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1.
Molecules ; 27(7)2022 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-35408536

RESUMO

Michelia formosana (Kanehira) Masamune is a broad-leaved species widespread in East Asia; the wood extract and its constituents possess antifungal activity against wood-decay fungi. Antifungal activities of leaf essential oil and its constituents from M. formosana were investigated in the present study. Bioassay-guided isolation was applied to isolate the phytochemicals from leaf essential oil. 1D and 2D NMR, FTIR, and MS spectroscopic analyses were applied to elucidate the chemical structures of isolated compounds. Leaf essential oil displayed antifungal activity against wood decay fungi and was further separated into 11 fractions by column chromatography. Four sesquiterpenoids were isolated and identified from the active fractions of leaf essential oil through bioassay-guided isolation. Among these sesquiterpenoids, guaiol, bulnesol, and ß-elemol have higher antifungal activity against brown-rot fungus Laetiporus sulphureus and white-rot fungus Lenzites betulina. Leaf essential oil and active compounds showed better antifungal activity against L. sulphureus than against L. betulina. The molecular structure of active sesquiterpenoids all contain the hydroxyisopropyl group. Antifungal sesquiterpenoids from M. formosana leaf essential oil show potential as natural fungicides for decay control of lignocellulosic materials.


Assuntos
Magnolia , Óleos Voláteis , Sesquiterpenos , Antifúngicos/química , Fungos , Óleos Voláteis/química , Folhas de Planta/química , Sesquiterpenos/análise , Sesquiterpenos/farmacologia , Madeira/microbiologia
2.
Int J Phytoremediation ; 24(4): 334-341, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34166152

RESUMO

Phytoextraction by native Taiwanese chenopod (Chenopodium formosanum Koidz.) and Napier grass (Pennisetum purpureum) for heavy metals such as chromium (Cr), nickel (Ni), and copper (Cu) was reported first. Maximum bioconcentration factors of Cu and Cr were 8.8 and 12.5 by Taiwanese chenopod. Napier grass cultivar Taishi No.4 plants demonstrated higher survivals than that of Taiwanese chenopod, under heavy metal stress in soils. All heavy metal accumulation and biomass data were employed, as well as historical engineering data were collected for conventional excavation-and-refill remediation of two sites. Life cycle assessment (LCA) was conducted for comparing environmental performances of phytoextraction and conventional remediation for two contaminated sites. Assuming one-year growth, three harvests were done and biomass was collected and sent to the nearest municipal incinerators, phytoextraction by both plants demonstrated superior environmental performances than conventional methods for contaminated site remediation. High quantities of fuels to haul the soils of conventional methods mainly contributed to the greenhouse gas emission. Phytoextraction has the most advantages for sites with lesser extents of pollution and time restraints. Environmental performances of phytoremediation were even better if energy recovered from biomass incineration is counted. Novelty statement Phytoextraction by native Taiwanese chenopod and Napier grass was firstly reported. Life cycle assessment was conducted for comparing the phytoextraction and conventional remediation. Phytoextraction demonstrated superior environmental performances. Energy reutilization of biomass recovered made phytoremediation more sustainable.


Assuntos
Metais Pesados , Poluentes do Solo , Animais , Biodegradação Ambiental , Estágios do Ciclo de Vida , Metais Pesados/análise , Solo , Poluentes do Solo/análise
3.
Biotechnol Bioeng ; 118(10): 4065-4075, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34245458

