双频超声空化效应强化提取中药有效成分的实验研究

设计了25kHz和40kHz的双频超声强化提取装置,以碘化钾中碘的释放量研究双频超声的空化效应,并以黄柏为原料研究双频超声对提取小檗碱的强化效果,结果表明:在相同实验条件下,双频超声的空化效应远大于单频超声的空化效应;25kHz与40kHz双频超声时的提取率为64.1%,单频25kHz及40kHz时的提取率分别为36.8%和19.0%,双频超声强化的提取率显著高于单频超声强化的提取率。研究还表明,双频超声强化可以降低提取温度,缩短提取时间,为热敏性药物的提取提供了新的强化方法。     

单频超声和双频复合超声的空化效应实验研究

从超声电功率、超声作用时间和溶液温度来研究超声的空化效应,采用碘化钾溶液中碘的释放量来测定超声的空化产额,研究结果表明：在相同的电功率输入情况下,双频复合超声（25kHz/40kHz）释放碘的量远大于单频25kHz超声和单频40kHz超声释放的碘的量,双频复合超声的空化产额高于单频超声。     

超声预处理和湿度控制对香蕉干燥特性的影响

目的研究超声预处理和湿度控制技术对香蕉干燥特性的影响,以缩短香蕉的干燥时间、减少色泽劣变。方法首先在超声波发生器功率为300 W,温度为30℃条件下对厚度为(5.0±0.1)mm的香蕉片进行单频(20,40,60 kHz)预处理,每个频率分3组,处理时间为20,30和40 min,得到的最佳超声预处理时间为30 min。再分别进行单频(20,40,60 kHz)、双频((20+40),(20+60),(40+60)kHz)和三频((20+40+60)kHz)的处理,在65℃条件下进行恒温热风干燥;在此基础上进行干燥介质相对湿度为5%,10%,15%的热风干燥。结果在超声波预处理中,单频(60 kHz)、双频((40+60)kHz)和三频((20+40+60)kHz)的超声波预处理对温湿度控制热风干燥速率的作用效果最佳,在同一干燥介质相对湿度条件下,干燥速率、复水率以及维生素C含量从大到小依次为三频((20+40+60)kHz)、双频((40+60)kHz)、单频(60 kHz)、空白对照组;在相同的超声波预处理条件下,干燥介质相对湿度越小,干燥速率和复水率越高,而维生素C含量越低。结论探索了不同相对湿度的干燥介质对超声预处理后的香蕉干燥特性的影响,为选择合适的干燥工艺提供了理论依据。     

超声处理污泥的影响因素讨论

超声处理污泥问题是一种超声技术新的应用的尝试,在已经进行的研究工作的基础上,介绍了超声处理污泥的机理、特点,就其影响的几大主要因素——频率、声强、功率、反应器的设计与换能器类型、污泥自身因素等进行分析。对于超声处理污泥这种极其复杂的过程,进一步讨论了超声技术处理污泥存在的问题和今后的发展方向。     

夹心式复频功率超声压电换能器及其电端匹配电路的研究

本文研究了夹心式复频功率超声压电换能器的理论设计及其电端匹配电路.探讨了换能器的电端电抗元件对换能器振动性能的影响,并提出了一种利用电抗元件改变换能器不同振动模式共振频率的方法.所得结果可用于复频换能器匹配电路的设计及换能器不同振动模式共振频率的调节.     

超声辐照促进声化学产额的研究及应用

针对多频超声促进声化学产额的研究热点问题,简述了单频、双频、三频超声辐照的声化学反映规律及其研究进展,分析了多频辐射能显著提高声化学产额的原因。指出了多频超声在医药方面的应用,尤其是在中药复方提取中更显示出其优越性,可以达到很好的提取率,多频辐射有很好的开发前景。     

剩余活性污泥的超声脱水及破解

文章从静态和动态研究了剩余活性污泥的超声脱水及污泥的破解。静态下,污泥的脱水应在低功率(以50W为例)短时间(7min)内进行,最高的脱水率(相对于未超声而言)可增加近16%;污泥破解应在高功率长时间下进行,本实验在250W的功率下连续处理20min,COD的增加值达到近1600mg/L;污泥的破解满足一级反应动力学。动态下,以低功率(50W)为例,脱水及破解曲线都比较平坦,污泥的总脱水率相对于未超声而言增加可达近23%;COD的增加值近似达1800mg/L。通过比较低功率下实验,动态实验效果明显优于静态实验。     

