防控支流库湾水华的三峡水库潮汐式生态调度可行性研究

三峡水库支流水华问题已成为影响库区生态和民生的重要问题,迫切需要采取有效防控措施。因三峡水库上游流域面积大,流域污染防治工作只能作为长期目标,生态调度可能是目前见效较快,最易接受的水华防控方法。通过总结防控支流库湾水华的生态调度研究进展,重点阐明了潮汐式生态调度对支流库湾水华的防控机理及效果。研究表明,水体分层是支流库湾水华发生的主要诱因;在支流库湾分层异重流背景下,潮汐式生态调度能够通过打破支流库湾水体分层,减小支流库湾水体滞留时间等方式抑制藻类水华;三峡水库调度试验表明,潮汐式生态调度不仅可有效缓解支流水华暴发强度,还能在常规调度的基础上增大三峡水库的综合效益,具有可行性,可作为三峡水库调度的定性指导方法。     

港口湾水库对水阳江上下游泥沙输移的影响

以水阳江干流宣城水文站、支流胡乐司水文站1974~2010年逐日输沙量和含沙量资料为基础,分析了港口湾水库建立前后对水阳江上下游泥沙输移影响的变化过程,采用M-K趋势法检验了建库前后的输沙量和含沙量,选取年内分配变差系数、年内分配不均匀系数、完全调节系数、集中度、FI指数5个指标分析了输沙量年内分配规律及不同时段的含沙量与输沙量。结果表明,港口湾水库对水阳江上下游泥沙输移影响显著,两站输沙量和含沙量减幅大,变化趋势明显,不同时间尺度下建库前后的泥沙输移均发生了不同程度的改变。总体上看,年内分配变化更大、集中度更小。     

水动力调控三峡库区支流水华方案初步研究

针对三峡水库蓄水运用后支流库湾春季水华频现问题,利用MIKE 21模型建立了香溪河—三峡库区整体平面二维水动力数学模型,对春季不同水文条件下香溪河口回水区的流速进行了数值模拟。计算结果表明,三峡水库单独调控时,小于香溪河库湾水华的临界流速0.05 m/s,而支流水库单独调控时,在丰水年香溪河口流速可大于0.05 m/s,仅利用三峡水库小幅度水位变动(0.6~1.0 m/d)对支流库湾流速的改善效果十分有限,而利用干支流水库对香溪河库湾流速的联合调控效果明显,可适度控制三峡库区支流库湾水华的爆发。     

夏季香溪河库湾溶解氧与叶绿素a日间垂向分布特征及影响因子初探

为了解三峡水库水华爆发时空特征，于2020年6月在三峡库区香溪河库湾未发生水华的条件下通过日间高频次连续加密监测，分析溶解氧、叶绿素a等指标的时空变化，甄别藻类生长特性。结果表明，温跃层和表中层倒灌异重流的存在阻碍了垂向水动力交换，进而促使水体表底均存在氧跃层；夏季连续的晴天可能会导致07:00～11:00、14:00～17:00爆发水华的几率增加；水华爆发存在滞后性，仅通过单层水体藻密度无法表征藻类生长状况，需通过藻类垂向迁移范围内的平均藻密度作进一步水华预警判断。     

三峡水库香溪河库湾水质预测

选取有代表意义的库区支流香溪河为研究对象,重点研究三峡建库后库湾的水质情况。以兴山水文站的实测资料为依据建立香溪河的一维流场模型,模拟其现时状态的流场,再用各断面水质的实测数据拟合模拟其水质场。在此基础上预测三峡水库蓄水达到１７５ｍ的设计水位时,香溪河库湾的水流运动和水质变化,为库湾水环境保护与管理提供依据。     

百家湖浮游植物种群结构及其富营养化状况

为揭示百家湖水环境问题,2015年对湖泊进行采样调查,选取3个生物多样性指数,采用冗余度分析(RDA)和指示物种法等方法,揭示了百家湖藻类种群构成特征、多样性及其水体富营养化状况。结果表明,百家湖检出浮游植物6门23种,优势种为隐藻、蓝隐藻、平裂藻和衣藻,优势度分别为0.32、0.09、0.03、0.03,且优势种夏、秋季略有不同,夏季以隐藻、弓形藻、二角盘星藻的丰度最高,秋季优势种为隐藻、蓝隐藻和平裂藻;生物多样性指数分析结果表明,百家湖浮游植物种群组成结构较为简单,主要由高丰度的单一耐污种组成,生物多样性不高;RDA分析结果表明TN和COD_(Mn)是影响百家湖种群结构的最主要因子,NO_3~-、Chl.a和SD等对优势种属时空分布也有一定影响;另外,水质评价结果表明百家湖水体为中度富营养化、夏季面临隐藻水华爆发的危险。     

