关于蓝藻危害与防治

近年来蓝藻暴发的事件频发,对景观及人们的生活造成了较大的影响。本文从蓝藻暴发的自然条件、危害等角度切入,探讨蓝藻治理的不同方法。     

蓝藻生长时变系统非线性动力学分析及水华预测方法

为解决现有蓝藻生长动力学模型难以有效描述实际水体中蓝藻生长时变系统的非线性动力学特性,导致水华预测准确性不高的问题,构建蓝藻摄食和营养盐循环模型,并考虑水温、光照等主要影响因素随时间变化对蓝藻生长的影响,进一步建立蓝藻生长时变系统非线性动力学模型,对其常值参数采用遗传算法与数值算法结合的方法进行优化率定,对其时变参数采用多元时序方法进行建模预测,根据分岔理论及时变系统理论分析水华暴发行为的非线性动力学机理,实现对蓝藻生长时变系统的水华预测。通过太湖流域监测实例表明,与现有研究相比,引入时变参数的蓝藻生长动力学模型更能反映蓝藻生长时变系统下水华暴发行为的非线性动力学特性,其水华预测结果更为准确。     

蓝藻生长时变系统非线性动力学分析及水华预测方法

为解决现有蓝藻生长动力学模型难以有效描述实际水体中蓝藻生长时变系统的非线性动力学特性,导致水华预测准确性不高的问题,构建蓝藻摄食和营养盐循环模型,并考虑水温、光照等主要影响因素随时间变化对蓝藻生长的影响,进一步建立蓝藻生长时变系统非线性动力学模型,对其常值参数采用遗传算法与数值算法结合的方法进行优化率定,对其时变参数采用多元时序方法进行建模预测,根据分岔理论及时变系统理论分析水华暴发行为的非线性动力学机理,实现对蓝藻生长时变系统的水华预测。通过太湖流域监测实例表明,与现有研究相比,引入时变参数的蓝藻生长动力学模型更能反映蓝藻生长时变系统下水华暴发行为的非线性动力学特性,其水华预测结果更为准确。     

水体中蓝藻毒素检测方法研究进展

蓝藻多肽类代谢产物（Cyanopeptides）占已知蓝藻生物活性物质数量的60%以上,具有多器官毒性、遗传毒性、强致癌性等特点,会通过饮用水进入人体,对人体健康造成威胁。近年来,蓝藻藻华频繁暴发,对饮用水体中蓝藻毒素进行检测刻不容缓。本文对不同类型蓝藻毒素进行阐述,重点归纳了不同毒素类型的结构特点及各种检测方式的优缺点,以期为进一步研究蓝藻毒素的精准测定提供参考。     

试析蓝藻毒素的监测及水华暴发的应急方案

近年来,随着全球水体富营养化现象不断严重,蓝藻"水华"对当地生态造成了严重的影响.因此,科研人员通过构建完善的监测蓝藻毒素的方法从而有效的控制蓝藻"水华"现象.本文主要通过生物学方法、免疫学方法以及化学分析方法来对蓝藻毒素进行监测控制,并且为市政、环境保护部门制定完善的水华暴发时的应急方案.     

太湖蓝藻的成因与启示

随着经济的快速发展、人类活动的加强,湖泊及其湖滨带的退化日益严重。介绍了太湖发生蓝藻的根源,从生态学原理上分析了太湖蓝藻的成因,概括了湖滨带的退化机理及现状。太湖水质变坏值得其他城市引以为戒,如果等到暴发水华,就需要付出更多的人力物力来解决富营养化问题。     

