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针对间歇式堆肥反应器处理效率低、不便移动、单次投加所需物料量大等不足,以及为更有效地处理分散型人粪便,使人粪便资源化,开发了梨形筒式好氧堆肥反应器。在获得该反应器的最佳通风与搅拌频率分别为3.0 L/min,5 min/h以及最佳m(粪便)︰m(锯末)为1︰2.5的条件下进行连续投加人粪便好氧堆肥。在不接种微生物的30 d堆制过程中,升-降温周期为36 h,平均温度为51.44℃,第15天时COD降解率达到63.99%并趋于稳定,TN损失率第17天时达到56.68%,GI于第21天时达到106.25%,堆肥完全腐熟,稳定期处理效率为23.81 g/(L·d)。接种土著菌种时,升-降温周期缩短至24 h,平均温度为53.96℃,COD降解率8 d可达65.28%,TN 损失率仅为25.75%,GI于第8天达到108.22%,稳定期处理效率可达35.71 g/(L·d),比不接种时提高1.5倍,同时节约能耗50%。 相似文献
34.
大多数传统的重金属污染治理技术成本高,会引起土壤肥力下降,对各类生态系统造成负面影响。植物修复技术是一种成本低、环境友好的方法,不会对土壤性质和生态系统产生不利影响。文章综述了植物修复治理重金属污染土壤的研究进展,探讨如何通过采取物理、化学、生物技术及农艺措施等方法提高修复植物的生物量和重金属积累量并展望了今后的研究方向。 相似文献
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Kumar A Baroth A Soni I Bhatnagar P John PJ 《Environmental monitoring and assessment》2006,116(1-3):1-7
Anupgarh is the most fertile area of Rajasthan state where a variety of seasonal crops are grown. The availability of three
manmade canals has enhanced the agricultural activities in this area. The farmers use huge amounts of pesticides to increase
the crop productivity. Exposure of humans to these hazardous chemicals occurs directly in the fields and indirectly due to
consumption of contaminated diet, or by inhalation or by dermal contact. The organochlorine pesticides are reported to be
lipophilic and their presence in human milk and blood has been documented in different parts of the world. Blood and milk
samples were collected from lactating women who were divided into four groups on the basis of different living standards viz
residence area, dietary habits, working conditions and addiction to tobacco. The level of total organochlorine pesticides
in blood ranged from 3.319mg/L—6.253mg/L while in milk samples it ranged from 3.209Mdash;4.608 mg/L. The results are in concurrence
with the reports from other countries. 相似文献
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Rundqvist S Hedenås H Sandström A Emanuelsson U Eriksson H Jonasson C Callaghan TV 《Ambio》2011,40(6):683-692
Shrubs and trees are expected to expand in the sub-Arctic due to global warming. Our study was conducted in Abisko, sub-arctic
Sweden. We recorded the change in coverage of shrub and tree species over a 32– to 34-year period, in three 50 × 50 m plots;
in the alpine-tree-line ecotone. The cover of shrubs and trees (<3.5 cm diameter at breast height) were estimated during 2009–2010
and compared with historical documentation from 1976 to 1977. Similarly, all tree stems (≥3.5 cm) were noted and positions
determined. There has been a substantial increase of cover of shrubs and trees, particularly dwarf birch (Betula nana), and mountain birch (Betula pubescens ssp. czerepanovii), and an establishment of aspen (Populus tremula). The other species willows (Salix spp.), juniper (Juniperus communis), and rowan (Sorbus aucuparia) revealed inconsistent changes among the plots. Although this study was unable to identify the causes for the change in shrubs
and small trees, they are consistent with anticipated changes due to climate change and reduced herbivory. 相似文献
38.
