Performance Evaluation of Two Series Vertical Flow Filters for Wastewater Treatment: A Case Study of the Prototype Installed at Gaston Berger University, Saint-Louis, Senegal

This paper evaluates the efficacy of two sequential vertical flow filters (VFF), FV1 and FV2, implanted with Typha, in a pilot-scale wastewater treatment system. FV1 comprises three cells (FV1a, FV1b, and FV1c), while FV2 consists of two cells (FV2a and FV2b), each designed to reduce various physicochemical and microbiological pollutants from wastewater. Quantitative analyses show significant reductions in electrical conductivity (from 1331 to 1061 μS/cm), biochemical oxygen demand (BOD5 from 655.6 to 2.3 mg/L), chemical oxygen demand (COD from 1240 to 82.2 mg/L), total nitrogen (from 188 to 37.3 mg/L), and phosphates (from 70.9 to 14.6 mg/L). Notably, FV2 outperforms FV1, particularly in decreasing dissolved salts and BOD5 to remarkably low levels. Microbiological assessments reveal a substantial reduction in fecal coliforms, from an initial concentration of 7.5 log CFU/100mL to 3.7 log CFU/100mL, and a complete elimination of helminth eggs, achieving a 100% reduction rate in FV2. The study highlights the impact of design parameters, such as filter material, media depth, and plant species selection, on treatment outcomes. The findings suggest that the judicious choice of these components is critical for optimizing pollutant removal. For instance, different filtration materials show varying efficacies, with silex plus river gravel in FV1c achieving superior pollutant reduction rates. In conclusion, VFFs emerge as a promising solution for wastewater treatment, underscoring the importance of design optimization to enhance system efficiency. Continuous monitoring and adaptation of treatment practices are imperative to ensure water quality, allowing for safe environmental discharge or water reuse. The research advocates for ongoing improvements in wastewater treatment technologies, considering the environmental challenges of the current era. The study concludes with a call for further research to maximize the effectiveness of VFFs in water management.

3D Visual Plant Models in Computational Fluid Dynamics Simulation of Ambient Wind Flow around an Isolated Tree

Plants can reduce the velocity of wind and wind erosion and prevent the movement of sand.But it may be extremely difficult to measure directly the aerodynamic characteristics of the airflow near the real vegetation in field experiments on account of restriction by many objective factors.Therefore,numerous investigations have been carried out to study the efficiency of windbreaks by conducting wind tunnel experiments on simulated models or using computational fluid dynamics(CFD) simulation instead of field measurements.Plant models are simplified at some level to be used for numerical simulation in existing literatures.It is a little distortion of leaves in details if the tree canopy is regarded as a whole region which can have a certain influence on the CFD simulation.Hence,one modeling approach that combines Visual Basic for applications(VBA) and computer aided design(CAD) technology is proposed to design 3D virtual plant models.The tree models used for numerical simulation of wind flow around trees are more lifelike.In addition,this method can be applied for creating a 3D virtual vegetation library.It is also more convenient to get the diversified biological indicators by digital plants in computer.

Investigation on Flow Accelerated Corrosion Mitigation for Secondary Circuit Piping of the Third Qinshan Nuclear Power Plant

Flow accelerated corrosion（FAC） is the main failure cause of the secondary circuit carbon steel piping in nuclear power plants.The piping failures caused by FAC have resulted in numerous unplanned outages and tragic fatalities.The existing researches focus on the main factors contributing to FAC,which include metallurgical factors,environmental factors and hydrodynamic factors. Some effective FAC management methods and programs with long term monitoring and inspection data analysis are recommended.But a comprehensive FAC management system should be developed in order to mitigate and manage FAC systematically.In this paper,the FAC influencing factors are analyzed in combination with the operating conditions of the secondary circuit piping in the Third Qinshan Nuclear Power Plant（TQNPP）,China（Third Qinshan Nuclear Power Company Limited,China）.A comprehensive FAC mitigation and management system is developed for TQNPP secondary circuit piping.The system is composed of five processes,viz.materials substitution,water chemical optimization,long-term monitor strategy for the susceptible piping,integrity evaluation of the local thinning defects,and repair or replacement.With the implementation of the five processes,the material of FAC sensitive pipe fittings are modified from carbon steel to stainless steel,N_2H_4 and NH_3 are finally selected as the water chemical regulator of secondary circuit,the secondary circuit pips are classified according to FAC susceptibility in order to conduct long term monitoring strategy,and an integrity evaluation flow for local thinning caused by FAC in carbon steel piping is developed.If the component with local thinning defects is not fit-for-service,corresponding repair or replacement should be conducted.The comprehensive FAC mitigation and management system with five interrelated processes would be a cost-effective method of increasing personnel safety,plant safety and availability.