超声破解联合湿法检测活性污泥中CODCr的研究

准确测定活性污泥中化学需氧量(Chemical Oxygen Demand, COD_Cr)含量,是实现污泥资源化利用的重要条件。文章提出一种超声破解联合湿法测定活性污泥中COD_Cr含量的检测方法。基于单因素实验结果,以COD_Cr浓度作为响应值,采用响应曲面法考察了污泥混合液的稀释倍数、超声功率和超声时间3个因素间单独及交互作用,并对影响因素进行了评估。结果表明,取样量为10 mL,稀释倍数为225倍,超声时间为18 min,超声功率为720 W时,样品平行测定的相对标准偏差小于等于2.00 %,加标回收率为96.51 %~105.32 %,测定结果的准确度、精密度较高。光学显微镜照片和激光粒度仪分析表明,超声破解能够有效破碎微生物细胞的絮体结构,显著降低污泥颗粒粒径,减少污泥取样过程中的误差。对不同f的污泥样品,COD_Cr测定值与理论值相关性拟合曲线的拟合值R²≥0.9961。研究结果证明超声破解联合湿法测定活性污泥中COD_Cr具有良好的可靠性和经济性。     

复频聚焦超声激活血卟啉杀伤肿瘤细胞K562的实验研究

为了研究单复频超声激活血卟啉对人体肿瘤细胞的杀伤效应，利用自制的复频聚焦换能器激活血卟啉，以肿瘤细胞K562：为研究对象，采用MTF法(四唑盐比色法)检测在不同超声处理时间、不同频率、不同溶液环境下、不同孵育时间条件下，声动力学激活血卟啉法对肿瘤细胞的杀伤效应。结果表明，复频聚焦超声激活血卟啉对肿瘤细胞具有较强的杀伤效应，是一种有应用前景的治疗肿瘤的新技术。     

如何解决污水处理中活性污泥膨胀上浮问题

活性污泥是一个动态的微生态系统,其中不同种属的微生物对水温、pH值、曝气池混合液浓度（MLSS）、污泥沉降比、污泥负荷、污泥回流比、停留时间、溶解氧（DO）、气水比等参数的适应性各不相同。本文对影响活性污泥的主要要素及其作用机理,作一简略探讨和研究。     

Mechanisms and kinetics models for ultrasonic waste activated sludge disintegration

Ultrasonic energy can be applied as pre-treatment to disintegrate sludge flocs and disrupt bacterial cells' walls, and the hydrolysis can be improved, so that the rate of sludge digestion and methane production is improved. In this paper, by adding NaHCO3 to mask the oxidizing effect of OH, the mechanisms of disintegration are investigated. In addition, kinetics models for ultrasonic sludge disintegration are established by applying multi-variable linear regression method. It has been found that hydro-mechanical shear forces predominantly responsible for the disintegration, and the contribution of oxidizing effect of OH increases with the amount of the ultrasonic density and ultrasonic intensity. It has also been inferred from the kinetics model which dependent variable is SCOD+ that both sludge pH and sludge concentration significantly affect the disintegration.     

Ultrasonic reduction of excess sludge from the activated sludge system

Sludge treatment has long become the most challenging problem in wastewater treatment plants. Previous studies showed that ozone or chlorine effectively liquefies sludge into substrates for bio-degradation in the aeration tank, and thus reduces the excess sludge. This paper employs ultrasound to reduce the excess sludge from the sequential batch reactor (SBR) system. Partial sludge was disintegrated into dissolved substrates by ultrasound in an external sono-tank and was then returned to the SBR for bio-degradation. The results showed that ultrasound (25kHz) effectively liquefied the sludge. The most effective conditions for sludge reduction were as following: sludge sonication ratio of 3/14, ultrasound intensity of 120kW/kgDS, and sonication duration of 15min. The amount of excess sludge was reduced by 91.1% to 17.8mg/(Ld); the organic content and settleability of sludge in the SBR were not impacted. The chemical oxygen demand (COD) removal efficiency was 81.1%, the total nitrogen (TN) removal efficiency was 17-66%, and high phosphorus concentration in the effluent was observed.     