RESUMO

Enzymatic hydrolysis is a rate-limiting process in lignocellulose biorefinery. The reaction involves complex enzyme-substrate and enzyme-lignin interactions in both liquid and solid phases, and has not been well characterized numerically. In this study, a kinetic model was developed to incorporate dynamic enzyme adsorption and product inhibition parameters into hydrolysis simulation. The enzyme adsorption coefficients obtained from Langmuir isotherm were fed dynamically into first-order kinetics for simulating the equilibrium enzyme adsorption in hydrolysis. A fractal and product inhibition kinetics was introduced and successfully applied to improve the simulation accuracy on adsorbed enzyme and glucose concentrations at different enzyme loadings, lignin contents, and in the presence of bovine serum albumin (BSA) and lysozyme. The model provided numerical proof quantifying the beneficial effects of both additives, which improved the hydrolysis rate by reducing the nonproductive adsorption of enzyme on lignin. The hydrolysis rate coefficient and fractal exponent both increased with increasing enzyme loadings, and lignin inhibition exhibited with increasing fractal exponent. Compared with BSA, the addition of lysozyme exhibited higher hydrolysis rates, which was reflected in the larger hydrolysis rate coefficients and smaller fractal exponents in the simulation. The model provides new insights to support process development, control, and optimization.


Assuntos
Celulase/química , Simulação por Computador , Lignina/química , Modelos Químicos , Hidrólise , Cinética
4.
Data Brief ; 27: 104613, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31667323

RESUMO

Assessing the biomass-based bioenergy production potential of nations is heavily dependent on the import source of fossil fuels. Taiwan can alleviate its fossil fuel dependency and greenhouse gas emissions. Key information (including published statistics and calculations) on biomass waste production from rice paddies in Taiwan considering the full production of available rice paddies was included in this study. In addition, key information on biomass waste production from forest sectors in Taiwan considering enhanced domestic production and the imported sources of harvested wood products (HWP) was also included. The volumes of decayed HWP could be used to predict available biomass waste for bioenergy production. The results of this study assist with the recent evaluation of the potential of the most prevailing available sources of biomass waste, rice paddies and forest sectors, for bioenergy generation, e.g. for more insight please see "Potential of Bioenergy Production from Biomass Wastes of Rice Paddies and Forest Sectors in Taiwan" [1].

5.
J Air Waste Manag Assoc ; 69(12): 1467-1478, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31524083

RESUMO

In this study, biomass of rice straw (RS) and wood (WD) and their torrefied biomass (RST and WDT) were used as solid biofuel (SBF) for co-firing individually with coal in a commercial continuous chain-grate steam boiler system, which was conducted at fixed input rate of heating value of mixture of SBF and coal and at fixed airflow rate. The effects of key system parameters on the gaseous and particulate pollutions and ash were examined. These include SBF type and blending ratio (RBL) of biomass (i.e., SBF) in the mixture of coal and biomass based on heating values for co-firing.The results indicated that wood, which possesses high heating value while less amount of ash, is more suitable for co-firing with coal than rice straw. Torrefaction can increase the heating value of biomass and homogenize its property, being beneficial to co-firing. Also, torrefaction can decompose the hydroxyl group of biomass, which makes biomass tending to possess hydrophobicity. This, in turn, helps the storage and transportation of biomass. Generally, adding the RS (with RBL = 5-10%), WD (2-15%), RST (2-10%) and WDT (2-20%), respectively, with coal decreases the emissions of NOx and SO2, but increases that of CO (except RST). The emission of HCl is little. The addition of biomass also increases the emission of fine particulate matters (PM) especially PM2.5 in the flue gases, raising PM2.5/PM100 from 34.87 to 78.35 wt.% (Case 50%WDT). These emissions for the Cases tested satisfy with Taiwanese emission standards of stationary sources which set limitations of NOx, SO2, CO and HCl < 350, 300, 2000 and 80 ppmv, while PM < 50 mg/m3, respectively. The results support the use of RS, WD, RST and WDT for co-firing with coal.Implications: This study examined the suitability of using solid bio-fuels to co-fire with coal in an industrial chain-grate steam boiler system with a capacity of 100 kW, in order to achieve carbon-free emissions. Both biomass and torrefied biomass of solid bio-fuel were tested. The findings would be useful for proper design and rational operation of solid bio-fuel/coal co-firing combustion matching the appeal of sustainable material management and circular economy of biomass, and of adaptation of global warming induced by greenhouse gases. It also provides information for policy-makers to promote the co-firing application of biomass and related bio-waste materials.