氧化铁行业污水氨氯处理难置破解

氧化铁生产过程中产生的污水量大,氨氮浓度高,一直是治理难题。特别是2007年5月,太湖大面积暴发蓝藻,使太湖流域的氨氮排放成为高度敏感的问题。     

利用蓝藻厌氧发酵液制备苏云金芽孢杆菌杀虫剂

[目的]富营养化湖泊蓝藻暴发已成突出的环境问题,打捞蓝藻的处理和利用是目前的技术难题,探究蓝藻的农药化利用可行性。[方法]以新鲜蓝藻为基质自然厌氧发酵不同时间得到蓝藻沼液,并以4种培养基(LB、新鲜蓝藻、蓝藻发酵2个月沼液、蓝藻发酵6个月沼液)为原料,接种苏云金芽孢杆菌(B.thuringiensis GIM1.32),对比菌种在不同培养基中生长代谢特征、杀虫晶体蛋白产量,并以3龄小菜蛾为测试对象测定毒力效价。[结果]蓝藻自然厌氧发酵是一个产酸过程,自然状况下(20~25℃)直接打捞富集的蓝藻藻泥产气潜力为27.27 mL/g。随蓝藻自然厌氧发酵时间的增加,沼液中TS、VS、pH值、粗脂肪、蛋白质含量均呈现下降趋势,多糖含量呈现上升趋势,灰分变化不明显。当含固率3%、pH值为7、接种物种龄10 h、接种量2%、培养温度30℃时,不同阶段蓝藻沼液制备B.t.的晶体蛋白含量、LC50值、Tx均低于新鲜蓝藻培养基。[结论]新鲜蓝藻是B.t.GIM 1.32菌种的生长代谢良好的培养基,能够使其正常完成芽孢和伴孢晶体的合成,为蓝藻资源化利用提供了一条新的、高值处理利用途径,既将蓝藻变废为宝,又可有效降低苏云金芽孢杆菌生物农药生产成本。     

再论硅藻生长促进复合物对蓝藻水华的控制作用

硅藻定向培养修复技术是近年来提出的一种新型有害藻华治理技术。硅藻生长促进复合物Nualgi是市场上常见的一种基于该技术的产品,目前已有一些研究验证了Nualgi营养素对硅藻生长促进及对有害藻类抑制的效果。然而,这些研究均是在未暴发蓝藻水华的水体中进行的。本研究以暴发蓝藻水华的湖水作为受试水体,考察了Nualgi对硅藻的促进和对蓝藻的抑制效果。研究表明,在蓝藻占据绝对优势的藻华水体中,Nualgi的处理效果并不显著,硅藻占比无显著提高。因此,采用硅藻定向培养修复技术治理蓝藻水华时,需要其他治理技术辅助。     

水力扰动及底泥悬浮对藻类生长影响的试验

近年来,水体富营养化程度日趋严重,河流、湖泊、水库等淡水藻类频繁暴发,严重影响供水安全。为探究水力扰动及底泥悬浮作用对水体中藻类生长的影响,以JZ水库原位藻样为研究对象,研究了其在不同扰动速率及底泥悬浮作用下的生长效果。结果表明,1 00 r/min的水力扰动能够有效促进水体中蓝藻生长,超过临界扰动速率后,200～400 r/min时藻类生长又会随着扰动速率增大而受到明显的抑制作用。在水力扰动造成底泥悬浮的情况下,水体中叶绿素a能够显著降低,4 h后去除率高达约82.4%,对藻类生长具有显著的抑制作用,有效控制蓝藻的繁殖和暴发。     

Flotation of blue-green algae using methylated egg ovalbumin

The removal of blue-green algae by dispersed gas flotation was conducted. Methylated ovalbumin (MeOA) was used as frother and flocculant, which is a biodegradable substance. The continuous flotation experiments were conducted at different feed mass flow rate of the blue-green algae cells and MeOA. The operating variables were the mass flow rate of blue-green algae cell and MeOA, the initial concentration of the cells and MeOA, and superficial gas velocity. The results showed that the mass flow rate of MeOA was the most dominant variable affected by the removal efficiency and that the removal efficiency achieved ca. 0.85 when a ratio of the mass flow rate of MeOA and that of the cells was over 0.3. A proposed flotation model considering the adsorptions of MeOA to the cells, MeOA to bubble surface and the cells bearing with MeOA to bubble surface was applied to explain the experimental removal efficiency. The experimental and the calculated removal efficiency were within error 19%, indicating that the proposed model was valid fundamentally.     

Anionic and nonionic surfactant sorption and degradation by algae cultures

Degradation of three surfactants has been determined by organic extraction procedures and infrared spectroscopy. Axenic cultures of five species of blue-green algae and three species of green algae which are common to waste stabilization ponds were test organisms. Analytical data are shown comparing the effects produced by the algae cultures and a heterogeneous microcosm. Linear alkyl sulfonate was the anionic surfactant compound tested. An alkyl polyethoxylate and an alkyl phenol polyethoxylate were the nonionic test surfactants. Sorption of the compounds by the algae usually was followed by release and degradation of up to 99% of some of the component parts of the surfactant molecule.     

