蓝藻毒素去除方法研究进展

蓝藻水华中产生的次生代谢产物蓝藻毒素对人类及陆生动物具有严重毒性和致癌作用,同时会危害水域生态系统的结构和功能。有毒藻华的频繁发生及其引发的环境和健康问题已经成为全球环境科学领域的研究热点。现有的净水技术去除饮用水中藻毒素效率不高,因此寻找高效的藻毒素去除方法是目前亟待解决的问题。本文首先阐述了蓝藻毒素的产生和释放机理,将蓝藻毒素的去除分为除藻和去除水体中溶解性藻毒素两类;其次,本文在国内外大量研究成果的基础上综述了当前蓝藻毒素的降解途径,并详细介绍了活性炭吸附法、高级氧化降解法、微生物降解法等具有实际应用前景的去除方法;最后,本文总结了当前蓝藻毒素去除方法的局限性,指出了未来的研究应向高效率、低能耗、无污染、实用性强的方向发展。     

藻毒素的类型、危害和防治

介绍了赤潮藻毒素：麻痹性贝毒、短裸甲藻毒素、溶血性毒素、细胞性毒素和氨毒：水华藻毒素：肝毒素、神经毒素、脂多糖内毒素的化学结构、性质和毒害机理等,以及藻毒素的防治方法。     

粘土改性技术用于絮凝除藻的研究进展

当前, 藻类水花及其带来的藻毒素污染愈演愈烈, 治理藻害成为改善水环境的当务之急。受安全、技术及成本的限制, 人们试图通过改性粘土实现更加高效、安全的藻害去除效果。基于已有的研究成果, 对改性粘土的除藻机理、改性方法及絮凝效果的影响因素进行了归纳总结。目前, 改性粘土去除藻害的研究和应用大多局限于海水水体, 很多淡水除藻的研究和实践尚未取得理想效果。今后可以考虑通过有机-无机改性结合的方法或开发新型改性剂拓展改性粘土技术絮凝除藻的应用范围。总之, 开发相对安全、可防止蓝藻泛起、藻毒素释放及底泥营养盐二次污染等问题的改性粘土来絮凝沉降藻类, 是未来利用改性粘土治理藻害需要解决的问题和重点研究方向。     

微囊藻毒素生物治理技术研究进展*

近年来,随着全球气候变暖和水体富营养化程度加深,蓝藻水华频繁暴发。微囊藻毒素是有害蓝藻产生及释放的危害最大的一类蓝藻毒素,对生态环境和公众健康造成了严重的威胁。因此,寻求有效的微囊藻毒素降解方法已成为全球科学领域的研究热点。针对微囊藻毒素生物治理技术展开综述,阐述了微囊藻毒素的产生、理化性质及生物毒性,总结了微生物、水生植物、浮游动物等自然生物降解微囊藻毒素的能力。在此基础上概述了生物滤池、人工湿地、生态浮床、膜生物膜反应器等生物治理技术对微囊藻毒素的去除效果,分析了现有微囊藻毒素生物处理方法的优势和局限性,并对今后的研究方向提出展望,为解决水环境中微囊藻毒素的污染问题提供思路。     

环境水体微囊藻毒素微生物降解技术研究进展

湖库水体富营养化及其产生的藻毒素污染已对生态环境和人类健康构成极大威胁,而目前常规水污染控制技术存在一定的局限性,因此水环境中藻毒素处理新工艺亟待研发.鉴于环境水体中的微囊藻毒素可被微生物降解为无毒或低毒的中间产物,本文综述了微囊藻毒素的降解菌株、生物降解过程影响因素与机理、降解产物及其结构特性等,总结了目前微囊藻毒素降解菌株在水环境修复中的应用,并对今后微生物降解微囊藻毒素的研究方向进行了展望,以期为解决我国日益严峻的湖库水体藻毒素污染和饮用水安全问题提供技术思路.     

环亚胺毒素gymnodimine的研究进展

Gymnodimine(GYM)是1994年从新西兰牡蛎中被鉴定出的藻毒素.其由凯伦藻（Karenia selliformis）产生,结构中含有一个位于螺环上的亚胺氮,属于环亚胺毒素.亚胺是GYM的毒理功能基团,具有很高的小鼠腹腔注射急性致死毒性,口服毒性很小,但详细的毒理作用机制尚不清楚.本文基于有限的研究资料,系统综述了GYM的结构、来源生物、毒性机理、携带生物、地理分布、降解代谢、剂量响应关系及风险评估等研究现状,并对今后藻毒素的重点研究方向进行了展望.     