Assuntos
Poluentes Atmosféricos/química , Biomassa , Carvão Mineral/análise , Madeira/química , Gases , Calefação , Incineração , Oryza , Material Particulado/análise
6.
J Environ Manage ; 241: 1-11, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-30978564

RESUMO

Refining is the major process of paper formation. This study focuses on the impact of a specific enzyme (Paenibacillus cellulase) for fibers on the surfaces, the roughness and height of the fibers are also investigated. Effects of enzyme dosages and the mechanical refining action (PFI revolution) on fiber physical properties were also analyzed. The fibers were observed by scanning electron microscopy (SEM), their roughness and height were analyzed by Atomic force microscopy (AFM). Results show that the Paenibacillus cellulase pretreatment increased the drainability of both kinds of pulp at the same level of refining energy. In other words, enzymatic treatment on pulp refining consumed less refining revolutions to reach the same drainability compared to the untreated pulp. Although the viscosity of both kinds of pulp was degraded with the enzymatic treatment, the physical properties of paper had no significantly negative influence on them. The results indicated the treatment with cellulase swelled the fibers in the absence of refining, and there were better fibrillation on the fibers treated with cellulase after refining. Furthermore, the statistical analysis of AFM suggested that both kinds of pulp treated with low cellulase dosage with PFI refining had higher roughness.


Assuntos
Celulase , Paenibacillus , Carboidratos , Fibras na Dieta , Papel
7.
Environ Sci Pollut Res Int ; 26(33): 34311-34320, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30796668

RESUMO

Employment of biosurfactants and biodegradable chelants could further promote sustainability of soil and groundwater remediation tasks. Biosurfactant (soapnut saponin) and biodegrading chelants (ethylenediamine-N,N'-disuccinic acid (EDDS)) were employed to enhance the phytoextraction by native Taiwanese chenopod (Chenopodium formosanum Koidz.), Napier grass (Pennisetum purpureum) cultivar Taishi No. 4, and soapwort (Saponaria officinalis). Ethylene diamine tetraacetic acid (EDTA) was also employed as the control. Contaminated soils as silty clay loam texture was collected from a defunct rice paddy, containing chromium (Cr), cadium (Cd), and copper (Cu). Addition of both soapnut saponin and EDDS proportionally increased bioaccumulation factors (BCFs) of aboveground biomass for all three plants. Taiwanese chenopod demonstrated the best BCF values among three plants, with BCF increased from 0.76 to 2.6 and 1.3 for Cu under the presence of the highest dosages of EDDS and saponin. Plant aboveground biomass did exhibit negative correlation toward biomass metal concentrations. Presence of saponin did exhibit the least negative slopes among the correlations of all three additives for three plants. Taiwanese chenopod did exhibit the least negative slopes among the correlations of all three additives for three plants. Above observations suggested that saponin may have some protection for plants, especially for Napier grass. Taiwanese chenopod could possess more tolerance toward heavy metals than Napier grass does.


Assuntos
Amaranthaceae/fisiologia , Biodegradação Ambiental , Etilenodiaminas/metabolismo , Metais Pesados/metabolismo , Pennisetum/fisiologia , Saponinas/metabolismo , Poluentes do Solo/metabolismo , Succinatos/metabolismo , Biomassa , Quelantes , Cromo , Cobre , Ácido Edético , Metais Pesados/análise , Plantas , Solo , Poluentes do Solo/análise
8.
Environ Sci Pollut Res Int ; 25(6): 5223-5230, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28551739

RESUMO

Oil meal is a by-product of the oil industry (peanut meal, sesame meal, and camellia meal). Oil is extracted from seeds, and the leftover meal is then pelletized, and this process generates a large amount of waste oil meal in Taiwan. In this study, peanut meal, sesame meal, and camellia meal derived fuels were prepared from the waste oil meal with waste cooking oil. The combustion behaviors of the oil meal derived fuels were also investigated. The characteristics of the derived fuel made from oil meal with waste cooking oil showed that the ash content is less than 10% and its calorific value reached 5000 kcal/kg. Additionally, the activation energy of the oil meal and waste cooking oil was analyzed by the Kissinger method. The results show that the fuel prepared in this work from the oil meal mixed with waste cooking oil is suitable for use as an alternative fuel and also avoids food safety issues.


