首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 109 毫秒
1.
浮床植物系统对富营养化水体中氮、磷净化特征的初步研究   总被引:75,自引:0,他引:75  
以浮床空心菜(Ipomoea aquatica)、水芹(Oenanthe javanica)和无植物系统为对象,研究了其在富营养化水体中对N、P的去除及其N2O的排放情况.结果表明,浮床植物系统对水体中N、P具有良好的净化效果,植物组织所累积的N、P量分别占各自系统去除量的40.32%~63.87%,说明植物的同化吸收作用是N、P去除的主要途径.换水周期内浮床植物系统中硝化反应进行充分,而反硝化反应相对缓慢,导致系统具有较高的NH4+-N去除率,而产生NO3--N累积.植物的存在降低了系统中N2O的排放通量.生长较好的空心菜系统在换水前后平均N2O排放量最低,为17.14μgN·m-2h-1,空白高达8.08μgN·m-2h-1,水芹为37.38μg N·m-2·h-1.  相似文献   

2.
以菖蒲和石菖蒲为对象,通过漂浮栽植研究了其在不同浓度生活污水中的生长特性及其对污水TN、NH3-N、TP、CODCr的去除情况。结果表明,菖蒲在中浓度污水中生长最好,其生物量显著高于低、高浓度,而石菖蒲在低浓度污水中生长最好,其生物量显著高于中、高浓度。菖蒲对中浓度污水中TN、TP、CODCr的去除率分别为96.85%、82.62%、88.89%,对低浓度污水中TN、TP、CODCr的去除率分别为99.87%、91.38%、83.34%,净化效果均高于高浓度(96.58%、80.96%、77.55%),但对NH3-N的去除率在高浓度污水中最好,为99.46%。石菖蒲净化中浓度污水的效果最好,对TN、NH3-N、TP、CODCr的去除率分别为94.20%、78.06%、89.43%、74.98%,对高浓度污水中的NH3-N、TP、CODCr的去除效果也较好,去除率分别为94.62%、91.95%、87.08%,但对TN去除率为59.14%,显著低于低浓度(98.73%)和中浓度(94.20%)。  相似文献   

3.
红树植物人工湿地对生活污水的净化效果   总被引:1,自引:0,他引:1  
研究了潜流型海桑(Sonneratia caseolaris)人工湿地、桐花树(Aegiceras corniculatum)人工湿地和木榄(Bruguiera gymnorrhiza)人工湿地对生活污水的净化效果。一年来,3种红树植物人工湿地对BOD5、CODCr、TP、TN、NH4^+-N和NO2^--N的平均去除率分别达到83%、71%、41%、55%、50%和84%以上。人工湿地各处理周期之间,BOD5和CODCr去除率波动较小,而TP、TN、NH4^+-N和NO2^--N去除率波动较大。3种红树植物人工湿地对各种污染物的净化效果存在一定的差异。海桑人工湿地和桐花树人工湿地对BOD5、CODCr、TP、TN和NH4^+-N去除率明显高于木榄人工湿地,而海桑人工湿地和桐花树人工湿地相比较,除TP外,BOD5、CODCr、TN和NH4^+-N去除率没有显著差异。人工湿地单一处理周期内,去除率随水力停留时间(HRT)的延长而增加。BOD5、CODCr、TN和NH4^+-N在HRT为1d和2d的去除率分别为HRT为3d去除率的54%-65%和73%-84%,NO2^--N在HRT为1d和2d的去除率分别达到了HRT为3d的70%-81%和85%-94%,而TP在HRT为1d和2d的去除率分别只有HRT为3d的39%-50%和65%-74%。另外,红树植物人工湿地与风车草(Cyperus alternifoliu)人工湿地相比,前者的BOD5、CODCr、TP、TN和NH4^+-N去除率明显小于后者(P〈0.05)。总体上看,3种红树植物人工湿地对生活污水的净化效果呈现海桑人工湿地≈桐花树人工湿地〉木榄人工湿地。  相似文献   

4.
陈重军  张蕊  吴伟祥  韩志英 《生态科学》2014,33(6):1067-1072
温室甲鱼养殖业是我国长三角地区村镇经济的重要产业, 但高氮磷含量温室甲鱼养殖废水的无序排放已严重影响了居民生活和生产用水质量与安全。采用静态蔬菜浮床系统处理温室甲鱼养殖废水, 并考察曝气和蔬菜种类对污染物去除的影响, 设置空白、空白+曝气、空心菜、空心菜+曝气、根达菜及根达菜+曝气等6 个处理, 经过46 d 的试验, 各系统对NH4+-N、TN、TP 和COD 的平均去除率分别为99.0%、67.7%、35.3%和87.5%, 对氮素和COD 的去除具有重要作用, 但对TP 的去除率较低, 但系统表现出较强的自净作用。通过曝气, 系统对TP 和COD 的去除能力显著增加, 但未增加对TN 的去除; 同时, 蔬菜种植显著增加了TN、TP 和COD 的去除, 种植空心菜具有更高的TP 和TN 去除效能, 但COD 的去除率却略低于种植根达菜。试验结果为植物浮床处理温室甲鱼养殖废水技术的应用和推广提供了技术支撑。  相似文献   