Effects of ultrasonic disintegration on sludge microbial activity and dewaterability

Ultrasonic treatment can disintegrate sludge, enhance microbial activity and improve sludge dewaterability at different energy inputs. To find their relationship, the three phenomena during ultrasonic treatment were investigated synchronously, and an experimental model was established to describe the process of ultrasonic sludge disintegration. Analysis results showed that the changes of sludge microbial activity and dewaterability were dependent on sludge disintegration degree during ultrasonic treatment. When sludge disintegration degree was lower than 20%, sludge flocs were disintegrated into micro-floc aggregates and the microbial activity increased over 20%. When sludge disintegration degree was over 40%, most cells were destroyed at different degree, and sludge activity decreased drastically. Only when sludge disintegration degree was 2-5%, sludge dewaterability was improved with the conditioning of FeCl(3). It was also found that the sonication with low density and long duration was more efficient than sonication with high density and short duration at the same energy input for sludge disintegration, and a transmutative power function model can be used to describe the process of ultrasonic disintegration.     

污水厂剩余污泥材料化和能源利用技术研究进展

剩余污泥为污水处理厂副产物,具有成分复杂难处理,易滋生二次污染的特性。主要介绍了近年来剩余污泥制吸附剂和能源化技术的研究进展。由于剩余污泥中有机质含量丰富,首先对单一污泥和剩余污泥添加工农业废弃物制备吸附剂的研究现状进行了介绍,指出吸附材料制备过程中活化剂大量使用会造成环境的再污染;随后综述了剩余污泥直接能源化,或通过热解等手段将其间接能源化的研究进展;最后提出用生物质废弃物代替化学活化剂制备污泥吸附剂的研究思路,并指出将污泥制备材料和能源利用技术相结合是今后剩余污泥资源化研究的主要发展方向。     

Study on Enhancement in Gibbsite Precipitation of Bayer Process under 33 kHz Ultrasound

The enhancement of gibbsite precipitation in Bayer process by 33 kHz ultrasound has been studied. From orthomethod experiment, the optimized operating parameters of treatment under 33 kHz ultrasonic cleaner have obtained.Compared with crystallization of Al(OH)3 without treatment of ultrasound, the precipitation time is reduced by 15 h when the precipitation ratio is 45%. From the results of grain size distribution and SEM photographs of gibbsite, it is found that secondary nucleation and agglomeration could be enhanced under 33 kHz ultrasound. The products are same from comparison of X-ray powder diffraction, but the Raman spectrum of sodium aluminate solution under 33 kHz ultrasound is different from that without ultrasound.     

The ultrasonically assisted metals recovery treatment of printed circuit board waste sludge by leaching separation

This paper provides a practical technique that realized industrial scale copper and iron separation from printed circuit board (PCB) waste sludge by ultrasonically assisted acid leaching in a low cost, low energy consumption and zero discharge of wastes manner. The separation efficiencies of copper and iron from acid leaching with assistance of ultrasound were compared with the one without assistance of ultrasound and the effects of the leaching procedure, pH value, and ultrasonic strength have been investigated in the paper. With the appropriate leaching procedure, a final pH of 3.0, an ultrasonic generator power of 160 W (in 1 l tank), leaching time of 60 min, leaching efficiencies of copper and iron had reached 97.83% and 1.23%, respectively. Therefore the separation of copper and iron in PCB waste sludge was virtually achieved. The lab results had been successfully applied to the industrial scaled applications in a heavy metal recovery plant in city of Huizhou, China for more than two years. It has great potentials to be used in even the broad metal recovery practices.     

Reduction of excess sludge production in sequencing batch reactor through incorporation of chlorine dioxide oxidation

In this study, chlorine dioxide (ClO₂) instead of chlorine (Cl₂) was proposed to minimize the formation of chlorine-based by-products and was incorporated into a sequencing batch reactor (SBR) for excess sludge reduction. The results showed that the sludge disintegrability of ClO₂ was excellent. The waste activated sludge at an initial concentration of 15 g MLSS/L was rapidly reduced by 36% using ClO₂ doses of 10 mg ClO₂/g dry sludge which was much lower than that obtained using Cl₂ based on similar sludge reduction efficiency. Maximum sludge disintegration was achieved at 10 mg ClO₂/g dry sludge for 40 min. ClO₂ oxidation can be successfully incorporated into a SBR for excess sludge reduction without significantly harming the bioreactor performance. The incorporation of ClO₂ oxidation resulted in a 58% reduction in excess sludge production, and the quality of the effluent was not significantly affected.