Assuntos
Agricultura , Biocombustíveis , Culinária , Óleos , Eliminação de Resíduos/métodos , Eliminação de Resíduos Líquidos/métodos , Biocombustíveis/análise , Conservação dos Recursos Naturais , Taiwan , Resíduos
9.
J Environ Manage ; 203(Pt 3): 1005-1010, 2017 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-28501336

RESUMO

Using plants to absorb and accumulate heavy metals from polluted soil, followed by the recycling of explants containing heavy metals, can help achieve the goal of reverting contaminated soil to low heavy-metal content soil. However, the re-use of recovered explants can also be problematic. Meanwhile, bioethanol has become a popular energy source. In this study, napier grass was used for the remediation of soil contaminated with heavy metals (artificially contaminated soil). The influence of bioethanol production from napier grass after phytoremediation was also investigated. The concentration of Zn, Cd, and Cr in the contaminated soil was 1000, 100, and 250 mg/kg, respectively. After napier grass phytoremediation, the concentration (dry biomass) of Zn, Cd, and Cr in the explants was 2701.97 ± 173.49, 6.1 ± 2.3, and 74.24 ± 1.42 mg/kg, respectively. Biomass production in the unpolluted soil was 861.13 ± 4.23 g. The biomass production ratio in high Zn-polluted soil was only 3.89%, while it was 4.68% for Cd and 21.4% for Cr. The biomass obtained after napier grass phytoremediation was pretreated using the steam explosion conditions of 180 °C, for 10 min, with 1.5% H2SO2, followed by enzymatic hydrolysis. The efficiency of enzymatic hydrolysis for Zn-polluted biomass was 90% of the unpolluted biomass, while it was 77% for Cd, and approximately the same for Cr. The fermentation efficiency of the heavy-metal-containing biomass was higher than the control biomass. The fermentation ethanol concentration obtained was 8.69-12.68, 13.03-15.50, and 18.48-19.31 g/L in Zn, Cd, and Cr environments, respectively. Results show that the heavy metals had a positive effect on bacteria fermentation. However, the fermentation efficiency was lower for biomass with severe heavy metal pollution. Thus, the utilization of napier grass phytoremediation for bioethanol production has a positive effect on the sustainability of environmental resources.


Assuntos
Metais Pesados/análise , Pennisetum/química , Biodegradação Ambiental , Biomassa , Fermentação , Hidrólise , Plantas , Solo
10.
Talanta ; 152: 475-81, 2016 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-26992544

RESUMO

A highly sensitive liquid chromatographic method was developed for the fluorometric determination of trace amounts of linear aliphatic primary amines. Prior to extraction, amines were derivatized with naphthalene-2,3-dicarboxaldehyde (NDA) in the presence of cyanide ion (CN) and extracted by vortex-assisted liquid-liquid microextraction (VALLME). The optimum conditions were as follows: derivatization reaction time for 5 min in 2.0 mL aqueous donor samples with 50 µM NDA/CN, and 10mM borate buffer at pH 9; vortex extraction time for 20s in the VALLME step with 50 µL of isooctane as the extractant phase; centrifugation for 1 min at 6000 rpm. Under the optimum conditions, the limits of detection (LOD) were between 0.01 and 0.04 nmol L(-1). The calibration curves showed good linearity in the range of 0.1-20 nmol L(-1). In comparison with previous work using o-phthalaldehyde/2-mercaptoethanol derivatization, the method has much more stable fluorescent derivatives, higher fluorescence intensities, and greater extraction efficiencies. The sensitivity enhancement factors (SEF) were between 2 and 70, which is in good agreement with the theoretical values calculated from partition coefficients in VALLME system.

