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1.
人工湿地污水处理系统研究及性能改进分析   总被引:109,自引:3,他引:106  
人工湿地污水处理系统是有效的污水处理与水资源再用相结合的方法,与传统的污水处理法相比具有基建、运行费用低,操作与维护简单等优点。该系统已被广泛应用于生活污水的处理,并通过工艺创新有向工业污水、农业废水等特殊污水处理方向发展的趋势。本文总结了人工湿地系统的研究现状,预测其研究与应用发展的趋势,探讨不同类型的污水在人工湿地系统中的净化过程,分析影响人工湿地污水处理性能的因素及技术性能改进的一些措施,并探讨人工湿地污水处理系统的应用前景。  相似文献   

2.
锌在红树植物白骨壤-土壤系统中的分布与迁移   总被引:4,自引:0,他引:4  
河口海湾沉积物中锌的污染已对水生生物构成了潜在的威胁.本研究在温室中建立红树植物白骨壤的模拟湿地系统,分别用不同浓度的人工配置污水和人工海水(对照)每周定时、定量地对模拟湿地系统进行为期1年的污灌试验,研究污水中的重金属锌在红树植物白骨壤-土壤系统中的分布、累积与迁移规律.结果表明,由人工污水加入模拟系统中的锌主要存留在土壤中(大于67%),只有一小部分(1.24%~10.4%)迁移到植物体和凋落物中,即白骨壤-土壤系统对生活污水中的锌具有较强的净化作用.根据物质平衡模型进行的计算表明,土壤子系统中锌的环境容量较大.  相似文献   

3.
污水排放对红树林湿地生态系统的影响   总被引:17,自引:0,他引:17  
利用湿地处理工农业和城市生活污水 ,是过去十多年来污水生物处理的主要研究课题之一。大量的研究表明 ,湿地具有很强的处理污水的潜力[1]。红树林湿地是分布在热带和部分亚热带海岸的典型海岸带湿地生态系统 ,长期以来被认为是排放污水和废水的便利场所。研究者认为 ,红树林湿地系统与其它类型的湿地一样具有潜在的净化污水的能力[2 ,3]。Ned well建议 ,红树林可以被更积极地加以利用和管理 ,作为整体污水处理设施的最后阶段 (理由是红树林生态系统对营养富集和富营养化具有良好的耐性 ) ,将初级处理污水排放到红树林生态系统内 (传…  相似文献   

4.
人工湿地污水处理系统三种红树植物抗性生理特性   总被引:5,自引:0,他引:5  
研究了淡水条件下潜流型人工湿地污水处理系统中红树植物海桑、桐花树和木榄的抗性生理特性.结果表明,在为期1年的试验中,人工湿地污水处理系统3种红树植物超氧物歧化(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活性持续升高并维持在较高水平,脯氨酸含量在7~9月达到最高水平,质膜透性没有明显的变化规律.对人工湿地与深圳福田自然保护区3种红树植物抗性生理指标进行比较,前者SOD、POD和CAT活性明显低于后者,脯氨酸含量前者明显高于后者,而丙二醛(MDA)含量和质膜透性则两者没有差别.3种红树植物能较好地适应淡水条件下潜流型人工湿地污水处理系统.  相似文献   

5.
人工湿地系统是模拟自然湿地,通过植物、土壤、微生物的相互作用去除污染物,从而实现净化污水、美化环境的功能,是一种经济环保且高效的污水处理技术。微生物作为人工湿地生态系统的重要组成部分,承担着对污水、废水中污染物的吸收和分解。本文从微生物种群分布特征和影响微生物生态分布及去污能力的三个因素,温度和营养物质、基质方面,总结归纳了人工湿地微生物去除污染物的研究进展。  相似文献   

6.
白骨壤模拟湿地系统中氮的分配、循环及其净化效应   总被引:8,自引:2,他引:6  
在温室中建立红树林植物白骨壤模拟湿地系统 ,分别用正常、5倍和 10倍浓度的人工配置的城市污水每周定时定量对模拟系统污灌 2次 ,用海水作对照 ,持续 1年。研究营养污染物氮在系统中的分配、循环及被净化的效果。结果表明 ,随污水处理浓度的升高 ,被更换的潮汐水中的含氮量和土壤含氮量都有较大提高 ;植物体各部分含氮量的高低顺序排列为叶 >茎>根 ;各处理组植物中氮元素的周转期依次为 4 81年、5 81年、4 5 8年和 5 86年 ;模拟系统对污水中氮的净化效果显著。  相似文献   