西南山区不同雨强下的坡面泥沙输移变化试验研究

为研究西南山区暴雨作用下坡面泥沙输移变化过程,进行了不同雨强下的坡面冲刷试验,判定了坡面泥沙输移激增时间节点,研究了雨强对坡面泥沙输移变化的影响.结果 表明,坡面细沟开始合并的时间点可作为坡面泥沙输移激增判定条件;雨强与泥沙激增时间点、泥沙垮塌时间点及泥沙进入水槽时间点均表现为负相关关系,与坡面平均输沙率表现为正相关关...     

水力输灰系统的结垢研究

针对电厂灰中氧化钙含量丰富的神府东胜煤进行了水力输灰系统的结垢系统，探讨了水力输灰系统的结垢机理、灰静态溶出特性并开展了结垢的动态模拟试验研究。在结垢的动态模拟试验研究中，我们分别分析了如下影响因素：灰成份，管道材质，灰水流速，输灰水回收率，灰水在灰库的停留时间，灰水在输灰管中的运行时间以及沿程情况对结垢的影响。研究结果对水力输灰系统的设计与应用具有一定参考价值。     

明槽支流交汇区水动力特性PIV试验研究

针对低流量比条件下明槽干支流交汇支流汇入区水流结构十分复杂的问题，基于物理模型试验的方法，采用PIV粒子图像测速技术观测不同交汇条件下明槽支流时均流速及三维流速空间分布，分析支流流场的变化特征。结果表明，汇流比较小时，由于干流水体的顶托作用，支流表层水体会出现不同程度上的回流现象，底层水体顺流汇入干流，且有较为明显的斜向混合界面；随着汇流比的增大，干流对支流左岸水流结构影响逐渐减小。在交汇角为30°、90°时，靠近支流右岸的水流结构受干流水体顶托作用影响最大；在交汇角为150°时，支流基本处于回流状态，交汇口处形成最大回流流速区。研究结果可为库区支流营养盐富集导致水华频发等研究提供理论支撑。     

风对南水北调东线工程东平湖输水流场影响的模拟

在东平湖正常设计调水条件下,借助于SMS地表水软件,根据东平湖地形、植被覆盖和调水流向等特征对东平湖进行网格划分,建立了二维水流模型,研究了不同风速、风向对东平湖输水流场的影响。结果表明,当湖区风速为3m/s(一般天气)时,风速、风向基本不会对东平湖输水流场产生影响;当湖区风速达10 m/s(极端天气)时,风速、风向对东平湖输水流场的影响很小,引起的湖水位变幅在5%以下。可见在正常设计调水条件下,风生流对东平湖湖区流场的影响可以忽略,在模拟研究湖区水质(溶质类污染物)时可以不考虑风的影响。     

基于传递闭包的湖泊水华暴发影响要素的结构分析方法

为将湖泊水华暴发各要素间的复杂关系解析成系统的多级递阶的结构形式,系统分析了水华暴发原因,采用传递闭包方法导出湖泊水华暴发要素整体关联的层次结构图,直观简便地反映了水华暴发过程,提供了一个比系统解释结构模型（ISM）更简便明晰的系统结构分析方法,为水华预防及治理提供了理论依据。     

Development of High-Speed and Large-Scale Culture Technology of Marine Algae Using Seawater With High Concentrations of Dissolved Carbon Dioxide