11.
Biomed Res Int ; 2016: 3640182, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-28119926

RESUMO

An antiadhesion barrier membrane is an important biomaterial for protecting tissue from postsurgical complications. However, there is room to improve these membranes. Recently, carboxymethylcellulose (CMC) incorporated with hyaluronic acid (HA) as an antiadhesion barrier membrane and drug delivery system has been reported to provide excellent tissue regeneration and biocompatibility. The aim of this study was to fabricate a novel hydrogel membrane composed of berberine-enriched CMC prepared from bark of the P. amurense tree and HA (PE-CMC/HA). In vitro anti-inflammatory properties were evaluated to determine possible clinical applications. The PE-CMC/HA membranes were fabricated by mixing PE-CMC and HA as a base with the addition of polyvinyl alcohol to form a film. Tensile strength and ultramorphology of the membrane were evaluated using a universal testing machine and scanning electron microscope, respectively. Berberine content of the membrane was confirmed using a UV-Vis spectrophotometer at a wavelength of 260 nm. Anti-inflammatory property of the membrane was measured using a Griess reaction assay. Our results showed that fabricated PE-CMC/HA releases berberine at a concentration of 660 µg/ml while optimal plasticity was obtained at a 30 : 70 PE-CMC/HA ratio. The berberine-enriched PE-CMC/HA had an inhibited 60% of inflammation stimulated by LPS. These results suggest that the PE-CMC/HA membrane fabricated in this study is a useful anti-inflammatory berberine release system.


Assuntos
Anti-Inflamatórios/química , Berberina/química , Materiais Biocompatíveis/química , Ácido Hialurônico/química , Hidrogel de Polietilenoglicol-Dimetacrilato/química , Animais , Anti-Inflamatórios/administração & dosagem , Materiais Biocompatíveis/administração & dosagem , Carboximetilcelulose Sódica/química , Linhagem Celular , Sistemas de Liberação de Medicamentos/métodos , Humanos , Hidrogel de Polietilenoglicol-Dimetacrilato/administração & dosagem , Membranas Artificiais , Camundongos , Células NIH 3T3 , Complicações Pós-Operatórias/prevenção & controle , Resistência à Tração , Aderências Teciduais/tratamento farmacológico , Cicatrização/efeitos dos fármacos
12.
Environ Technol ; 36(23): 2952-8, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25191877

RESUMO

The purpose of this study was to develop a resource recovery procedure for recovering copper and zinc from dust produced by copper smelting furnaces during the manufacturing of copper-alloy wires. The concentrations of copper in copper-containing dust do not meet the regulation standards defined by the Taiwan Environmental Protection Administration; therefore, such waste is classified as hazardous. In this study, the percentages of zinc and copper in the dust samples were approximately 38.4% and 2.6%, respectively. To reduce environmental damage and recover metal resources for industrial reuse, acid leaching was used to recover metals from these inorganic wastes. In the first stage, 2 N of sulphuric acid was used to leach the dust, with pH values controlled at 2.0-3.0, and a solid-to-liquid ratio of 1:10. The results indicated that zinc extraction efficiency was higher than 95%. A selective acid leaching process was then used to recover the copper content of the residue after filtration. In the second stage, an additional 1 N of sulphuric acid was added to the suspension in the selective leaching process, and the pH value was controlled at 1.5-2.0. The reagent sodium hydroxide (2 N) was used as leachate at a pH greater than 7. A zinc hydroxide compound formed during the process and was recovered after drying. The yields for zinc and copper were 86.9-93.5% and 97.0-98.9%, respectively.


