水生植物模拟湿地对受污河水中氮素去除的初步研究

分别以芦苇、茭草和宽叶香蒲构建人工模拟湿地系统，开展关于湿地中水生植物氮素去除效果的对比研究。研究结果表明：（1）人工湿地对污染河水中的无机氮有很高的去除效果，但不同植物的去除率有所不同；（2）铵态氮和硝态氮的去除是影响湿地系统总氮去除率的重要因素，且铵态氮的去除起主导作用；（3）芦苇特殊的根系结构增加了湿地系统中溶解氧的含量，进而改善水中各种动物、微生物的生活环境；（4）植物吸收不是湿地氮去除的主要途径，但它的存在足以直接和间接的影响到水体中各种形态氮素的转化以及系统中微生物的硝化／反硝化过程的进行。     

人工湿地改善长江水体透明度的示范研究

根据自然水体湿生植物、浮叶植物以及沉水植物的空间分布规律,利用水生高等植物构建由挺水植物、浮叶植物到沉水植物的野外示范研究区（面积9 048 m2）,模拟长江潮汐规律每天调长江水（浊度77.62 NTU,透明度17.6 cm）4 320 m3流经试验区,进行长江水体透明度改善试验。试验共进行100 h,进水量18 000 m3,试验区平均水力负荷0.477 5 m/d。结果表明：① 人工湿地对长江水体透明度的改善与维持具有重要作用,试验水体流经串连湿地系统后浊度降低为9.47 NTU（减小88%）,透明度提高到64.5 cm（提高2.66倍）;② 湿地植物对长江水体N、P等元素具有良好的净化作用;③ 由挺水、浮叶、沉水等水生高等植物组成的串连湿地系统对改善长江水体透明度和降低水体浊度具有良好的效果,是长江水体透明度和水质改善的重要措施之一。     

3种挺水植物对石佛寺人工湿地沉积物中有机质、氮、磷含量变化影响研究

选择石佛寺人工湿地芦苇(reed)、水烛(cattail)、荷花(lotus)3种具有代表性的挺水植物作为研究对象,采集2013—2015年每年3—12月的表层底泥,测出沉积物中有机质含量、氮含量、磷含量,总结3种营养物质含量的年际变化规律、每年3种营养物质含量变化的相关关系,分析3种挺水植物在不同生长期对沉积物中3种营养物质含量变化的影响。通过计算,得出3种挺水植物对不同营养物质的净化效果。结果显示,沉积物中的营养物质含量主要受挺水植物生长周期影响,挺水植物区域沉积物中的营养物质含量变化具有一定的规律(在快速生长期沉积物中营养物质含量最少,在植物死亡腐解期含量最高),同一年的3种营养物质含量变化是正向显著相关的。挺水植物对沉积物中营养物质具有一定的净化作用,但由于挺水植物类型不同,对沉积物中营养物质的净化效果也不同,其中芦苇对于沉积物中的有机质和磷的净化效果高于其他2种挺水植物,荷花对氮的净化效果高于芦苇和水烛。     

盐龙湖工程中试系统去除原水中氮磷效果研究

氮、磷是水体富营养化和蓝藻水华发生的主要驱动和限制因子,是饮用水水质监测所关注的重要指标。本研究在盐城市龙冈镇境内蟒蛇河南岸设计构建了饮用水水源生态净化工程中试系统,沿中试系统水流方向依次布设5个水质采样点,分别位于进水口和预处理区、挺水植物区、沉水植物区与深度净化区的出水口,通过近1年的运行研究表明,该工艺对水体有机物及营养盐去除效率高,净化效果好,出水水质稳定达到地表Ⅲ类水标准,且感官效果良好,出水透明度可达2 m。     

污染物浓度和水力负荷双重作用下人工湿地的净化效果

研究从徐州地区大沙河西人工湿地基地中筛选6种挺水植物系统和2种沉水植物作为室内实验的供试植物,从丰县康达污水处理厂出水取样作为实验用水,研究人工湿地的水生植物对不同污染程度水体和水力负荷条件下的净化能力.研究可为人工湿地的实际运行和处理效果提供理论依据.     

