Coupled DTA–TGA–FT-IR investigation of pyrolytic decomposition of EVA, PVC and cellulose

Soudais, Yannick; Moga, Ludivine; Blaz̆ek, Jaroslav; Lemort, Florent

doi:10.1016/j.jaap.2006.04.005

Cited by 115 publications

(71 citation statements)

References 26 publications

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“…In the finger print region, 600-1000 cm −1 , the spectra of used and pure tassel exhibited two and one peaks respectively. Observations from similar cellulosic compound have been reported Ali et al, 2001;Soudais et al, 2007).…”

Section: Discussionsupporting

confidence: 68%

Recovery of Lead(II) from Aqueous Solutions by Zea mays Tassel Biosorption

Zvinowanda¹

2010

American Journal of Biochemistry and Biotechnology

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Problem statement:Major adsorbent materials used in heavy metal ion removal from polluted aqueous streams are expensive and difficult to regenerate. In this study, the possibility of using Zea mays tassel, as an alternative low cost biosorbent material to remediate heavy metal pollution was investigated. Lead (II) was used because of its wide application in industrial products and well documented toxicity. Approach: Tassel was obtained from mature Zea mays cultivar R52 hybrid plants. The tassel was milled to a powder and was used to adsorb lead(II) ions from simulated solutions in batch experiments. The desorption of lead(II) was carried out using nitric acid and sodium citrate solutions. The adsorbent was characterized by FTIR, EDX and ESCA before and after application of lead(II) solutions. Results: For samples with concentrations of 100 mg L −1 Pb(II), 94-98% was adsorbed and 57-74 and 57-67% recoveries were achieved with 0.5-5 M nitric acid and 0.01-0.2 M sodium citrate as the stripping solutions, respectively. EDX spectrum of pure tassel indicated that group 1 and 2 metals were the major exchangeable ions present on its surface. ESCA analysis picked up small amounts of lead(II) in the form of Pb(OH) + and Pb(NH) + ions on the surface of tassel adsorbent exposed to Pb 2+ ions and none on pure tassel sample. Functional groups such as -H, -NH 2 , -C = O and -COOH which are polar and are legends which are capable of binding heavy metals were identified by FTIR. Conclusion: The potential of Zea mays tassel to adsorb and recover heavy metals from aqueous solution was successfully demonstrated with Pb(II) sample solutions. The results obtained thus far demonstrated the possibility of using tassel powder in the removal as well as recovery of metals from aqueous solutions.

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Section: Discussionsupporting

confidence: 68%

Recovery of Lead(II) from Aqueous Solutions by Zea mays Tassel Biosorption

Zvinowanda¹

2010

American Journal of Biochemistry and Biotechnology

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“…In the process of dehydrochlorination, most of the Cl is released as hydrogen chloride (HCl). This HCl is accompanied by small amounts of hydrocarbons, mainly aromatics such as benzene (14,17).…”

Section: State Of the Artmentioning

confidence: 99%

Comparative scanning electron microscope study of the degradation of a plasticized polyvinyl chloride waterproofing membrane in different conditions

Pedrosa

Rı́o

2017

Mater. construcc.

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This paper discusses the analysis of several samples of a plasticized polyvinyl chloride (PVC-P) waterproofing membrane. The samples were extracted from different areas of the same flat roof, which was in service for over 12 years. An original sample of an identical PVC-P membrane that was not installed on the roof was also analyzed. The analysis of the materials was carried out using a scanning electron microscope (SEM). An elemental analysis of every sample was also performed by energy dispersive X-ray spectroscopy (EDS). Micrographs and the elemental composition of the samples were compared with the data obtained in the analysis of the original sample. The results show dehydrochlorination of the polymer in two of the samples studied and great deterioration that was not visible to the naked eye in the sample that was totally exposed to the weather.