Assuntos
Cobre/química , Reciclagem/métodos , Óxido de Zinco/química , Cobre/análise , Poeira/análise , Concentração de Íons de Hidrogênio , Resíduos Industriais/análise , Metalurgia , Ácido Nítrico/química , Hidróxido de Sódio/química , Ácidos Sulfúricos/química
13.
Ecotoxicology ; 23(10): 1969-78, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25236867

RESUMO

This study employed Jatropha curcas (bioenergy crop plant) to assist in the removal of heavy metals from contaminated field soils. Analyses were conducted on the concentrations of the individual metals in the soil and in the plants, and their differences over the growth periods of the plants were determined. The calculation of plant biomass after 2 years yielded the total amount of each metal that was removed from the soil. In terms of the absorption of heavy metal contaminants by the roots and their transfer to aerial plant parts, Cd, Ni, and Zn exhibited the greatest ease of absorption, whereas Cu, Cr, and Pb interacted strongly with the root cells and remained in the roots of the plants. J. curcas showed the best absorption capability for Cd, Cr, Ni, and Zn. This study pioneered the concept of combining both bioremediation and afforestation by J. curcas, demonstrated at a field scale.


Assuntos
Jatropha/metabolismo , Metais Pesados/metabolismo , Poluentes do Solo/metabolismo , Biodegradação Ambiental , Jatropha/crescimento & desenvolvimento , Metais Pesados/análise , Solo/química , Poluentes do Solo/análise
14.
Ecotoxicology ; 23(10): 1987-95, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25204813

RESUMO

83 acres of rice paddy fields in Taoyuan county, Taiwan, were polluted by cadmium (Cd), chromium (Cr) and copper (Cu) through a nearby irrigation channel, and rice plantation was ceased in 1987. Camphor trees (Cinnamomum camphora) have been planted in 2 acre of the above fields since 1991. Heavy metal accumulation of roots, leaves, branches and heartwood of camphor trees were analyzed during 20-year afforestation. Averaged Cd contents of the roots were found larger than the ones of the branches, leaves, sapwood and heartwood of camphor trees growing in three polluted plots. Averaged diameters at breast height (DBH) of the planted camphor trees were 13-15 cm. Cd pollution did not significantly impact the growth of camphor trees, as similar DBH's were found from both polluted and control sites. Annual growths of DBH were from 0.63 to 0.77 cm year(-1). Planting camphor trees sequestered 68.8 ton biomass per acre. During 20-year period, 0.69-1.98 ton C year(-1) ha(-1) were sequestered on three polluted plots. The above numbers exceeded IPCC LULUCF reference values 0.31-0.53 ton C year(-1) ha(-1) for activities at forest lands.


Assuntos
Cinnamomum camphora/fisiologia , Metais Pesados/metabolismo , Poluentes do Solo/metabolismo , Biodegradação Ambiental , Metais Pesados/análise , Solo/química , Poluentes do Solo/análise , Taiwan
15.
Biomol NMR Assign ; 8(2): 303-6, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23835623

RESUMO

Paenibacillus campinasensis BL11 isolated from black liquor secretes multiple glycoside hydrolases (GHs) against all kinds of polysaccharides. GH consists of a catalytic module and non-catalytic carbohydrate-binding modules (CBMs), in which CBMs append to the catalytic module, mediating specific interactions with insoluble carbohydrates to promote the hydrolysis efficiency of the cognate enzyme. Endo-ß-1,4-xylanase (XylX) is one of the GHs reveals high enzymatic activity in a wide range of pH and thermal endurance, suitable for bioconversion and bio-refinement applications. In this work, we report the resonance assignments of a family 36 CBM (characterized as CBM36) derived from XylX. Our investigations will facilitate molecular structure determination and molecular dynamics analysis of CBMs.


Assuntos
Metabolismo dos Carboidratos , Endo-1,4-beta-Xilanases/química , Endo-1,4-beta-Xilanases/metabolismo , Ressonância Magnética Nuclear Biomolecular , Paenibacillus/enzimologia , Sequência de Aminoácidos
16.
Bioresour Technol ; 141: 240-4, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23623433

RESUMO

The organic sludge and waste oil were collected from the industries of thin film transistor liquid crystal display and the recycled cooking oil. The mixing ratio of waste cooking oil and organic sludge, fry-drying temperatures, fry-drying time, and the characteristics of the organic sludge pellet grain were investigated. After the fry-drying process, the moisture content of the organic sludge pellet grain was lower than 5% within 25 min and waste cooking oil was absorbed on the dry solid. The fry-drying organic sludge pellet grain was easy to handle and odor free. Additionally, it had a higher calorific value than the derived fuel standards and could be processed into organic sludge derived fuels. Thus, the granulation and fry-drying processes of organic sludge with waste cooking oil not only improves the calorific value of organic sludge and becomes more valuable for energy recovery, but also achieves waste material disposal and cost reduction.


