Distribution characteristics of ammonia-oxidizing bacteria in the Typha latifolia constructed wetlands using fluorescent in situ hybridization(FISH)

A molecular biology method, fluorescent in situ hybridization（FISH）, in which the pre-treatment was improved in allusion to the media of the constructed wetlands（CW）, e.g. the soil and the grit, was used to investigate the vertical distribution characteristics of ammonia-oxidizing bacteria（AOB） quantity and the relation with oxidation-reduction potential（ORP） in the Typha latifolia constructed wetlands under three different Ioadings in summer from May to September. Results showed that the quantity of the AOB decreased in the Typha latifolia CW with the increase of vertical depth. However, the AOB quantity was 2-4 times the quantity of the control in the root area. Additionally, ORP in the rhizosphere was found to be higher than other areas, which showed that Typha latifolia CW was in an aerobic state in summer when using simulated non-point sewage at the rural area of Taihu Lake in China and small town combined sewage.     

蒲绒-芦苇机械混合复合材料的吸油性能

2010年本实验室开始生物质对柴油的吸附实验,和前人的结论一致,生物质热改性后其吸油和漂浮性能提高,但成本增加很多。受到前人复合吸油材料的启发,2012年开展了蒲绒-芦苇机械混合复合材料吸油和漂浮性能的研究,并采用正交实验对影响除油效果的因素进行优化。结果表明,蒲绒-芦苇复合材料较之芦苇吸油性能提高,且比各组分的叠加饱和吸油量还高。震荡使芦苇的漂浮率明显降低,但对蒲绒及复合材料的影响较小。正交实验结果显示,投加量0.7g,油膜厚度0.55 mm,不震荡时,蒲绒除油最佳;在相同条件下,粒径为380~500μm的芦苇除油最佳,蒲绒和该粒径的芦苇按质量比为1∶4混合成的复合材料的除油效果最佳。     

湿生环境中丛枝菌根(AM)对香蒲耐Cd胁迫的影响

湿生植物在城市景观绿化和美化中应用越来越多,但也经常遭遇环境污染胁迫的问题.大量研究证实丛枝菌根(AM)可提高陆生植物耐受环境污染胁迫的能力,但对湿生植物的影响却鲜有认识.通过水培实验,探索接种AM真菌(Glomus etunicatum)对香蒲(Typha latifolia)耐受Cd2+(0、2.5、5.0 mg·L-1)胁迫的影响,旨在为评估菌根技术能否用于提高湿生植物抗耐环境污染胁迫的能力提供参考.结果表明,在湿生环境中AM真菌可与香蒲建立良好的共生关系,侵染率高于30%,但菌根化香蒲移入水溶液1个月后侵染率均呈下降趋势,最大下降25.5%(P0.05).AM增加了香蒲子叶的色素含量和POD酶活性,提高了根系的泌氧速率,但仅显著促进了5 mg·L-1Cd2+下香蒲的生长.虽然高浓度Cd2+抑制了香蒲的生长且侵染率下降,但AM仍能促进两个Cd2+浓度下香蒲对Cd的吸收,地上、地下部Cd含量最大增加40.24%和56.52%.本研究表明,AM具有增强湿生植物抗耐和修复环境重金属污染的潜力.     

芦苇和香蒲对重金属钼的吸收特性研究

研究了水生植物芦苇和香蒲对重金属钼的吸收特性.通过短期室内水培实验,对比考察了2种植物对重金属钼的耐毒性、动态去除率、吸收过程及富集情况,并对在不同浓度营养液中植物对重金属钼吸收的影响进行了分析.结果表明,2种植物钼中毒导致其茎叶发黄、蒸腾能力下降,在钼浓度为2～20 mg.L-1时,香蒲对重金属钼的耐毒性较芦苇强.香蒲对重金属钼的去除率高于芦苇,在钼浓度为2 mg.L-1时,香蒲和芦苇去除率分别为87%和62%.2种植物对重金属钼的吸收是一个动态平衡过程,且以被动吸收为主.香蒲对钼的富集量较芦苇高,且植物地上部重金属积累量大于根部,符合超积累植物特征之一.营养液浓度的增加不会提高植物对重金属钼的吸收量,反而会因离子竞争等因素使去除率有所下降.芦苇和香蒲对溶液中钼的吸收均具有显著效果,香蒲吸收效果较芦苇好.     

