scholarly journals The Effect of Natural Clays Catalysts on Thermal Degradation of a Plastic Waste Mixture

2013 ◽  
Vol 8-9 ◽  
pp. 103-114 ◽  
Author(s):  
Miuţa Filip ◽  
Aurelia Pop ◽  
Ioana Perhaiţa ◽  
Roxana Trusca ◽  
Tiberiu Rusu
Keyword(s):  
Electronic Energy ◽  
Catalytic Degradation ◽  
Plastic Waste ◽  
Gas Chromatography Mass Spectrometry ◽  
Infrared Spectrometry ◽  
Chemical Compositions ◽  
Polymer Waste ◽  
Plastic Wastes ◽  
Natural Clays ◽  
Waste Mixture

The thermal and catalytic degradation of a plastic wastes mixtures using two types of natural clays catalysts has been carried out in order to obtaining liquid oils with potential use in the chemical industry. Thus, the polymer waste mixture (PWM) of polystyrene (PS), poly (ethylene terephthalate) (PET) and poly (vinyl chloride) (PVC) were thermally degraded at 420 °C in absence and presence of studied catalysts in mass ratio 1:10, catalyst/PWM. The catalysts were characterized by N2 adsorption-desorption isotherms (BET), Scanning Electron Microscopy (SEM) and Fourier-transform infrared spectrometry (FTIR) for determined the structural and textural properties. The degradation of plastic wastes produces gases, liquids and solid residue products. The effect of the catalyst types on the yields and distribution of end-products obtained by thermal and catalytic degradation of mixed plastic waste has been studied. The yields of liquid oils fractions were calculated between 54.98 wt.% and 62.18 wt.%. The liquids and solid products were analyzed by different analytical techniques: gas chromatography mass spectrometry (GC-MS), ultraviolet visible spectroscopy (UV-Vis) and/or FTIR, in order to establish the chemical compositions. The GC-MS results showed that the liquid products contain in principal monoaromatic compounds like styrene, toluene, ethylbenzene or α-methylstyrene. The FTIR and UV-Vis spectra of products indicated the specific vibration bands or transitions between electronic energy levels of the functional groups of the constituent compounds.

scholarly journals Investigation of thermal and catalytic degradation of polystyrene waste into styrene monomer over natural volcanic tuff and Florisil catalysts

2013 ◽  
Vol 11 (5) ◽  
pp. 725-735 ◽  
Author(s):  
Miuţa Filip ◽  
Aurelia Pop ◽  
Ioana Perhaiţa ◽  
Mărioara Moldovan ◽  
Roxana Truşcă
Keyword(s):  
Textural Properties ◽  
Product Distribution ◽  
Catalytic Degradation ◽  
Gas Chromatography Mass Spectrometry ◽  
Conversion Degree ◽  
Infrared Spectrometry ◽  
Volcanic Tuff ◽  
Styrene Monomer ◽  
Liquid Products ◽  
Polystyrene Waste

AbstractThermal and catalytic degradation of polystyrene waste over two different samples of natural volcanic tuff catalyst comparative with Florisil catalyst has been carried out in order to establish the conversion degree into styrene monomer. The polystyrene waste (PS) was subjected to a thermal degradation process in the range of 380–500°C in presence of studied catalysts in a ratio of 1/10 in mass, catalyst/PS. The catalysts were characterized by N2 adsorption-desorption isotherms (BET), Scanning Electron Microscopy (SEM) and Fourier-transform infrared spectrometry (FTIR). Influences of temperature and type of catalysts on the yields and on the distribution of end-products obtained by thermal and catalytic degradation of polystyrene waste have been studied. The maximum yields of liquid products were obtained at 460°C degradation temperature and were calculated between 83.45% and 90.11%. The liquid products were characterized by gas chromatography mass spectrometry (GC-MS) and FTIR analytical techniques. The GC-MS results showed that the liquid products contained styrene monomer up to 55.62%. The FTIR spectra of liquid products indicated the specific vibration bands of the functional groups of compounds of liquid products. The amounts of styrene monomer obtained were influenced by structural and textural properties of studied catalyst and the contribution on product distribution is discussed.