The effective use of marine biomass has recently been identified as a feasible method of renewable energy production. Therefore, to facilitate the effective use of algae biomass, it is essential to develop techniques for the mass production of algal cultures. It is also important to develop artificial culture techniques that are not affected by natural phenomena such as weather. This study utilized a newly developed culture technology that uses seawater with high concentrations of dissolved CO₂ (CO₂ seawater). The experiments in this study were conducted to test the effects of CO₂ seawater on algal growth. In addition to experimental conditions that were previously investigated in industrial algae farming scenarios, it is also necessary to consider the effects of new parameters associated with increased CO₂ concentrations. The following four conditions were experimentally investigated: (1) the tolerance of algae to changes in pH, (2) the effect of CO₂ seawater on long-term culture growth, (3) the effect of continuous culture experiments, and (4) the effect of water flow rate on cultured algae. The results in terms of having excelled especially indicate that a 1-month long-term algae culture period in seawater with CO₂ concentration of 1.0% led to growth that was approximately 4.5 times faster than growth in seawater without the CO₂ additive. Furthermore, the results also provided useful information regarding the proper flow rate needed to enhance algal growth.     

Cogeneration of hydrogen and methane from the pretreated biomass of algae bloom in Taihu Lake

In order to efficiently utilize the biomass waste of algae bloom in Taihu Lake, China and improve energy conversion efficiency, a three-stage process comprising dark hydrogen fermentation with acid-domesticated hydrogenogens, photohydrogen fermentation, and methanogenesis was undertaken. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analyses showed that algal cells pretreated by microwave heating with diluted acid were degraded into smaller fragments (<5 μm) than those pretreated by steam heating with diluted acid. The microwave pretreatment of algae resulted in higher saccharification efficiency. The domesticated hydrogenogens in presence of acids improved the dark hydrogen production from microwave-pretreated algae biomass and led to a total combined dark and photofermentation hydrogen yield of 283.4 mL/g-total volatile solid (TVS). The energy conversion efficiency of steam-pretreated algae biomass remarkably increased to 47.0% by cogenerating 256.7 mL/g-TVS hydrogen and 253.5 mL/g-TVS methane in the three-stage process: dark-fermentation, photofermentation, and methanogenesis.     

新型水质藻类传感器及遥测预警系统研究

为满足我国主要湖泊及河流藻类污染实时监测预警需求,研发了一套新型水质藻类遥测预警系统,采用基于暗激光束的单个粒子监测方法（IPSA）对藻类进行监测,借助新型水质藻类遥测预警系统的传感器、遥测设备、应用软件、系统集成等核心技术对藻类信息进行分析。试验结果表明,该系统实时性强、精度高,为预防水华现象的发生提供了及时的预报和监控。     

地表水中藻毒素的监测与控制研究

随着大量含氮和磷的废水流入湖泊和江河，导致淡水污染现象日趋严重。污染的最主要危害是释放多种藻毒素，因此如何有效控制、去除藻毒素是摆在中外环境科学领域的一个难题。目前水体中藻毒素的监测方法主要是生物法、化学法、免疫法等；控制的方法主要是常规净水工艺、生物处理、光降解与光催化氧化以及臭氧氧化等。     

Sustainable biohythane production from algal bloom biomass through two-stage fermentation: Impacts of the physicochemical characteristics and fermentation performance

Algal bloom biomass, sourced from a freshwater lake in Chongqing, was pre-treated by hydrothermal pre-treatments with or without acid/alkali catalysts, and subsequently used as a substrate for sustainable biohythane production via fermentation. Fourier transform infrared (FTIR) spectroscopy analyses suggested hydrothermal acid/alkali pre-treatments significantly changed peak intensities of chemical compositions in algal bloom biomass. Derivative thermogravimetric (DTG) analyses showed more macromolecular substances hydrolysed after hydrothermal acid/alkali pre-treatments. When bloom algae were pre-treated with 1% HCl at 140 °C for 10 min, an optimal specific hydrogen yield (SHY) of 39.4 mL/g volatile solid (VS) was obtained, which is 38.2% higher than raw biomass. However, a 34.4% decrease in SHY occurred under hydrothermal pre-treatment with 1% NaOH due to the enhancement of Maillard reaction. When using the effluents in methane fermentation, specific methane yields (SMYs) were 177.1–276.8 mL/g VS. Two-stage process effectively reduced the total fermentation time by 22.7% compared with single-stage fermentation.     