乳酸菌对微囊藻毒素的清除

【目的】研究唾液乳杆菌(Lactobacillus salivarius BBE09-18)、发酵乳杆菌(L.fermentum BBE09-29)以及干酪乳杆菌(L.casei Zhang)对藻毒素的清除能力以及影响乳酸菌清除藻毒素的主要因素,以期为进一步解析乳酸菌清除藻毒素的作用机制提供理论基础,并为去除食品体系中的藻毒素提供新的思路。【方法】研究乳酸菌细胞的不同生理状态(活细胞与死细胞)对藻毒素清除能力的影响,考察菌浓差异、起始藻毒素浓度差异、葡萄糖的供给等对乳酸菌清除藻毒素效能的影响。【结果】3株实验乳酸菌均具有清除藻毒素的能力,其中,L.casei Zhang的藻毒素清除能力最强,当藻毒素初始浓度为150μg/L时,24h后残留藻毒素浓度为85.5μg/L,清除率可达43%。此外,研究还发现乳酸菌活细胞的清除能力显著高于热失活后的死细胞。添加外源物质葡萄糖能显著提高实验菌株清除藻毒素的效率,在初始浓度为1800μg/L的藻毒素溶液中,当添加5%(w/v)葡萄糖后,L.casei Zhang经24h可清除92%的藻毒素。【结论】3株乳酸菌均具有藻毒素清除能力;同时,菌体浓度以及菌体自身的生理状态对藻毒素的清除效率具有重要影响,乳酸菌对藻毒素的清除可能与菌体的代谢活性相关。     

微囊藻毒素对水环境的影响研究进展

微囊藻毒素是富营养化淡水水体中最常见的藻类毒素,是湖泊蓝藻产生的一类肽类毒素,它的产生受到藻类的遗传和环境因素的共同影响。由于其毒性大,分布广,结构稳定,从而成为水环境中的潜在危害物质。有关微囊藻毒素性质、毒理毒性、在环境中的迁移、转化以及控制预防已成为关注热点。在总结国内外研究的基础上,综述了微囊藻毒素的性质、产生机理以及其与水环境、水生生物(水生植物、鱼类、无脊椎动物)间的相互作用,讨论了微囊藻毒素对水生生物的影响以及水生生物对微囊藻毒素的降解作用,为水体中微囊藻毒素的防治提供科学的依据。     

样品制备过程对测定水中溶解态微囊藻毒素的影响

系统比较了5种不同材质滤膜对于制备溶解态微囊藻毒素的影响,发现了影响藻毒素测定样品前处理的关键操作步骤。结果表明,醋酸纤维滤膜（CA filter）最多可吸附样品中79%的藻毒素,导致测得的MCs浓度严重偏低。玻璃纤维（GF/C）滤膜和聚醚砜（PES）材质滤器对制备溶解态微囊藻毒素过程影响很小。另外,发现离心法无法完全去除野外水华样品中藻细胞,反而可能导致藻细胞破裂,释放藻毒素,影响水中溶解态微囊藻毒素的测定。研究结果将对发展水体中溶解态藻毒素测定标准方法提供依据。       

微囊藻毒素生态学研究

通过对微囊藻毒素的生态学进行综述,认为藻毒素的产生和含量的变化受水环境生物多样性、环境因子和微囊藻自身生物量等的影响。保障蓝藻在种群竞争、生态演替中获得竞争优势的各因素中,藻毒素发挥了重要调节作用。研究蓝藻的产毒机制,对于理解水体富营养化机制,实施蓝藻水华的生物控制,最终对富营养化水体进行生态修复具有重要的理论意义和现实作用;     