scholarly journals Thermo-catalytic studies on a mixture of plastic waste and biomass

2021 ◽  
Author(s):  
Zoltán Sebestyén ◽  
Marianne Blazsó ◽  
Emma Jakab ◽  
Norbert Miskolczi ◽  
János Bozi ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Plastic Waste ◽  
Zeolite Catalysts ◽  
Beta Zeolite ◽  
Gas Chromatography Mass Spectrometry ◽  
Fast Heating ◽  
Alumina Support ◽  
Pyrolysis Gas ◽  
Decomposition Products ◽  
Waste Mixture

AbstractThe effects of various catalysts on the composition of volatile pyrolysis products of a plastic waste and biomass mixture (1:1) were studied, by pyrolyzing the mixture sample using slow and fast heating rate. Various zeolite catalysts (β-and Y-zeolites, ZSM-5 and FCC) and nickel-molybdenum catalyst on alumina support were applied to find suitable catalysts for upgrading the quality of the thermal decomposition products of the waste mixture. A sample to catalyst ratio of 2:1 was used in the experiments. The rate of evolution of the decomposition products under slow pyrolysis was measured by thermogravimetry/mass spectrometry (TG/MS). The composition of the pyrolyzates was analyzed in detail by pyrolysis–gas chromatography/mass spectrometry (Py-GC/MS) method. The influence of all applied catalysts was more pronounced on the plastic content of the sample than on biomass. The pyrolysis experiments revealed that the catalysts promoted the cracking reactions of the evolved hydrocarbons; furthermore, the formation of aromatic products was enhanced remarkably in the presence of all zeolite catalysts. Beta-zeolite and ZSM-5 catalysts were found the most effective in cracking hydrocarbons to gaseous products and in aromatization, while the highest CO2 formation was obtained by FCC from the biomass part of the studied waste mixture. NiMo catalyst promoted the H2 production from the plastic part; furthermore, slight aromatization and cracking effects were also observed.

scholarly journals UV Stimulated Manganese Dioxide for the Persulfate Catalytic Degradation of Bisphenol A

Catalysts ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 502
Author(s):  
Guihua Dong ◽  
Bing Chen ◽  
Bo Liu ◽  
Stanislav R. Stoyanov ◽  
Yiqi Cao ◽  
...  
Keyword(s):  
Bisphenol A ◽  
Reaction Mechanisms ◽  
Reduction Rate ◽  
Catalytic Degradation ◽  
Gas Chromatography Mass Spectrometry ◽  
Degradation Pathways ◽  
Industrial Chemicals ◽  
Oh Groups ◽  
Long Term Adverse Effects

One of the most commonly produced industrial chemicals worldwide, bisphenol A (BPA), is used as a precursor in plastics, resins, paints, and many other materials. It has been proved that BPA can cause long-term adverse effects on ecosystems and human health due to its toxicity as an endocrine disruptor. In this study, we developed an integrated MnO2/UV/persulfate (PS) process for use in BPA photocatalytic degradation from water and examined the reaction mechanisms, degradation pathways, and toxicity reduction. Comparative tests using MnO2, PS, UV, UV/MnO2, MnO2/PS, and UV/PS processes were conducted under the same conditions to investigate the mechanism of BPA catalytic degradation by the proposed MnO2/UV/PS process. The best performance was observed in the MnO2/UV/PS process in which BPA was completely removed in 30 min with a reduction rate of over 90% for total organic carbon after 2 h. This process also showed a stable removal efficiency with a large variation of pH levels (3.6 to 10.0). Kinetic analysis suggested that 1O2 and SO4•− played more critical roles than •OH for BPA degradation. Infrared spectra showed that UV irradiation could stimulate the generation of –OH groups on the MnO2 photocatalyst surface, facilitating the PS catalytic degradation of BPA in this process. The degradation pathways were further proposed in five steps, and thirteen intermediates were identified by gas chromatography-mass spectrometry. The acute toxicity was analyzed during the treatment, showing a slight increase (by 3.3%) in the first 30 min and then a decrease by four-fold over 2 h. These findings help elucidate the mechanism and pathways of BPA degradation and provide an effective PS catalytic strategy.

