人工湿地处理污水时水生植物形态和生理特性对污水长期浸泡的响应

主要比较了污水和净水培养水生植物(芦苇、香蒲)形态特征的改变,测定了污水和净水培养的水生植物体内(根、叶片)过氧化物酶(POD)、过氧化氢酶(CAT)的活性,分析判断了水生植物对长期污水浸泡所采取的响应的途径和方式.结果表明,与天然净水培养的芦苇相比,长期污水浸泡致使芦苇的植株高度显著变小,平均值之差为71.1cm;芦苇叶片长度显著减小,叶片长度平均值之差为11.3 cm,最大叶片宽度减小,叶片最大宽度平均值之差为0.62cm;植株密度明显增大,增幅达4倍以上.长期污水浸泡显著影响了香蒲根部POD活性,使其比净水培养高73.51U·g-1·min-1;污水浸泡对芦苇和香蒲叶片CAT活性影响显著,污水培养芦苇和香蒲的叶片CAT活性分别较净水培养芦苇和香蒲低0.068、0.1071mg·g-1·min-1.     

滨海区芦苇和香蒲耐盐碱性及除氮磷效果对比研究

滨海河口区水体盐碱含量高,生态景观萧条,亟需筛选既能耐盐碱又能有效去除氮磷的植物.通过水培实验研究了盐碱胁迫下,芦苇、香蒲的耐受性及对水体中氮、磷的去除率.结果表明,芦苇至少能够耐受10‰的盐度和高达8.5的p H,香蒲能耐受的盐度为7.5‰、p H为8.0,结合生长、生理指标(叶片相对电导率、脯氨酸、叶绿素和根系活力)的变化,芦苇耐盐碱性强于香蒲;盐胁迫下,芦苇对氨氮去除率相对较高,由于香蒲生物量较高,对硝氮、总磷去除效果好,分别比芦苇高2.5%、7.3%,对总氮去除两者相当;碱胁迫下,芦苇耐碱性较强,对氨氮、总磷的去除效果较香蒲稍好,而香蒲对总氮的去除率比芦苇高8.2%.综上所述,芦苇、香蒲可作为修复滨海高盐碱水体生态景观的备选植物.     

Optimal conditions for chlorothalonil and dissolved organic carbon in horizontal subsurface flow constructed wetlands

The most efficient system of horizontal subsurface flow constructed wetlands (HSSFCW) for removing dissolved organic carbon (DOC) in the presence of chlorothalonil pesticide (CLT) present in synthetic domestic wastewater was determined using the macrophyte Phragmites australis. Two concentrations of CLT (85 and 385 μg L^?1) and one concentration of glucose (20 mg L^?1) were evaluated in four pilot scale horizontal surface flow constructed wetlands coupled with two sizes of silica gravel, igneous gravel, fine chalky gravel (3.18–6.35 mm), coarse gravel (12.70–25.40 mm) and two water surface heights (20 and 40 cm). For a month, wetlands were acclimated with domestic wastewater. Some groups of bacteria were also identified in the biofilm attached to the gravel. In each treatment periodic samplings were conducted in the influent and effluent. Chlorothalonil was quantified by gas chromatography (GC-ECD m), DOC by an organic carbon analyzer and bacterial groups using conventional microbiology in accordance with Standard Methods. The largest removals of DOC (85.82%–85.31%) were found when using fine gravel (3.18–6.35 mm) and the lower layer of water (20 cm). The bacterial groups quantified in the biofilm were total heterotrophic, revivable heterotrophic, Pseudomonas and total coliforms. The results of this study indicate that fine grain gravel (3.18–6.35 mm) and both water levels (20 to 40 cm) can be used in the removal of organic matter and for the treatment of agricultural effluents contaminated with organo-chloride pesticides like CLT in HSSFCW.     

