我国浅水湖泊富营养化治理的可用水生植物修复技术

结合国内外水体富营养化的研究现状,分析了水生植物的重要生态功能和生态地位,归纳了浅水湖泊水生植物生态修复和水华水体水生植物生态治理相关技术,并展望了今后的治理思路.     

生物表面活性剂及其在土壤重金属修复中的研究进展

介绍了生物表面活性剂制取、种类和性能.叙述了其在土壤重金属修复方面的作用机理和应用情况.提出了在该领域中有待解决的问题并作出了展望.     

湖泊湿地富营养化模型的研究进展

湖泊湿地富营养化是目前全球面临的最普遍的水环境问题之一,富营养化模型能够较有力地研究水质动态变化,可将理论分析与试验结果有机地结合起来,并且应用到具体的湖泊中.重点阐述了3类湖泊湿地富营养化模型,指明研究中出现的问题及其发展趋势,对于以后开展对湖泊湿地富营养化模型的研究具有重要的意义.     

安徽省湖泊富营养化现状调查与评价

对安徽省境内17个湖泊的水质状况和沉积物营养盐水平进行调查与评价.水质评价结果表明,1个湖泊为Ⅴ类水,16个湖泊为Ⅵ类水;富营养化评价结果表明,2个湖泊为中营养,14个湖泊为轻度富营养化,1个湖泊为中度富营养化.     

稀土元素在水体富营养化治理中的应用

稀土元素在富营养化水体中具有长期的环境效应,在水体治理中具有广阔的前景。介绍了稀土元素在治理水体富营养化中的几种应用,重点讨论了脱氮除磷稀土吸附剂的分类和各自作用特点,以及在底泥中对活性磷的稳定化和修复底泥中的作用。稀土元素作为示踪剂揭示了磷流失类型和流失途径,探讨了对水生生物的剂量-效应关系和在富营养化水体实际应用。最后总结了稀土元素应用于富营养化水体治理中存在的问题,对稀土元素在水体富营养化中的应用提出了建议。     

新型生物反应墙原位修复石油烃污染地下水

以功能微生物、泥炭和粗砂为填充介质设计新型生物反应墙,研究了反应墙对地下水中石油烃污染物的修复效果与机理.结果表明:运行期内生物反应墙修复效果良好,苯系物、萘系物及菲去除率为83.6%～99.85%,其中71.23%～99.71%在墙体前半部分被去除.泥炭介质和功能微生物能够稳定发挥对污染物的吸附与降解功能,32.63%～77.98%的BTEX和97.14%～99.81%的目标PAHs被泥炭吸附去除;18.96%～50.98%的BTEX和已吸附于泥炭上的大部分石油烃污染物均显示被生物降解.微生物对污染物的降解可有效延长泥炭的吸附寿命,泥炭对功能微生物的营养供给可使反应墙内长期保持较高的功能微生物数量,每克干介质约含有3.46×106～6.16×109个.因此新型生物反应墙原位修复石油烃污染地下水是可行的.     

矿区污染地下水的生物修复

矿产资源的开发、加工和使用，产生各种污染物质，造成地下水污染，给矿区生态环境和人类带来不利影响。本文在分析矿区地下水污染源的基础上，介绍了修复地下水环境新技术—生物修复的原理和技术。     

镉污染土壤修复治理技术研究

镉是一种毒性较强的重金属元素,易被动植物吸收富集而产生危害。研究镉污染农田土壤修复技术及安全利用方法对保护生态环境及保障食品安全具有重大意义。目前,镉及其镉化合物被广泛应用,导致越来越多的土壤被镉等重金属污染,环境问题也变得越来越突出。文章就土壤镉污染修复技术及安全利用方法存在效率低、体系不稳定等问题,探究土壤镉生物有效性关键调控因子及其作用机制、充分挖掘特殊镉累积特性的植物资源并探寻改造植物镉耐性的方法以提高镉污染土壤修复效率。     

