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1.
Qiao WM Song Y Yoon SH Korai Y Mochida I Yoshiga S Fukuda H Yamazaki A 《Waste management (New York, N.Y.)》2006,26(6):592-598
Efficient removal of chlorine from PVC achieved by two-stage heat-treatment (280 and 410 degrees C) provided chlorine-free isotropic pitch containing additive. The pitch was stabilized and carbonized into porous carbons with surface areas of approximately 300 m2/g. Resultant porous carbons showed three pore structures of supermicropore, micropore and mesopore. The generation of CO2 from the decomposition of the CaCO3 additive in waste PVC is responsible for the development of porous structures. The surface area of the carbonized product increased after the removal of CaO. 相似文献
2.
Efficient dehalogenation of automobile shredder residue in NaOH/ethylene glycol using a ball mill 总被引:1,自引:0,他引:1
We investigated the effectiveness of sodium hydroxide/ethylene glycol (NaOH/EG) for dehalogenation of automobile shredder residue (ASR) using a ball mill. Efficient dehalogenation was achieved at atmospheric pressure by combining the use of EG (196 degrees C b.p.) as a replacement solvent for NaOH with ball milling, which improved contact between ASR and OH(-) in solution. Moderate NaOH concentrations and increased ball mill rotation speeds produced high dechlorination that was not significantly affected by the weight ratio of ASR to EG. NaOH/EG dechlorination increased with temperature with an apparent activation energy of 50 kJ mol(-1) confirming that the reaction proceeded under chemical reaction control. The modified shrinking-core model was appropriate to explain the dechlorination process. Low chloro levels in our NaOH/EG-treated ASR suggested that this material could be used for feedstock recycling and the wet process may be applicable for dehalogenation of other important waste streams. 相似文献
3.
A larval medaka (Oryzias latipes) assay was proposed to evaluate the fish safety level of river waters and wastewaters. Organic toxicants were 10-100 times concentrated with adsorption cartridges from 4 l of river water or 1-10 times concentrated from 400 ml of wastewater. Toxicity of these concentrated solutions was determined by exposing 48-72 h post-hatch age larvae for 48 h. The method effectively revealed a variation of the median lethal concentration ratio (LCR50) from 13 to >100 in 125 river water samples, and from <1 to >10 in five typical wastewater samples. Ayase River, which takes water mostly from agricultural or household discharge, showed significantly (P<0.001) lower LCR50 than Sagami River that takes natural water as the source. Safety Levels in both Sagami River and Ayase River were influenced by the irrigation activity, LCR50 at some sites showing a seasonal-specific decrease in winter. Pollution from pulp and paper industries contributed to the low LCR50 in several tributaries of Ayase River. Required little manpower in sampling, pretreatment and testing, the proposed larval medaka assay was proved as an efficient tool for screening those high risk sites for priority management. 相似文献
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Arpita Bhowmik Koji Ishimura Kohei Nakamura Kazuhiro Takamizawa 《Journal of Material Cycles and Waste Management》2012,14(3):212-219
We showed the cis-1,2-dichloroethylene (cis-1,2-DCE) dechlorination ability of Clostridium species DC-1 in association with other bacteria. Result of denaturing gradient gel electrophoresis showed the dominant band pattern of DC-1 during the degradation time of cis-1,2-DCE and dominance of some other Clostridium species. Experiment with addition of Escherichia coli (E. coli) showed that dechlorinating activity of DC-1 was not inhibited by the presence of E. coli. Pour plate experiment with DC-1 and E. coli revealed that the dominance of Clostridium species caused the decrease of E. coli growth in a bioremediation state. This result suggested the possibility of Clostridium species DC-1 as a degrader of cis-1,2-DCE, in a cis-1,2-DCE contaminated site where an indigenous microbial community is present. Experiment conducting with E. coli suggested that the strain in the contaminated site did not inhibit the degradation of cis-1,2-DCE and during the degradation period, rather some other Clostridium species became dominant and the growth of E. coli would be decreased. This finding could be a very positive approach for implementing the dechlorinating bacteria at aliphatic chlorinated component contaminated sites. 相似文献
7.