水平潜流人工湿地脱氮功效中植物的作用

为了研究芦苇(Phragmites australis)在收割期前/后、湿地床体内部各个区域内、一年四季中在水平潜流人工湿地脱氮效用所起的作用,实验设置了有/无植物2组平行反应器。结果表明,芦苇在收割前/后对于水平潜流人工湿地脱氮效果均有促进作用,植物地上部分氮吸收量占湿地脱氮量的10.2%。在芦苇收割前/后(5月~9月、10月~次年5月),芦苇湿地日均脱氮量分别是无植物湿地的1.55倍与1.11倍。高、矮芦苇不同组织中总氮浓度分布趋势一致,2种芦苇各组织含量分别为:穗(28.69 g/kg)>叶(13.69 g/kg)>茎(5.31 g/kg)、穗(28.06 g/kg)>叶(14.61 g/kg)>茎(8.46 g/kg)。在湿地的各个沿程区域,总氮、氨氮累加去除率变化趋势一致,并且从反应器前部到尾部呈上升趋势,从上部到下部呈下降趋势。有芦苇湿地的脱氮效用优于无植物湿地,且底部氮积累含量也较少。一年四季中有芦苇湿地在各个季节脱氮量是无植物湿地的1.06~1.47倍。     

Investigation and Long-Term Monitoring of Phragmites australis Within Virginia's Constructed Wetland Sites

Phragmites australis Trin., and/or aggressive species, Typha spp. Tidally influenced wetlands that have subtidal perimeter ditches have significantly less (P < 0.05) P. australis in the wetland interior than those without perimeter ditches. Fractured regression analyses show that 6 years after construction, P. australis invasion can be extensive. Linear regression analysis suggests that, if conditions remain favorable for P. australis colonization, constructed wetlands could be overrun in 40 years.     

Varying Stable Nitrogen Isotope Ratios of Different Coastal Marsh Plants and Their Relationships with Wastewater Nitrogen and Land Use in New England, USA

The stable nitrogen isotope ratios of some biota have been used as indicators of sources of anthropogenic nitrogen. In this study the relationships of the stable nitrogen isotope ratios of marsh plants, Iva frutescens (L.), Phragmites australis (Cav.) Trin ex Steud, Spartina patens (Ait.) Muhl, Spartina alterniflora Loisel, Ulva lactuca (L.), and Enteromorpha intestinalis (L.) with wastewater nitrogen and land development in New England are described. Five of the six plant species (all but U. lactuca) showed significant relationships of increasing δ ¹⁵N values with increasing wastewater nitrogen. There was a significant (P < 0.0001) downward shift in the δ ¹⁵N of S. patens (6.0 ± 0.48‰) which is mycorrhizal compared with S. alterniflora (8.5 ± 0.41‰). The downward shift in δ ¹⁵N may be caused by the assimilation of fixed nitrogen in the roots of S. patens. P. australis within sites had wide ranges of δ ¹⁵N values, evidently influenced by the type of shoreline development or buffer at the upland border. In residential areas, the presence of a vegetated buffer (n = 24 locations) significantly (P < 0.001) reduced the δ ¹⁵N (mean = 7.4 ± 0.43‰) of the P. australis compared to stands where there was no buffer (mean = 10.9 ± 1.0‰; n = 15). Among the plant species, I. frutescens located near the upland border showed the most significant (R ² = 0.64; P = 0.006) inverse relationship with the percent agricultural land in the watershed. The δ ¹⁵N of P. australis and I. frustescens is apparently an indicator of local inputs near the upland border, while the δ ¹⁵N of Spartina relates with the integrated, watershed-sea nitrogen inputs.     

崇明东滩芦苇湿地氧化亚氮排放

采用静态箱-气相色谱法,研究了崇明东滩芦苇带氧化亚氮(N2O)的排放通量.结果表明,在生长季,高潮滩无植被覆盖沉积物与芦苇根际土中NO3--N的含量变化趋势基本一致,而两者的NH4+-N的含量变化趋势则有所不同;芦苇对高潮滩沉积物N2O排放有较强的促进作用,特别是7月份,使高潮滩沉积物的排放量由0.71μg·m-·2h-1增加到566.28μg·m-·2h-1.而在1月份,芦苇根际土N2O的通量也存在小幅排放,由-4.02mg·m-·2h-1增加到67.54μg·m-·2h-1.对于芦苇根际沉积物而言,除NO3--N、NH4+-N、温度和水分以外,植物的生理过程也是控制N2O排放通量的主要因子.     