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“…Fisher et al (2002) report that their studies on the thermolysis of biomass materials indicate that methane and benzene evolution occurs above 500°C and that hydrogen does not appear in the evolved gases until above 600°C. Soudais et al (2007), using IR-analysis of evolved gases from a TG analysis of cellulose pyrolysis in nitrogen at 30°C/min, found cellulose pyrolyzes in a two-step process. The first step begins near 335°C and produces CO, CO 2 , and water vapor.…”

Section: Literature Review On Cellulose Decompositionmentioning

confidence: 99%

Thermal Flammable Gas Production from Bulk Vitrification Feed

Scheele¹,

McNamara²,

Bagaasen³

2008

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SummaryThe baseline bulk-vitrification (BV) process (also known as in-container vitrification ICV™) includes a mixer/dryer to convert liquid low-activity waste (LAW) into a dried, blended feed for vitrification. Feed preparation includes blending LAW with glass-forming minerals (GFMs) and cellulose and drying the mixture to a suitable dryness, consistency, and particle size for transport to the ICV TM container. The cellulose is to be added to the BV feed at a rate sufficient to destroy 75% of the nitrogen present as nitrate or nitrite based on Smith et al.'s (1999) Concern exists that flammable gases may be produced during drying operations at levels that could pose a risk. The drying process is conducted under vacuum in the temperature range of 60 to 80°C. These flammable gases could be produced either through thermal decomposition of cellulose or waste organics or as a by-product of the reaction of cellulose and/or waste organics with nitrate or the postulated small amount of nitrite present in the waste.To help address the concern about flammable gas production during drying, Pacific Northwest National Laboratory (PNNL) performed studies to identify the gases produced at dryer temperatures and at possible process upset conditions. These studies combined simultaneous thermogravimetric and differential thermal analysis (TG/DTA) with Fourier transform infrared spectroscopy (TG/DTA/FTIR) of gases evolved up to 525°C and isothermal studies up to 120°C with mass spectrometry (MS) analysis of evolved gases to determine flammable gas production from the cellulose and organic constituents in simulated BV feed.In the TG/DTA/FTIR studies, we investigated the effects of water and the amount of stoichiometric cellulose added on the evolved gases from simulated S-109 BV feed containing both cellulose and acetate (chosen as the representative waste organic). Water was tested at 4 and 12 wt%. Cellulose was tested at 75 and 100% of the Smith et al. postulated stoichiometry (C:N ratios of 0.75:1 and 1.0:1.0, respectively).In the TG/DTA/FTIR studies, we found that added water (free water) evolved by 120°C well before any TG/DTA/FTIR-detected reactions between cellulose and nitrate and/or nitrite began. The BV feed did not produce any flammable hydrocarbon gases such as methane or ethane at concentrations sufficient to be observed by FTIR. FTIR cannot see hydrogen or other symmetrical molecules such as nitrogen or oxygen. Based on the FTIR evolved gas analyses, the reaction between nitrate and/or nitrite with cellulose qualitatively produces CO 2 , N 2 O, NO, and NO 2 . Water was not observed, although it was expected based on Equation S-1. The presence of NO and NO 2 in trace quantities indicates that secondary reactions are occurring; the FTIR analyses were not quantitative.In the isothermal studies, we investigated the effects of temperature, initial water content, cellulose presence, and waste organics as acetate presence. We tested simulated S-109 BV feed with cellulose and without acetate at room temperature (22°C), 80 ...

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Coupled DTA–TGA–FT-IR investigation of pyrolytic decomposition of EVA, PVC and cellulose

Cited by 115 publications

References 26 publications

Recovery of Lead(II) from Aqueous Solutions by Zea mays Tassel Biosorption

Recovery of Lead(II) from Aqueous Solutions by Zea mays Tassel Biosorption

Comparative scanning electron microscope study of the degradation of a plasticized polyvinyl chloride waterproofing membrane in different conditions

Thermal Flammable Gas Production from Bulk Vitrification Feed

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