双功能陶瓷膜生物反应器处理废水的研究

研制了一种具有抽滤和曝气双重功能的陶瓷膜生物反应器并用于处理废水.比较了废水经陶瓷膜抽滤后的出水浊度和自然沉降后的浊度,经过陶瓷膜过滤后的出水浊度达到自然沉降4～24h的效果.在处理废水的过程中,进行曝气/抽滤的切换,可有效地解决膜的堵塞问题.分别进行了间歇和连续的方法处理废水的试验,其COD负荷分别达到1.1kg/(m³·d)和1.5kg/(m³·d).     

旋转直线切向流聚丙烯管式膜器环隙切剖面流场测试

实验研究了旋转直线切向流管式膜器环隙切剖面的流场特征.通过建立膜滤实验装置系统,首次采用PIV激光粒子成像测速系统定量实测了旋转直线切向流管式膜器在不同工况,即不同流体压力、不同入口流量或不同人口切向流速等操作参数下环隙切剖面的流线图和涡量图,并在环隙切剖面内测出了流体切向速度和轴向速度及其分布规律:①在非涡区域,无论操作参数如何变化,在横坐标相同时,靠近旋转切向流人口方向的速度比远离人口方向的速度要大;涡内区域流体的速度一般小于涡外部的流体速度;涡心处速度最低,而且切向速度一般为0;涡心附近的切向速度小     

动态膜-生物反应器对城市污水的处理

应用动态膜原理,以0.1mm孔径的普通筛网代替固定膜材料构成一体式动态膜-生物反应器(DMBR)处理实际城市污水.HRT＝3.5h时,出水水质良好.DMBR在小于数cm的液位差下自流出水,出水中的SS最高检测值为4.05mg/L,但在多数情况下为0.在MLSS约7000～8000mg/L下,当动态膜通量为14.9L/(m²·h)时,出水水头仅为5.8mm;27d连续运行,出水水头没有明显改变.动态膜对反应器上清液中的COD和TOC的平均去除率分别为28.74%和36.9%.当溶解氧浓度大于2～3mg/L时,氨氮去除率大于96%.     

Aggravation of membrane fouling and methane leakage by a three-phase separator in an external anaerobic ceramic membrane bioreactor

The existence of three-phase separator did not affect COD removal in the EAnCMBR. The existence of three-phase separator aggravated methane leakage of EAnCMBR. The existence of three-phase separator aggravated membrane fouling rate of EAnCMBR. Start-up of EAnCMBR equipped three-phase separator was slightly delayed. The three-phase separator is a critical component of high-rate anaerobic bioreactors due to its significant contribution in separation of biomass, wastewater, and biogas. However, its role in an anaerobic membrane bioreactor is still not clear. In this study, the distinction between an external anaerobic ceramic membrane bioreactor (EAnCMBR) unequipped (R1) and equipped (R2) with a three-phase separator was investigated in terms of treatment performance, membrane fouling, extracellular polymers of sludge, and microbial community structure. The results indicate that the COD removal efficiencies of R1 and R2 were 98.2%±0.4% and 98.1%±0.4%, respectively, but the start-up period of R2 was slightly delayed. Moreover, the membrane fouling rate of R2 (0.4 kPa/d) was higher than that of R1 (0.2 kPa/d). Interestingly, the methane leakage from R2 (0.1 L/d) was 20 times higher than that from R1 (0.005 L/d). The results demonstrate that the three-phase separator aggravated the membrane fouling rate and methane leakage in the EAnCMBR. Therefore, this study provides a novel perspective on the effects of a three-phase separator in an EAnCMBR.     

反渗透膜污染预测模型的改进

在反渗透非平衡热力学模型的基础上,从膜表面污染层阻力和浓差极化阻力的角度对常见的膜通量模型进行了探讨与改进,推导出了新的反渗透膜污染预测模型,为准确预测膜污染进程提供了理论支持。采用卷式反渗透膜装置对氢氧化铁胶体溶液进行处理,对模型计算值与实测值进行相关性分析,相关系数大于0.95。由此认为,改进的反渗透膜污染预测模型可用于计算运行过程中的膜通量。     

