响应面法优化水力空化——次氯酸钠氧化大肠杆菌的工艺

以大肠杆菌作为水中微生物的指示细菌,采用水力空化-次氯酸钠强化氧化技术去除水中微生物,考察了入口压力、次氯酸钠含量、空化时间等因素对水中大肠杆菌的去除效果,并用响应面分析方法对实验结果进行分析和参数优化。结果表明,大肠杆菌初始含量为5.0×10~6 CFU/m L、水温为30℃时,水力空化-次氯酸钠强化氧化消毒工艺的优化参数为:入口压力0.37 MPa、Na Cl O的质量浓度6.0 mg/L、空化时间38 min,在此条件下所得大肠杆菌去除量的对数为4.96,与模型的预测值相近,说明采用响应面优化得到的工艺参数可靠。     

水力空化对水中微生物的灭活作用及特性

在以文丘里管为空化发生器的水力空化装置中,对含有大肠杆菌的水体进行灭菌处理。通过检测大肠杆菌的灭菌率,考察了水力空化对水中微生物的灭活效果。分析了水流空化数、文丘里管入口压力、空化作用时间、文丘里管结构特性等参数对灭菌效果的影响。结果表明,水力空化的能量效应对水中微生物能够产生灭活作用,实现对含菌污水的灭菌消毒处理。提高文丘里管入口压力、增加空化处理时间、优化空化器结构设计均有利于增强空化灭菌效果。     

水力空化对亚甲基蓝的去除研究

采用多孔孔板水力空化器对亚甲基蓝进行去除实验。研究了温度、入口压力、空化时间与孔径、孔数对亚甲基蓝去除效果的影响,探讨了水力空化去除亚甲基蓝机理。结果表明,水力空化对亚甲基蓝的去除效果随着时间的增加而增强,随着入口压力与温度的增大先增强后减弱,亚甲基蓝去除的优化条件为:入口压力0.35 MPa,时间4.0 h,温度35℃。对于排布与孔个数相同而孔径不同的孔板空化器,小孔径的孔板空化器可以提高亚甲基蓝的去除效果。对于流动面积相同而孔数不同的孔板空化器,多孔数的孔板空化器可以提高亚甲基蓝的去除效果。水力空化去除亚甲基蓝的机理是羟基自由基的氧化降解作用。     

水力空化对亚甲基蓝的去除研究

采用多孔孔板水力空化器对亚甲基蓝进行去除实验。研究了温度、入口压力、空化时间与孔径、孔数对亚甲基蓝去除效果的影响,探讨了水力空化去除亚甲基蓝机理。结果表明,水力空化对亚甲基蓝的去除效果随着时间的增加而增强,随着入口压力与温度的增大先增强后减弱,亚甲基蓝去除的优化条件为:入口压力0.35 MPa,时间4.0 h,温度35℃。对于排布与孔个数相同而孔径不同的孔板空化器,小孔径的孔板空化器可以提高亚甲基蓝的去除效果。对于流动面积相同而孔数不同的孔板空化器,多孔数的孔板空化器可以提高亚甲基蓝的去除效果。水力空化去除亚甲基蓝的机理是羟基自由基的氧化降解作用。     

水力空化联合二氧化氯处理苯酚废水研究

以苯酚废水作为研究对象,采用水力空化技术处理,考察了入口压力、孔板开孔率、孔板排布方式对苯酚降解率的影响,并研究了水力空化联合二氧化氯对苯酚的降解率。研究表明,苯酚降解率随着入口压力的增大,呈现先增大后减小的趋势,存在最佳压力;孔板开孔率对苯酚的降解效果有较大的影响,且环状分布孔板比均匀分布孔板有更好的降解效果;水力空化比超声空化有更高的能量利用率。水力空化联合二氧化氯对苯酚的降解符合一级反应动力学规律,且降解率是2个单独处理工艺之和的1.4倍,并结合对降解机理的探究,表明两者对苯酚的降解存在协同效应。     

水力空化强化臭氧降解罗丹明B的初步研究

进行了水力空化强化臭氧降解水中罗丹明的研究,考察得知罗丹明B溶液初始浓度、臭氧浓度、多孔板和入口压力等因素对水力空化强化臭氧降解罗丹明B影响显著,水力空化强化臭氧对罗丹明B的降解效果是单独使用臭氧的1.46倍,单独使用水力空化的14.5倍,因此水力空化联合臭氧降解罗丹明B有一定的研究价值.     

