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11.
为了在酸性条件下实现剩余污泥中磷的高效回收,对pH=3时剩余污泥水解酸化过程中氨氮、正磷酸盐和钙镁离子的溶出现象以及磷回收进行了研究分析。结果表明:当pH=3时,所溶出的氨氮、镁离子和钙离子与磷酸盐的摩尔比均大于1,能满足采用鸟粪石沉淀法或者羟磷灰石沉淀法回收磷的要求;但所溶出的钙镁离子的摩尔比大于1,会对鸟粪石沉淀法回收磷的顺利进行有较大影响;有无外加镁剂对磷回收率影响不大。采用改型后的镁型强酸性阳离子交换树脂进行离子交换可以得到较高纯度的鸟粪石沉淀产品,通过XRD检测其纯度为95%以上。 相似文献
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Xu Y Wu Z Yu B Peng X Yu G Wei Z Wang G Li R 《Environmental pollution (Barking, Essex : 1987)》2008,156(1):162-167
It is well known that several morphospecies of Microcystis, such as Microcystis aeruginosa (Kützing) Lemmermann and Microcystis viridis (A. Brown) Lemmermann can produce hepatotoxic microcystins. However, previous studies gave contradictory conclusions about microcystin production of Microcystis wesenbergii (Komárek) Komárek. In the present study, ten Microcystis morphospecies were identified in waterblooms of seven Chinese waterbodies, and Microcystis wesenbergii was shown as the dominant species in these waters. More than 250 single colonies of M. wesenbergii were chosen, under morphological identification, to examine whether M. wesenbergii produce hepatotoxic microcystin by using multiplex PCR for molecular detection of a region (mcyA) of microcystin synthesis genes, and chemical analyses of microcystin content by ELISA and HPLC for 21 isolated strains of M. wesenbergii from these waters were also performed. Both molecular and chemical methods demonstrated that M. wesenbergii from Chinese waters did not produce microcystin. 相似文献
15.
Yu FC Chen CY Lin SC Lin YC Wu SY Cheung KW 《Environmental monitoring and assessment》2007,132(1-3):419-428
As the embodiment of human activities, the change of regional industrial structure is an essential driving factor of global
environmental change. Consequently, the research on the change of regional industrial structure and associated effects on
the environment is one of the key issues of researches on sustainable development, human–environment relationship, and regional
response to global environment change. However, compared to the flourish of researches on environmental impact assessment
of industrial departments, few studies have been conducted to assess the environmental impact of regional industrial structure.
In this study, based on a synthetic analysis of environmental disturbances of different industrial departments, the environmental
impact coefficient of industrial department associated with the index of environmental impact of industrial structure was
constructed, so as to make a quantitative assessment of environmental impact of the change of regional industrial structure.
And the results of the case study in Lijiang City, a rural region of China, have showed that there are two obvious changes
of industrial structure in the study area from 1992 to 2003, associated with a continuous decreasing of the index of environmental
impact of industrial structure, which indicated a positive environmental effects of the change of regional industrial structure. 相似文献
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17.
An experimental study on recolonization and succession of marine macrobenthos in defaunated sediment 总被引:3,自引:0,他引:3
Hypoxia/anoxia in coastal waters is a world wide problem which often results in mass mortality and defaunation of benthos.
In this study, field experiments were carried out to examine recolonization and succession of macrobenthic infauna in defaunated
sediments, and the time required for recovery from complete defaunation to a stable community. Trays (33 cm length × 25.5 cm
width × 11 cm depth) of defaunated sediment were exposed at the subtidal of a pristine site in subtropical Hong Kong. Temporal
changes of macrobenthic communities in defaunated sediment were analyzed by univariate and multivariate statistics, and compared
with those in undisturbed natural sediment at the same site. Initial colonization of macrobenthos occurred rapidly. A total
of 42 species was found, with an average of 258 animals per tray and 24 species per tray recorded in the first month. Abundance
showed a small peak (496 animals per tray) after 3 months, reached a sharp peak (1154 animals per tray) after 6 months, and
declined thereafter. Species number increased gradually, reached a maximum (68 species per tray) after 9 months, and then
decreased. Recolonization was predominantly contributed by larval settlement rather than adult migration. Temporal changes
in abundance, species number and diversity of the macrobenthic community in defaunated sediment resemble the spatial changes
along a decreasing pollution gradient previously defined by other authors. Results of this experiment suggest that newly available
sediment may allow more species to colonize (or coexist) than sediment pre-occupied by an established community. This is probably
due to less interspecific competition in the former habitat. No significant difference in abundance or species richness was
observed between defaunated and natural sediments after 15 months, suggesting that a stable community had been achieved, although
minor variations in species composition were still discernible between defaunated and natural sediments.
Received: 24 May 1999 / Accepted: 20 October 1999 相似文献
18.
聚苯乙烯基硫代磺酸钾树脂的合成及其与卤代烃的反应 总被引:2,自引:2,他引:0
由聚苯乙烯基磺酰氯树脂与硫化氢钾反应制备聚苯乙烯基硫代磺酸钾树脂(I),树脂I与亲电的卤代烃反应,生成聚苯乙烯基硫代磺酸酯树脂(Ⅱ),树脂Ⅱ经过乙硫醇处理,使卤代烃结构部分以不对称二硫醚的形式游离下来,用GC/MS对其结构进行鉴定。从不对称二硫醚的结构可推导出原卤代烃的结构,所制备的聚苯乙烯基硫代磺酸钾树脂的转化效率为1.11mmol·g^-1。 相似文献
19.
羊角月芽藻摄取磷形态的动力学研究 总被引:4,自引:0,他引:4
将湖水中的磷分成总溶解磷,溶解反应磷,总反应磷、溶解的水解性磷,溶解的光解性磷。研究其在羊角月芽过程中的变化。 相似文献
20.
CVM法对长江口海洋生态价值的评价应用 总被引:3,自引:1,他引:3
运用CVM法探讨评价长江口海洋生态价值,结合长江口海洋产业的发展与生态环境实际,模拟市场条件进行主观意愿评价,阐述CVM法在长江口海洋生态价值评价应用中的可行性和有效性的同时,对CVM法使用时产生的偏差提出解决的方法,为长江口海洋产业绿色GDP核算提供科学方法和依据。 相似文献