation demonstrated that P300 and P53 competitively bound HIF-1α to regulate the expression of HMOX1. Under normal conditions, P300 interacted with HIF-1α to inhibit HMOX1 expression, while reduced expression of P300 induced by ferroptosis inducers would favor HIF-1α binding to P53 to trigger HMOX1 overexpression. Furthermore, the aggravated effects of P300 knockdown on HASMC ferroptosis were largely nullified by HIF-1α knockdown or the HIF-1α inhibitor BAY87-2243. CONCLUSION: Thus, our results revealed that P300 deficiency or inactivation facilitated CD- and IKE-induced VSMC ferroptosis by activating the HIF-1α/HMOX1 axis, which may contribute to the development of diseases related to VSMC ferroptosis.
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Ferroptose , Músculo Liso Vascular , Humanos , Heme Oxigenase-1/genética , Heme Oxigenase-1/metabolismo , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Músculo Liso Vascular/metabolismo , Miócitos de Músculo Liso/metabolismo , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismoRESUMO
The behavior of vascular smooth muscle cells (VSMCs) contributes to the formation of neointima. We previously found that EHMT2 suppressed autophagy activation in VSMCs. BRD4770, an inhibitor of EHMT2/G9a, plays a critical role in several kinds of cancers. However, whether and how BRD4770 regulates the behavior of VSMCs remain unknown. In this study, we evaluate the cellular effect of BRD4770 on VSMCs by series of experiments in vivo and ex vivo. We demonstrated that BRD4770 inhibited VSMCs' growth by blockage in G2/M phase in VSMCs. Moreover, our results demonstrated that the inhibition of proliferation was independent on autophagy or EHMT2 suppression which we previous reported. Mechanistically, BRD4770 exhibited an off-target effect from EHMT2 and our further study reveal that the proliferation inhibitory effect by BRD4770 was associated with suppressing on SUV39H2/KTM1B. In vivo, BRD4770 was also verified to rescue VIH. Thus, BRD4770 function as a crucial negative regulator of VSMC proliferation via SUV39H2 and G2/M cell cycle arrest and BRD4770 could be a molecule for the therapy of vascular restenosis.
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Músculo Liso Vascular , Neointima , Humanos , Neointima/metabolismo , Proliferação de Células , Movimento Celular , Células Cultivadas , Histona-Lisina N-MetiltransferaseRESUMO
Introduction: The pathophysiology of coronary chronic total occlusion (CTO) has not been fully elucidated. Methods: In the present study, we aimed to investigate the potential plasma biomarkers associated with the pathophysiologic progression of CTO and identify protein dynamics in the plasma of CTO vessels immediately after successful revascularization. We quantitatively analyzed the plasma proteome profiles of controls (CON, n = 10) and patients with CTO pre- and post- percutaneous coronary intervention (PCI) (CTO, n = 10) by data-independent acquisition proteomics. We performed enzyme-linked immunosorbent assay (ELISA) to further confirm the common DEPs in the two-group comparisons (CON vs. CTO and CTO vs. CTO-PCI). Results: A total of 1936 proteins with 69 differentially expressed proteins (DEPs) were detected in the plasma of patients with CTO through quantitative proteomics analysis. For all these DEPs, gene ontology (GO) analysis and protein-protein interaction (PPI) analysis were performed. The results showed that most of the proteins were related to the negative regulation of proteolysis, regulation of peptidase activity, negative regulation of hydrolase activity, humoral immune response, and lipid location. Furthermore, we identified 1927 proteins with 43 DEPs in the plasma of patients with CTO vessels after immediately successful revascularization compared to pre-PCI. GO analysis revealed that the above DEPs were enriched in the biological processes of extracellular structure organization, protein activation cascade, negative regulation of response to external stimulus, plasminogen activation, and fibrinolysis. More importantly, we generated a Venn diagram to identify the common DEPs in the two-group comparisons. Seven proteins, ADH4, CSF1, galectin, LPL, IGF2, IgH, and LGALS1, were found to be dynamically altered in plasma during the pathophysiological progression of CTO vessels and following successful revascularization, moreover, CSF1 and LGALS1 were validated via ELISA. Conclusions: The results of this study reveal a dynamic pattern of the molecular response after CTO vessel immediate reperfusion, and identified seven proteins which would be the potential targets for novel therapeutic strategies to prevent coronary CTO.