汞污染修复技术研究进展

汞污染作为全球性的污染问题,已广泛影响到人们的生活。随着工业化进程的加快,汞污染带来的不良影响日趋严重,这使得人们越发关注对汞污染修复方法的研究。为了更好地掌握当前汞污染修复技术的发展现状,介绍了环境介质(大气、水和土壤)中汞的来源及汞对环境造成的危害,从物理修复、化学修复、生物修复、基因工程修复和纳米修复5个方向具体阐述了当前各种汞污染修复技术的原理和适用场景,并对各修复技术的优缺点进行分析,同时对汞污染修复技术发展方向提出了展望。     

Conceptual Model of Aquatic Plant Decay and Ammonia Toxicity for Shallow Lakes

A conceptual process model was developed to examine the potential for late summer ammonia toxicity in shallow lakes. Processes represented in the model were macrophyte decay; growth, death, and sedimentation of phytoplankton; growth and death of zooplankton; nitrification; volatilization; and chemical equilibria (carbonate and ammonium systems). Peak NH3 concentrations occur at the peak of the phytoplankton bloom that develops about 2 weeks after macrophyte decay starts, when the pH is elevated. Ammonia peaks are highly transient, lasting <1 day. It is hypothesized that late summer ammonia toxicity following macrophyte senescence may be a common but generally unrecognized phenomenon in shallow lakes.     

Biological Function of REE in Plants & Microbes

Rare earth elements (REE) and their compounds are widely applied in agronomic and medical fields for many years. The bioinorganic chemical research of REE during the past few years indicates that REE play important roles in the promotion of photosynthetic rate as well as root absorption, regulation of hormone and nitrogen metabolism, and suppression of microbes, etc. The metallic or non-metallic targets of key biomolecule in various physiological processes can be chosen by REE for the chelation or replacement, which enables REE to regulate the biological functions or behaviors of those biomolecule and consequently leads to significant embodiment of biological function of REE in plants and microbes.Overdose of REE, however, shows an inhibitory effect on living organisms. Therefore, this paper proposes two suggestions that will be available in the extension of full use of REE's biological function. One is to obey the dose law of REE and control REE concentrations within a safe range. The other is to further test the bioaccumulation and long-period influence of REE on organisms.     

Biological Function of REE in Plants ＆ Microbes

Rare earth elements （REE） and their compounds years. The bioinorganic chemical research of REE during the are widely applied in agronomic and medical fields for many past few years indicates that REE play important roles in the promotion of photosynthetic rate as well as root absorption, regulation of hormone and nitrogen metabolism, and suppression of microbes, etc. The metallic or non-metallic targets of key biomolecule in various physiological processes can be chosen by REE for the chelation or replacement, which enables REE to regulate the biological functions or behaviors of those biomolecule and consequently leads to significant embodiment of biological function of REE in plants and microbes. Overdose of REE, however, shows an inhibitory effect on living organisms. Therefore, this paper proposes two suggestions that will be available in the extension of full use of REE＇s biological function. One is to obey the dose law of REE and control REE concentrations within a safe range. The other is to further test the bioaccumulation and long-period influence of REE on organisms.     

黄河三角洲湿地水生维管束植物资源及其区系研究

在参照相关资料的基础上,结合实地调查,对黄河三角洲湿地水生维管束植物种类、生态类群及其区系特征进行了分析.结果表明,黄河三角洲湿地共有水生维管束植物64种,隶属25科40属,含3种以上的9个较大科构成了区系的主体,共24属44种,占总属数的60%和总种数的68.75%.其中以挺水植物为主要生态类群,共有32种,占总种数的50%;区系中单种属多,属的分化程度较高;从分布区类型来看,世界分布属最多,温带分布属次之,热带分布属亦较多,区系总体表现出明显的温带特征.并具有向亚热带过渡的特点.     