表面流人工湿地不同植物及其组合净化污水处理厂尾水研究

为提高表面流人工湿地对低污染水的生态净化效率,对人工湿地中湿生植物的组成进行比选研究,设置8个由不同湿生植物(包括挺水、沉水和浮叶植物)组成的表面流人工湿地,比较其净化尾水氮磷效果。结果表明:挺水植物圆币草(Hydrocotyle verticillata)和大聚藻(Myriophyllum aquaticum)组合的表面流人工湿地净化尾水氮磷效果最好,其人工湿地对TN、NO-3-N和NH3-N的平均去除率分别为68.6%、62.6%和78.2%,对TP和溶解性无机磷(DIP)的平均去除率分别为64.5%和80%。浮叶植物睡莲(Nymphaea L.)人工湿地去除氮磷能力次之,TN、NO-3-N、NH3-N、TP和DIP平均去除率分别为55%、55.2%、63.3%、56.1%和64.7%,体现一定的污染物去除潜力。沉水植物苦草[Vallisneria natans(Lour.)Hara]在与圆币草等共存净化尾水过程中逐渐失去优势种地位。而由黄菖蒲(Iris pseudacorus L.)和再力花(Thalia dealbata)等挺水植物构建的表面流人工湿地,虽然生物量高,但其氮磷去除效果较差,尤其是再力花人工湿地对TN、NO-3-N和NH3-N平均去除率仅在18%~36.2%之间,对TP和DIP平均去除率也分别只有41.5%和38.7%。因此,采用圆币草和大聚藻组合构建的表面流人工湿地能更有效净化污水处理厂尾水中氮磷,对TN的去除尤为高效,能有效提升尾水水质。     

六种沉水植物对三种不同氮磷浓度水体的净化效果

以6种沉水植物苦草、黑藻、金鱼藻、微齿眼子菜、竹叶眼子菜、粉绿狐尾藻为材料,静态水培的方式,研究其在不同氮(N)、磷(P)浓度下的生长情况及去除总氮(TN)、总磷(TP)情况。结果表明:一定浓度的N、P对沉水植物的生长具有促进作用,表现为株高、生物量增加。随着N、P浓度升高,植物生长受到一定程度的抑制。6种沉水植物对不同N、P浓度水体中TN、TP的净化能力各不相同。高浓度N、P水平下,黑藻、苦草对水体中TN的净化能力较好;中浓度、低浓度N、P水平下,微齿眼子菜、苦草对TN的净化能力较好;6种沉水植物对不同N、P浓度水体中TP均有较好的去除效果,其中黑藻、苦草、粉绿狐尾藻具有较高的去除TP能力,去除率最高可达77.8%。综合来看,黑藻、苦草对不同N、P浓度水体中N、P去除率及生长适应性最好。     

丹麦人工湿地技术治污的实践研究

人工湿地去除污染物的范围广泛,包括氮、磷、悬浮物、有机物、微量元素、病原体等,其对污水的处理有十分复杂的净化机理.湿地中填料、微生物、植物3者协同作用,通过物理、化学及生化反应等过程实现污水的净化.通过丹麦人工湿地技术在污水治理中的实践应用与研究,分析了该项技术在温榆河流域污水治理的适用性及功能性,以求为温榆河流域污水治理提供技术支撑.     