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The recovery of polymeric substances from excess sludge is gaining significant research interest in future wastewater treatment technologies. We present a surfactant-enhanced ultrasonic method to extract mixed polymeric substances with typical functional groups from excess sludge. Four potential reasons were revealed for the higher efficiency upon ultrasonication with surfactant: low surface tension, damage of non-covalent bonds between extracellular polymeric substances and cells, enhanced dissolution of polymeric substances, and release of intracellular polymeric substances caused by cell lysis. The increase in extraction efficiency after the addition of cetyltrimethylammonium bromide and sodium dodecyl sulfate reached the maximum of 76.5% and 53.1%, respectively. The contents of polysaccharides, proteins, and DNA were approximately 50% of the total polymeric substances, and the content of protein was higher than that of polysaccharide; the concentration change of the surfactant had a minimal effect on these contents. For the polymeric substances extracted via ultrasonication with surfactant, the size was smaller than that for the non-surfactant extraction; moreover, the contents of metals decreased significantly (Al: 0.18% â 0%; Na: 0.15% â 0%; Ca: 0.24% â 0.11%), which was probably caused by the interaction between the surfactant and metal ions in the excess sludge. The surfactant had a negligible effect on the properties of polymeric substances, adsorption capacity of polymeric substances for heavy metal ions, and dewatering performance of sludge. The recycled polymeric substances may be used as a substitute for commercial adsorbents of heavy metal ions. Thus, the obtained results provide further insight into the recovery of polymeric substances from excess sludge via the surfactant-enhanced ultrasonic method.
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Esgotos , Eliminação de Resíduos Líquidos , Matriz Extracelular de Substâncias Poliméricas , Tensoativos , UltrassomRESUMO
Laboratory investigations were conducted to test the toxicity of aged petroleum sludge collected from Shengli Oil Field, the second largest oilfield in China, to earthworm Eisenia fetida. Various end points were measured in the earthworms, including mortality, growth, cocoon output, juvenile production, and avoidance behavioral response, to determine their comparative sensitivity for assessing harmful effects of petroleum-hydrocarbon-contaminated soil. The results showed that all these assays responded in a concentration-dependent manner, and two chronic end points, juvenile production and cocoon output, as well as avoidance behavioral response appeared to be sensitive end points for detecting toxicity of petroleum-hydrocarbon-contaminated soil. Comparatively, juvenile production exhibited similar sensitivity to avoidance behavior response, both of which were more sensitive than cocoon output, while mortality and adult growth were proposed as the least sensitive parameters. It was suggested that large amounts of petroleum sludge deposited in Shengli Oil Field may pose a potential threat to the local ecosystem, and the utility of multiple effects-based end points in earthworm E. fetida is useful to facilitate ecological risk assessments in hydrocarbon-contaminated sites.
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Monitoramento Ambiental , Oligoquetos/efeitos dos fármacos , Petróleo/toxicidade , Poluentes do Solo/toxicidade , Animais , Comportamento Animal/efeitos dos fármacos , Relação Dose-Resposta a Droga , Laboratórios , Oligoquetos/anatomia & histologiaRESUMO
Kitchen waste from dining rooms accounts for a considerable proportion of municipal solid garbage, and economical recycle ways are needed to be developed. This study investigated glucoamylase production from kitchen waste and the feasibility of kitchen waste hydrolysis by the crude enzymes produced. The key problems of high water content and poor porosity in kitchen waste for glucoamylase production under solid-state fermentation could be solved readily by the addition of corn stover or paddy husk. As a support medium, corn stover was better than paddy husk. Smashed kitchen waste (sKW) mixed with corn stover in the ratio of 3.75 : 1 (dry basis) produced 1838 U g(-1) of glucoamylase by Aspergillus niger UV-60 within 96 h. The enzyme productivity from kitchen waste was over two-fold higher than that from wheat bran with additional nutrients. Without any recovery treatment, the produced glucoamylase could be used directly to hydrolyse sKW slurry. The optimum enzyme dose 8% (crude enzyme/kichen waste, w/w) was not too big, and was sufficient to hydrolyse 10% (dry basis) sKW slurry to produce a maximum amount of reducing sugar of 55.4 g L(-1).