吉林西部退化草原土壤盐渍化特征分析

对吉林西部退化草原六种常见植被类型下的土壤(0～20 cm)盐渍化特征进行了分析。采用国际上通用的土壤饱和浸提液电导率(ECe)、碱化度(ESP)和pH分别表征土壤的盐度、钠质化和酸碱程度。土壤盐度分为轻度、中度、重度和极度四个等级,对应的变化范围分别为:2～4、4～8、8～16、>16 dS m-1;土壤钠质化程度分为轻度、中度、重度和极度四个等级,对应的ESP范围分别为:5～10%、10～20%、20～40%、>40%;土壤酸碱性分为酸性、中性和碱性三种,对应pH范围分别为<6.5,6.5～8.5、>8.5。结果表明,植被类型对土壤盐度具有很好的指示作用,按土壤盐度由高到低排列,植被类型的顺序依次为:无植被(碱斑)、碱蓬(Suaeda glauca)、碱茅(Puccinellia tenuiflora)、虎尾草(Chloris virgata)、芦苇(Phragmites australis)、羊草(Leymus chinensis)。碱斑地、碱蓬地、碱茅地和虎尾草地的盐渍土类型均为盐化钠质土(ECe>2 dS m-1,ESP>5%),其中碱斑地和碱蓬地土壤盐化程度为极度(26.54≤ECe≤176.80 dS/m)、钠质化程度为极度(50.22≤ESP≤94.54%);碱茅和虎尾草植被下土壤盐度分别为10.70≤ECe≤27.62 dS m-1和6.86≤ECe≤13.88 dS m-1,钠质化程度分别为30.97≤ESP≤60.26%和16.21≤ESP≤58.11%;芦苇地的盐化程度为1.56≤ECe≤3.37 dS/m,钠质化程度为轻度(7.82≤ESP≤15.88%);羊草地的土壤盐度和钠质化程度分别2.43≤ECe≤6.66 dS m-1和1.43≤ESP≤8.34%。就土壤pH而言,羊草地为中性(7.44≤pH≤8.23),芦苇地为中性和/或碱性(8.18≤pH≤10.02),虎尾草地、碱茅地、碱蓬地和碱斑地均为碱性(8.83≤pH≤10.63)。     

不同植物覆盖下黄河三角洲湿地土壤中微塑料的分布

为揭示黄河三角洲湿地地区土壤中微塑料分布与植物覆盖的相关性,选择低盐优势物种芦苇（Phragmites communis）和高盐优势物种盐地碱蓬（Suaeda salsa）为研究对象,探讨其生长土壤共计16个样点中微塑料的分布特征.结果表明,该地区植物覆盖土壤中微塑料丰度范围为80~4640 n·kg^-1,粒径范围为13 μm~5 mm,大粒径微塑料成分主要有聚乙烯（PE）、聚对苯二甲酸乙二醇酯（PET）和聚苯乙烯（PS）,其中PET含量为0.22~1.16 μg·kg^-1.芦苇相对盐地碱蓬对土壤中微塑料有更大的阻隔.芦苇生长点位上土壤微塑料丰度和PET含量均值分别为1423 n·kg^-1和0.62 μg·kg^-1,以50 μm以下粒径的小颗粒为主;盐地碱蓬生长点位上土壤微塑料丰度均值和PET含量分别为584 n·kg^-1和0.33 μg·kg^-1,以100~1000 μm粒径的碎片和纤维为主.微塑料丰度与植物生长状况具有显著相关性（P=0.001）.因此,同一区域不同植物覆盖下土壤中微塑料的分布可能会存在空间差异.     

白洋淀两种生境中芦苇地上生物量及其影响因子分析

文章在野外调查的基础上,在白洋淀台田和沼泽中各选择6个样区,统计分析了2种生境芦苇地上生物量;运用冗余分析方法(RDA),分析了芦苇生长季(4~9月)平均水深、土壤/底泥有机质、全氮和全磷等对两类生境中芦苇地上生物量的影响。结果表明,台田、沼泽中芦苇地上生物量分别为1408.2±527.5 g DW/m^2、723.2±109.1 g DW/m^2,两类生境中的芦苇地上生物量沿水深梯度均呈先增加后减小的变化趋势。台田芦苇在水深为?77.3 cm时地上生物量最大,为2065 g DW/m^2,沼泽芦苇在水深为59.7 cm时地上生物量最大,为869.2 g DW/m^2。台地芦苇地上生物量与水深的相关系数为?0.813(P<0.05),与其他3个环境因子的相关性不显著;沼泽芦苇地上生物量与4个环境因子的相关性均不显著,表明沼泽芦苇地上生物量的影响因素较为复杂。