Phthalate exposure was found to be associated with endocrine disruption, respiratory effects, reproductive and developmental toxicity. The intensive use of plastics may be increasing the exposure to phthalates in Taiwanese population, particularly for young children.We studied phthalate metabolites in pregnant women and their newborns in a prospective cohort from a medical center in Central Taiwan. One hundred maternal urine samples and 30 paired cord blood and milk samples were randomly selected from all of participants (430 pregnant women). Eleven phthalate metabolites (MEHP, 5OH-MEHP, 2cx-MEHP, 5cx-MEPP, 5oxo-MEHP, MiBP, MnBP, MBzP, OH-MiNP, oxo-MiNP, and cx-MiNP) representing the exposure to five commonly used phthalates (DEHP, di-isobutyl phthalate (DiBP), DnBP, BBP, DiNP) were measured in urine of pregnant women, cord serum and breast milk after delivery, and in urine of their children. Exposure was estimated with excretion factors and correlation among metabolites of the same parent compound. Thirty and 59 urinary samples from 2 and 5 years-old children were randomly selected from 185 children successfully followed.Total urinary phthalate metabolite concentration (geometric mean, μg L−1) was found to be higher in 2-years-olds (398.6) and 5-years-olds (333.7) than pregnant women (205.2). Metabolites in urine are mainly from DEHP. The proportion of DiNP metabolites was higher in children urine (4.39 and 8.31%, ages 2 and 5) than in adults (0.83%) (p < 0.01). Compared to urinary levels, phthalate metabolite levels are low in cord blood (37.45) and milk (14.90). DEHP metabolite levels in women’s urine and their corresponding cord blood are significantly correlated. Compared to other populations in the world, DEHP derived metabolites in maternal urine were higher, while phthalate metabolite levels in milk and cord blood were similar. The level of phthalate metabolites in milk and cord blood were comparable to those found in other populations. Further studies of health effects related to DEHP and DiNP exposure are necessary for the children. 相似文献
39.
Detection of dicofol and related pesticides in human breast milk from China, Korea and Japan 总被引:1,自引:0,他引:1
Fujii Y Haraguchi K Harada KH Hitomi T Inoue K Itoh Y Watanabe T Takenaka K Uehara S Yang HR Kim MY Moon CS Kim HS Wang P Liu A Hung NN Koizumi A 《Chemosphere》2011,82(1):25-31
Previously, we demonstrated that the concentrations of DDTs were greater in breast milk collected from Chinese mothers than from Japanese and Korean mothers. To investigate dicofol as a possible source of the DDTs in human breast milk, we collected breast milk samples from 2007 to 2009 in China (Beijing), Korea (Seoul, Busan) and Japan (Sendai, Takarazuka and Takayama). Using these breast milk samples, we quantified the concentrations of dichlorobenzophenone, a pyrolysis product of dicofol (simply referred to as dicofol hereafter), dichlorodiphenyltrichloroethane and its metabolites (DDTs) using GC-MS. Overall, 12 of 14 pooled breast milk samples from 210 mothers contained detectable levels of dicofol (>0.1 ng g−1 lipid). The geometric mean concentration of dicofol in the Japanese breast milk samples was 0.3 ng g−1 lipid and significantly lower than that in Chinese (9.6 ng g−1 lipid) or Korean breast milk samples (1.9 ng g−1 lipid) (p < 0.05 for each). Furthermore, the ΣDDT levels in breast milk from China were 10-fold higher than those from Korea and Japan. The present results strongly suggest the presence of extensive emission sources of both dicofol and DDTs in China. However, exposure to dicofol cannot explain the large exposure of Chinese mothers to DDTs because of the trace levels of dicofol in the ΣDDTs. In the present study, dicofol was confirmed to be detectable in human breast milk. This is the first report to identify dicofol in human samples. 相似文献
40.
We measured the concentration of each polychlorinated biphenyl (PCB) congener in whole blood, plasma and blood cells, and investigated the distribution of PCBs in human blood using high-resolution gas chromatography/high-resolution mass spectrometry (HRGC/HRMS). The PCB concentrations in plasma and whole blood in terms of lipid concentrations were almost equal, with a correlation coefficient of r = 0.972. In the blood, the ratio of PCBs in blood cells to those in plasma was generally about 1:9 and the congener distribution patterns in blood cells and plasma were similar.We performed verification of a simple mass screening method by obtaining information on the main PCB congeners for investigations on human accumulation and exposure. The total concentration of the seven PCB congeners (UNEP-7) proposed to the United Nations Environment Programme (UNEP) by Muir and Morita was about 50% of the total concentration of all PCB congeners, and UNEP-30 was about 80%. The seven main congeners in the blood (MCB-7) showed a value that was about 60%, and MCB-30 showed a value that was about 90%. Determinations with the main congeners in the blood showed a correlation of r = 0.990 or more between the main eight congeners (MCB-7 plus #74) and the total PCB concentration for all congeners. The results suggest that, although total PCB concentration can be effectively estimated from the main seven congeners, the main eight congeners would be preferable, and that the use of these congeners in the simple mass screening method would be effective for populations in areas uncontaminated by PCBs. 相似文献