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Resíduos de Alimentos , Glucana 1,4-alfa-Glucosidase/metabolismo , Eliminação de Resíduos/métodos , Aspergillus niger/enzimologia , Biodegradação Ambiental , Glucana 1,4-alfa-Glucosidase/química , Hidrólise , Resíduos/análiseRESUMO
With a high rejection coefficient for trace pharmaceuticals and personal care products (PPCPs), forward osmosis (FO) membrane separation has become a cutting-edge technology in water treatment owing to its low energy consumption and low membrane fouling. Wastewater contains many types of PPCPs, and one pharmaceutical molecule affects the separation behaviors of other pharmaceuticals in FO. Therefore, simultaneous FO of multiple PPCPs needs to be investigated. In this study, the separation behaviors of four trace pharmaceuticals (ciprofloxacin (CIP), sulfamethoxazole (SMX), acetaminophen (ACP), carbamazepine (CBZ)), individually (termed "single pharmaceuticals") and in combination (termed "binary pharmaceuticals" as two pharmaceuticals were studied simultaneously), during FO were investigated at trace concentrations using ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The results showed that for single pharmaceuticals, the molecular sieve dominates their retention rate-the retention rate increases with increasing Stokes radius of the molecules (29.1 â 94.8% for 0.35 â 0.47 nm). For binary pharmaceuticals, the retention rates of both pharmaceuticals without charge decrease with increasing total molecule number (for ACP + CBZ, 31.4 â 52.1% (ACP), 75.1 â 83.0% (CBZ)). Negatively charged pharmaceuticals are mutually exclusive with the negatively charged FO membrane, resulting in the increase of the retention rate of pharmaceuticals (83.1 â 90.1% (CIP) when CIP + ACP â CIP + SMX). In the presence of a positively charged pharmaceutical, the retention rate of negatively charged pharmaceuticals decreases (85.7 â 80.4% (SMX) when SMX + ACP â SMX + CIP) because the positively charged pharmaceutical neutralizes the negative charge on the FO membrane surface, resulting in the weakening of electrostatic repulsion between the negatively charged pharmaceutical and FO membrane surface. The positively charged molecule attracts the negatively charged molecule, forming a couple of molecules with larger molecule weight and increasing the retention rate of the pharmaceuticals (80.4 â 88.2% (SMX) when pH = 7 â 5 for SMX + CIP). The results suggest that the interactions between pharmaceuticals cannot be ignored in the process of removing PPCPs by FO.
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Osmose , Purificação da Água , Cromatografia Líquida , Espectrometria de Massas em Tandem , Águas ResiduáriasRESUMO
OBJECTIVE: Well-differentiated fetal adenocarcinoma (WDFA) is a rare pulmonary carcinoma with low malignancy and favorable prognosis. All cases were collected, analyzed and summarized to better understand this disease. METHODS: We used the keywords "fetal adenocarcinoma" and "epithelial pulmonary blastoma (EPB)" to search WANFANG MED ONLINE, CNKI and NCBI PUBMED for cases reported by Chinese authors from 1987 to July 2015. RESULTS: A total of 64 cases reported in China were reviewed, and the details of the clinicopathological features of 45 cases were summarized. Among these 45 patients, 23 (23/45, 51.1%) patients were male and 22 (22/45, 48.9%) patients were female. The mean age at diagnosis was 35 ± 15 years old (range, 6-72 years old) with a bimodal peak in the second and third decades. Furthermore, 24 tumors (24/31, 77.4%) were found to have progressed past stage I, while only three (3/45, 6.7%) tumors had lymph nodes metastases. These tumor cells were 100% reactive for keratin, ß-catenin, Napsin A and PDGFRα when stained by these antibodies. Better survival could be obtained if the metastatic tumor is removed in some patients with metastases. Four (4/31, 12.9%) patients died due to their tumors. CONCLUSIONS: WDFA is very different to conventional adenocarcinoma in clinicopathology. It prefers to occur in the second and third decades. Lymph node metastasis is infrequent. Beta-catenin may be a potential marker for disease. Surgery is the best therapy method if the technology is feasible.