Assuntos
Reciclagem/métodos , Esgotos/química , Indústria Alimentícia , Cristais Líquidos , Óleos/química , Gerenciamento de Resíduos/métodos
17.
J Environ Manage ; 122: 42-6, 2013 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-23542569

RESUMO

The disposal of chromated copper arsenate (CCA)-treated waste wood is becoming a serious problem in many countries due to potential leaching of hazardous elements from in-service use in the environment or disposal of solutions after remediation; therefore, it is necessary to develop proper remediation techniques. The effects of concentration, extraction period, temperature, and sequential extraction on the extraction of Cr, Cu, and As from CCA-treated wood using [S,S]-ethylenediaminedisuccinic acid (EDDS), ethylenediaminetetraacetic acid (EDTA), and nitrilotriacetic acid (NTA) were studied. Mobility of metal in the samples was evaluated by using a sequential extraction scheme that could give the information needed to explain different extraction efficiencies for different metals. Results of long-term leaching tests of CCA-treated wood before and after EDDS extraction were used to evaluate Cr, Cu, and As leachability. Kinetic experiments showed that 6 h was the optimum extraction time for all metals and CCA-treated wood. Experimental results showed that EDDS is a very effective chelating agent for the extraction of Cr, Cu, and As from CCA-treated wood. Increased temperature significantly enhanced the extraction efficiency of CCA metals, especially Cr and As. The much better extractability of Cu compared to Cr and As by chelating agents can be attributed to the presence of larger weakly bound fractions. The CCA-treated woods after EDDS extraction have met the EPA's TCLP regulatory limit and could be classified as a non-hazardous waste according to identification standard of hazardous wastes.


Assuntos
Arseniatos/química , Quelantes/química , Madeira/química , Ácido Edético/química , Etilenodiaminas/química , Ácido Nitrilotriacético/química , Eliminação de Resíduos/métodos , Succinatos/química
18.
J Hazard Mater ; 237-238: 116-20, 2012 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-22947185

RESUMO

The high levels of alkali chloride and soluble metal salts present in MSWI fly ash is worth noting for their impact on the environment. In addition, the recycling or reuse of fly ash has become an issue because of limited landfill space. The chloride content in fly ash limits its application as basis for construction materials. Water-soluble chlorides such as potassium chloride (KCl), sodium chloride (NaCl), and calcium chloride hydrate (CaCl(2) · 2H(2)O) in fly ash are easily washed away. However, calcium chloride hydroxide (Ca(OH)Cl) might not be easy to leach away at room temperature. The roasting and washing-flushing processes were applied to remove chloride content in this study. Additionally, air and CO(2) were introduced into the washing process to neutralize the hazardous nature of chlorides. In comparison with the water flushing process, the roasting process is more efficient in reducing the process of solid-liquid separation and drying for the reuse of Cl-removed fly ash particles. In several roasting experiments, the removal of chloride content from fly ash at 1050°C for 3h showed the best results (83% chloride removal efficiency). At a solid to liquid ratio of 1:10 the water-flushing process can almost totally remove water-soluble chloride (97% chloride removal efficiency). Analyses of mineralogical change also prove the efficiency of the fly ash roasting and washing mechanisms for chloride removal.