广州市城市河流低水位运行生态修复理念与实践

在系统分析城市河流治理突出难题的基础上，研究了低水位运行下底泥污染物生化降解机理及河流生态构建原理，创新提出了城市河流低水位运行生态修复理念。相对于高水位，低水位运行使河道水体光照、溶解氧、水温和水动力等条件明显改善，显著提升泥-水界面好氧硝化效率，快速消除底泥黑臭，并驱动底泥深层厌氧反硝化效应，实现污染底泥碳、氮、硫等耗氧物质同步去除，从而将底泥从污染“源”转变为“汇”，有助于上覆水体净化。此外，低水位运行有利于营造洲-滩-槽多样化生境，构建更为复杂的河流生态系统，显著提升城市河流污染“免疫力”。     

北京未来科技城滨水森林公园潜流人工湿地净化效果对比研究

以北京未来科技城滨水公园的潜流人工湿地为研究对象,在5个试验单元中,分别选用焦炭、沸石、火山岩、砾石和生物质焦作为填料,比较了不同试验单元对水体净化效果的差异。研究结果表明,潜流人工湿地可以有效地去除河水中的氮、磷、有机污染物,针对不同水质要求和修复目标,应选用适当的填料基质。     

Coastal wetland plant community responses to record-high Lake Superior water levels: An Allouez Bay case study

Here we present findings from a natural experiment to better understand coastal wetland plant community responses to rising water levels. Plant communities were monitored in three vegetation zones (submergent, emergent, and wet meadow) at Allouez Bay, a lacustrine coastal marsh, six times over years 2011–2020. Lake Superior water levels reached record-highs in 2017, and again in 2019. During our six sampling campaigns, we encountered eighty-four vascular plant species, seven of which were non-native. Except for reductions in total plant cover in the wet meadow zone, emergent and wet meadow plant communities were only marginally affected by rising water. Percent cover of non-native species did not increase in a clear pattern. Temporal changes in floristic quality were non-significant at the whole site level, and mean coefficient of conservatism values ranged from 5.3 to 6.0. Aquatic vegetation in the submergent zone was most affected by rising water. Submergent zone richness declined from sixteen plant species in 2011 to zero in 2020. Multivariate PERMANOVA analysis showed significant effects of year on site-wide plant composition. Temporal composition changes were predominately driven by species turnover in the submergent vegetation zone, whereby floating aquatic species were replaced by non-floating species from 2011 to 2017, and an absence of aquatic vegetation along research transects in 2020. Tracking regeneration of aquatic vegetation is a focus of future research as unknown effects from prolonged exposure to record-high water levels may affect natural regenerative processes at Allouez Bay, and potentially at other lacustrine Great Lakes wetlands throughout the basin.     

黑土洼湿地水质净化效果及存在问题和对策研究

为研究如何利用人工湿地技术处理永定河直接进入官厅水库的受污染水体,削减污染物总量,在黑土洼人工湿地进行了相关试验研究。试验选取典型监测断面取样,采用标准化方法重点对水质净化效果进行了初步分析,结果表明湿地系统对官厅水库水质净化及水环境改善取得了较好的处理效果。经过多年运行的湿地,出现了堵塞、水质深度处理能力下降、植物维护等问题,经过研究提出了相应的对策措施。该研究为北方低温地区利用人工湿地系统处理河道微污染水体提供了技术支撑。     

北方某人工湿地净化能力分析

在对北方某人工湿地长期观测取得的大量详尽数据的基础上,分析了人工湿地系统总体净化能力和潜流人工湿地水质动态变化特征。结果表明:该人工湿地示范工程对水质净化效果较为明显,对各类污染物的去除率平均可达40%;潜流人工湿地可对污水进行深度处理,对BOD5、NH4-N的去除效果最好,去除率为80%～90%,对NO3-N、TN的去除效果较好,去除率为65%～75%,对CODMn和SS的去除效果一般,去除率为40%～60%,对TP的去除效果随着时间推移逐渐减弱,碎石吸附对TP去除起主要作用。     

Declines in aquatic vegetation in navigation pool no. 8, upper Mississippi River between 1975 and 1991