Improving fermentative hydrogen and methane production from an algal bloom through hydrothermal/steam acid pretreatment

Algal blooms can be harvested as renewable biomass waste for gaseous biofuel production. However, the rigid cell structure of raw algae may hinder efficient microbial conversion for production of biohydrogen and biomethane. To improve the energy conversion efficiency, biomass from an algal bloom in Dianchi Lake was subjected to a hydrothermal/steam acid pretreatment prior to sequential dark hydrogen fermentation and anaerobic digestion. Results from X-ray diffraction and Fourier transform infrared spectroscopy suggest that hydrothermal acid pretreatment leads to stronger damage of the amorphous structure (including hemicellulose and amorphous cellulose) due to the acid pretreatment, as evidenced by the higher crystallinity index. Scanning electron microscopy analysis showed that smaller fragments (∼5 mm) and wider cell gaps (∼1 μm) on algal cell surfaces occurred after pretreatment. In comparison to steam acid pretreatment, hydrothermal acid pretreatment resulted in a maximum energy conversion efficiency of 44.1% as well as production of 24.96 mL H₂/g total volatile solids (TVS) and 299.88 mL CH₄/g TVS.     

潘家口水库浮游植物分布特征及其富营养化防治

基于潘家口水库水环境状况,描述了2009~2011年潘家口水库优势藻种及其密度演变过程,概括了藻类对水温、营养盐等水环境因子的响应机制;并由2010年10月~2011年8月多断面水质监测数据,分析了潘家口水库优势藻种与水环境因素的适应性。结果表明,各断面优势藻种有向单一种群演化的趋势,水体富营养状况逐渐恶化;识别出潘家口水库富营养化控制的关键区域和重点防范对象,并结合潘家口水库的运行条件提出富营养化防治的建议。     

Algae as a promising resource for biofuel industry: facts and challenges

Energy is the main driving force of society today that should be handled as a whole starting from production to consumption. With the rapid increase in the energy necessity, alternative methods and sources are becoming a crucial topic that should be scientifically highlighted with all their pros and cons. Especially the problems related to the fossil sources of energy triggered the search on the renewable alternatives like algae. In order to reach the desired amounts of energy with the satisfactory quality and quantity, understanding the algae as a living thing with the biological mechanism and existing production technologies are the key points to have a projection for commercialization. In this regard, technical facts and challenges on algal biofuel production should be evaluated. Keeping in mind the specifications and possible advantages related to their taxonomy, algae can serve as a promising source to reduce fossil fuel consumption. With the progress in the modern technology, reaching an effective production process will be possible, and this will help the algal biofuels to prove their maturity as a sustainable source for future. Within this context, the aim of this review is to point out the crucial technical challenges about algal fuels comprising both the macroalgae and microalgae as a reliable source of renewable energy. Copyright © 2016 John Wiley & Sons, Ltd.     

Monitoring and maintaining the water clarity of salinity gradient solar ponds

A common problem encountered in salinity-gradient solar ponds is the growth of various types of algae and bacterial populations, which affects the brine clarity and hence reduces thermal performance. Algae and bacterial populations are enhanced by the presence of organic nutrient such as nitrogen and phosphorus. A comprehensive study was undertaken on three salinity-gradient solar ponds in Australia: a 3000 m² sodium chloride solar pond at Pyramid Hill in Northern Victoria; a 50 m² sodium chloride; and 15 m² magnesium chloride solar pond at RMIT University in Bundoora, Victoria. The experimental study involved monitoring the clarity of these three ponds and testing chemical and biological treatment methods to see their effect on the brine transparency. The sources of turbidity and their impacts on clarity and efficiency of salinity-gradient solar ponds are presented in detail in this paper. The initial observation showed that the amount of sunlight is reduced due to the heavy algal growth creating instability in the solar pond as it absorbs light. Two treatment methods were applied to these solar ponds and experiments were conducted to study the turbidity reduction in the solar ponds. In the RMIT magnesium chloride solar pond, diluted hydrochloric acid was injected in the pond to reduce the pH and turbidity levels. Algal blooms were observed and found in the pond where the pH was between 5.5 and 8. It was observed from the experimental study that pH values should be kept below 4.5 to maintain low turbidity and prevent algae growth. The introduction of brine shrimps was also found to be very effective and economical to control algae, provided the oxygen has not depleted due to advanced heavy algal growth. The investigation concluded that hydrochloric acid could be used initially as a shock treatment to kill all the algae and then brine shrimps could be introduced to control the growth of algal and maintain transparency. This analysis showed that by using a combination of chemical and biological treatment methods, the pond clarity can be maintained and the thermal efficiency of the solar pond can be improved.