文丘里管式空化器的数值模拟

水利空化是一个较复杂的过程,反应过程中会受到工作环境、仪器设备各项参数、液体的状态等因素的影响。针对基于水力空化相关原理及文丘里管的特性,利用Fluent模拟软件建立了模拟模型,考察了文丘里管空化装置入口压力、喉部直径、入口角度及入口直径等参数对空化效果的影响,得到了各个因素的影响规律及优化条件,确定了空化效果最好的空化器,为同类空化器的实际应用提供了较好的理论基础和借鉴。     

水力空化技术降解石油废水效能研究

采用水力空化技术对水中石油污染物的催化降解性能及影响因素进行研究。结果表明,适当提高入口压力、升高反应温度、延长反应时间,有利于石油污染物的降解。当入口压力0.3 MPa、反应温度25℃、反应时间5 h时,水力空化系统对石油的去除率为84.28%。经GC-MS分析,在空化催化降解作用下,石油污染物中大多数有机物被直接氧化成CO2和H2O,同时避免了新的小分子有机物生成。水力空化技术可以有效地去除水中的石油污染物,可以作为处理石油废水的一种有效方法。     

水力空化强化臭氧降解水中苯酚影响因素研究

研究了在水力空化强化臭氧降解苯酚时臭氧通入量、多孔板的参数、多孔板的入口压力对苯酚降解的影响。研究表明:三者对苯酚的降解均有较大影响。增加臭氧通入量、提高入口压力都有利于苯酚的降解。研究水力空化强化臭氧氧化作用的动力学,结果表明,苯酚在单独水力空化、臭氧氧化以及它们的联合工艺下的降解均符合表观一级动力学;且在水力空化强化臭氧氧化的工艺中苯酚的去除率比在单独水力空化、臭氧氧化时有显著的提高,表明水力空化强化臭氧氧化的工艺中存在协同作用。     

水力空化强化稠油加碱乳化降黏的研究

利用碳酸钠(Na₂CO₃)乳化稠油，采用机械搅拌法探究稠油质量分数、Na₂CO₃质量分数、乳化温度和搅拌速率对水包油(O/W)型乳状液的影响；利用水力空化技术强化制备乳状液，探究Na₂CO₃质量分数、空化入口压力、空化次数对乳状液的影响。基于机械搅拌法确定最优实验条件为：稠油质量分数为70%、Na₂CO₃质量分数为2 000μg/g、乳化温度为30℃、搅拌速率为1 000 r/min。水力空化技术制备乳状液的实验结果表明，随着Na₂CO₃质量分数的增加，乳状液表观黏度升高、分水率降低。空化入口压力为0.3～0.7 MPa时，随着空化次数的增加，乳状液的表观黏度升高，分水率降低；入口压力为0.9 MPa时呈相反规律。结果表明，与机械搅拌法相比，水力空化所制备乳状液油滴粒径小且分布均匀，在大规模制备稠油O/W型乳状液领域有很大的应用潜力。     

基于水力空化技术的废水处理装置及设计

水力空化技术是一种新的水处理技术。本试验利用两种孔板水力空化装置对若丹明B降解进行了试验研究,试验结果表明：水力空化对若丹明B确实有降解作用。探讨和分析了两种孔板的空化数和进口压力等因素对其降解的影响作用,提出了水力空化降解与时间的规律和不同的孔板存在最佳的操作运行参数的观点。     

Hydrodynamic cavitation as an efficient method for the formation of sub-100 nm O/W emulsions with high stability

Hydrodynamic cavitation, a newly developed process intensification technique, has demonstrated immense po-tential for intensifying diverse physical and chemical processes. In this study, hydrodynamic cavitation was ex-plored as an efficient method for the formation of sub-100 nm oil-in-water (O/W) emulsions with high stability. O/W emulsion with an average droplet size of 27 nm was successful y prepared. The average droplet size of O/W emulsions decreased with the increase of the inlet pressure, number of cavitation passes and surfac-tant concentration. The formed emulsion exhibited admirable physical stability during 8 months. Moreover, the hydrodynamic cavitation method can be generalized to fabricate large varieties of O/W emulsions, which showed great potential for large-scale formation of O/W emulsions with lower energy consumption.     

