富营养化水体中蓝藻毒素的危害及其控制

本文较详细地介绍了水体中藻毒素的种类、特性及其危害。按毒素的靶器官分类，可分为肝脏毒素、神经毒素和皮肤、肠胃刺激性毒素3种，其中已解明藻毒素分子结构的有70余种。本文还介绍了关于藻毒素净化研究的主要成果。为防范和减少藻毒素的危害，同时还提出了藻毒素危险管理对策的主要内容。     

基于遗传算法改进的一阶滞后滤波和长短期记忆网络的蓝藻水华预测方法

河湖藻类水华形成过程中所具有的突发性和不确定性,导致对藻类水华爆发预测准确性不高。为解决此问题,以叶绿素a的浓度值作为蓝藻水华演化过程表征指标,提出基于长短期记忆（LSTM）循环神经网络（RNN）蓝藻水华预测模型。首先,用遗传算法改进的一阶滞后滤波（GF）优化算法对数据进行平滑滤波处理;然后,搭建GF-LSTM网络的蓝藻水华预测模型,实现对水华发生的精准预测;最后,以太湖水域梅梁湖区域的采样数据为样本,对预测模型进行检验,并与传统的RNN和LSTM网络进行对比。仿真结果表明,提出的GF-LSTM网络模型平均相对误差控制在16%~18%,而RNN模型的预测平均相对误差为28%~32%,LSTM网络模型的平均相对误差为19%~22%,对采用数据的平滑性处理效果较好,预测精度更高,对样本具有更好的适应性,克服了传统RNN模型在长期训练时出现的梯度消失与梯度爆炸缺点。     

用振荡射流抑制蓝藻滋长防止泥沙淤积

按照控制论的"反馈—放大—振荡"原理所构建的双稳态流体自控振荡器,可交替地从其两个输出孔断续地喷射出变向的水射束,从而促使周围水体激烈紊动,加强水中物质的交换能力.振荡射流扰动后,蓝藻能获得的光合能量将降低4倍.由于悬浮功Ws相对于自变量体积含沙量Sv的二阶导数为负值,高含沙浓度的泥浆流不但不会淤积反而会急剧冲刷河床.流控振荡器激扰促紊会导致分层流失稳,从而增大河流输沙能力.     

Upconversion Nanoparticles Hybridized Cyanobacterial Cells for Near-Infrared Mediated Photosynthesis and Enhanced Photodynamic Therapy

The hypoxic hallmark of tumor has aroused substantial burdens on a variety of therapeutic modalities including photodynamic therapy (PDT). Recently, biological oxygen evolution enabled by photosynthetic cyanobacterial cells has emerged as one of the most advanced and promising tissue oxygenation strategies, which is particularly beneficial for in situ tumor-PDT. Herein, a near infrared-driven PDT platform based on the photosynthetic cyanobacterial cells hybridized with photosensitizer rose bengal (RB)-loaded upconversion nanoparticles, named as UR-Cyan cells, is reported. Upon the irradiation of 980 nm laser and its upconversions to shorter wavelengths, the formulated UR-Cyan cells are both photosynthetically active for oxygen production and photosensitive for the subsequent singlet oxygen generation by the photosensitizer, resulting in enhanced and sustainable PDT efficacy against tumor cells/tissues. The present design offers a practical approach to conquer the hypoxic burden of PDT operations against a wide range of pathological lesions with excellent biocompatibility and clinical promises.     

蓝藻毒素的监测及水华暴发的应急方案

目前有毒蓝藻水华在世界范围内频繁发生,建立一整套控制蓝绿藻及其毒素的监测系统是非常必要的。为此针对给水以及市政、环境保护部门,提供了一套水华暴发时的应急解决方案,包括监测流程及应急措施。     

Limnological characteristics, eutrophication and cyanobacterial blooms in an inland reservoir, Australia