Sasai Ryo Fujimura Takuya Uesugi Ryohei Aketo Tsuyoshi Komatsu Kohei 《Journal of Material Cycles and Waste Management》2023,25(1):389-395
Journal of Material Cycles and Waste Management - To cater to the increasing demand for secondary lithium-ion batteries, the recovery of valuable metal species in spent batteries is increasingly... 相似文献
8.
Potential dietary effects on the fatty acid composition of the common jellyfish Aurelia aurita 总被引:2,自引:0,他引:2
Fatty acid composition of the natural and aquarium-reared common jellyfish Aurelia aurita was investigated. Fatty acid composition of the aquarium-reared A. aurita clearly reflected that of the diet, brine shrimp (Artemia). In the same way, fatty acid composition of the natural A. aurita was assumed to reflect those of natural diets. Samples of natural A. aurita were collected from April 1995 to September 1995 in the Seto Inland Sea, Japan, and their fatty acids were analyzed by gas
chromatography and mass spectrometry. Variation of fatty acid compositions was seasonal rather than dependent on body size.
Two major seasonal groups were divided by the cluster analysis of the A. aurita fatty acid composition: the April–June and the August–September clusters. The April–June cluster was characterized by high
contents of the (n − 3)-fatty acids of diatom origin, accumulated via the grazing food chain. By contrast, the August–September cluster was
characterized by an increase in (n − 6)-fatty acids of macroalgal origin, probably transferred via the detritus food chain. These results suggest that the diet
of natural A. aurita may shift between the diatom-based food chain and the detritus-based food chain.
Received: 12 April 2000 / Accepted: 1 December 2000 相似文献
9.
This study compared the accuracy of fuzzy habitat preference models (FHPMs) and habitat preference curves (HPCs) obtained from the FHPMs in order to assess the effect of two types of data [log-transformed fish population density (LOG) and presence-absence (P/A) data] on the habitat preference evaluation of Japanese medaka (Oryzias latipes). Three independent data sets were prepared for each type of data. The results differed according to the data sets and the types of data used. The HPCs showed a similar trend, whilst the degrees of preference were different. The model accuracy also differed according to the data sets used. Although almost no statistical difference was observed, on average, the P/A-based models showed a better performance according to the threshold-independent performance measures, whilst the LOG-based models showed better performance in predicting absence of the fish. These results can be explained partly from the different shapes of HPCs. This case study of Japanese medaka demonstrated the effect of different types of data on habitat preference evaluation. Further studies should build on the present finding and evaluate the effects of data characteristics such as the size of data sets and the prevalence for better understanding and reliable assessment of the habitat for target species. 相似文献
10.
Physico-chemical characteristics of some river and hand-dug well waters used for drinking and domestic purposes in the oil
rich Niger Delta area of Nigeria were assessed using standard methods. The concentrations of the parameters in the river water
samples ranged in the following order: pH (5.6–6.9), temperature (26.90–28.60°C), turbidity (23–63 NTU), electrical conductivity
(52–184 μs/cm), DO (5.4–7.2 mg/l), BOD (21–57 mg/l), TDS (6.0–217 mg/l), PO4
3− (0.19–1.72 mg/l), SO4
2− (25–36.8 mg/l), NO3
− (20.3–28 mg/l), Fe (6.07–15.71 mg/l), Zn (0.04–0.24 mg/l), Pb (0.01–0.17 mg/l), Ni (0.01–0.13 mg/l), Vn (0.01–0.20 mg/l)
and Hg (0.001–0.002 mg/l). The concentrations of these parameters in the hand-dug well water ranged in the following order:
pH (5.7–6.8) temperature (26–30°C), turbidity (134–171 NTU), electrical conductivity (160–340 μs/cm), DO (5.4–6.4 mg/l), BOD
(13–34 mg/l), TDS (110–190 mg/l), PO4
3− (0.84–1.84 mg/l), SO4
2− (10.6–28.1 mg/l), NO3
− (11.3–23 mg/l), Fe (13.17–16.31 mg/l), Ni (0.01–0.02 mg/l), Vn (0.01–0.04 mg/l) and Hg (0.001–0.004 mg/l). The concentrations
of BOD, turbidity, NO3
− and Fe in the water samples were above WHO and FMENV permissible limits for safe drinking water. The results suggest that
the use of such waters for drinking and domestic purposes pose a serious threat to the health of the users and calls for the
intervention of government agencies. 相似文献