The biomass and frequency of occurrence of aquatic macrophytes observed during 1975 and 1991 in Navigation Pool No. 8 of the upper Mississippi River were compared. Samples were collected from contiguous backwater, isolated backwater and impounded habitat types. Overall declines were observed in both frequency and biomass between the two years. Changes in depth, water clarity and bed sediment texture were also observed. About 50% of the samples collected in 1991 had no vegetation, compared with 20% in 1975. The greatest reduction in frequency occurred among submergent taxa (77% in 1975 to 31% in 1991), whereas only slight declines were observed for emergent taxa. However, the mean biomass of both lifeforms decreased substantially (48 to 1 g/m² for submergent and 61 to 27 g/m² for emergent lifeforms). The mean total biomass declined from 114g/m² in 1975 to 35 g/m² in 1991. Declines were most evident in the impounded habitat, where the frequency of occurrence of submergent taxa decreased from 83% in 1975 to 11% in 1991, and mean biomass decreased from 90 to 1 g/m². Similar but less extensive reductions in frequency and biomass of submergent taxa were observed in the contiguous backwater habitat. In contrast, both the frequency and biomass of floating-leaved macrophytes increased slightly in contiguous backwater habitats. Changes in frequency and biomass of macrophytes in isolated backwater habitats were neligible between 1975 and 1991. It is hypothesized that changes in the macrophyte community structure may be related to physical changes associated with 57 years of impoundment.     

Relative importance of macrophyte community versus water quality variables for predicting fish assemblages in coastal wetlands of the Laurentian Great Lakes

Fish have been shown to be sensitive indicators of environmental quality in Great Lakes coastal wetlands. Fish composition also reflects aquatic macrophyte communities, which provide them with critical habitat. Although investigators have shown that the relationship between water quality and fish community structure can be used to indicate wetland health, we speculate that this relationship is a result of the stronger, more direct relationship between water quality and macrophytes, together with the ensuing interconnection between macrophyte and fish assemblages. In this study, we use data collected from 115 Great Lakes coastal marshes to test the hypothesis that plants are better predictors of fish species composition than is water quality. First we use canonical correspondence analysis (CCA) to conduct an ordination of the fish community constrained by water quality parameters. We then use co-correspondence analysis (COCA) to conduct a direct ordination of the fish community with the plant community data. By comparing the statistic ‘percent fit,’ which refers to the cumulative percentage variance of the species data, we show that plants are consistently better predictors of the fish community than are water quality variables in three separate trials: all wetlands in the Great Lakes basin (whole: 21.2% vs 14.0%; n = 60), all wetlands in Lakes Huron and Superior (Upper: 20.3% vs 18.8%; n =  32), and all wetlands in Georgian Bay and the North Channel (Georgian Bay: 18% vs 17%; n =  70). This is the largest study to directly examine plant–fish interactions in wetlands of the Great Lakes basin.     

不同生物联合对滇池草海水质的净化作用

为了解不同沉水植物种植密度、不同沉水植物组合、沉水植物和鲫组合对滇池草海富营养化水体的净化效果,于2017年9—12月在滇池草海东风坝试验平台,选取4种滇池现存土著沉水植物(篦齿眼子菜(Stuckenia pectinata)、轮叶黑藻(Hydrilla verticillata)、穗花狐尾藻(Myriophyllum spicatum)、马来眼子菜(Potamogeton wrightii))、1种鱼(鲫(Carassius auratus))进行不同组合模拟试验。结果表明:种植密度为(0.63±0.06)g/L的篦齿眼子菜和轮叶黑藻对于TP的去除效果明显优于(0.33±0.05)g/L的种植密度;不同沉水植物组合均能够提高水体中的氮磷比,对草海富营养化水体的TN、TP、Chl-a具有明显的去除效果,试验组TN、TP、Chl-a的平均去除率分别提高了49.67%、9.06%、39.41%;鲫对于轮叶黑藻和篦齿眼子菜的生长具有明显的促进作用,加入鲫的穗花狐尾藻和马来眼子菜组合TN去除率提高了87.48%,且试验结束后,水体TN、TP去除效果稳定;沉水植物组合中,穗花狐尾藻和轮叶黑藻在高营养盐水体中生长状况最好,同时能有效控制水体中的TN、TP和Chl-a的质量浓度;鲫+穗花狐尾藻+马来眼子菜组合对草海富营养化水体的SS、TN、TP、Chl-a都具有较高的去除能力。     