Assuntos
Cloretos/análise , Cinza de Carvão/análise , Incineração , Gerenciamento de Resíduos/métodos , Resíduos Industriais , Reciclagem
19.
Bioresour Technol ; 102(9): 5431-7, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21106369

RESUMO

This study investigated the correlations between the system treatment efficiencies and total nitrogen (TN) and total phosphorus (TP) accumulations of aboveground tissues of the wetland macrophytes of Hsin-Hai Bridge phase II constructed wetland. Among 19 emergent macrophytes studied, the optimal TN contents, 3.82% and 3.52% (w/w) were found for water spinach (Ipomoea aquatica) and Ludwigia x taiwanensis; while the optimal TP contents were found for the above two macrophytes at 0.64% and 0.83% (w/w). The accumulations of total plant TN and TP uptakes increased from 213 to 403 kg and 41 to 75 kg from March 2007 to the peak at September 2007, respectively. The TN ratios between plant tissue accumulations and the removals from the influents were 1.57%, 2.76%, 1.51% and 3.2% from March 2007 to March 2008. In the same period, the TP ratios between plant tissue accumulations and the removals from influents were 1.71%, 8.0%, 0.58% and 10.1%. The roles of the uptakes by aboveground portions of emergent macrophytes in system nutrient removals from the influents were more significant during growth seasons.


Assuntos
Nitrogênio/isolamento & purificação , Fósforo/isolamento & purificação , Plantas/metabolismo , Purificação da Água/métodos , Áreas Alagadas , Biodegradação Ambiental , Biomassa , Carbono/análise , Desenvolvimento Vegetal , Taiwan , Eliminação de Resíduos Líquidos
20.
Bioconjug Chem ; 21(9): 1642-55, 2010 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-20690641

RESUMO

Chemical conjugations of nucleic acids with macromolecules or small molecules are common approaches to study nucleic acids in chemistry and biology and to exploit nucleic acids for medical applications. The conjugation of nucleic acids such as oligonucleotides with peptides is especially useful to circumvent cell delivery and specificity problems of oligonucleotides as therapeutic agents. However, current approaches are limited and inefficient in their ability to afford peptide-oligonucleotide conjugates (POCs). Here, we report an effective and reproducible approach to prepare POCs and other nucleic acid conjugates based on a newly developed nucleic acid phosphoramidation method. The development of a new nucleic acid phosphoramidation reaction was achieved by our successful synthesis of a novel amine-containing biotin derivative used to systematically optimize the reactions. The improved phosphoramidation reactions dramatically increased yields of nucleic acid-biotin conjugates up to 80% after 3 h reaction. Any nucleic acids with a terminal phosphate group are suitable reactants in phosphoramidation reactions to conjugate with amine-containing molecules such as biotin and fluorescein derivatives, proteins, and, most importantly, peptides to enable the synthesis of POCs for therapeutic applications. Polymerase chain reactions (PCRs) to study incorporation of biotin or fluorescein-tagged DNA primers into the reaction products demonstrated that appropriate controls of nucleic acid phosphoramidation reactions incur minimum adverse effects on inherited base-pairing characteristics of nucleotides in nucleic acids. The phosphoramidation approach preserves the integrity of hybridization specificity in nucleic acids when preparing POCs. By retaining integrity of the nucleic acids, their effectiveness as therapeutic reagents for gene silencing, gene therapy, and RNA interference is ensured. The potential for POC use was demonstrated by two-step phosphoramidation reactions to successfully synthesize nucleic acid-tetraglycine conjugates. In addition, phosphoramidation reactions provided a facile approach to prepare nucleic acid-BSA conjugates with good yields. In summary, the new approach to phosphoramidation reactions offers a universal method to prepare POCs and other nucleic acid conjugates with high yields in aqueous solutions. The methods can be easily adapted to typical chemistry or biology laboratory setups which will expedite the applications of POCs for basic research and medicine.


Assuntos
Biotina/análogos & derivados , Ácidos Nucleicos/química , Compostos Organofosforados/química , Ácidos Nucleicos Peptídicos/síntese química , Peptídeos/química , Aminas/química , Fluoresceínas/química , Ácidos Nucleicos Peptídicos/química , Fosfatos/química , Reação em Cadeia da Polimerase
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