Case Study: Effect of Submerged Aquatic Plants on Turbulence Structure in a Lowland River

Interactions of aquatic plants with turbulent flows in fluvial systems have attracted considerable interest. While there have been recent advances in theories that describe vegetation-flow interactions in idealized laboratory flows, their practical application is still problematic due to limited knowledge of effects caused by heterogeneously (patchy) distributed plants in naturally formed vegetative mosaics in rivers. This paper reports on a study in a lowland river, aimed at quantification and parameterization of vegetation effects on redistribution of mean and turbulent characteristics of the flow and their consequences for hydraulic resistance. The measurements were carried out in summer on a river reach with a patchy mosaic dominated by submerged flexible aquatic plants and repeated at the same water level in early spring before the plants start growing. This design of the study allowed for quantitative evaluation of the effects caused by flow-plants interactions on bulk flow parameters at comparable submergences of riverbed roughness elements (sediment grains and sand bars). The study indicates that symmetrical quasi-two-dimensional open-channel flow structure in unvegetated riverbed was transformed into highly fragmented complex flow pattern spatially arranged by patches and free paths in the mosaic. Despite complexities and three dimensionality of the flow, normalized mean velocity profiles in the patches were satisfactory described by hyperbolic tangent function while flow in the free paths, similarly to unvegetated channel, was in a reasonable agreement with the conventional logarithmic law.     

植物4CL基因家族结构功能与表达特性研究进展

4-香豆酸:辅酶A连接酶(4CL)是植物苯丙烷衍生物,如类黄酮和木质素等,生物合成途径的一种关键酶,在大多数雏管植物中4CL基因以基因家族的形式出现.4CL基因家族成员在植物组织中存在差异表达,并参与不同的苯丙烷类衍生物的生物合成.从4CL酶的基因结构、基因家族组成与表达特性等方面详细论述了当前最新研究进展,这将有助于更好地理解植物4CL基因参与苯丙烷类衍生物途径的合成与代谢机制.     

Toxaphene in the Great Lakes

This paper presents the most current data for toxaphene in the water, sediments, and biota of the Laurentian Great Lakes of North America. Concentrations in water range from 1.1 ng/L in Lake Superior to 0.17 ng/L in Lake Ontario. Lake Superior has the highest water concentration, which is contrary to the pattern seen for other pollutants. The observed log particle-water partition coefficient was 4.5. Recent sediments had similar concentrations among the lakes (approx. 15 ng/g dry weight), but different homolog compositions. The log bioaccumulation factors (BAFs) normalized to lipid or organic carbon were 5.8, 6.5, 6.3, 6.7, 6.7, and 7.0 for phytoplankton, net zooplankton, Mysis, Bythotrephes, sculpin, and lake trout. These data clearly show that toxaphene biomagnifies in the foodweb.     

Plant-Enhanced Subsurface Bioremediation of Nonvolatile Hydrocarbons

In recent years, phytoremediation, i.e., the use of plants to clean up soils contaminated with organics, has become a promising new area of research, particularly for in-situ cleanup of large volumes of slightly contaminated soils. A model that can be used as a predictive tool in phytoremediation operations was developed to simulate the transport and fate of a residual hydrocarbon contaminant interacting with plant roots in a partially saturated soil. Time-specific distribution of root quantity through soil, as well as root uptake of soil water and hydrocarbon, was incorporated into the model. In addition, the microbial activity in the soil rhizosphere was modeled with a biofilm theory. A sandy loam, which is dominant in soils of agricultural importance, was selected for simulations. Cotton, which has well-documented plant properties, was used as the model plant. Model parameters involving root growth and root distribution were obtained from the actual field data reported in the literature and ranges of reported literature values were used to obtain a realistic simulation of a phytoremediation operation. Following the verification of the root growth model with published experimental data, it has been demonstrated that plant characteristics such as the root radius are more dominant than contaminant properties in the overall rate of phytoremediation operation. The simulation results showed enhanced biodegradation of a hydrocarbon contaminant mostly because of increased biofilm metabolism of organic contaminants in a growing root system of cotton. Simulations also show that a high mean daily root-water uptake rate increases the contaminant retardation factors because of the resulting low water content. The ability to simulate the fate of a hydrocarbon contaminant is essential in designing technically efficient and cost-effective, plant-aided remedial strategies and in evaluating the effectiveness of a proposed phytoremediation scheme. The model presented can provide an insight into the selection and optimization of a specific strategy.