7.
红树林人工湿地对生活污水的净化效果   总被引:2,自引:0,他引:2  
建立3条结构相同的潜流人工湿地带(长×宽×高为33 m×3 m×0.5 m),带内分别种植外来种海桑和本地种秋茄、桐花树,水力负荷为5 m3·d-1,停留时间约3 d,连续2年监测。结果表明:各湿地带对CODcr、BOD5、TN、NH3-N、TP和SP的平均去除率分别为65%、74%、53%、52%、67%和70%;不同红树植物湿地带的去除能力不同,且与植物生长状况相关;湿地运行初期,海桑生长速度最快,其去污能力最强;其后海桑受到化学试剂的影响死亡1/2,其去污能力显著低于桐花树和秋茄;各湿地带对肠道菌群的去除率均高于80%,不同植物之间无显著差异,但出水中的菌体数量远高于国家污水排放标准,应结合其他措施(如氯化消毒等)处理肠道菌群;红树林是比较理想的人工湿地净化植物,但外来种海桑对化学试剂、低温等不良环境敏感,生长不稳定,需进一步探讨红树林作为人工湿地净化植物的可行性。  相似文献   

8.
红树林作为重要的海岸湿地类型之一,具有极高的生态系统服务价值。过去的50年中,中国红树林曾遭到极大的破坏。本文简要介绍了世界红树林分布现状,对中国红树林的分布、面积及红树植物种类组成进行详细叙述,并就红树植物分类体系进行讨论,认为中国红树植物种类应为38种,其中真红树植物13科15属27种,半红树植物有9科11属11种;对中国红树林的保护现状进行分析总结,以期为红树林的研究和管理提供参考。  相似文献   

9.
人工湿地污水处理的应用现状及前景展望   总被引:8,自引:0,他引:8  
杨琼  陈章和 《生态科学》2002,21(4):357-360
本文分析了人工湿地系统在污水处理中的作用,叙述了人工湿地在发展中国家的应用现状及所取得的效果。人工湿地的特点适合我国国情,特别适合广大农村、中小城市的污水处理,在我国具有极其广阔的应用前景。对湿地用于污水处理方面的不足,如缺乏污水对植物影响的研究(特别是对乡土植物的研究)、缺乏对重要工艺的理解、人工湿地占地面积大等也进行了分析。  相似文献   

10.
红树林与水产养殖系统初步研究   总被引:9,自引:0,他引:9  
为研究红树林对养殖水体的净化效应,选择3种红树植物海桑、秋茄和桐花树,每种分别按45%、30%和15%的面积比例种植于滩涂海水养殖塘,塘中养殖美国红鱼和星洲红鱼1年后收获,养殖期间通过对水质和鱼的生长情况进行监测,结果显示,种植红树植物的养殖塘水质均有不同程度的改善,可以减少鱼类病害。其中以种植比例为45%的桐花树养殖塘水质最好,鱼类生长速度最快。  相似文献   

11.
We proposed that cortical organization for the execution of adequate licking in cats was processed under the control of two kinds of affiliated groups for face and jaw & tongue movements (Hiraba H, Sato T. 2005A. Cerebral control of face, jaw, and tongue movements in awake cats: Changes in regional cerebral blood flow during lateral feeding Somatosens Mot Res 22:307–317). We assumed the cortical organization for face movements from changes in MRN (mastication-related neuron) activities recorded at area M (motor cortex) and orofacial behaviors after the lesion in the facial SI (facial region in the primary somatosensory cortex). Although we showed the relationship between facial SI (area 3b) and area M (area 4δ), the property of area C (area 3a) was not fully described. The aim of this present study is to investigate the functional role of area C (the anterior part of the coronal sulcus) that transfers somatosensory information in facial SI to area M, as shown in a previous paper (Hiraba H. 2004. The function of sensory information from the first somatosensory cortex for facial movements during ingestion in cats Somatosens Mot Res 21:87--97). We examined the properties of MRNs in area C and changes in orofacial behaviors after the area C or area M lesion. MRNs in area C had in common RFs in the lingual, perioral, and mandibular parts, and activity patterns of MRNs showed both post- and pre-movement types. Furthermore, cats with the area C lesion showed similar disorders to cats with the area M lesion, such as the dropping of food from the contralateral mouth, prolongation of the period of ingestion and mastication, and so on. From these results, we believe firmly the organization of unilateral cortical processing in facial SI, area C, and area M for face movements during licking.  相似文献   