Dynamic Characteristics Analysis on MHTGR Plant’s Secondary Side Fluid Flow Network

Multipe NSSS (Nuclear Steam Supply System) modules use the common feeding-water system to drive the common turbine power generation set. The SSFFN (secondary side fluid flow network) of MHTGR plant has features i.e. strong-coupling and nonlinearity. A wide range of power switching operation will cause unsteady flow, which may destroy the working elements and will be a threat for normal operation. To overcome those problems, a differential-algebraic model and PI controllers are designed for the SSFFN. In MATLAB\SIMULINK environment, a simulation platform is established and used to make a simulation of SSFFN of a MHTGR plant with two NSSS modules, which uses feedwater valves to control the mass flow rate in each module instead of feedwater pump. Results reflect good robustness of controllers.

Performance of a Horizontal Flow Constructed Reed Bed Filter for Municipal Wastewater Treatment: The Case Study of the Prototype Installed at Gaston Berger University, Saint-Louis, Senegal

In Saint-Louis, Senegal, a constructed wetland with horizontal flow reed beds (FHa and FHb) has demonstrated significant efficacy in treating municipal wastewater. Analyzing various treatment stages, the system showed only a slight temperature variation, from an influent average of 26.3°C to an effluent of 24.7°C. Electrical conductivity decreased from 1331 mS/cm to 974.5 mS/cm post-primary treatment, with suspended solids (SS) dramatically reduced from 718.9 mg/L to 5.7 mg/L in the final effluent. Biochemical oxygen demand (BOD5) and chemical oxygen demand (COD) saw a notable decrease, from initial levels of 655.6 mg/L and 1240 mg/L to 2.3 mg/L and 71.3 mg/L, respectively. Nitrogenous compounds (N-TN) and phosphates () also decreased significantly, indicating the system’s nutrient removal capacity. Microbiological analysis revealed a reduction in fecal coliforms from 7.5 Ulog/100ml to 1.8 Ulog/100ml and a complete elimination of helminth eggs. The presence of Phragmites and Typha was instrumental in enhancing these reductions. The system’s compliance with the Senegalese standards for disposal into natural environments, WHO recommendations for unrestricted water reuse in irrigation, and the European legislation for water reuse was established. The effluent quality met the stringent criteria for various classes of agricultural reuse, illustrating the system’s potential for sustainable water management. This wetland model presents a robust solution for water-stressed regions, ensuring environmental protection while supporting agricultural needs. The study calls for ongoing research to further refine the system for optimal, reliable wastewater treatment and water resource sustainability.

不同生态流量需求下雅砻江中下游梯级电站联合优化调度

为协同雅砻江干流水力发电与河道生态流量需求,以中下游7座电站为研究对象,进行不同生态流量需求下雅砻江中下游梯级电站联合优化调度。基于改进型可变月径流法,计算了雅砻江主要生态控制断面最小、适宜及最佳生态流量过程;构建了以梯级发电量最大化为目标的雅砻江中下游梯级电站联合优化调度模型,并用遗传算法对其求解。结果表明:(1)随河道生态流量需求的提高,梯级电站发电效益和水资源利用效率均下降,其中锦屏二级电站发电量下降最为显著;(2)梯级电站保障发电效益正常发挥的同时,实施联合优化调度,其下游河道能维持更高层次的生态流量,一定程度缓解了流域水能开发利用与河道生态保护间的关系。

Em-plant在生产线作业仿真中的应用研究

Tecnomatix的 Em-plant软件能够模拟生产和运输系统 ,是对物流系统规划进行仿真的理想选择 ,文中分析了 Em-plant在一个流水线作业中装配的仿真过程及方法 ,阐明了 Em-plant在离散系统仿真中的优势 .以一个制作电脑桌的流程为例 ,说明 Em-plant在流水线仿真中的优越性 .