scholarly journals Application of Plastic Wastes in Construction Materials: A Review Using the Concept of Life-Cycle Assessment in the Context of Recent Research for Future Perspectives

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3549
Author(s):  
Tulane Rodrigues da Silva ◽  
Afonso Rangel Garcez de Azevedo ◽  
Daiane Cecchin ◽  
Markssuel Teixeira Marvila ◽  
Mugahed Amran ◽  
...  
Keyword(s):  
Life Cycle Assessment ◽  
Life Cycle ◽  
Solid Waste ◽  
Building Materials ◽  
Construction Materials ◽  
Plastic Waste ◽  
Plastic Wastes ◽  
Solid Waste Generation ◽  
Alternative Processes

The urbanization process contributes to the growth of solid waste generation and causes an increase in environmental impacts and failures in the management of solid waste. The number of dumps is a concern due to the limited implementation and safe disposal of this waste. The interest in sustainable techniques has been growing in relation to waste management, which is largely absorbed by the civil construction sector. This work aimed to review plastic waste, especially polyethylene terephthalate (PET), that can be incorporated with construction materials, such as concrete, mortars, asphalt mixtures, and paving. The use of life-cycle assessment (LCA) is related, as a tool that allows the sustainability of products and processes to be enhanced in the long term. After analyzing the recent literature, it was identified that studies related to plastic wastes in construction materials concentrate sustainability around the alternative destination of waste. Since the plastic waste from different production chains are obtained, it was possible to affirm the need for a broader assessment, such as the LCA, providing greater quantification of data making the alternative processes and products more sustainable. The study contributes to enhance sustainability in alternative building materials through LCA.

scholarly journals Secondary Metabolic Profile as a Tool for Distinction and Characterization of Cultivars of Black Pepper (Piper nigrum L.) Cultivated in Pará State, Brazil

2021 ◽  
Vol 22 (2) ◽  
pp. 890
Author(s):  
Luccas M. Barata ◽  
Eloísa H. Andrade ◽  
Alessandra R. Ramos ◽  
Oriel F. de Lemos ◽  
William N. Setzer ◽  
...  
Keyword(s):  
Black Pepper ◽  
Plant Diseases ◽  
Gas Chromatography Mass Spectrometry ◽  
Piper Nigrum ◽  
Volatile Components ◽  
Chemical Compositions ◽  
Multivariate Statistical ◽  
Protein Targets ◽  
Fruit Samples ◽  
Sesquiterpene Hydrocarbons

This study evaluated the chemical compositions of the leaves and fruits of eight black pepper cultivars cultivated in Pará State (Amazon, Brazil). Hydrodistillation and gas chromatography–mass spectrometry were employed to extract and analyze the volatile compounds, respectively. Sesquiterpene hydrocarbons were predominant (58.5–90.9%) in the cultivars “Cingapura”, “Equador”, “Guajarina”, “Iaçará”, and “Kottanadan”, and “Bragantina”, “Clonada”, and “Uthirankota” displayed oxygenated sesquiterpenoids (50.6–75.0%). The multivariate statistical analysis applied using volatile composition grouped the samples into four groups: γ-Elemene, curzerene, and δ-elemene (“Equador”/“Guajarina”, I); δ-elemene (“Iaçará”/“Kottanadan”/“Cingapura”, II); elemol (“Clonada”/“Uthirankota”, III) and α-muurolol, bicyclogermacrene, and cubebol (“Bragantina”, IV). The major compounds in all fruit samples were monoterpene hydrocarbons such as α-pinene, β-pinene, and limonene. Among the cultivar leaves, phenolics content (44.75–140.53 mg GAE·g−1 FW), the enzymatic activity of phenylalanine-ammonia lyase (20.19–57.22 µU·mL−1), and carotenoids (0.21–2.31 µg·mL−1) displayed significant variations. Due to black pepper’s susceptibility to Fusarium infection, a molecular docking analysis was carried out on Fusarium protein targets using each cultivar’s volatile components. F. oxysporum endoglucanase was identified as the preferential protein target of the compounds. These results can be used to identify chemical markers related to the susceptibility degree of black pepper cultivars to plant diseases prevalent in Pará State.