Unsaponifiable matter of green and blue-green algal lipids as a factor of biochemical differentiation of their biomasses: I. Total unsaponifiable and hydrocarbon fraction

As part of a program to study the chemical composition of algal biomasses, the composition of the unsaponifiable matter of the lipids of ten algal species (fiveMyxophyceae and fiveChlorophyceae) was investigated. The total unsaponifiable content, its general composition, and the components of the hydrocarbon fraction are discussed in the present paper. The unsaponifiable content of green algae is constantly higher than that of the blue-green ones, with the exception ofChlorella. In both algal classes, the major components are hydrocarbons and sterols. Blue-green algae are richer in hydrocarbons, whereas the green ones contain higher amounts of sterols. In most of the species examined, at least 48 components are present in the hydrocarbon fraction. Each algal species shows a characteristic gas liquid chromatography pattern, but n-C₁₇ is always one of the most abundant components. Generally, the prokaryotic blue-green algae show a simpler hydrocarbon composition than the eucaryotic green algae, which contain higher amounts of high mol wt components. Unsaturated hydrocarbons are generally present in very limited quantities, with the exception ofSpirulina sp. andChlorella, sp., which contain a C₁₇ alkene. Green algae also contain appreciable amounts of a C₂₇ monoene and of squalene.     

Unsaponifiable matter of green and blue-green algal lipids as a factor of biochemical differentiation of their biomasses: II. Terpenic alcohol and sterol fractions

The composition of the terpenic alcohol and sterol fractions of the unsaponifiables of ten algal species, fiveMyxophyceae and fiveChlorophyceae, is discussed. The major component of the terpenic fraction is phytol, a diterpenic alcohol. Minor amounts of straight chain and triterpenic alcohols are also present. Practically all the species examined contain ten components in the sterol fraction: cholesterol, brassicasterol, Δ⁵-ergostenol, poriferasterol, Δ⁷-ergostenol, clionasterol, chondrillasterol, Δ⁵-avenasterol, Δ⁷-chondrillastenol, and an unidentified component. Identification of the sterols was made by gas chromatography-mass spectrometry, and a 24 S configuration was assumed. The prokaryotic blue-green algae are characterized by a higher content in cholesterol (3.5–14%) than the eucaryotic green algae (0–2.5). Also, brassicasterol, poriferasterol, clionasterol, and Δ⁵-avenasterol are more abundant in blue-green algae. Δ⁷-Ergostenol, chondrillasterol, and Δ⁷-chondrillastenol predominate, on the contrary, in green algae.     

Fatty acid metabolism in the chloroplast lipids of green and blue-green algae

The pattern of uptake of radioactivity into chloroplast lipids when a green alga (Chlorella vulgaris) was incubated with sodium 2-¹⁴C-acetate differed appreciably from that obtained when two blue-green algae (Anabaena cylindrica andAnacystis nidulans) were incubated under similar conditions. The fatty acids of the digalactosyl diglyceride and sulphoquinovosyl diglyceride fractions from the blue-green algae were labeled more rapidly than were those of the corresponding fractions fromC. vulgaris, whereas the activity in the acids of the phosphatidyl glycerol fraction fromA. cylindrica andA. nidulans was relatively lower than that in the green alga. The results indicate that the metabolic behavior of chloroplast lipids may vary considerably according to the class of alga concerned. In all three alga, the evidence points to an intermediary function for the chloroplast lipids in fatty acid synthesis. Only limited exchange of acyl groups between the different chloroplast lipids seemed to occur during photoautotrophic growth.     

Recovery of15N from ammonium nitrate and algal biomass-amended soil

A greenhouse experiment was conducted to compare the effectiveness of blue-green algae (Anabaena flos aquae) produced in a simulated inorganic-wastewater medium and NH₄NO₃ as sources of N for bermudagrass (Cynodon dactylon L.) on a Decatur silt loam soil (clayey, kaolinitic, thermic Rhodic Paleudult).¹⁵N-labeled blue-green algae and¹⁵N-labeled NH₄NO₃ were used as N sources to supply up to 300 mg N per pot (3 kg of soil). Bermudagrass was clipped at 42, 63, and 102 d after planting and dry matter yield, total, and¹⁵N were determined at each clipping. Results indicated a highly significant increase in total dry matter (shoots and roots) and N uptake over the control for both algae and NH₄NO₃ treatments at all N rates. There were no significant effects of N source on bermudagrass yields, but total N uptake was significantly higher with NH₄NO₃. The net mineralization of N from blue-green algal biomass ranged from 36 to 59% of the total N applied and the corresponding net release for NH₄NO₃ ranged from 65 to 86%. From 29 to 54% of the total N applied as blue-green algal biomass and from 50 to 75% of the N applied as NH₄NO₃ were assimilated by bermudagrass plants. For N rates above 100 mg N pot^–1, higher proportions of the labeled N in the shoots of the third harvest were derived from algal biomass than from NH₄NO₃. A large portion of the labeled N remained undecomposed or immobilized in the algae treated soil (41–64%) as compared to NH₄NO₃ treated soil (14–35%). More loss of N occurred in the NH₄NO₃ treatments from 3 to 15%, while the corresponding figures for algae treated soil were 2 to 8%.     