超滤膜系统污染物的形貌及组成分析

通过SEM、能谱、FTIR以及电感耦合等离子体质谱的分析方法对被污染超滤膜面的无机污染物、有机污染物和微生物进行了识别和分析。研究结果表明:超滤膜面无机污染物主要为Fe(OH)3、Cu(OH)2、Al(OH)3和Si等胶体物和少量CaSO4;有机污染物主要为多菌霉素类化合物;微生物可能富含铁类化合物。同时污染膜的清洗液分析结果说明该超滤膜污染物主要为无机胶体和有机物。     

电渗析技术及其应用

电渗析技术是膜分离技术之一,具有低能耗,高效率,连续运行、环境友好等显著优点,在多个行业中有着广泛的使用。简述了几种常见的电渗析技术,包括填充床电渗析,倒极电渗析和双膜电渗析等,着重介绍了电渗析技术在水处理、食品和化工方面的应用,并简单探讨了电渗析技术其发展前景。     

Multi-criteria PSO-based optimal design of grid-connected hybrid renewable energy systems

ABSTRACT

Human-induced climate change through the over liberation of greenhouse gases, resulting in devastating consequences to the environment, is a concern of considerable global significance which has fuelled the diversification to alternative renewable energy sources. The unpredictable nature of renewable resources is an impediment to developing renewable projects. More reliable, effective, and economically feasible renewable energy systems can be established by consolidating various renewable energy sources such as wind and solar into a hybrid system using batteries or back-up units like conventional energy generators or grids. The precise design of these systems is a critical step toward their effective deployment. An optimal sizing strategy was developed based on a heuristic particle swarm optimization (PSO) technique to determine the optimum number and configuration of PV panels, wind turbines, and battery units by minimizing the total system life-cycle cost while maximizing the reliability of the hybrid renewable energy system (HRES) in matching the electricity supply and demand. In addition, by constraining the amount of conventional electricity purchased from the grid, environmental concerns were also considered in the presented method. Various systems with different reliabilities and potential of reducing consumer’s CO₂ emissions were designed and the behavior of the proposed method was comprehensively investigated. An HRES may reduce the annualized cost of energy and carbon footprint significantly.     

Refrigeration waste heat utilization for drying applications: a review

ABSTRACT

Cold chain industry has a vast potential for waste heat recovery. It is a matter of importance for energy efficiency point of view, as global energy demand is increasing day by day. Ample amount of low-grade energy is either unutilized or underutilized. The heat rejected by a Heat pump or refrigeration system emerged as a promising solution for dehydration by utilizing low-grade waste heat despite higher investment. As compared to solar drying technology, heat pump drying evolved as a reliable method regarding better process control, energy efficiency, and quality of the product to be dried. Energy utilized through the refrigeration system’s waste/exhaust heat recovery in combination with or without renewable energy source enhances the overall efficiency of the system and also reduces the cost. This useful review investigated and compared the research findings of waste heat utilization through heat pump and from condenser of refrigeration system on laboratory, pilot as well as industrial scale for drying of various fruits, vegetables, and agro products. Various drying parameters like drying rate, moisture content, Specific Moisture Extraction Rate (SMER), Coefficient of Performance (COP), Exergy efficiency, and temperature as well as humidity conditions inside the drying chamber were also reviewed to promote the technological advancement of energy utilization by commercial cold storage waste heat recovery.     

Accurate power-sharing,voltage regulation,and SOC regulation for LVDC microgrid with hybrid energy storage system using artificial neural network

ABSTRACT

In this paper, an artificial neural network-based control strategy is proposed for low voltage DC microgrid (LVDC microgrid) with a hybrid energy storage system (HESS) to improve power-sharing between battery and supercapacitor (SC) to suit the demand-generation imbalance, maintain state-of-charge (SOC) within boundaries and thereby to regulate the dc bus voltage. The conventional controller cannot track the SCs current rapidly with the high-frequency component that will place dynamic stress on the battery, further resulting in shorter battery life. The significant advantage is that in the proposed control strategy, redirections of unwaged battery currents to SCs for fast compensations enhance battery life span. The proposed control strategy effectiveness was investigated by simulations, including a comparison of overshoot/undershoot and settling time in dc bus voltage with a conventional control strategy. The results have been experimentally verified by hardware-in-loop (HIL) on a field-programmable gate array (FPGA)-based real-time simulator.