基于生态浮床的乡村微污染河道水质净化研究

为了综合解决乡村河流微污染问题,文章以上夹河退水渠河道微污染水体为对象,以净化能力强且观赏性较好的9种水生植物为试验供试植物,构建了单一植物型生态浮床,研究了植物型生态浮床对水体中氨氮(NH4^+-N)、总磷(TP)、化学需氧量(COD)等指标的去除情况,结果表明:9种植物生态浮床对乡村微污染河道水体中污染物的去除率有一定差异;其中,象草、芦苇、水葫芦对NH4^+-N去除率较高,分别为54.58%、61.04%、67.50%;黄菖蒲、美人蕉、水葫芦对TP去除率较高,分别为83.93%、86.26%、89.17%;黄菖蒲、风车草、水葫芦对COD去除率较高,分别为31.82%、31.83%、33.39%;该研究能够为植物型生态浮床技术在今后乡村微污染河流中的应用提供理论指导。     

Bioassessment of Benthic Macroinvertebrates in Wetland Habitats of Lake Saint-Pierre (St. Lawrence River)

We evaluated the potential of vegetation and sediment habitats in wetlands of the St. Lawrence River for developing a macroinvertebrate bioassessment program with reference conditions. During September 2004, we collected macroinvertebrates in emergent vegetation and sediment in both fluvial sites (reference) and tributary-plume sites (impacted) in waters of the north and south shores of Lake Saint-Pierre (St. Lawrence River). In each habitat, we compared taxa richness, abundance, and community structure of macroinvertebrates between reference and impacted sites, and used multivariate models to relate macroinvertebrate community to environmental conditions. Each habitat was suitable for discriminating reference fluvial sites from impacted tributary-plume sites based on macroinvertebrate communities. In emergent vegetation, macroinvertebrates were dominated by epibenthic fauna such as crustaceans (Gammaridae, Asellidae) and molluscs (Valvatidae) at fluvial sites, and insect larvae (Chironomidae, Caenidae) at tributary-plume sites. In sediment, macroinvertebrates comprised a greater proportion of endobenthic fauna such as Oligochaeta and Sphaeridae. Crustaceans and molluscs were still dominant at fluvial sites and Oligocheata and Chironomidae at tributary-plume sites. No strong difference was depicted in macroinvertebrate composition between north and south shore water masses. Environmental variables explained a higher proportion of variance in macroinvertebrate community composition in emergent vegetation than in sediment (68% versus 44%). Macroinvertebrate composition in sediment was more related to metal contamination, whereas macroinvertebrate composition in emergent vegetation was related primarily to vegetation type and water quality. Relevance of the study for bioassessment of macroinvertebrates in the St. Lawrence River using the reference condition approach is discussed.     

Wetland to pond treatment gradients.

This paper presents information on the hydraulic efficiency of wetlands and ponds, and examines the differences and similarities between degrees of mixing, short-circuiting and dead zones. It reports the pollutant removal performance of over 50 wetlands and ponds over the range of macrophyte cover from 100% (densely vegetated wetlands) to 0% (ponds). Not surprisingly, there exist performance continua, characterized by a smooth transition from fully vegetated to unvegetated systems. Factors influencing the choice of ponds, wetlands or combinations are examined. Wetlands are more efficient, and can produce lower TSS. Both wetlands and ponds can provide BOD, FC and ammonia removal, with ponds being better choices at high loading rates.