超声除藻的参数优化及其在太湖除藻中的应用

设计、制备了一种低频超声除藻装置,通过调节超声频率、功率和辐射时间等不同的参数,得到优化的超声参数组合,并将该技术应用于太湖除藻的现场研究.结果表明:当超声参数组合为频率20 kHz,功率40 W,辐射时间15 s时,具有较好的实验除藻效果.在太湖现场实验中,载有超声除藻装置的实验船在400 m2实验区域作用1 h后,水表层的藻细胞由107个/mL降低到105个/mL,透明度由0 cm上升为35 cm,叶绿素a含量降低为初始浓度的3.3%,水质得到明显改善.这说明超声处理对藻类生长有显著的抑制作用,尤其适于水华发生期间的应急处理.     

基于WebGIS技术的海洋环境在线监测信息系统

在对海洋环境监测系统数据发布进行全面需求分析的基础上，引入WebGIS信息建立发布平台．该平台不但充分发挥了WebGIS的属性信息的发布和检索功能，而且整合了监测数据的实时聚类分析，对有害藻类密度进行预测．GIS结合互联网技术，扩大了传统地理信息发布平台的信息发布范围，直观而又高效地实现了海洋环境监测系统监测数据的网络共享．     

Bloom Filter在手机垃圾短信过滤中的应用

针对当前手机垃圾短信过滤系统的不足和手机资源紧张的特点,构建了基于独立空间布隆过滤器的手机垃圾短信过滤系统,具体给出了系统结构、工作流程及其算法。实验分析结果表明,在允许一定"假阳性"误报率的条件下,该系统可以有效节省手机资源。     

水体富营养化和水华的控制技术研究现状

针对我国日益严重的水体富营养化现象,从物理化学、生物和水力学三个方面对国内外富营养化和水华控制技术的研究现状进行了综述。结果表明,基于理性的氮磷营养物控制策略仍是水体富营养化控制的优先策略,科学合理的水力调度对库湾水体、城市河道抑制富营养化和控制藻类生长具有重要作用,传统的物理和化学方法及生物技术在小范围水华应急和水质维持较为有效,但一些方法的生态安全性及理论依据仍需加强研究。实际水体修复过程中仍需要不断调整方法以适用不同水体需求。     

三种机器学习模型在太湖藻华面积预测中的应用

基于2014—2018年太湖气象水文水质数据与卫星遥感数据,分别采用支持向量机(SVM)、长短记忆神经网络(LSTM)、极端梯度提升树(XGBoost)模型模拟全太湖、贡湖、南部沿岸区、中西北湖区的蓝藻水华(简称藻华)面积。结果表明:(a)XGBoost全太湖与分区藻华面积回归模型模拟效果较好,其次是SVM、LSTM回归模型;不同时间尺度下SVM、XGBoost回归模型对全太湖藻华面积模拟结果偏小,但有效模拟了藻华的发展趋势。(b)XGBoost分类模型在全太湖、中西北湖区模拟准确率较高,优于SVM、LSTM分类模型;在贡湖、南部沿岸区,3种分类模型准确率均较高。(c)以当天、提前1 d的气象水文水质因子作为全太湖与分区藻华面积模型输入,XGBoost回归与分类模型模拟精度较高、稳健性较好,预测应用情景较好。     

有害赤潮的形成机制、危害效应与防治对策

近些年来,全球有害赤潮发生的频率、规模及其危害效应呈现逐渐上升的趋势。有害赤潮的形成受到赤潮原因种适应特征与竞争策略、水体富营养化状况,以及水文、气象等环境因子的影响。有害赤潮藻种可以通过产生毒素、改变水体理化特征等对人类健康、水产养殖和海洋生态系统带来危害。迫切需要协调人类活动与环境的关系,建立和发展赤潮应急治理技术,以降低有害赤潮的规模及其危害效应。我国近海有害赤潮问题近年来有加剧的趋势,而且有毒有害藻种形成的赤潮越来越多,对于我国近海赤潮演变的趋势与潜在危害效应应给予充分关注。     