植物激素调控橡胶树产排胶机制研究进展

巴西橡胶树(Hevea brasiliensis)是重要热带经济作物之一,其次生代谢产物天然橡胶(NR)是中国重要的工业原料及战略物资。植物激素对植物生长发育、萌发和环境应答等多方面均具有重要调控作用。本文详细介绍了乙烯、脱落酸、油菜素内酯和赤霉素4种植物激素在橡胶树生长发育、橡胶生物合成、产排胶和品质形成等关键环节中应用的研究进展,并展望4种激素在提高橡胶树产排胶机制研究中的应用前景,为支撑橡胶产业发展提供理论支撑。

面向分布式能源能量交互画像的虚拟电厂信息流量预测方法

虚拟电厂的信息流能够表示分布式资源与电力系统交互的活跃程度,信息流的精准预测对了解虚拟电厂的运行特性进而提高系统的控制效率至关重要。然而,虚拟电厂涉及的交互主体较多,其能量特性既受资源个体随机性的影响,又与海量资源聚合后的整体特性息息相关。因此传统的预测模型难以有效拟合虚拟电厂的信息流,亟需提出一种面向虚拟电厂信息流预测的模型。文章提出一种基于长短期记忆网络和变分模态分解的短期混合预测模型。首先采用变分模式分解基于变分原理提取流量序列的本征模态分量;然后,利用长短期记忆网络分别对每个模态分量序列进行建模和预测,并创新性地引入注意力机制来筛选本征模态分量中的重要特征序列;最后,所有子预测算法被整合为一个完整的预测模型。仿真结果表明,相比传统方法,该模型可以有效地提高虚拟电厂信息流量预测的准确性。

混合式抽水蓄能电站对下泄水温影响的数值模拟研究

【目的】混合式抽水蓄能电站运行特性与常规电站相比存在差异,本文旨在掌握抽水蓄能电站水温的变化规律,为水库管理调度提供参考。【方法】以紧水滩水库为研究对象,采用MIKE3水温模型模拟不同进/出水口高程以及不同抽水流量工况的下泄水温,据此探讨混合式抽水蓄能电站对下泄水温的影响。【结果】抽蓄水流会对下泄水温产生影响,相对于现状无抽水工况的下泄水温,抽蓄工况下的下泄水温基本表现为5—9月略有下降,其余月份略有升高,下泄水温的最大降幅不超过0.7℃,最大升幅不超过0.8℃。【结论】进/出水口高程对于下泄水温影响较大,且高程越低,下泄水温差异越大。然而抽水流量对于下泄水温差异影响并不显著,但整体上也呈现出随着抽水流量增加,水温差异增大的趋势。

MBR膜生物反应器在城镇污水处理厂中的应用

近年来,我国城镇化进程的步伐越来越快,城镇人口的规模也越来越大,城市污水处理成为环境保护和可持续发展的重要议题。传统的污水处理工艺在处理效率和出水水质要求方面已经面临一定的挑战,MBR膜生物反应器是一种相对新型的污水处理技术及装备,它结合了微生物降解技术和膜分离技术,近年来在城镇污水处理领域引起了广泛的关注。本文以某城镇地区X污水处理厂为例,分析MBR膜生物反应器系统的布置以及实施应用,结果表明,X污水处理厂在应用了MBR膜生物反应器后的污水处理效果有显著的提升。

选矿厂安全事故分析及预防对策

选矿是富集有用矿物的一种系统工程,工艺流程复杂,常常采用大型机械设备,生产过程中安全事故频发。为了降低选矿厂的安全事故,对全国5家典型选矿厂2017—2022年事故进行统计分析。选矿厂生产过程中的不安全因素主要有物体打击、机械伤害、粉尘、噪声、放射性危害、灼伤、中毒、高处坠落、淹溺等。除上述可能的危险性因素外,同时还存在起重伤害、触电和窒息等危险有害因素。表明选矿厂安全事故重心已经从工艺安全事故转移到机械设备事故方向,而机械事故因素主要仍是由人因造成。因此,运用4M要素和5S管理对不安全的因素提出了预防的对策,以期降低安全事故的发生。