Ben Chifley Reservoir, the only potable water supply for Bathurst, New South Wales, Australia, has been experiencing recurrent cyanobacterial bloom problems since 1991. A study was undertaken from June 1998 to July 1999 to assess the limnological characteristics pertinent to eutrophication and the associated cyanobacterial blooms. From January–May 1999, the reservoir exhibited significant numbers of cyanobacterial cells, totalling > 9000 cells mL^?1. The highest number of cells (> 27 000 cells mL^?1) was recorded during April 1999. The water quality characteristics of the reservoir, and the river inflow and climatic data, were grouped into three distinct periods; before, during and after cyanobacterial blooms. High water temperature (15–22°C), thermal stratification (ΔT = 2.7–2.8°C), depletion of dissolved oxygen and high nutrient concentrations, all of which are conducive to enhanced cyanobacterial blooms, were evident before and during the bloom periods. Based on its nitrogen to phosphorus molar ratio, Ben Chifley Reservoir can be considered as being phosphorus‐deficient, in contrast to nitrogen, which is readily available from a number of sources in its drainage basin, including atmospheric fixation. Thus, it is recommended that adopting management strategies to reduce the quantity of bioavailable phosphorus in the reservoir would be the most effective way to minimize the occurrence of algal blooms.     

基于GF-5的滇池蓝藻水华空间分布特征研究

滇池水体富营养化严重导致蓝藻水华爆发,因此文章基于GF-5高光谱数据,运用归一化植被指数(Normalized Difference Vegetation Index,NDVI)识别滇池的蓝藻水华发生状况,并通过对NDVI值域进行分类,进一步对比分析草海、外海蓝藻水华的空间分布特征及差异.结论如下:①NDVI值域的一般...     

蓝藻藻泥固结特性的试验研究

蓝藻藻泥的脱水减量处理已成为湖泊治理的一个新的问题,脱水的本质是藻泥的固结排水过程。因此通过藻泥的固结试验研究其固结特性,对于提高藻泥的脱水效率具有重要意义。通过对固结仪进行改进,对1种蓝藻藻泥和1种湖泊淤泥进行试验,研究藻泥的固结特性及区别。结果表明:藻泥的固结排水时间很长,孔压消散非常慢;藻泥的固结系数及渗透系数非常小,并随着固结压力的增加而减小的非常明显;通过分析认为藻泥中的生物质细胞体是造成固结时间长、水分排出缓慢的主要原因。     

Seasonal and diel changes of dissolved oxygen in a hypertrophic prairie lake

Humboldt Lake, a hypertrophic prairie lake typical of many found on the Great Plains of North America, is usually ice‐covered from early November to about mid‐May. The lake is an important recreational fishery, now mainly stocked with walleye. It has a high potential risk of experiencing fish kills because of the very large cyanobacterial blooms that develop in it, the high rates of algal and bacterial production and the high concentrations of ammonia (NH₃‐N) and dissolved organic matter. Following the collapse of cyanobacterial blooms, shallow prairie lakes are known to undergo periods of anoxia that can lead to summer fish kills. In some of the lakes, anoxia forms during the long period of ice cover, causing winter fish kills. Two years of seasonal and diel data (total phosphorus, dissolved oxygen (DO), NH₃‐N and chlorophyll‐a concentrations, and bacterial production) were analysed in this study to assess why significant fish kills did not occur during this period or during the ≈ 30 years of records from Saskatchewan Environment. Humboldt Lake did not become anaerobic, either following the collapse of the cyanobacterial bloom or under ice cover, indicating that the oxygen (O₂) influx (strong mixing) and production processes were greater than the microbial and chemical O₂ demands, both over seasonal and diel time scales. Several published risk threshold criteria to predict the probability of summer and/or winter fish kills were applied in this study. The threshold criteria of maximum summer chlorophyll and maximum winter NH₃‐N concentrations indicated that a summer fish kill was unlikely to occur in this hypertrophic prairie lake, provided its water quality remained similar to that during this study. Similarly, the threshold criteria of initial DO storage before ice cover and the rate of O₂ depletion under ice cover also indicated a winter fish kill was unlikely. However, recent development in the watershed might have resulted in significant water quality deterioration and the winter fish kill that occurred in 2005.     

卫津河蓝藻“水华”形成的原因及治理建议

介绍了国内外多年来关于水域富营养化治理的研究成果,对卫津河蓝藻“水华”的形成原因进行了分析,并提出了将生物操纵、底泥微生物修复、生物促生、人工增氧、生物浮床、网箱养草、生物移出等技术组合使用的治理建议。