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In order to realize the disposal feasibility of rural garbage by incineration, 72 rural garbage sampling points of 12 provinces in China were chosen to analyse mass fraction of full component and combustible component, moisture content of full component and low heating value of rural garbage in spring, summer, autumn and winter of 2015. The results revealed that the mass fraction of combustible rural garbage components in wet basis followed the order of kitchen residual(13%-53%) > the rubber(10%-18%) > the paper(10%-15%) > the wood(0-10%) > the fabric(0-8%). The compositional difference of rural garbage was not apparent between villages and towns within the same administrative region. The average moisture content of full component in southern rural garbage was higher than that in northern area, and the average moisture content of national rural garbage was about 40.1%. The low heating value of rural garbage in full composition which surpassed 3500 kJ·kg-1 was more than 81% in the north China, but in the south China, it was 44%, 50%, 61% and 72% in spring, summer, autumn and winter, respectively. After sorting, the low heating value increased greatly, but the low heating value of southern rural garbage in spring was still less than 3500 kJ·kg-1, more than 56% towns and villages of southern rural garbage in summer, autumn and winter and annual northern rural garbage heating value met the heating value requirement of incineration disposal. Therefore, after sorting, the rural garbage by incineration disposal method was feasible to the north China rural garbage, but the south China rural garbage requires strengthened pretreatment process.
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A new method of determining the cumulate concentration of hydroxyl radicals in the TiO2/Ti photoelectrocatalytic (PEC) oxidation system was established by o-phenanthroline-Fe(II)(Fe(phen)3(2+)) spectrophotometry and using anion exchange membrane. Fe (phen)3(2+) can be oxidized to o-phenanthroline-Fe(III)(Fe(phen)3(3+)) by strong oxidization of hydroxyl radicals(*OH). Then the cumulate concentration of hydroxyl radicals can be calculated through determining the change of the Fe(phen)3(3+) absorbency at 509 nm. In addition, the research results showed the production rate of hydroxyl radicals was affected obviously by pH of solution, the cumulate concentration of hydroxyl radicals was the largest at nearby the initial pH 6.3 (isoelectric point), and the change direction of pH after illumination tended to nearby isoelectric point.
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Compostos Ferrosos/química , Radical Hidroxila/análise , Fenantrolinas/química , Análise Espectral/métodos , Titânio/química , Catálise , Eletroquímica , Concentração de Íons de Hidrogênio , Oxirredução , FotoquímicaRESUMO
We used polylactic acid (PLA) and starch to develop a slow-release carbon source and biofilm carrier by blending and fusing techniques for removing nitrate contamination from groundwater, investigated the changes of nitrate, nitrite concentrations and COD in denitrification process supplied by the slow-release carbon source in different mass ratios [PLA/starch (P: S) were 8:2, 7:3, 6:4, 5:5, respectively]. The experimental results demonstrated that the best mass ratio of PLA/starch was 5:5, resulting in a nitrate removal rate of more than 99%. A high denitrification performance was achieved in continuous fixed-bed reactor, the effluent nitrate concentration was below 2 mg x L(-1). These experiments provide scientific basis for the development of environmentally-friendly and controllable slow-release carbon source.
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Biofilmes , Carbono/química , Desnitrificação , Ácido Láctico/química , Polímeros/química , Amido/química , Nitratos/química , PoliésteresRESUMO
In this study, PCR-DGGE was used to analyze the microbial community structure in lactic acid fermentation from kitchen waste. The results showed that with Lactobacillus amylophilus inoculation, both the microbial diversity and lactic acid production in the open fermentation system were higher than those in the sterilized fermentation system. These results indicated that the microbial diversity and the lactic acid production have great correlation in the kitchen waste fermentation system. Through analyzing the sequence of some DNA bands excised from the DGGE gel, it showed that in addition to the inoculation of Lactobacillus amylophilus there were some indigenous lactic acid bacteria, such as Lactobacillus sp., Lactobacillus casei, Lactobacillus plantarum and indigenous hydrolytic bacteria, such as Pseudomonas sp.. These indigenous bacteria can help to promote lactic acid production. PCR-DGGE is feasible for analyzing the dynamic changes of microbial community structure in kitchen waste with complicated composition.
