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21.
Thallada Bhaskar Nona Merry M. Mitan Jude A. Onwudili Akinori Muto Paul T. Williams Yusaku Sakata 《Journal of Material Cycles and Waste Management》2010,12(4):332-340
Pyrolysis of brominated flame retardant-containing high-impact polystyrene (HIPS-Br) was performed at 430°C in the presence
of 0.1 wt% of polyethylene terephthalate (PET) in a Pyrex glass reactor. Two different types of brominated flame retardants
(decabromodiphenyl ether and decabromodiphenyl ethane) with or without antimony trioxide (as synergist) 5 wt% were used. The
presence of PET had a significant effect on the material balance, decreasing the gaseous product and increasing the residue.
The type of flame retardant had no effect on the yield of liquid product; however, the presence of Sb resulted in a marked
difference in the distribution of decomposition products. Analysis by a gas chromatograph equipped with a flame ionization
detector showed that the hydrocarbons were distributed in the range n-C7 to n-C25 with major peaks at n-C9 and n-C17. The presence of PET increased the formation of brominated compounds by several times and affected both the type and quantity
of polybrominated compounds. The liquid products obtained from the pyrolysis of HIPS-Br/PET have to be treated before they
can be used 相似文献
22.
An estrogen receptor (ER)/androgen receptor (AR) ligand competitive binding assay (ER/AR-binding assay) and chemical analyses
were used to evaluate the endocrine disrupting chemicals (EDCs) behavior of two municipal wastewater treatment plants (WWTPs) (K
and S). In the influents, estrone (E1), androsterone (A), androstenedione (AD), BPA (bisphenol A), NP (nonylphenol) and daidzein (DZ)
were detected in high amounts with subsequent 24 h-average concentrations of 350, 1000, 29, 1300, 3900, and 5700 ng/L in K-WWTP
and of 310, 620, 59, 1600, 2600, and 8400 ng/L in S-WWTP. The estrogenic (androgenic) activity as 17 -estradiol (E2) equivalents
(EEQ) or testosterone (Te) equivalents (TEQ) was consequently 620 ng E2/L (570 ng Te/L) and 580 ng E2/L (800 ng Te/L) for the
two WWTPs. The removal e ciencies of the above mentioned sole target chemicals were 51%–100% for K-WWTP and 55.6%–100%
for S-WWTP. The removal e ciencies of EEQ were about 73% for both WWTPs, while the removal e ciencies of TEQ were 62.1%
for K-WWTP and 98.4% for S-WWTP. In addition, chemical-derived EEQ were about 1.2%–52.4% of those by ER-binding assay for
K-WWTP and the corresponding ratios were 1.3%–83.3% for S-WWTP, while chemical derived TEQ were less than 3% of values
measured by the AR-binding assay for both WWTPs. 相似文献
23.
Nona Merry M. Mitan Mihai Brebu Thallada Bhaskar Akinori Muto Yusaku Sakata Mitsuo Kaji 《Journal of Material Cycles and Waste Management》2007,9(1):62-68
Waste DVDs and CDs were thermally degraded at 450°C by a semibatch process. In total, 40–50 wt% was converted into liquid
product that consisted of phenol derivatives (∼75 wt%), bisphenol (∼10 wt%) and its derivatives, and small amounts of aromatic
hydrocarbons such as benzene, toluene, ethylbenzene, dimethylbenzene, methylethylbenzene, diethylbenzene, and methylisopropyl
benzene. Degradation of the polycarbonate support from DVDs and CDs was enhanced by coprocessing with vegetable cooking oil,
the degradation of which gave a homologue series of hydrocarbons and organic acids with up to 25 and 18 atoms of carbon, respectively.
Silver from the reflective coating on DVDs and CDs remained in the solid residue, its concentration increasing about 2.5 times
compared to that of the original disks. 相似文献
24.
Polychlorinated dibenzo-p-dioxin and dibenzofuran (PCDD/DF) levels in plywood combustion gas were investigated for the effects of ammonium chloride (NH4Cl) and paint. For combustion systems in which neither NH4Cl nor paint were present in the plywood samples, total amounts of PCDD/DFs in the combustion gas were in the order of 35-529 ng/Nm3, and were higher in the systems with softwood trees than broadleaf ones, depending on the Cl concentrations. For the systems with added NH4Cl and no paint, and those without NH4Cl but were painted, higher PCDD/ DF rates were observed at combustion temperatures of 270 degrees C and 500 degrees C, respectively. However, for the systems with both NH4Cl and paint, their amounts in the range of 0.6-13 ng/Nm3 were the lowest in all systems. The PCDD/DF abundance profiles were similar to their patterns in pentachlorophenol (PCP). Furthermore, it was found that the 2,3,7,8-chlorine substituted penta- and hexa-CDDs contributed more than other 2,3,7,8-chlorine substitutes to toxicity equivalency (TEQ). 相似文献
25.
