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321.
Xiaodong Chen M. Nils Peterson Vanessa Hull Chuntian Lu Dayong Hong Jianguo Liu 《Ambio》2013,42(1):52-60
Rapid environmental degradation in China makes understanding how perceived exposure to environmental harm influences environmental attitudes and participation in pro-environmental behaviors among the Chinese people crucial. We used a nation-wide survey dataset in urban China to test two hypotheses: experiencing environmental harm directly affects environmental behavior; environmental attitudes mediate the relationship between experiencing environmental harm and environmental behavior. We found respondents who experienced environmental harm had more pro-environmental attitudes. Experiencing environmental harm positively influenced pro-environmental behavior both directly and indirectly through the mediation of pro-environmental attitudes. Among the pro-environmental behaviors, environmental litigation was most strongly related with exposure to environmental harm. Our results suggest that more participation in pro-environmental behaviors may be expected as rapid economic development increases public exposure to environmental harm in urban China. 相似文献
322.
采用生物接触氧化(BCO)+曝气生物滤池(BAF)组合工艺深度处理洗涤剂废水,研究了溶解氧浓度(DO)、水力停留时间(HRT)对其处理性能的影响。实验结果表明,随着DO浓度的提高,组合工艺对COD和LAS的去除率都随之增加;水力停留时间的增加有利于对COD与LAS的去除,最佳停留时间选为21.2h为宜;在BCO段DO为3.0 mg/L,HRT为20.0 h,BAF段DO为4.0 mg/L,HRT为1.2 h的运行条件下,COD与LAS的去除率分别为90.5%和94.3%,出水COD和LAS均能达到排放标准。 相似文献
323.
为了提高吸附剂对乙烯气体的吸附量,对常见的MCM-41分子筛进行了过渡金属离子改性研究。通过镍离子交换实验,确定了改性条件,改性后的样品对乙烯的吸附行为发生改变。使用镍离子改性后的MCM-41在常温常压下对乙烯的最大吸附量为可达416cm3/g,约为商用颗粒活性炭的6倍,远高于其他文献的报道。吸附质的检测结果说明乙烯在其吸附过程中发生多聚反应,高碳数的直链烯烃为最终产物。CO原位红外吸附的引人证实经过热处理后,一价镍能在镍离子改性后的MCM-41样品中形成并成为乙烯聚合反应的活性中心。 相似文献
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为实现二恶英快速检测,指导废物焚烧炉二恶英减排,通过检测生活垃圾焚烧炉烟气中氯苯和二恶英浓度,研究了三氯苯、四氯苯和二恶英之间的关联关系,并利用实验室自行研制的飞行时间质谱仪对烟气样品的三氯苯进行在线检测。结果表明,三氯苯与二恶英毒性当量(I-TEQ)之间存在良好关联性,相关系数(R2)可达到0.89。仪器检测信号强度与三氯苯浓度之间具有良好的线性关系,根据在线检测烟气样品中三氯苯的信号可得到三氯苯浓度,并根据关联模型计算得到二恶英毒性当量值I-TEQ,实现了对烟气样品中二恶英的快速间接测量。 相似文献
326.