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Bactérias/classificação , Alimentos , Ácido Láctico/análise , Lactobacillales/isolamento & purificação , Eliminação de Resíduos/métodos , Bactérias/metabolismo , Biodiversidade , Eletroforese em Gel de Gradiente Desnaturante , Fermentação , Lactobacillales/classificação , Lactobacillales/metabolismo , Reação em Cadeia da Polimerase , Pseudomonas/isolamento & purificação , Pseudomonas/metabolismo , RestaurantesRESUMO
Cold-adapted microorganisms such as psychrotrophs and psychrophiles widely exist in the soils of sub-Arctic, Arctic, Antarctic, alpine, and high mountains, being the important microbial resources for the biodegradation of petroleum hydrocarbons at low temperature. Using the unique advantage of cold-adapted microorganisms to the bioremediation of petroleum hydrocarbon-contaminated soils in low temperature region has become a research hotspot. This paper summarized the category and cold-adaptation mechanisms of the microorganisms able to degrade petroleum hydrocarbon at low temperature, biodegradation characteristics and mechanisms of different petroleum fractions under the action of cold-adapted microorganisms, bio-stimulation techniques for improving biodegradation efficiency, e. g., inoculating petroleum-degrading microorganisms and adding nutrients or bio-surfactants, and the present status of applying molecular biotechnology in this research field, aimed to provide references to the development of bioremediation techniques for petroleum hydrocarbon-contaminated soils.
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Bactérias/metabolismo , Hidrocarbonetos/isolamento & purificação , Petróleo/metabolismo , Microbiologia do Solo , Poluentes do Solo/isolamento & purificação , Adaptação Fisiológica , Bactérias/classificação , Fenômenos Fisiológicos Bacterianos , Biodegradação Ambiental , Temperatura Baixa , Hidrocarbonetos/metabolismo , Poluentes do Solo/metabolismoRESUMO
One silicate bacteria strain SDB6 with good performance in silicon removal was isolated and screened from soil. Based on the morphological, physiological, biochemical characteristics and 16S rDNA sequence analysis, SDB6 was identified as Bacillus mucilaginosus strain. The effects of nitrogen source, pH, temperature, rotate speed and medium volume on the growth of SDB6 were investigated. The above factors were optimized using the orthogonal design. The optimized condition was described as follows: 10 g/L yeast, 250 mL flask with 50 mL culture medium, pH 7.5, 30 degrees C, 180 r/min. The bioleaching of un-desilicated and desilicated fly ash using the adapted Aspergillus niger AS 3.879M strain was carried out for 20d. The results indicated that the metal extraction yield in bioleaching increased obviously with desilication treatment comparing to that without desilication treatment. The extraction yield of Cu, Mn, Cr, Zn and Fe from desilicated fly ash was 31%, 75%, 60%, 60% and 48%, respectively. The total metals extraction yield of desilicated fly ash increased to 50%. The TCLP results of the fly ash after bioleaching indicated that the leaching toxicities of the treated fly ash were far lower than the regulated levels of China and permitted to the further landfill or reuse.
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Aspergillus niger/metabolismo , Bacillus/metabolismo , Carbono/metabolismo , Material Particulado/metabolismo , Eliminação de Resíduos/métodos , Silicatos/metabolismo , Bacillus/isolamento & purificação , Biodegradação Ambiental , Carbono/química , Cidades , Cinza de Carvão , Material Particulado/química , Silicatos/análiseRESUMO
Batch experiments were carried out to investigate the adsorption kinetics and thermodynamic characteristics of heavy metal ions Cu2+, Cd2+ and Pb2+ on the electric are furnace (EAF) slag from Baoshan Steel Factory. Several kinds of techniques including XRD analysis, BET specific surface analysis and SEM/EDS analysis were employed to determine the physico-chemical and surface characteristics of slag. Results indicated that the adsorption rate of heavy metal ions on the EAF slag was relatively high, and the sorption rate followed the order Cd2+ > Pb2+ > Cu2+. The adsorption kinetics obeyed first-order kinetics model (R2 > 0.99). Adsorption isotherm experiment showed that adsorption isotherm of heavy metal ions on slag fitted Langmuir model, and the maximum adsorption capacity of Cu2+, Cd2+ and Pb2+ was 0.101, 0.058 and 0.120 mmol x g(-1), respectively. The adsorption of heavy metal ions on slag was a spontaneous reaction (deltaG0 < 0) with endotherm (delta H0 < 0) and the increase of enthopy (AS0 > 0). The effect of enthopy was the main driving force of the spontaneous adsorption reaction. The analysis results of SEM/EDS revealed the changes of surface morphology and chemical proportion before and after adsorption. Due to low-cost and high-efficiency, electric are furnace slag showed great potential for the treatment of heavy metal polluted wastewaters.