Direct evidence of phosphorus outbreak release from sediment to overlying water in a large shallow lake caused by strong wind wave disturbance

Concentration variations of suspended solids (SS), total phosphorus (TP), dissolved total phosphorus (DTP), dissolved reactive phosphorus (SRP), and algae available phosphorus (AAP) in overlying water were observed during the coldest week in a year in Lake Taihu, a large shallow lake in China. Water samples at different water depths were collected with wind speeds of 8, 12, 0 and 0 m/s on 23, 24, 26 and 30 January 2004, respectively. On 23 January 2004, SS concentration increased to 258 mg/L with a wind speed of 8 m/s lasting for 1 h. SS concentration kept increasing and reached to 507 mg/L when the strong wind lasted for 24 h and the peak value of wind-speed reached to 12 m/s on 24 January 2004. On 26 January 2004, SS concentrution decreased to 51 mg/L with the wind speed smaller than 2 m/s lasting for about half a day. Then after five continuous waveless days, SS concentration decreased to 21 mg/L on 30 January 2004. The observed results confirmed that sediments in Lake Taihu would be intensively suspended if the surface wind speed is greater than 8 m/s, and the magnitude of SS would increase with increasing wind-speed. Coupled with the intensive sediment suspending, concentrations of TP, DTP and SRP on 23 January were 0.210, 0.048 and 0.035 mg/L, respectively. And they were 0.299, 0.054 and 0.026 mg/L on 24 January, which were significantly higher than those on 26 and 30 January. SRP concentration on 23 January was twice as high as that observed on 30 January. It indicates that the strong wind may result in an outbreak release of phosphorus. Moreover, AAP contents in suspended solids were 132, 97 and 226 mg/kg on 23, 24 and 26 January, respectively. Therefore, it could be estimated that this strong wind process resulted in 987 t of TP, 80 t of SRP and 167 t of AAP releasing from sediments into overlying water. Since such strong wind process is frequent in the area of Lake Taihu, dynamical release driven by wind-induced wave disturbance may be the main mode for internal release of phosphorus. It must have important effects on the nutrient supply during Microcystis bloom in Lake Taihu.     

环境因子对衣藻水华消长影响的初步研究

通过对一小型水体中衣藻水华发生全过程的研究,获得几种环境因子对衣藻水华消长影响的相关数据。此次水华的发生期为2000年2月至3月,水温的变化范围在8－20℃之间。观测发现,水体中氮、磷的含量是影响水华发生的主要因素：其中有效氮磷的比值为17,这有可能就是导致水华中优势藻类的决定因素,并且当正磷酸盐浓度随着水华的不断发生而降至0．655mg/L时,衣藻的生长就受到了限制。此外我们还发现水华的消退与水体中细菌、浮萍、浮游动物等生物因素的作用有关。     

水花微囊藻多糖复合物的提取

研究了热水和碱提取法在不同溶剂体积、不同时间和不同温度条件下,对水花微囊藻多糖提取率的影响．结果表明：藻干重与水体积之比为 １∶１５、１００ ℃、提取６ ｈ 的条件下多糖提取率最高,为３４５．５ ｍ ｇ／ｇ 干藻,为最佳提取条件．在 ３０ ℃、６０ ℃、１００ ℃下以碱抽提,以 ４％ Ｎａ Ｏ Ｈ 浓度下多糖得率最高,分别为９９．５、２７３．２ ｍ ｇ／ｇ 干藻;热水提取效果好于碱提取．用冷水预浸泡结合等电点沉淀的方法脱蛋白对粗提取物进行纯化,结果使提取液中水溶蛋白除去率达 ６３．０％ ．用最佳提取条件获得的多糖溶液,经氯仿脱蛋白,乙醇沉淀得多糖１４．５％ ．