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71.
Seas and oceans are confronted with a plethora of environmental problems, caused by land-based activities (agriculture, industries, and ports) and by maritime activities (such as shipping, fishing, oil and gas drilling, tourism, and navigational dredging). Environmental problems at sea challenge the efficacy of state sovereignty. Who is responsible, accountable, and regulates environmental and spatial problems at the level of regional seas, and what is the role of states in these processes of governance? In the regional seas and on the high seas, the environmental state is challenged by two developments: states become players at different levels, and states are confronted with the activities of big market players where they have no or little jurisdiction. The different forms of the environmental state in Europe’s regional seas and in the Arctic Ocean are examined.  相似文献   
72.
利用N,N’-双(水杨醛)缩邻苯二胺配体(L)与稀土金属离子合成了稀土水杨醛Salphen希夫碱配合物{[M(NO3)2]·2H2O;M=La,Nd,Sm},并利用红外光谱(IR)、紫外-可见光谱(UV)、元素分析、摩尔电导率和差热热重(TG—DTA)对配合物的结构做了表征。结果表明,配合物中稀土金属离子M(Ⅲ)的配位数为6,同时还有2个NO3-和配位中心配位。  相似文献   
73.
Chung K  Lee I  Han JI 《Chemosphere》2012,86(4):415-419
As an effort to better utilize the microbial fuel cell (MFC) technology, we previously proposed an innovative MFC system named M2FC consisting of ferric-based MFC part and ferrous-based fuel cell (FC) part. In this reactor, ferric ion, the catholyte in the MFC part, was efficiently regenerated by the FC part with the generation of additional electricity. When both units were operated separately, the ferric-based MFC part produced approximately 1360 mW m−2 of power density with FeCl3 as catholyte and Fe-citrate as anolyte. The ferrous-based FC part with FeCl3 as catholyte and Fe-EDTA as anolyte displayed the highest power density (1500 mW m−2), while that with ferricyanide as catholyte and Fe-noligand as anolyte had the lowest power density (380 mW m−2). The types of catholytes and chelating complexes as anolyte were found to play important roles in the reduction of ferric ions and oxidation of ferrous ion. Linear sweep voltammetry results supported that the cathode electrolytes were electrically active and these agreed well with the M2FC reactor performance. These results clearly showed that ligands played critical role in the efficiency and rate for recycling iron ion and thus the M2FC performance.  相似文献   
74.

Organic amendments are sometimes applied to agricultural soils to improve the physical, chemical, and microbiological properties of the soils. The organic fractions in these soil amendments also influence metal reaction, particularly the adsorption and desorption of metals, which, in turn, determine the bioavailability of the metals and hence their phytotoxicities. In this study, a Quincy fine sandy (mixed, mesic, Xeric Torripsamments) soil was treated with 0 to 160 g kg?1 rates of either manure, sewage sludge (SS), or incinerated sewage sludge (ISS) and equilibrated in a greenhouse at near field capacity moisture content for 100 days. Following the incubation period, the soil was dried and adsorption of copper (Cu) was evaluated in a batch equilibration study at either 0, 100, 200, or 400 mg L?1 Cu concentrations in a 0.01M CaCl2 solution. The desorption of adsorbed Cu was evaluated by three successive elutions in 0.01M CaCl2. Copper adsorption increased with an increase in manure rates. At the highest rate of manure addition (160 g kg?1 soil), Cu adsorption was two-fold greater than that by the unamended soil at all rates of Cu additions. With increasing rates of Cu additions, the adsorption of Cu decreased from 99.4 to 77.6% of Cu applied to the 160 g kg?1 manure amended soil. The desorption of Cu decreased with an increase in rate of manure amendment. Effects of sewage sludge amendments on Cu adsorption were somewhat similar to those as described for manure additions. Likewise, the desorption of Cu was the least at the high rate of SS addition (160 g kg?1), although at the lower rates there was not a clear indication of the rate effects. In contrast to the above two amendments, the ISS amendment had the least effect on Cu adsorption. At the highest rate of ISS amendment, the Cu adsorption was roughly 50% of that at the similar rate of either manure or SS amendments, across all Cu rates.  相似文献   
75.
金属络合吸收剂在湿法脱硝中的应用   总被引:3,自引:1,他引:3  
湿法络合脱硝是联合脱硫脱硝的重要研究方向.从金属络合吸收剂的结构出发,分析了铁、钴等金属中心离子和氨基羧酸类或巯基类配体的配位化学;归纳了金属络合吸收剂在不同条件下(如温度和pH值等)的动力学参数;总结了生物法、还原法和电解法再生吸收液的方法.提出了研究抗氧化能力强的吸收剂和吸收产物变废为宝的研究方向.  相似文献   
76.