Partitioning of model toxins to hydrophobically terminated DAB dendrimers

Dendrimers are attractive in biological and biomedical applications due to the similarity in their molecular size to biologically relevant molecules and the large number of chain ends available functionalization. In the current work, we examined the potential of diamino butane (DAB) dendrimers functionalized with long alkyl chains as partitioning agents for hydrophobic toxins for use as a prefiltering stage in a bioartiticial liver. DAB dendrimers of various generations that had been previously fully modified with palmitoyl chloride were obtained. A study of the kinetics of partitioning of acetylsalicylic acid (ASA) suggested that while significant toxin removal occurred in 30 s, although a slight time dependent increase in removal was noted up to 60 minutes. The partitioning of 6 hydrophobic toxins from aqueous solution to the modified dendrimers in 30 minutes was examined. The results demonstrated that a number of factors, including the pKa of the toxin, its octanol water partitioning coefficient and molecular size contributed to the level of toxin removal. Toxin removal on a molar basis increased with increasing dendrimer generation for all toxins, with the modified G5 dendrimers partitioning 50-100 toxin molecules in most cases. Dendrimer modification with C4 alkyl chains rather than Cl5 chains significantly decreased toxin removal, although chains longer than C10 seemed to partition equal amounts of toxins. The results of the study demonstrate that water-soluble dendrimers modified with hydrophobic end groups may be useful for the removal of toxins from the blood in a prereaction step for a bioartificial liver, but that a better understanding of the molecular mechanisms of removal may be necessary before it is possible to predict the levels of toxin removal.     

不同类型生物土壤结皮覆盖下风沙土的入渗特征及模拟

干旱荒漠区广泛分布的生物土壤结皮(BSCs)对土壤水分入渗过程有重要影响。以古尔班通古特沙漠南缘的BSCs为研究对象,基于野外采样与室内模拟实验等方法,探究藓类、地衣和藻等3种类型BSCs覆盖下沙土的入渗特征。结果表明:与无结皮覆盖的风沙土对照,3种类型BSCs均显著降低了沙土初渗速率,藓类结皮、地衣结皮、藻结皮覆盖下初渗速率降低幅度依次为36.10%、46.42%、50.39%;藓类结皮、地衣结皮(P0.05)和藻结皮(P0.05)均明显降低了沙土稳渗速率,降低幅度依次为16.50%、33.98%和35.92%;3种类型BSCs均限制了湿润锋在沙土的推进过程,表现为:藓类结皮、地衣结皮、藻结皮的渗漏时间分别为裸沙对照的2.13、3.04和2.98倍;各类型BSCs均减小了沙土累积入渗量,阻碍了沙土水分入渗,与裸沙对照相比,藓类结皮、地衣结皮、藻结皮的1 h累积入渗量分别降低16.10%、28.56%和26.56%。在实验条件下,Kostiakov模型最适用于模拟不同类型BSCs覆盖下土壤水分入渗过程,Horton模型模拟效果次之。     

Applied simulations and integrated modelling for the understanding of toxic and harmful algal blooms (ASIMUTH): Integrated HAB forecast systems for Europe's Atlantic Arc

Reasons for the emergent interest in HABs are abundant, including concerns associated with human health, adverse effects on biological resources, economic losses attributed to recreation, tourism and seafood related industries, and the cost of maintaining public advisory services and monitoring programs for shellfish toxins and water quality. The impact of HABs can potentially be mitigated by early warning of their development. In this regard the project ASIMUTH (Applied Simulations and Integrated Modelling for the Understanding of Toxic and Harmful algal blooms) was borne in order to develop short term HAB alert systems for Atlantic Europe. This was achieved using information on the most current marine conditions (weather, water characteristics, toxicity, harmful algal presence etc.) combined with high resolution local numerical predictions. This integrated, multidisciplinary, trans-boundary approach to the study of HABs developed during ASIMUTH led to a better understanding of the physical, chemical and ecological factors controlling these blooms, as well as their impact on human activities. The outcome was an appropriate alert system for an effective management of areas that are usually associated with HAB events and where these episodes may have a more significant negative impact on human activities. Specifically for the aquaculture industry, the information provided enabled farmers to adapt their working practices in time to prevent mortalities in finfish farms and/or manage their shellfish harvest more effectively. This paper summarises the modelling and alert developments generated by the ASIMUTH project.     