Preparation of activated carbon from cattail and its application for dyes removal

Activated carbon was prepared from cattail by H3PO4 activation. The effects influencing the surface area of the resulting activated carbon followed the sequence of activated temperature activated time impregnation ratio impregnation time. The optimum condition was found at an impregnation ratio of 2.5, an impregnation time of 9 hr, an activated temperature of 500°C, and an activated time of 80 min. The Brunauer-Emmett-Teller surface area and average pore size of the activated carbon were 1279 m2/g and 5.585 nm, respectively. A heterogeneous structure in terms of both size and shape was highly developed and widely distributed on the carbon surface. Some groups containing oxygen and phosphorus were formed, and the carboxyl group was the major oxygen-containing functional group. An isotherm equilibrium study was carried out to investigate the adsorption capacity of the activated carbon. The data fit the Langmuir isotherm equation, with maximum monolayer adsorption capacities of 192.30 mg/g for Neutral Red and 196.08 mg/g for Malachite Green. Dye-exhausted carbon could be regenerated effectively by thermal treatment. The results indicated that cattail-derived activated carbon was a promising adsorbent for the removal of cationic dyes from aqueous solutions.     

Use of created cattail (Typha) wetlands in mitigation strategies

In order to balance pressures for land-use development with protection of wetland resources, artificial wetlands have been constructed in an effort to replace lost ecosystems. Despite its regulatory appeal and prominent role in current mitigation strategies, it is unclear whether or not created systems actually compensate for lost wetland resources. Mitigation predictions that rely on artificial wetlands must be analyzed critically in terms of their efficacy. Destruction of wetlands due to burial by coal fly ash at a municipal landfill in Danvers, Massachusetts, USA, provided an opportunity to compare resulting growth of created cattail (Typha) marshes with natural wetland areas. Once the appropriate cattail species was identified for growth under disturbed landfill conditions, two types of artificial wetlands were constructed. The two systems differed in their hydrologic attributes: while one had a surface water flow characteristic of most cattail wetlands, the second system mimicked soil and water conditions found in naturally occurring floating cattail marshes. Comparison of plant growth measurements for two years from the artificial systems with published values for natural cattail marshes revealed similar structure and growth patterns. Experiments are now in progress to investigate the ability of created cattail marshes to remove and accumulate heavy metals from polluted landfill leachate. Research of the type reported here must be pursued aggressively in order to document the performance of artificial wetlands in terms of plant structure and wetland functions. Such research should allow us to start to evaluate whether artificial systems actually compensate for lost wetlands by performing similar functions and providing the concomitant public benefits.     

淹水时长对3种丛枝菌根(AM)真菌侵染2种湿地植物的影响

以不同淹水时长为唯一影响因子,以香蒲(Typha orientalis)和水稻(Oryza sativa L.)为宿主植物,选用Glomus属的3种AM真菌(F1菌:Glomus intraradices;F2菌:Glomus versiforme;F3菌:Glomus etunicatum),研究淹水时长对3种AM真菌侵染2种湿地植物的影响,以期为阐明淹水对湿地植物AM结构与功能的影响提供参考.结果表明,淹水时间越长,3种AM真菌对2种植物的侵染率越低;相同淹水时间下,F3菌对香蒲、F1菌和F2菌对水稻的侵染率高于其他菌.3种AM真菌的侵染结构分析表明,菌丝侵染是2种湿地植物形成AM的主要途径,而丛枝和泡囊贡献较小;淹水时间越长,香蒲的菌丝侵染比例越高,但水稻的菌丝侵染比例没明显变化规律;淹水时间越长,2种植物的丛枝侵染比例越低,不淹水时最高.AM真菌产孢数分析表明,淹水时间越长,AM真菌的产孢数越多;相同淹水时长下,F3菌产孢数最多.2种植物的湿重变化表明,3种AM真菌在长时间淹水条件下仍能明显促进香蒲地上和地下部分的生长,但对水稻的生长影响不明显.本研究表明,淹水时长影响AM真菌对湿地植物的侵染水平和侵染结构,淹水条件下AM真菌对湿地植物生长仍有促进作用,但这受宿主植物对AM真菌的菌根依赖性影响.所以,在湿地植物上应用AM真菌时,应考虑植物的菌根依赖性和淹水时长对接种效果的影响.     