Comparison of effectiveness of acoustic and hydrodynamic cavitation in combined treatment schemes for degradation of dye wastewaters

Cavitation has shown promising applications but individually it cannot prove to be an energy efficient approach for wastewater treatment. The present study reports the use of combined treatment strategies based on cavitation and different oxidizing agents (H₂O₂, Na₂S₂O₈ and NaOCl). Decolorization of two biorefractory dye pollutants viz. orange acid-II (OA-II) and brilliant green (BG) has been investigated as model systems for comparison of the effectiveness of cavitating conditions generated by acoustic and hydrodynamic modes. The optimum conditions for temperature, pH and power dissipation in the case of acoustic cavitation and inlet pressure in the case of hydrodynamic cavitation have been established initially. At the optimum operating conditions, the effect of combination of different oxidizing agents has been examined with an objective of obtaining the maximum decolorization. Basic extent of decolorization due to the use of oxidizing agents has also been quantified by performing experiments in the absence of cavitating conditions. The obtained results for cavitational yields indicate that the decolorization is most efficient for the combination of hydrodynamic cavitation and chemical oxidation as compared to chemical oxidation and acoustic cavitation based combination for both the dye effluents.     

水力空化强度与空化自由基产量的关系

利用空化释放出的能量对过程进行强化是能量利用的新途径。定量分析空化引发·OH产量与空化强度的关系,对研究空化对过程的强化效应有着十分重要的意义。以亚甲基蓝作为羟自由基捕捉剂,利用紫外-可见分光光度法,间接测定了水力空化产生的·OH产量。分析了管路上游压力、液体温度、空化作用时间等宏观参数对自由基产量的影响,以及自由基产量与空化强度的关系,寻求出有利于空化发生以及提高空化作用强度的适宜操作条件。     

Optimization of Hydrodynamic Cavitation Using a Model Reaction

The decomposition of potassium iodide to liberate iodine, the model reaction to study cavitational effects, has been carried out under different cavitational conditions. The effect of various parameters (inlet pressure, flow geometry of orifice plates) on the iodine liberation rate has been studied. It is found that the flow geometry of the orifice plates considerably affects the rate of the iodine liberation. Recommendations are given for the arrangement of the holes in order to achieve maximum benefits from the hydrodynamic cavitation. The experimental results obtained in the present work are very much consistent with the results based on the theoretical model developed for the hydrodynamic cavitation. Due to this fact, it can be said that the model can be extended to any geometry of construction in the hydrodynamic cavitation setup and will be helpful in designing cavitational reactors.     

Degradation of BTEX in Aqueous Solution by Hydrodynamic Cavitation

A self‐made low‐pressure device (up to 100 psi) for hydrodynamic cavitation was tested with the reaction of BTEX (benzene, toluene, ethylbenzene, and xylenes) in water. Experimental parameters, such as inlet pressure, solution temperature, and concentration of the chosen substrates, as well as the effect of different restrictions were investigated. The energy efficiency of the process was measured in comparison to two acoustic cavitation systems (24 and 850 kHz). The products of the BTEX degradation were identified and a pyrolytic degradation pathway is concluded.     

基于水力空化的化工过程强化研究进展

水力空化（HC）是一种利用声化学效应（即空泡溃灭时释放出的巨大能量）的高效、绿色化工过程强化技术,是国内外的研究热点。该技术具有设备造价低、可放大性强、可与其他物理及化学方法高效耦合等优点,工业应用前景广泛。本文介绍了HC现象及其特性;归纳了近年来HC技术在有机废水处理、水消毒与生物燃料制备等代表性应用的研究、应用进展以及作用机理,展示了其工业应用的潜力;总结了用于诱发HC现象的水力空化反应器的发展过程与研究现状;最后,结合发展趋势与作者的研究经历,归纳了国内外在HC研究方面存在的问题,指出了其未来发展方向,为HC技术的发展与工业应用探索提供建设性意见。     

Measurement and interpretation of cavitation noise in a hybrid hydrodynamic cavitating device

In the recent past, a number of new methods of utilizing hydrodynamic cavitation to create more intense and energy efficient liquid processes have come into existence. However, it is technically challenging to characterize these processes either quantitatively or qualitatively (Patil NM, M. chemical engineering Thesis submitted to Mumbai University, India, 2001). In this work, a hybrid device producing more energy intensive cavitation has been described, which has a blade positioned in the back pressure zone (downstream side of the orifice plate). This method of cavitation production route has been quantitatively described in the form of hydrophone measured pressure signals. Fast Fourier Transform analysis (FFT) analysis has been applied to the signal obtained at various positions of the blade, and at different inlet and outlet (back) pressures. Qualitatively analysis in terms of cavity size distribution and the total number of cavitational bubbles has been conducted, using a slightly modified technique of inverse FFT reconstruction procedure originally developed by Avvaru and Pandit to model cavity size distribution. © 2010 American Institute of Chemical Engineers AIChE J, 2011