饮用水源藻类污染及其防治对策

对富营养化水体的形成原因,藻类污染的情况,某水源藻类的种类,导致藻类爆发的限制因子,及不同的藻类对水处理工艺带来不同的危害进行研究。藻类的防治处理有三种措施:强化混凝、投加活性炭、投加高锰酸钾,通过进行净水新工艺的研究,提出藻类防治的设想。     

An integrated algal sulphate reducing high rate ponding process for the treatment of acid mine drainage wastewaters

Acid mine drainage pollution may be associated with large water volume flows and exceptionally long periods of time over which the drainage may require treatment. While the use and role of sulphate reducing bacteria has been demonstrated in active treatment systems for acid mine drainage remediation, reactor size requirement and the cost and availability of the carbon and electron donor source are factors which constrain process development. Little attention has focussed on the use of waste stabilisation ponding processes for acid mine drainage treatment. Wastewater ponding is a mature technology for the treatment of large water volumes and its use as a basis for appropriate reactor design for acid mine drainage treatment is described including high rates of sulphate reduction and the precipitation of metal sulphides. Together with the co-disposal of organic wastes, algal biomass is generated as an independent carbon source for SRB production. Treatment of tannery effluent in a custom-designed high rate algal ponding process, and its use as a carbon source in the generation and precipitation of metal sulphides, has been demonstrated through piloting to the implementation of a full-scale process.The treatment of both mine drainage and zinc refinery wastewaters are reported. A complementary role for microalgal production in the generation of alkalinity and bioadsorptive removal of metals has been utilised and an Integrated 'Algal Sulphate Reducing Ponding Process for the Treatment of Acidic and Metal Wastewaters' (ASPAM) has been described.     

Novel insight into the process of nutrients removal using an algal biofilm: The evaluation of mechanism and efficiency

Eutrophication of water by nutrient pollution remains an important environmental issue. The aim of this study was to evaluate the nutrient uptake capacity of an algal biofilm as a means to treat polluted water. In addition, the study investigated the nutrient removal process. The algal biofilm was able to remove 99% of phosphorus within 24 hours of P addition, with the PO₄-P concentration in inflowing water ranging from 3 to 10 mg L^?1. Different patterns of phosphorus and nitrogen removal were observed. Daily quantity of removed NO₃-N ranged from 2 to 25% and was highly dependent on solar irradiance. Precipitation of phosphorus during the removal process was studied using X-ray diffraction analyses and was not confirmed in the biofilm. The biofilm system we constructed has a high efficiency for phosphorus removal and, therefore, has great potential for integration into wastewater treatment processes.     

60 Identification of diatom‐lytic bacterium sk‐02 and its capability to degrade stephanodiscus hantzschii

In order to control harmful algal blooms, many biological approaches have been tried. Specially, there have recently been discussions concerning the roles of bacteria in algal bloom dynamics. Then, algicidal bacteria are expected as an agent considerate for harmful algal blooms control. Development of these organisms as biological control agents involves isolation from environmental samples. With the aim of develop eco‐technology controlling water blooms in fresh waters, we isolated the diatom‐lysing bacteria from the sediments of Lake Seokchon and Pal¡¯tang River‐Reservoir. A soft agar‐overlay technique was used to isolate the diatom lytic bacteria. The SK‐02 showed a diatom lytic activity against Stephanodiscus hantzschii. Taxonomic identification including 16S rDNA base sequencing, and phylogenetic analysis indicated that the isolate SK‐02 had a 99.20% homology in its 16S rDNA base sequence with Pseudomonas putida. The nature of these diatom‐lying components is still under investigation. These results suggest that the indigenous bacteria isolated from the sediments may have a potential in the application and development of eco‐technology controlling harmful water blooms in the fresh water environments.     

人工湿地脱除富营养化水体氮磷的研究进展

水体中氮磷营养物质不断积累,部分藻类及水生生物的过度繁殖,导致了水体的富营养化。水体富营养化防治的关键是减小水中氮、磷的含量。人工湿地是一项新型的废水处理技术,近年来在脱除富营养化水体氮磷中获得广泛研究和应用。本文在简述脱氮除磷机理的基础上,较系统地阐述了影响人工湿地脱除氮磷的因素及工艺的在改善水体富营养化的研究进展,以便在构建人工湿地中对各项因素综合考虑及兼顾利用,提高人工湿地修复富营养化水体的综合效能。     

赤潮藻毒素生物合成研究进展

合成毒素是赤潮藻类的一个常见特征,已知能够产生毒素的微藻有70多种。作为次级代谢产物,藻毒素的产生可能是一种压制或清除其它藻类竞争者的一种反应,在群落演替、种间竞争中发挥重要作用。目前,人们对藻毒素生物合成机理依然知之甚少,相关基因的研究仍无明显突破。利用环境因子诱导毒素生成变化进而分离差异表达基因或者比较不同产毒藻株间基因表达的差异,从中克隆藻毒素生物合成基因似乎是一种极具潜力的研究方向。