12.
油菜绿色面积指数动态模拟模型   总被引:2,自引:0,他引:2       下载免费PDF全文
准确模拟绿色面积指数是作物生长模拟模型可靠预测作物生长和产量的关键。该研究的目的是以生理生态过程为基础,构建油菜(Brassica napus)叶面积指数和角果面积指数变化动态的模拟模型。油菜叶面积指数模型综合考虑了库或源限制下的叶面积增长模式,其中库限制下叶面积指数的增长呈指数方程,且受到温度、水分和氮素因子的影响;源限制下叶面积指数增长用比叶面积法来模拟。油菜角果面积指数由比角果面积和角果干物重来决定。比叶面积和比角果面积均为生理发育时间的函数。利用不同类型品种的播期试验及氮肥试验资料分别对模型进行了校正和检验,结果表明模型能较好地模拟不同条件下油菜叶面积指数和角果面积指数。  相似文献   

13.
Based on area P lesion experiments, we hypothesized that tongue protrusion adapted for licking might be regulated by the lateral wall of the presylvian sulcus (bilateral areas P) of the cerebral cortex (Hiraba H, Sato T, Nakakawa K, Ueda K. . Cortical control of appropriate tongue protrusion during licking in cats—Increase in regional cerebral blood flow (rCBF) of the contralateral area P and in tongue protrusion after the unilateral area P lesion. Somatosens Mot Res 26:82–89). We propose that the right and left lingual muscles are dominated by the right and left hypoglossal nucleus, respectively, and that right and left pyramidal cells projecting to the right and left hypoglossal nucleus, respectively, exist in unilateral area P. These cells project via an inhibitory interneuron relay to the lateral branches toward the left or right pyramidal cells in contralateral area P. In this study, we aimed to demonstrate the existence of inhibitory interneurons using injections of a gamma-aminobutyric acid (GABA) agonist (muscimol), a GABA antagonist (bicuculline), and kainic acid into unilateral area P, followed by examination of tongue protrusion and lateral movements during trained licking and changes in regional cerebral blood flow (rCBF) values in the contralateral area P. We found disordered protrusion toward both sides and a marked decrease in rCBF values in the contralateral area P after bicuculline injection. We also found abnormal tongue protrusion toward the front and a marked increase in rCBF values after muscimol and kainic acid injections. These results suggest that cortical networks between the bilateral areas P are relayed by inhibitory interneurons.  相似文献   

14.
冬小麦单产的光谱数据估测模型研究   总被引:10,自引:0,他引:10       下载免费PDF全文
 本文在分析冬小麦群体经济产量与叶面积系数关系的基础上,以地面实测冬小麦反射光谱数据为依据,提出了一种新的动态VI-产量模型,即LAD-产量模型。该模型具有冬小麦生育后期(抽穗一灌浆末期)光合面积和光合时间等信息,其冬小麦单位面积产量(简称单产)估测精度为98%。另外,本文根据常用的某一特定生育期VI-产量模型,用冬小麦各生育期的VI值分别估测小麦单产,确定山东省禹城市冬小麦的灌浆中期为最佳估产时间。此时期.小麦单产估测精度为96%。  相似文献   