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Cádmio/isolamento & purificação , Cobre/isolamento & purificação , Chumbo/isolamento & purificação , Aço/química , Eliminação de Resíduos Líquidos/métodos , Adsorção , Cádmio/química , Cobre/química , Resíduos Industriais/prevenção & controle , Chumbo/química , Purificação da Água/métodosRESUMO
HCl was used as extractant to leach Cd, Cr, Cu, Mn, Ni, Pb and Zn from municipal solid waste incinerator (MSWI) fly ash under traditional and microwave acid extraction conditions. The redistributions of heavy metals were determined using the sequential extraction procedure before and after extraction. The extraction efficiencies and speciation transformation of heavy metals were investigated. The result indicated that acid extraction can extract heavy metals effectively and extraction efficiencies of heavy metals following the sequence of Zn approximately Pb > Cd > Mn > Cu > Cr > Ni. The microwave energy can improve the extraction efficiencies evidently. By the treatment with 1 mol/L HCl, 80.17% of Cd, 15.05% of Cr, 58.25% of Cu, 62.42% of Mn, 8.88% of Ni, 89.25% of Pb and 93.03% of Zn were extracted under the condition of L/S at 25 mL/g fly ash, radiation time at 7 min. The results of sequential extraction procedure reveal that fractions of exchangeable, carbonate, Fe-Mn oxide decreased significantly after acid extraction and the remaining heavy metals mostly bound to residual form. Acid extraction process can increase the environmental safety of fly ash.
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Carbono/química , Incineração , Metais Pesados/química , Micro-Ondas , Material Particulado/química , Poluentes Atmosféricos/análise , Poluentes Atmosféricos/química , Poluição do Ar/análise , Poluição do Ar/prevenção & controle , Carbono/análise , Cinza de Carvão , Ácido Clorídrico/química , Metais Pesados/análise , Material Particulado/análiseRESUMO
Kitchen garbage was chosen to produce ethanol through simultaneous saccharification and fermentation (SSF) by Zymomonas mobilis. Plackett-Burman design was employed to screen affecting parameters during SSF process. The parameters were divided into two parts, enzymes and nutritions. None of the nutritions added showed significant effect during the experiment, which demonstrated that the kitchen garbage could meet the requirement of the microorganism without extra supplementation. Protease and glucoamylase were determined to be affecting factors for ethanol production. Single factor experiment showed that the optimum usage of these two enzymes were both 100 U/g and the corresponding maximum ethanol was determined to be 53 g/L. The ethanol yield could be as high as 44%. The utilization of kitchen garbage to produce ethanol could reduce threaten of waste as well as improve the protein content of the spent. This method could save the ethanol production cost and benefit for the recycle of kitchen garbage.
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Fontes de Energia Bioelétrica/microbiologia , Etanol/metabolismo , Eliminação de Resíduos/métodos , Zymomonas/metabolismo , Proteínas de Bactérias/metabolismo , Fermentação , Glucana 1,4-alfa-Glucosidase/metabolismo , Peptídeo Hidrolases/metabolismo , Projetos de Pesquisa , Restaurantes , Zymomonas/enzimologiaRESUMO
The bioleaching of municipal solid waste incinerator (MSWI) fly ash for metals extraction by Aspergillus niger was investigated. The influence of fly ash concentrations on the biomass concentration, the pH of suspension, the kinds of bio-produced organic acids and the metals extraction yield during the bioleaching process were studied and the leaching toxicities of fly ash before and after bioleaching were compared. The results showed that the decrease of pH was due to generated organic acids by Aspergillus niger during bioleaching, which resulted in the metals extraction from the fly ash. The alkaline and the heavy metals toxicities of fly ash inhibited the Aspergillus niger growth, which was shown as the "lag phase". When fly ash concentration was 20 g/L, the maximum biomass was 28.61 g/L (after bioleaching 192 h), and the minimum pH was 3.85 (after finished bioleaching). The bioleaching efficiency was the highest (i.e., 93.06% for Cd, around 70% for Mn, Pb and Zn, 22%, 33% and 47% for Fe, Cr and Cu, respectively). The TCLP results of the fly ash after bioleaching indicated that the leaching toxicities of the treated fly ash were far lower than the regulated levels of China.