scholarly journals Heterogeneous Photo-Fenton Catalytic Degradation of Practical Pharmaceutical Wastewater by Modified Attapulgite Supported Multi-Metal Oxides

Water ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 156
Author(s):  
Manjing Lu ◽  
Jiaqi Wang ◽  
Yuzhong Wang ◽  
Zhengguang He
Keyword(s):  
Photocatalytic Oxidation ◽  
Removal Rate ◽  
Catalytic Degradation ◽  
Gas Chromatography Mass Spectrometry ◽  
Pharmaceutical Wastewater ◽  
High Concentration ◽  
Modified Attapulgite ◽  
Cod Removal Rate ◽  
Pre Treatment ◽  
Almost All

Chemical synthetic pharmaceutical wastewater has characteristics of high concentration, high toxicity and poor biodegradability, so it is difficult to directly biodegrade. We used acid modified attapulgite (ATP) supported Fe-Mn-Cu polymetallic oxide as catalyst for multi-phase Fenton-like ultraviolet photocatalytic oxidation (photo-Fenton) treatment with actual chemical synthetic pharmaceutical wastewater as the treatment object. The results showed that at the initial pH of 2.0, light distance of 20 cm, and catalyst dosage and hydrogen peroxide concentration of 10.0 g/L and 0.5 mol/L respectively, the COD removal rate of wastewater reached 65% and BOD5/COD increased to 0.387 when the reaction lasted for 180 min. The results of gas chromatography-mass spectrometry (GC-MS) indicated that Fenton-like reaction with Fe-Mn-Cu@ATP had good catalytic potential and significant synergistic effect, and could remove almost all heterocycle compounds well. 3D-EEM (3D electron microscope) fluorescence spectra showed that the fluorescence intensity decreased significantly during catalytic degradation, and the UV humus-like and fulvic acid were effectively removed. The degradation efficiency of the nanocomposite only decreased by 5.8% after repeated use for 6 cycles. It seems appropriate to use this process as a pre-treatment for actual pharmaceutical wastewater to facilitate further biological treatment.

scholarly journals Phytochemical Analysis and Potential Biological Activities of Essential Oil from Rice Leaf

Molecules ◽  
2019 ◽  
Vol 24 (3) ◽  
pp. 546 ◽  
Author(s):  
Truong Minh ◽  
Tran Xuan ◽  
Truong Van ◽  
Yusuf Andriana ◽  
Tran Viet ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Essential Oil ◽  
Atmospheric Pressure Chemical Ionization ◽  
Biological Activities ◽  
Methyl Ricinoleate ◽  
Gas Chromatography Mass Spectrometry ◽  
Phytochemical Analysis ◽  
Chemical Compositions ◽  
Rice Leaf ◽  
Rice Leaves

Although many investigations on phytochemicals in rice plant parts and root exudates have been conducted, information on the chemical profile of essential oil (EO) and potent biological activities has been limited. In this study, chemical compositions of rice leaf EO and in vitro biological activities were investigated. From 1.5 kg of fresh rice leaves, an amount of 20 mg EO was obtained by distillation and analyzed by gas chromatography-mass spectrometry (GC-MS), electrospray ionization (ESI), and atmospheric pressure chemical ionization (APCI) to reveal the presence of twelve volatile constituents, of which methyl ricinoleate (27.86%) was the principal compound, followed by palmitic acid (17.34%), and linolenic acid (11.16%), while 2-pentadecanone was the least (2.13%). Two phytoalexin momilactones A and B were first time identified in EO using ultra-performance liquid chromatography coupled with electrospray mass spectrometry (UPLC/ESI-MS) (9.80 and 4.93 ng/g fresh weight, respectively), which accounted for 7.35% and 3.70% of the EO, respectively. The assays of DPPH (IC50 = 73.1 µg/mL), ABTS (IC50 = 198.3 µg/mL), FRAP (IC50 = 700.8 µg/mL) and β-carotene oxidation (LPI = 79%) revealed that EO possessed an excellent antioxidant activity. The xanthine oxidase assay indicated that the anti-hyperuricemia potential was in a moderate level (IC50 = 526 µg/mL) as compared with the standard allopurinol. The EO exerted potent inhibition on growth of Raphanus sativus, Lactuca sativa, and two noxious weeds Echinochloa crus-galli, and Bidens pilosa, but in contrast, the growth of rice seedlings was promoted. Among the examined plants, the growth of the E. crus-galli root was the most inhibited, proposing that constituents found in EO may have potential for the control of the problematic paddy weed E. crus-galli. It was found that the EO of rice leaves contained rich phytochemicals, which were potent in antioxidants and gout treatment, as well as weed management. Findings of this study highlighted the potential value of rice leaves, which may provide extra benefits for rice farmers.