15.
目的:通过定量CT检测哈尔滨地区人群腹部脂肪面积,并分析其与血脂、血糖水平的相关性。方法:选取于哈医大附属一院体检中心行肺部CT检查、20周岁以上的患者411例,年龄23~90岁,中位年龄58岁。分别进行体格检查和生化指标测定,根据体重指数(Body Mass Index,BMI)值将患者分为正常组、超重组及肥胖组,并使用定量CT(quantitative CT,QCT)脂肪测量软件定量测量患者L2~3水平层面腹部内脏脂肪面积(visceral fat area,VFA)和皮下脂肪面积(subcutaneous fat area,SFA)。将VFA和SFA数据分组,比较各组间VFA值、SFA值的差异,并进行相关性分析。结果:三组VFA值(P=0.000、0.000、0.033)及SFA值(P=0.000、0.000、0.000)比较均有显著性差异(P均<0.05),均为肥胖组>超重组>正常组。VFA值均与血脂、血糖有显著的相关性(VFA与TG的r值分别为0.466、0.15、0.318,P值分别为0、0.042、0.033;VFA与FBG的r值分别为0.357、0.171、0.417,P值分别为0、0.02、0.004)。绘制VFA诊断甘油三酯(TG)及空腹血糖(FBG)值异常的ROC曲线图,当VFA分别为166.035 cm2和172.65cm2时,对于诊断TG、FBG异常敏感度及特异度最高。结论:BMI正常组及非正常组人群腹部脂肪面积具有显著差异,且VFA的升高会增加高血脂、高血糖的患病风险。VFA对于评估TG、FBG值是否正常具有重要的应用价值。  相似文献   

16.
The supramammillary area (SUM) of the hypothalamus has wide spread connection with numerous brain structures. It is known that the SUM can control the frequency of the hippocampal theta rhythm, which plays a role in the cognitive functions of the hippocampal formation. In order to examine the role of the specific cells of the SUM in learning and memory, selective cholinergic neurotoxic or excitotoxic lesioned rats of the SUM were tested for spatial memory on the Morris water maze (MWM) test. After the behavior tests, the expression of acetylcholinesterase (AChE) in the hippocampus was studied using the immunohistochemistry. In the MWM test, both lesion of the SUM with 192 IgG-saporin or ibotenic acid produced the impairment of spatial learning and memory. The expression of AChE immunreactive neurons in the hippocampal CA3 region was decreased after injections of 192 IgG-saporin into the SUM. These findings suggest that cholinoceptive cells of the SUM area may play a critical role in the process of learning and memory.  相似文献   

17.
The aim of this study is to examine mastication-specific activity of orofacial neurons in the motor and masticatory cortices of the awake cat. We examine properties of mastication-related neurons (MRNs) in masticatory (MA, the rostral region of the orbital gyrus) and motor (area P, the lateral wall of the presylvian sulcus) cortical areas that are related to mastication of cats. MRNs in MA and area P had in common mechanoreceptive fields (RFs) in perioral, mandibular and lingual regions, and many MRNs had bilateral RFs in the tongue and mandibular regions. Facial RF size was the largest in area P. Eleven percent of MRN recording sites in MA, and 43% in area P evoked various motor effects with the use of intracortical microstimulation (ICMS). MRNs of the pre-movement type showing activities prior to mastication, or masticatory or lingual EMG, were 14% in MA and 45% in area P. Based on wheat germ agglutinin–horseradish peroxidase (WGA-HRP) injection into area P and MA, cortico-cortical connections were examined. After the unilateral area P injection, were reciprocal connections between the contralateral area P and bilateral MA were demonstrated. After the unilateral MA injection, there were reciprocal connections between the contralateral MA, bilateral area P and bilateral orofacial SI (the orofacial region of the first somatosensory area). These findings suggest that accurate masticatory movements may be executed by the cortical processing in MA and area P.  相似文献   