5.
DCD不同施用时间对水稻生长期CH4和N2O排放的影响   总被引:4,自引:0,他引:4  
李香兰  马静  徐华  曹金留  蔡祖聪  K.Yagi 《生态学报》2008,28(8):3675-3681
硝化抑制剂传统的施用方法是在作物移栽或播种前与基肥配合施用.通过温室盆栽试验研究相同施肥条件下,硝化抑制剂双氢胺(dicyandiamide, DCD)不同施用时间(与基肥混施、分孽肥后施入、穗肥后施入)对水稻生长期CH4和N2O排放的影响.结果表明,施入DCD能同时降低CH4和N2O排放量.就整个水稻生长期而言,与基肥混施DCD分别降低21.41%的CH4排放量和8.00%的N2O排放量;调节DCD施用时间至分孽肥后显著降低30.30%的N2O排放量,同时降低5.24%的CH4排放量.就施入DCD到水稻收获的特定生长阶段而言,缓施DCD分别降低32.65%的N2O排放量和11.18%的CH4排放量;晚施DCD对CH4和N2O排放的影响不大.CK、早施DCD、缓施DCD及晚施DCD处理CH4平均排放通量分别为0.95、0.75、0.87 mg/(m2 · h)及0.94 mg/(m2 · h),N2O平均排放通量为155.67、143.24、108.50 μg/(m2 · h)及153.24 μg/(m2 · h),缓施DCD显著降低CH4和N2O排放量(p<0.01).土壤温度是影响N2O排放的主要因素,而CH4排放通量与土壤Eh呈显著负相关(p<0.01).  相似文献   

6.
通过设施大棚内容积为1.5m3的人工模拟池试验,研究了浮床黑麦草对模拟城市生活污水氮循环细菌繁衍和脱氮效果的影响。通过研究,阐明浮床植物去除污染水体氮素的可能途径。研究结果表明:浮床黑麦草对模拟城市生活污水总氮和氨氮的去除效果分别达到了31.6%和43.0%;浮床黑麦草根际和根系正下方是各类氮循环细菌生长的最佳区域;浮床黑麦草处理有效地提高了系统氮循环细菌的数量,16d的试验结束时细菌总数(A,单位为CFU.mL-1)达到最大值,其lg(A/(CFU.mL-1))增加至8.82,各类氮循环细菌比对照高3-5个数量级;同时,浮床黑麦草处理显著提高了氮循环细菌的群落多样性,系统内氨化菌、硝化菌、亚硝化菌和反硝化菌共存;明确了浮床黑麦草的吸收同化和氮循环细菌的生物脱氮是浮床黑麦草净化水质的两个重要途径。  相似文献   

7.
李隐  田昆  肖德荣  杨倩  谢雯颖 《生态学杂志》2012,31(6):1425-1431
采用野外调查和室内模拟实验相结合的方法,对云南高原湿地常见的7种湖滨带植物群落开展污水净化试验研究,为云南高原退化湿地恢复与污染湖泊治理中植物的选择与空间配置提供依据。结果表明,湖滨带植物群落对污水浓度的耐受和净化降解是有限度的,在适合植物生长的污水浓度范围(TN:8.39~22.95mg·L-1;TP:0.61~1.96mg·L-1;NH4+-N:6.42~19.80mg·L-1)内,植物群落才能对污水起到高效的净化效果,对TP和NH4+-N的去除率均能达到30%以上,对TN的去除率也能达到20%。在较高浓度范围内,由茭草(Zizana caduciflora)、蓖齿眼子菜(Potamogeton pectinatus)和金鱼藻(Ceratophyllumdemersum)几种喜氮、磷植物组成的群落对污水的净化效果更好。但不同植物群落对污水的净化效果存在着差异(P<0.05),含同一种植物但其他组成植物不同的群落净化效果不同,表明植物种间存在相互作用,不同种类、不同生活型间相互协作,发挥着最大功能作用。  相似文献   