Effects of age and food source on secondary chemistry of larvae of Lymantria species (Lepidoptera: Lymantriidae)

2004 ◽  
Vol 94 (2) ◽  
pp. 137-143 ◽  
Author(s):  
R. Deml
Keyword(s):  
Secondary Metabolites ◽  
Developmental Stages ◽  
Secondary Compounds ◽  
Food Plants ◽  
Gas Chromatography Mass Spectrometry ◽  
Chemical Compositions ◽  
Clustering Methods ◽  
Single Linkage ◽  
Secondary Chemistry ◽  
Dissimilarity Coefficients

AbstractHaemolymph and osmeterial secretions of caterpillars of Lymantria monacha (Linnaeus) and L. concolor Walker were analysed by gas chromatography/mass spectrometry for low molecular weight secondary metabolites. The similarities of their chemical compositions were determined by means of cluster analysis techniques in order to characterize possible chemical variations related to developmental stage or food of the larvae. For this purpose, two dissimilarity coefficients (Euclidean distances, Canberra metrics) and four clustering methods (UPGMA, WPGMA, WPGMC, single linkage) were combined. The patterns of secondary compounds obtained from the haemolymph and osmeterial secretions studied did not differ statistically significantly between two groups of L. monacha larvae fed with either larch, Larix decidua Mil., or Norway spruce, Picea abies (L.), indicating no relevant influence of plant chemistry. However, haemolymph of penultimate instar larvae of L. concolor fed on Rhododendroncontained a mixture of compounds differing statistically significantly from that of last instar caterpillars. The total compositions of the corresponding gland secretions were statistically identical though the presence/amounts of individual compounds varied. This suggested that the haemolymph composition reflected changing physiological requirements of the successive instars, whereas the composition of the defensive mixtures remained comparatively constant, possibly due to a constant spectrum of potential enemies. A more pronounced age-dependence of larval chemistry was shown by a similar analysis of data from various developmental stages of L. dispar (Linnaeus) and one of its food plants. This analysis suggested plant composition affected the secondary chemistry of early larval instars of L. dispar. The results are discussed in terms of the roles of secondary metabolites in defence against natural enemies.

scholarly journals Potential Chemicals from Plastic Wastes

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3175
Author(s):  
Ravindra Prajapati ◽  
Kirtika Kohli ◽  
Samir K. Maity ◽  
Brajendra K. Sharma
Keyword(s):  
Environmental Protection Agency ◽  
State Of The Art ◽  
Plastic Waste ◽  
Chemical Production ◽  
Protection Agency ◽  
Medical Apparatus ◽  
Plastic Materials ◽  
Future System ◽  
Plastic Wastes ◽  
The U.S

Plastic is referred to as a “material of every application”. From the packaging and automotive industries to the medical apparatus and computer electronics sectors, plastic materials are fulfilling demands efficiently. These plastics usually end up in landfills and incinerators, creating plastic waste pollution. According to the Environmental Protection Agency (EPA), in 2015, 9.1% of the plastic materials generated in the U.S. municipal solid waste stream was recycled, 15.5% was combusted for energy, and 75.4% was sent to landfills. If we can produce high-value chemicals from plastic wastes, a range of various product portfolios can be created. This will help to transform chemical industries, especially the petrochemical and plastic sectors. In turn, we can manage plastic waste pollution, reduce the consumption of virgin petroleum, and protect human health and the environment. This review provides a description of chemicals that can be produced from different plastic wastes and the research challenges involved in plastic waste to chemical production. This review also provides a brief overview of the state-of-the-art processes to help future system designers in the plastic waste to chemicals area.

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