Macrokinetics and mathematical modelling of quinone reduction by cyanobacteria

The kinetics of the reduction of externally added 2-hydroxy-1,4-naphthoquinone by blue-green algae of the strains Anabaena PCC 7120 and Anacystis nidulans PCC 6301 were studied in aqueous cell suspensions by electrochemical monitoring of the concentration of the formed hydroquinone. This reaction is of potential interest for bioelectrochemical fuel cells. The experimental curves obtained could be interpreted by a model that takes into account that both substrate and product have to be transported through the microbial cell walls and that the conversion reaction takes place with firstorder kinetics within the microbial cells. No clear evidence was found for the involvement of photosynthesis. It is suggested that the reduction of the quinone probably occurs via the enzyme-catalyzed oxidation of endogenous storage product(s), presumably glycogen.     

Biliproteins: Some Relationships Among Aggregation States,Spectra, and Excitation-Energy Transfer

The key aggregation steps for C-phycocyanin consist of denatured subunits (α and β polypeptide chains), monomers, trimers, hexamers and stacks. For allophycocyanin the steps are denatured subunits, monomers and trimers. Ultimately these assembly states lead to the formation of phycobilisomes in blue-green and red algae. The spectroscopic changes that accompany each stage in the assembly can be monitored as a function of the ratio of visible to near-UV absorption. For C-phycocyanin, monomers and hexamers are the important levels in the modulation of tetrapyrrole conformation by protein-chromophore interaction. The effect of protein aggregation on the protein-chromophore interactions is the key to solar-energy harvesting and excitation-energy migration in photosynthesis.     

炭砂双层滤料浮滤池工艺处理藻污染水库水的试验研究

目前水库水源藻污染日益严重,传统沉淀固液分离工艺难以满足净水要求。以鹊山引黄水库高藻原水为研究对象,开发了炭砂双层滤料浮滤池,考察了浮滤池工艺运行特性及运行效果。试验表明,絮凝剂选用聚合氯化铝铁（PAFC）,在投药量4.0 mg·L^-1（以Al³⁺计）,回流比8%,溶气压力0.4 MPa时,运行效果较优。炭层所含生物量约占滤料层总生物量的97.4%（最高值50.2 nmol P·g^-1）,是砂滤层 （3.0 nmol P·g^-1）的16.7倍,污染物的去除主要发生在活性炭层。试验期间,浮滤池工艺对颗粒物、蓝绿藻、浊度、COD_Mn、NPOC、UV₂₅₄、氨氮的去除率分别达到96.48%、92.40%、92.56%、57.41%、51.60%、52.50%、75.67%,嗅味由4级降为0级,出水土臭素、二甲基异冰片含量均小于检出限,一氯二溴甲烷、三氯甲烷前体物的去除率分别达到55.1%和60%,表明浮滤池工艺对常规指标、藻类、嗅味物质、消毒副产物前体物去除效果显著。     

The distribution of sterols in algae

Available analytical techniques are now sufficient for the separation and identification of sterols from complex mixtures in plants. Gas and thin layer chromatography and mass spectroscopy in particular, have been used to resolve some of the confusion concerning the sterol composition of algae. Red algae (Rhodophyta) contain primarily cholesterol, although several species contain large amounts of desmosterol, and one species contains primarily 22-dehydrocholesterol. Only a few Rhodophyta contain traces of C-28 and C-29 sterols. Fucosterol is the dominant sterol of brown algae (Phaeophyta), apparently the major sterol of every species examined. Most Phaeophyta also contain traces of cholesterol and biosynthetic precursors of fucosterol. The sterols of green algae (Chlorophyta) are much more varied and complex than those of other groups of algae. Whereas the Phaeophyta and Rhodophyta contain one primary sterol, many of the Chlorophyta contain a complex mixture of sterols such as occurs in higher plants. The Chlorophyta contain such sterols as chondrillasterol, poriferasterol, 28-isofucosterol, ergosterol, cholesterol and others. Sterol composition may be of value in the systematics of plants such as the Chlorophyta. Recently (for the first time) complex mixtures of sterols have been isolated in very small amounts in the blue-green algae (Cyanophyta). Available data on the sterols of other groups of algae are insufficient for making useful comparisons. One of 12 papers to be published from the “Sterol Symposium” presented at the AOCS Meeting, New Orleans, April 1970. Scientific Article No. A2606, Contribution No. 4331 of the Maryland Agricultural Experiment Station.