水生植物对水体流速的影响规律

为探究水生植物对水体流速的影响规律,设计波—流—水生植物试验方案,其试验装置系统包含P-FIS水生植物-水槽集成系统、HCS水动力控制系统和HMS水动力监测系统;试验条件设计涵盖3类水生植物、6套植株密度及8种水动力工况。研究结果表明,在不规则波作用下,柔性挺水植物和柔性沉水植物的消浪和阻流效果优于刚性挺水植物。波条件下,植株矮的柔性沉水植物过流能力较强;流条件下,植株高的挺水类植物过流能力较强。在测点位置z/H=(0.28±0.04)范围,流速波动达到峰值。柔性挺水植物和柔性沉水植物,在水面以下有繁茂的枝叶结构,其种植密度会显著影响水体流速。研究结果可为水域种植适宜、适量的水生植物提供依据,以期保持水体流动性,同时削减对底泥的冲刷作用,改善水质。

乌东德水电站日调峰对下游裂腹鱼类栖息地的影响

日调峰是乌东德水电站日常运行的主要出力约束和调度目标。为了探讨电站调度引起的出库流量大幅涨落对下游生态环境的不利影响,采用河道内流量增量法,通过构建二维水动力模型,研究了乌东德水电站日调峰引起的下游河段水文水动力条件波动对裂腹鱼类繁殖期栖息地适宜性的影响,并分析了2023年电站基荷发电生态调度试验效果。结果表明,乌东德电站下泄流量低于1160 m^(3)/s,坝下江段裂腹鱼类潜在产卵场面积相对较大;流量高于2000 m^(3)/s,裂腹鱼类潜在的产卵场面积显著减少。电站日调峰结束时,出库流量降幅越大,裂腹鱼类潜在产卵场脱水面积及鱼卵脱水风险越大。乌东德电站基荷发电生态调度期间,坝下江段裂腹鱼类潜在产卵场的加权面积有所减少,但潜在产卵场和鱼卵早期的脱水风险显著降低。为提高繁殖期裂腹鱼类生境适宜性和持续性,有必要进一步减少电站日调峰频率,降低出库流量至适宜区间。

覆膜种植措施对垄作农地土壤优先流空间异质性的影响

为进一步针对垄作田间农业生产制定高效的需水用肥策略提供科学支撑,将野外染色示踪试验和室内土柱水分入渗实验相结合,利用图像形态学解析、模拟入渗分析、熵权分析和灰色系统理论分析等方法,对垄作覆膜和垄作(对照)种植措施下的农地土壤优先流空间异质性特征进行分析,阐明覆膜种植措施下的垄作农地土壤优先流空间分布及其运动变化规律,揭示覆膜种植措施影响下的优先流与垄作田间土壤水分运动过程的作用关系。结果表明:在相同外部供水条件下,垄作覆膜种植农地的水分集中分布在0~10 cm土壤表层,随着土壤深度的增加分布范围逐渐缩小,其土壤染色复杂程度随着土壤深度的增加先增大后减少。而垄作种植农地在10~30 cm土壤深度范围内的水分分布出现显著的指状优先流分化现象。同时,垄作覆膜农地土壤达到饱和状态的时间是垄作农地的1.36倍,其单位时间内的平均土柱水流出流量(质量流率为0.20 g/s)显著(P<0.05)小于垄作农地(质量流率为0.35 g/s),土壤优先流程度相较更高,土壤属性中饱和导水率对优先流程度影响最大。垄作覆膜种植措施相较垄作在一定程度上能够进一步降低农地土壤空间内优先流的发生及其分布,减少水分向土壤深层渗漏,起到一定程度的蓄水保墒作用。

融合注意力机制与SAC算法的虚拟电厂多能流低碳调度

虚拟电厂(virtual power plant,VPP)作为多能流互联的综合能源网络,已成为中国加速实现双碳目标的重要角色。但VPP内部资源协同低碳调度面临多能流的耦合程度紧密、传统碳交易模型参数主观性强、含高维动态参数的优化目标在线求解困难等问题。针对这些问题,文中提出一种融合注意力机制(attention mechanism,AM)与柔性动作评价(soft actor-critic,SAC)算法的VPP多能流低碳调度方法。首先,根据VPP的随机碳流特性,面向动态参数建立基于贝叶斯优化的改进阶梯型碳交易机制。接着,以经济效益和碳排放量为目标函数构建含氢VPP多能流解耦模型。然后,考虑到该模型具有高维非线性与权重参数实时更新的特征,利用融合AM的改进SAC深度强化学习算法在连续动作空间对模型进行求解。最后,对多能流调度结果进行仿真分析和对比实验,验证了文中方法的可行性及其相较于原SAC算法较高的决策准确性。