8.
刈割对人工湿地风车草生长及污水净化效果的影响   总被引:1,自引:0,他引:1  
刈割对人工湿地植物的生长和净化作用的影响,国内外学者的意见存在分歧。实验于2010年7月至2011年1月在华南师范大学生物园进行。利用水池(2m×2m×0.6m)构建风车草人工湿地生活污水处理系统,研究了刈割对人工湿地风车草生长和污水净化效果的影响。结果表明,刈割组风车草在整个实验过程中均保持着良好的生长态势,而对照组在11月以后生长减缓。刈割组风车草2010年7月至2011年1月的累积地上生物量、累积地上氮磷含量以及新增分蘖数均大于对照组,表现为超补偿生长。刈割组风车草的叶绿素含量、净光合速率、蒸腾速率和气孔传导率均显著高于对照组。刈割组和对照组的TN、TP、NH4-N和NO3-N的平均去除率分别为77%、84%、64%、72%和65%、67%、55%、63%,前者显著大于后者。刈割组和对照组的CODcr和BOD5平均去除率分别为58%、79%和54%、76%,两者差异不显著。总之,刈割对人工湿地风车草的生长和污水净化效果有明显的促进作用,这可为风车草人工湿地的科学管理提供参考。  相似文献   

9.
水培经济植物对污水中磷的吸收利用及去除效果   总被引:13,自引:0,他引:13  
对13种经济植物在污水水培条件下净化污水中磷的能力进行了研究。结果表明,黑麦草(Lolium multiflorum)、水芹(Oenanthe stolonifera)、莴苣(Lactuca sativavar.angustana)、酸模(Poly-gonum iapathifolium)、生菜(Lactuca sativa)、小葱(Allium ascalonicum)、五月慢青菜(Brassica chinen-sis)等品种具有较高的净化能力。在4个半月的水培中,TP的去除量分别达到10.27、10.35、6.5~6.896、.91、5.72、5.46和6.19 g.m-2;TP的去除率分别达到94.5%、95.2%、93.6%~99.3%、99.6%、99.5%、95%和89.2%。植物吸收作用是最主要的污水磷去除机制,沉淀在污水磷净化中的作用较小。污水中磷的去除与植物的生长期密切相关。黑麦草、水芹等7种植物适宜作为苏南地区冬季化粪池污水水培植物。  相似文献   

10.
香根草和风车草人工湿地对猪场废水氮磷处理效果的研究   总被引:58,自引:5,他引:58  
分别以香根草 (Vetiveriazizanioides )和风车草 (Cyperusalternifolius)为植被 ,按 1.0m× 0 .5m×0 .8m建立人工湿地 ,通过四季测试研究其对猪场废水N、P的净化功能及其随季节、进水浓度及水力停留时间变化的规律 .结果表明 ,两湿地对NH3 N和S PO3 -4 去除率受污水停留时间和污水浓度影响较大 .香根草或风车草人工湿地在春季对NH3 N和S PO3 -4 有明显的去除效果 ;在秋季 ,则对去除废水TN均有效果 ,在去除TP上 ,香根草湿地效果明显 ,风车草湿地效果差 .秋春季人工湿地随水力停留时间 (t)延长 ,TP或S PO3 -4 (Y)的去除遵从指数方程Yt=Y0 ·e-kt规律 .冬季和夏季 ,进水浓度对湿地去除P影响较大 ;在相同停留时间内 ,冬夏季人工湿地随进水浓度变化 ,进出水S PO3 -4 遵从直线方程 y =a +bx规律  相似文献   

11.
《环境昆虫学报》2014,(5):790-804
综述了白蚁螱客的主要种类、共生关系及相关机制的研究进展。白蚁螱客中,已报道的动物种类达170种。在与动物的共生关系中存在偏利共生(宾主共栖和异种共栖)、互利共生和无关共生三种;在与微生物的共生关系中,存在与内生菌(原生动物、细菌、真菌和放线菌)和外生菌(蚁巢伞菌等)间的互利关系。指出了白蚁与螱客研究中存在的问题,给出了解决方案,并提出了今后可能的研究热点或方向,为白蚁的综合利用(如纤维素酶)及今后研究物种间的协同进化提供了基础资料。  相似文献   

12.
New sulfur derivatives of phosphoramidite ligands were synthesized and the impact of the sulfur unit on the spectroscopic properties of their rhodium and iridium complexes was investigated. The new ligands Bn2NPSCH2CH2Sa(P-Sa) (Bn = benzyl, 4), Bn2NPSCHCHSa(CH2)3CaH2(P-Sa)(Ca-Sa) (6) and Bn2NP(4-XC6H4OMe)2 (X = S, 7a; X = O, 7b) were converted to the rhodium and iridium complexes trans-[Rh(CO)Cl(L)2] (L = 4, 6, 7), [RhCl(COD)(L)] (L = 4, 6, 7), [IrCl(COD)(7a)] and [IrCl2Cp∗(6)]. For comparison, some phosphoramidite complexes of these formulations also were synthesized. The new metal complexes were spectroscopically analyzed. For the carbonyl complexes, the νCO IR stretching frequencies were lower than for the corresponding phosphite and phosphoramidite ligands. The 1JPRh coupling constants for the rhodium complexes with the new ligands were also smaller than for the respective phosphoramidite and phosphite complexes. Finally, the 1JPSe coupling constants of the selenides of the new ligands were lower than those of the phosphoramidite ligands but higher than for PPh3. The spectroscopic data reveal that the new thio ligands 4, 6 and 7a are more electron donating than phosphites and phosphoramidites but less electron donating than PPh3.  相似文献   