The incorporation of xenobiotics into soil, especially via covalent bonds or sequestration has a major influence on the environmental behavior including toxicity, mobility, and bioavailability. The incorporation mode of 4-chloro-2-methylphenoxyacetic acid (MCPA) into organo-clay complexes has been investigated under a low (8.5 mg MCPA/kg soil) and high (1000 mg MCPA/kg soil) applied concentration, during an incubation period of up to 120 days. Emphasis was laid on the elucidation of distinct covalent linkages between non-extractable MCPA residues and humic sub-fractions (humic acids, fulvic acids, and humin). The cleavage of compounds by a sequential chemical degradation procedure (OH?, BBr3, RuO4, TMAH thermochemolysis) revealed for both concentration levels ester/amide bonds as the predominate incorporation modes followed by ether linkages. A possible influence of the soil microbial activity on the mode of incorporation could be observed in case of the high level samples. Structure elucidation identified MCPA as the only nonextractable substance, whereas the metabolite 4-chloro-2-methylphenol was additionally found as bioavailable and bioaccessible compound.  相似文献   
77.
坝上高原生境脆弱与人为不合理活动的叠加影响,导致票钙土退化。表现为土壤代换量降低,养分含量减少,有机复合体破坏;松结合态、稳结合仓和紧结合态腐殖质下降,其下降率依序为21%~34%、44%~55.5%和5%~62%。  相似文献   
78.
原位水解生成的羟基氧化铁凝聚吸附除磷效能与机制   总被引:1,自引:0,他引:1  
将不同摩尔比Fe3+与OH-([Fe3+]:[OH-]=1:0、1:1、1:2和1:3)反应获得原位水解生成的羟基氧化铁(in situ FeOxHy),研究了具有不同水解程度的羟基氧化铁对凝聚吸附除磷效能与机制。研究显示,In situ FeOxHy对磷的去除率随铁投量增大而升高,且均在中性pH范围内具有最佳除磷效果;在相同铁投量条件下,磷去除率随着[OH-]:[Fe3+]的升高而降低;当体系碱度较低时(pH<6),引入OH-可促进Fe3+水解而提高除磷效果。4种羟基氧化铁均可在15 s内可快速吸附磷,且吸附过程符合准二级动力学模型;Freundlich模型均可很好地描述磷在4种羟基氧化铁表面的吸附行为。磷酸盐吸附后,In situ FeOxHy表面Zeta电位明显降低,且[Fe3+]:[OH-]为1:0的羟基氧化铁降低最为显著。结合MINITEQ计算软件磷酸盐、铁盐形态分析结果显示,对于碱度较低的体系,通过投加一定量OH-可促进Fe3+水解,进而使得其更易与水中H2PO4-与HPO42-结合,生成具有多核羟基的磷酸铁络合物,进而提高除磷效果。  相似文献   
79.
80.
海藻多糖稀土配合物对蔬菜有机磷农药残留的降解作用   总被引:1,自引:0,他引:1  
以小白菜、甘蓝、芹菜为试验材料,采用大田试验研究了海藻多糖稀土配合物对蔬菜中有机磷农药残留的影响.试验结果表明,叶面喷施海藻多糖稀土配合物对小白菜、甘蓝、芹菜中毒死蜱、氧化乐果、敌敌畏等有机磷农药残留具有明显的降解作用;对甘蓝中毒死蜱和氧化乐果的降解效果优于小白菜,但对芹菜中毒死蜱的降解效果远不及甘蓝和小白菜,表现出一定的作物选择性.叶面喷施海藻多糖稀土配合物对敌敌畏等磷酸酯类有机磷农药的降解作用比毒死蜱、氧化乐果等硫代磷酸酯类有机磷农药的降解强烈,表现出一定的农药选择性;另外,喷水对叶片表面残存农药具有一定的冲洗作用,可减少叶面农药的残留量;叶面喷施海藻多糖稀土配合物对甘蓝和小白菜中有机磷农药的降解率远高于叶面喷水.以上结果表明海藻多糖稀土配合物确实具有降解有机磷农药残留的作用.在蔬菜生产中将海藻多糖稀土配合物作为农药残留降解制剂是可行的,有利于蔬菜安全生产和提高蔬菜产品的食用安全性。  相似文献   
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