Formation of polychlorinated diphenyl ethers from condensation of chlorophenols with chlorobenzenes 总被引:1,自引:1,他引:0
Liu W Zheng M Liu W Ma X Qian Y Zhang B 《Environmental science and pollution research international》2008,15(1):84-88
BACKGROUND AND AIMS: Polychlorinated diphenyl ethers (PCDEs), which are among the members of persistent organic pollutants, and PCDEs have been determined in a number of environmental samples. The main possible sources are the technical production of chlorinated phenols and all processes of incomplete combustion. PCDEs were observed in the fly ash from a municipal waste incinerator (MWI). It was speculated that the condensation of chlorophenols with chlorobenzenes occurred via PCDEs to form polychlorinated dibenzofurans (PCDFs). Nevertheless, PCDEs formation from condensation of chlorophenols with chlorobenzenes has not been confirmed by experimental observation. The objective of this paper is to investigate the formation mechanism of PCDEs from the condensation of chlorophenols with chlorobenzenes. The results are expected to be helpful in understanding the formation of PCDEs and in controlling and abating PCDEs emissions from MWI. METHODS: The pyrolysis of pentachlorophenol (PCP) and/or polychlorobenzenes (PCBz) was carried out in a sealed glass tube. The reaction products were extracted and purified with K2CO3 solution. The samples were concentrated and then cleaned up on an alumina column. GC/MS was used for identification and quantification of reaction products. RESULTS AND DISCUSSION: The results showed that the pyrolysis of hexachlorobenzene (HCB) at 340 degrees C for 6 h led to the formation of decachlorodiphenyl ether (DCDE) (2.41 microg/mg) and octachlorodibenzo-p-dioxins (OCDD) (0.24 micropg/mg), while the pyrolysis of PCP yielded DCDE (13.08 microg/mg) and OCDD (180.13 microg/mg). In addition, the amount of DCDE formation from the pyrolysis of the mixture of PCP and HCB was 4.65 times higher than the total amount of DCDE formation from the pyrolysis of HCB and PCP, respectively. This indicated that PCP and HCB were prone to condensation and formation of DCDE. DCDE was the main congener of PCDEs from condensation of PCP with HCB at 340, 400 and 450 degrees C. A small amount of nonachlorodiphenyl ether (NCDE) was formed by dechlorination reaction at 450 degrees C. The condensation of PCP with 1,2,4,5-tetrachlorobenzene (Cl4Bz) formed 2,2',3,4,4',5,5',6-octachlorodiphenyl ether (OCDE). Small amounts of heptachlorodiphenyl ether (HpCDE) and hexachlorodiphenyl ether (HxCDE) were detected at 450 degrees C. Meanwhile, polychlorinated dibenzo-p-dioxins (PCDDs) and PCDFs were detected from the condensation of PCP and PCBz. CONCLUSIONS: Experimental studies clarified the behavior of the formation of PCDEs from condensation of polychlorophenols and PCBz. The condensation of polychlorophenols with PCBz formed PCDEs through elimination of HCl between polychlorophenols and PCBz molecules. Another pathway of PCDEs formation was elimination of H2O between two polychlorophenol molecules. In addition, dechlorination processes had caused the specific homologous pattern of PCDEs under higher temperatures. 相似文献
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329.
He G Chen X Liu W Bearer S Zhou S Cheng LY Zhang H Ouyang Z Liu J 《Environmental management》2008,42(6):1017-1025
Ecotourism is widely promoted as a conservation tool and actively practiced in protected areas worldwide. Theoretically, support for conservation from the various types of stakeholder inside and outside protected areas is maximized if stakeholders benefit proportionally to the opportunity costs they bear. The disproportional benefit distribution among stakeholders can erode their support for or lead to the failure of ecotourism and conservation. Using Wolong Nature Reserve for Giant Pandas (China) as an example, we demonstrate two types of uneven distribution of economic benefits among four major groups of stakeholders. First, a significant inequality exists between the local rural residents and the other types of stakeholder. The rural residents are the primary bearers of the cost of conservation, but the majority of economic benefits (investment, employment, and goods) in three key ecotourism sectors (infrastructural construction, hotels/restaurants, and souvenir sales) go to other stakeholders. Second, results show that the distribution of economic benefits is unequal among the rural residents inside the reserve. Most rural households that benefit from ecotourism are located near the main road and potentially have less impact on panda habitat than households far from the road and closer to panda habitats. This distribution gap is likely to discourage conservation support from the latter households, whose activities are the main forces degrading panda habitats. We suggest that the unequal distribution of the benefits from ecotourism can be lessened by enhancing local participation, increasing the use of local goods, and encouraging relocation of rural households closer to ecotourism facilities. 相似文献
330.