Nona Merry M. Mitan Mihai Brebu Thallada Bhaskar Akinori Muto Yusaku Sakata 《Journal of Material Cycles and Waste Management》2007,9(1):56-61
Brominated high-impact polystyrene (HIPS-Br), which contained decabromodiphenyl ether flame retardant, and brominated acrylonitrile
butadiene styrene (ABS-Br), which contained bromine-containing epoxy-type flame retardant, were degraded at 450°C individually
and in a 1/1 mixture by a thermal and catalytic procedure using folded sheet mesoporous (FSM) and ZSM-5 zeolite in liquid
phase contact mode. The two polymers produced similar degradation oils but at a higher yield for HIPS-Br. However, the composition
and distribution of Br-, N-, and O-containing compounds depended on the type of flame retardant in HIPS-Br and ABS-Br. Multiphase
catalytic systems consisting of FSM in liquid phase contact mode and various CaH-, FeO-, CoMo-, and NiMo-based catalysts,
or combinations of these catalysts, in vapor phase contact mode were used to decrease the amount of heteroatoms (Br, N, and
O) in the degradation oils. Each system gave particular results in terms of mass balance and concentrations of heteroatoms.
A FSM (liquid phase contact)/CaHC (vapor phase contact) combination was the best catalytic system to remove Br-, N-, and O-containing
compounds from degradation oils. 相似文献
26.
27.
Various elements and inorganic ions in rice straw and ash samples were analyzed by using inductively coupled plasma atomic emission spectrometry (ICP‐AES) and ion chromatography (IC). Five major elements: Mg, Mn, Al, Ca, and Fe and eight minor and trace elements: Cr, Cu, Ti, Zn, La, Sr, Ba, and Hg were detected in these samples, at more than ppm‐level. In ash samples the trace elements such as Y, As, V, Se, and Sc were also identified. The concentrations of SO4, PO4, Cl, Na, and K ions in these samples were higher than those of other ions measured. These elements and inorganic ion concentrations were approximately one order of magnitude higher in the ash than in the straw samples. Gas chromatography/mass spectrometry (GC/MS) and library search showed the presence of fatty‐, carboxylic‐ and nicotinic acids, and their derivatives in small quantities in the straw samples. 相似文献
28.
Joon-Woo Kim Tomohiko Isobe Agus Sudaryanto Govindan Malarvannan Kwang-Hyeon Chang Mamoru Muto Maricar Prudente Shinsuke Tanabe 《Environmental science and pollution research international》2013,20(2):812-822
The use of organophosphorus flame retardants (PFRs) as flame retardants and plasticizers has increased due to the ban on common polybrominated diphenyl ether mixtures. However, only limited information on PFR contamination is available so far from Southeast Asia. In the present study, residual levels of PFRs in house dust and exposure through dust ingestion were investigated in the Philippines. House dust samples (n?=?37) were collected from Malate (residential area) and Payatas (municipal dumping area) in the Philippines and analyzed using ultra-high-performance liquid chromatography coupled with tandem mass spectrometry. Among the targeted seven PFRs, triphenyl phosphate (TPP) was the predominant compound. Median levels of ΣPFRs in Malate (530 ng/g) were two times higher (p?<?0.05) than in Payatas (240 ng/g). The estimated daily intake of PFRs in the Philippines (of areas studied) via house dust ingestion was below the guideline values. House dust may be an important contributor in the overall exposure of humans to TPP even when considering dietary sources. To our knowledge, this is a first report on PFR contamination in house dust from developing country. PFRs were ubiquitously detected in the home environments in the Philippines. Although estimated exposure levels through dust ingestion were below the guideline, it was suggested that toddlers are at higher risk. Therefore, further investigations to understand the behavior of PFRs in house and other microenvironments and overall exposure pathways for the country’s populace to PFRs are necessary. 相似文献
29.
Kazunori Ueno Mamoru Tanaka Kei Miyakoshi Chen Zhao Hiroshi Shinmoto Gen Nishimura Yasunori Yoshimura 《黑龙江环境通报》2002,22(12):1071-1075
We describe prenatal diagnosis in a male fetus at 21 weeks of gestation with atelosteogenesis type I (AO I). Fetal ultrasonography (US) revealed absent or deficient ossification of the posterior neural arches of the thoracic spine, humeri, radii, ulnae, fibulae, and short tubular bones other than the distal phalanges, in addition to extremely short, thick femora. Fetal magnetic resonance imaging (MRI) using an ultrafast imaging sequence depicted dysmorphic features, pulmonary hypoplasia, and large cisterna magna. Postmortem radiographs warranted a diagnosis of AO I. Autopsy corroborated not only pulmonary hypoplasia but also laryngeal stenosis. The chondro-osseous histological findings were consistent with those of AO I. Meticulous evaluation using fetal US and MRI permits a definitive prenatal diagnosis of AO I to be made. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
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