13.
Astrocytes transport the monocarboxylate acetate, but synaptosomes do not. The reason for this is unknown, because both preparations express monocarboxylate transporters (MCT). The transport and metabolism of lactate, another monocarboxylate, was examined in these two preparations, and the results were compared to those for acetate. Lactate transport is more rapid in astrocytes than in synaptosomes, but of lower affinity (Kms of 17 and 4 mM, respectively). Lactate (0.2 mM) is metabolized to CO2 more rapidly in synaptosomes than in astrocytes (rates of 0.37 and 0.07 nmol x mg protein(-1) x min(-1), respectively). The reason for this is unclear, but cellular differences in lactate dehydrogenase isotype expression may be involved. Acetate is metabolized to CO2 more rapidly in astrocytes than in synaptosomes (rates of 0.43 and 0.02 nmol x mg protein(-1) x min(-1), respectively). This is likely due to cellular differences in the expression of monocarboxylate transporter subtypes.  相似文献   

14.
The first and second sessions of the Workshop focussed on the basics of ultrasound and infrasound, their applications in both industry and medicine, and metrology and protection standards for ultrasound applications.  相似文献   

15.
To elucidate accumulation of minerals in human iliac arteries with aging, the content of minerals was analyzed by inductively coupled plasma atomic emission spectrometry. Bilateral common, internal, and external iliac arteries of 16 men and 8 women, ranging ages from 65 to 93 yr, were examined. It was found that an extremely high accumulation of calcium and phosphorus occurred in the common iliac artery at old age, being higher than that of the internal and external iliac arteries. It should be noted that the accumulation of calcium and phosphorus is the highest in the common iliac artery among the human arteries examined to date. Regarding sexual differences, the content of calcium and phosphorus in the common and internal iliac arteries was higher in women than in men, whereas their content in the external iliac artery was lower in women than in men.  相似文献   

16.
17.
18.
The ability of partially purified human and guinea-pig haematogenous cell populations, when cultured in vitro, to metabolise arachidonic acid (AA) has been studied. Supernatants from 24 hour cell culture have been subjected to analysis for products of AA metabolism by gas chromatography with electron-capture detection.The cell types studied were human peripheral blood monocytes (both glass adherent and non-adherent), neutrophils, eosinophils and leukemic leucocytes; thoracic duct lymphocytes and lung alveolar macrophages. From the guinea-pig, induced and non-induced macrophage or neutrophil enriched peritoneal exudate populations, lymph node cells, peritoneal eosinophils and peripheral blood platelets were examined. Supernatants were assayed for the presence of PGE2, PGD2, PGF, TXB2 and 6-keto-PGF. In all types studied PGE2 and TXB2 were the major products formed. The identification of PGE2 and TXB2 was confirmed by GC/MS with multiple ion monitoring.The results have been compared with other reports and their possible significance discussed in relation to the proposed role of prostaglandins as mediators and modulators in immunopathology.  相似文献   

19.
Allergic asthma can be precipitated by many factors. For the atopic person, fungus, pollen, dust mites, cockroach antigens, and diesel exhaust are all agents that may trigger an allergic attack. Cytokines and chemokines are integral mediators of fungal asthma. From the earliest time points, they recruit and activate the cells required for the clearance of fungus as well as being critical factors involved in the immunopathology of this disease. In the final analysis, it is clear that these mediators can act to the benefit or the detriment of the host.  相似文献   

20.
In spite of the many studies on protein modifications by reactive species, knowledge about the products resulting from the oxidation of protein-aromatic residues, including protein-derived radicals and their stable products, remains limited. Here, we compared the oxidative modifications promoted by peroxynitrite and myeloperoxidase/hydrogen peroxide/nitrite in two model proteins, ribonuclease (6Tyr) and lysozyme (3Tyr/6Trp). The formation of protein-derived radicals and products was higher at pH 5.4 and 7.4 for myeloperoxidase and peroxynitrite, respectively. The main product was 3-nitro-Tyr for both proteins and oxidants. Lysozyme rendered similar yields of nitro-Trp, particularly when oxidized by peroxynitrite. Hydroxylated and dimerized products of Trp and Tyr were also produced, but in lower yields. Localization of the main modified residues indicates that peroxynitrite decomposes to radicals within the proteins behaving less specifically than myeloperoxidase. Nitrogen dioxide is emphasized as an important protein modifier.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号