3种水生植物潜流人工湿地模拟处理池塘养殖尾水的研究

为了解潜流人工湿地对养殖尾水的处理效果,比较蕹菜、凤眼莲、喜旱莲子草三种水生植物潜流人工湿地对草鱼养殖池塘尾水的净化效果,并探讨潜流人工湿地在不同水力负荷、排停水和排水转换对池塘养殖尾水的处理效果,以及潜流人工湿地微生物群落多样性和组成。结果显示:蕹菜、凤眼莲和喜旱莲子草分别对总磷(TP)、氨氮(NH_(4)^(+)-N)和化学需氧量(COD_(Mn))去除率最高,为24.7%、25.1%和25%。停水时,蕹菜、凤眼莲和喜旱莲子草均对NH_(4)^(+)-N去除率最低,分别为-526.07%、-871.08%和-1196.46%。水力负荷为低(5.76 m^(3)/d)时,蕹菜、凤眼莲和喜旱莲子草分别对COD_(Mn)、NH_(4)^(+)-N和TP去除率最高,为30.4%、42.5%和22.1%。蕹菜Shannon、Ace和Chao 1均最高,喜旱莲子草Simpson最高。3组样本共分析出5131个OTU,注释为45个门,293个目和974个属;蕹菜停水前、中和后共分析出5021个OTU,注释为47个门,294个目和953个属。研究表明,水生植物潜流人工湿地对养殖尾水具有一定的净化效果,运行期间停水会降低净化效果,水力负荷低的净化效果大于中和高,微生物群落多样性和组成的差别影响了人工潜流湿地对养殖池塘尾水的净化效果。

流式细胞术检测药用植物基因组大小的研究策略

流式细胞术是一种可以对悬浮于液体中微小颗粒进行分选和计数的方法。该方法的步骤包括制备完整的细胞核悬浮液、对核酸荧光染色、根据相关荧光含量分类。分析荧光标记悬液中的单细胞或其他微小颗粒信号,可以实现蛋白质含量、细胞DNA含量、酶活性、细胞膜受体和表面抗原、细胞体积等参数的快速测定。该技术可以用于植物倍性分析和基因组大小估测等研究。目前利用流式细胞术对药用植物进行基因组大小评估的研究较少,未来有待深入研究,以期为利用流式细胞术检测基因组大小提供相关资料。

单向流水域蘑菇头式排水口热扩散特性三维数值模拟

由于蘑菇头排水口近区温排水受排水射流、环境流和密度流多因素协同驱动,输移扩散规律较复杂,理清蘑菇头式排水口近区水力及热力特性对指导工程设计具有重要意义。采用三维数值模拟方法,研究单向流环境水域蘑菇头式排水口(四面开窗)近区三维水力和热力特性,结果表明:随着单向流流速的增大,各窗口排出的温排水向单向流下游方向的偏移程度逐渐增大;逆单向流方向窗口排出的水流受单向流顶冲影响显著,流量随着单向流流速的增大而减小,减小的流量主要通过垂直于单向流方向的两个窗口排出,顺单向流方向窗口的流量对单向流的响应并不敏感;随着单向流流速的增大,顺单向流方向窗口射流逐渐由向水面的“上喷射”流态转变为向海床的“下扫掠”流态;各窗口温排水的温升分布随着流速比增大,先汇合后逐渐呈“元宝”形;单向流流速增加能有效减小1.0℃温升水体积。

基于电碳点对点交易的虚拟电厂联盟与配电网协同低碳运行策略研究

虚拟电厂(virtual power plant,VPP)可以通过先进的控制技术对海量分散的分布式能源进行有效聚合,为实现低碳发展提供了有效途径。为促进VPP在碳减排方面的积极作用,提出了一种VPP联盟和配电网多主体协同优化框架。首先,基于碳排放流理论制定了电-碳综合定价方法,激励VPP低碳运行。其次,考虑多个VPP之间采用合作联盟的形式进行共享交易,构建一种基于纳什议价理论的多VPP电碳点对点(peer-to-peer,P2P)交易机制模型,实现资源共享的同时兼顾个体利益和联盟效益。在此基础上,建立一种基于电-碳综合价格引导VPP间电碳P2P交易的VPP联盟-配电网协同优化双层模型。上层模型是多VPP之间电碳P2P最优交易问题,采用自适应步长交替方向乘子法实现多VPP间的分布式求解。下层模型则是配电网的最优经济调度问题。最后,通过算例验证了所提模型和方法的有效性。