18.
Grime’s competition–stress–ruderal (CSR) theory is widely used to study plant species’ responses to multiple environmental factors. We compared two models to allocate CSR types the global “StrateFy” model (Pierce et al. Funct Ecol, 31:444–457, 2017) and a locally developed morpho-physiological model (Novakovskiy et al. Int J Ecol, p e1323614, 2016). The “StrateFy” model is based on three morphological leaf traits: leaf area (LA), leaf dry matter content (LDMC) and specific leaf area (SLA). The morpho-physiological model additionally uses plant height (PH), leaf dry weight (LDW), photosynthetic capacity (PN) and respiration rate (RD), leaf nitrogen, and carbon concentration (LNC, LCC). We applied both models to 74 plant species, the traits of which were measured at mountain (Northern Urals) and plane (Komi Republic, Russia) landscapes of European Northeast. The comparison of the calculated C, S, and R scores showed two groups of species with large and unidirectional differences. The first group consists of species with a shift from S (morpho-physiological model) to CR (StrateFy model) strategy. Species of this group are typical for deep shaded habitats and characterized by low LDMC (10–25%) and high SLA (30–60 mm2 mg−1). The second group consists of C species (morpho-physiological model) which were classified as S (StrateFy model) strategy. This group includes mainly tall shrubs, graminoids, and forbs with relatively small leaves (300–2000 mm2). In our opinion, the CSR strategies obtained by the morpho-physiological model showed better agreement with the basic principles underlying Grime''s theory. The use of a limited number of morphological traits (LA, LDMC, SLA) in the StrateFy model does not always allow to determine the life strategy correctly. For example, these traits are insufficient for a clear separation of deeply shaded stress-tolerant species and ruderals. On the other hand, the use of the morpho-physiological model requires a large number of field measurements, which makes it difficult to use this model to allocate CSR strategies for a large number of species.Supplementary InformationThe online version contains supplementary material available at 10.1007/s12298-021-00973-9.  相似文献   

19.
千烟洲针叶林的比叶面积及叶面积指数   总被引:19,自引:1,他引:18       下载免费PDF全文
根据实测数据计算了湿地松(Pinus elliotii)、马尾松(P. massoniana) 和杉木(Cunninghamia lanceolata)不同年龄、不同类型叶片的生物量和比叶面积,并结合样地调查数据和相对生长方程计算了中国科学院千烟洲试验站20年生湿地松林、马尾松林、杉木林和针叶混交林的叶面积指数。根据拟合结果,选择如下方程计算3个树种的叶生物量:湿地松W=12.074 1D2.151 5、马尾松W=6.972 7D2.197 3和杉木W=5.261 9D2.302 7。湿地松林的叶生物量(0.822 kg·m-2)最大,其次为针叶混交林(0.679 kg·m-2),马尾松林和杉木林相差不大(分别为林0.528和0.572 kg·m-2)。不同树种、不同年龄、不同类型叶片的比叶面积比较发现,新叶的比叶面积大于老叶,三针一束叶的比叶面积略大于两针一束叶,马尾松的平均半比表面积(8.62 m2·kg-1)大于湿地松(6.04 m2·kg-1)和杉木(7.91 m2·kg-1)。胸径与单木叶片半表面积之间的经验方程为:湿地松LA=0.073D2.151 5、马尾松LA=0.060D2.197 3和杉木LA=0.042D2.302 7。据此计算湿地松林的叶面积指数为5.03,马尾松林和杉木林为4.31,针叶混交林为4.77,该结果比利用CI-110植被冠层数字图像仪测得的结果偏大。  相似文献   

20.
S. H. Russell  R. F. Evert 《Planta》1985,164(4):448-458
The vascular system of the Zea mays L. leaf consists of longitudinal strands interconnected by transverse bundles. In any given transverse section the longitudinal strands may be divided into three types of bundle according to size and structure: small, intermediate, large. Virtually all of the longitudinal strands intergrade structurally however, from one bundle type to another as they descend the leaf. For example, all of the strands having large-bundle anatomy appear distally as small bundles, which intergrade into intermediates and then large bundles as they descend the leaf. Only the large bundles and the intermediates that arise midway between them extend basipetally into the sheath and stem. Most of the remaining longitudinal strands of the blade do not enter the sheath but fuse with other strands above and in the region of the blade joint. Despite the marked decrease in number of longitudinal bundles at the base of the blade, both the total and mean cross-sectional areas of sieve tubes and tracheary elements increase as the bundles continuing into the sheath increase in size. Linear relationships exist between leaf width and total bundle number, and between cross-sectional area of vascular bundles and both total and mean cross-sectional areas of sieve tubes and tracheary elements.  相似文献   

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