EVAPOTRANSPIRATION MEASUREMENT AND ESTIMATION OF THREE WETLAND ENVIRONMENTS IN THE UPPER ST. JOHNS RIVER BASIN,FLORIDA1

ABSTRACT: Accurate estimates of evapotranspiration from areas dominated by wetland vegetation are needed in the water budget of the Upper St. Johns River Basin. However, local data on evapotranspiration rates, especially in wetland environments, were lacking in the project area. In response to this need, the St. Johns River Water Management District collected evapotranspiration field data in Fort Drum Marsh Conservation Area over the period 1996 through 1999. Three large lysimeters were installed to measure the evapotranspiration from different wetland environments: sawgrass (Cladium jamaicense), cattail (Typha domingensis), and open water. In addition, pan evaporation was measured with a standard class “A” pan. Concurrently, meteorological data including rainfall, solar radiation, wind speed, relative humidity, air temperature, and atmospheric pressure were collected. By comparing computed evapotranspiration rates with those measured in the lysimeters, parameters in the Penman‐Monteith, the Priestley‐Taylor, and Reference‐ET methods, and evaporation pan coefficients were estimated for monthly and seasonal cycles. The results from the data collected in this study show that mean monthly evapotranspiration rates, computed by the different methods, are relatively close. From a practical point of view, results indicate that the evaporation pan can be used equally well as the more complex and data‐intensive methods. This paper presents the measured evapotranspiration rates, evaporation pan coefficients, and the estimated parameter values for three different methods to compute evapotranspiration in the project area. Since local data on evaporation are often scarce or lacking, this information may be useful to watershed hydrologists for practical application in other project regions.     

香蒲植物在环境保护中的开发利用

我国香蒲植物资源丰富 ,但对其开发利用重视不够 ,尤其在环境保护方面的利用极少 ,资源优势尚未转化为环境优势和经济优势。加强香蒲植物资源在环保方面的开发利用 ,具有巨大的市场潜力和较好的环境效益、经济效益。     

EVAPOTRANSPIRATION MEASUREMENTS AND MODELING FOR THREE WETLAND SYSTEMS IN SOUTH FLORIDA1

ABSTRACT: At the Everglades Nutrient Removal project in south Florida, three lysimeters were installed to measure daily evapotranspiration (ET) rates from cattails (Typha domingensis), mixed marsh vegetation, and an open water/algae system. The cattail lysimeter began operation in February 1993. The mixed marsh vegetation lysimeter began operation in January 1994, and the open water lysimeter with occasional algae cover began operation in December 1993. The mean measured ET rate was 3.6 mm, 3.5 mm, and 3.7 mm per day for the cattail, mixed marsh vegetation, and open water/algae system, respectively. High resolution weather data were continuously measured at the site. Six models were applied to estimate daily ET rates of the three systems. The Penman-Monteith equation best estimated ET of cattail and mixed marsh vegetation, and the Penman Combination equation was most suitable for the open water/algae system. Empirical equations based on solar radiation and maximum temperature produced estimates of daily ET from the three systems that are comparable to models that require many more parameters. In cases where limited data is available, the calibrated simple models can be used to estimate ET from wetlands in south Florida.