超滤与泡沫分离内耦合应用于表面活性物质浓缩分离的实验研究

Membrane separation and foam separation are widely used separation techniques.To make use of their advantages,membrane separation and foam separation were integrated to dispose waste water with low concentration of linear alkylbenzene sulfonate（LAS）.A method of forcing bubbles through a single hollow fiber ultrafiltration tube was put forward to study the separation efficiency of the integrated process.The effects of pressure,gas-liquid ratio and LAS concentration on the separation efficiency were investigated.Under the conditions of pressure 0.03—0.1 MPa,gas-liquid ratio 0—0.9,and LAS concentration 0—70 mg·L^-1,the membrane permeate flux was raised from 26.5 to 38.6 L·m^-2·h^-1,increased by 48.6%,and the retention rate was raised from 37.0% to 64.9%,increased by 75.5%.The results show that the integrated process can reduce the concentration polarization and membrane fouling.Moreover,this method reduces the back-mixing of foam separation and increases the concentration of bulk liquid phase for foam separation.Therefore,the integrated separation promotes mass transfer and improves separation efficiency.     

微波强化臭氧氧化降解苯酚水溶液

The degradation of phenol in aqueous solution with the combination of microwave and ozone（MW/O₃）was studied with laboratory-scale experiments.Effects of ozone dose,pH value,initial phenol concentration and reaction temperature on the reaction kinetics were investigated.In all cases,the degradation of phenol follows a pseudo-first-order kinetics relation.MW/O₃ combined technology is favorable for enhancing the removal efficiency of phenol,with the enhancement factor of the first-order kinetics constant being around 3.6.Experimental results showed that the synergetic effect of MW/O3 combined technology was obvious and up to 99 % of phenol was removed after 30 min reaction with initial phenol concentration of 100 mg·L^-1,ozone dose of 1.1 mg·min^-1,pH value of 9—11,and reaction temperature of 25℃.     

3,6-二氯吡啶甲酸电化学合成及其工业化生产

The industrialization of electrochemical synthesis of 3,6-dichloropicolinic acid(3,6-DCP) from 3,4,5,6-tetrachloropicolinic acid(3,4,5,6-TCP) in a tank-type undivided electrolytic cell with silver cathode was investigated. The experimental results showed that the electrolytic performance greatly depended on the operation parameters, such as flow rate of electrolyte, temperature, and concentration of NaOH. The reduction of 3,4,5,6-TCP to 3,6-DCP was favored by increasing temperature and flow rate of electrolyte. Industrialization tests of electrochemical synthesis of 3,6-DCP were conducted under the following conditions: silver cathode, temperature 313 K, flow rate 6 cm·s^-1, concentration of NaOH 8%(mass), concentration of 3,4,5,6-TCP 5%（mass）, cathode current density 600 A·m^-2. The current efficiency and conversion ratio of 3,4,5,6-TCP were more than 76% and 99%, respectively. The yield of 3,6-DCP was up to 90% and DC power consumption was 2. 939 kW·h·(kg 3,6-DCP)^-1. The purity of the product was higher than 95%, and its melting point was 151—153℃.     

高颗粒通量循环流化床的构型作用

In order to achieve high solids circulation rate (G_s),an idea of coupling a moving bed to the bottom section of the riser of a circulating fluidized bed (CFB) was proposed and tested.The results from the preliminary study demonstrated that the solids circulation rate in the new-structure bed approached 370 kg·m^-2·s^-1 at superficial gas velocities around 10.5 m·s^-1 for sand particles with an average Sauter mean size of 378 μm.This study was devoted to further justifying the effects of the coupled moving bed by performing comparative studies in two CFBs with conventional configurations.It was shown that the pressure at the riser bottom and the realized solid circulation rate were only about 15 kPa and 230 kg·m^-2·s^-1 in the two conventionally configured CFBs,obviously lower than 25 kPa and 370 kg·m^-2·s^-1 in the moving bed coupled CFB.These verified that the coupled moving bed increased the force driving particles form the particle recycling side into the riser.The study further tested the effect of a few specially designed riser exit configurations,revealing that a smooth riser exit could facilitate solids circulation to increase the solids circulation rate.     

HIGH—PURITY WATER PRODUCTION BY RO／EDI SYSTEM

Electrodeionization(EDI),also known as continuous deionization(CDI)and packed-cell electrodialysis,is a novel hybrid separation process combining ion-exchange resin with ion-exchange membrane in one unit.The EDI process was discovered in the 1950's［1，2］in laboratory,the first commercial apparatus for the production of high-purity water was available in 1987［3］.Now the EDI technology has been found and will be continuously found its great applications in many engineering fields. In EDI,the dilute compartments are filled with mixed-bed ion-exchange resins,which enhance the transport to the membranes under the force of a direct current.The ion transport is almost entire through the ion-exchange resins and is not effected through the water.Under certain conditions,water-splitting reaction occurs in the dilute chambers and then the relative high concentrations of H+ and OH- are able to regenerate the resins continuously, With the unique “electroregeneration",the EDI unit can be considered as a mixed-bed ion-exchange column with continuous regeneration.and therefore is capable of deep deionization.Comparing with electrodialysis and ion exchange respectively,EDI has put up much superiority in water desalination. In our experiments,the processes for production of high-purity water from tap water are consisted of pretreatment (with ultrafiltration,active carbon and 10 μm-filtration),RO and EDI.     

碱性溶液中硼氢化钠在铜阳极上的氧化行为

Polarization data of BH^-₄ oxidation on Cu anode in alkaline solution were measured at steady state by a self-made experimental cell. The experimental polarization curve showed three regions：the region at lower over-potential η（below 0.4 V approximately）,the region at higher η（above 0.6 V approximately）and the transitional region at medium η. It was found that the limiting current density is caused by the limiting elemental step rather than the external mass transport. The apparent reaction order with respect to BH^-₄ changes from 0 to 1. The active energy is about 40 kJ·mol^-1 in both regions with lower and higher η,and is higher than 40 kJ·mol^-1 in the transitional region. With the experimental temperatures and NaOH concentration,the hydrogen production rates released by the electrode reaction were measured at ［BH^-₄］/［OH^-］ratios of 1∶40,1∶20,1∶6. 7 and 1∶4,which is strongly dependent on the over-potential. The apparent number of released electron n by the reaction was calculated by using the measured amounts of hydrogen and coulomb. Higher value of n was obtained at lower ［BH^-₄］/［OH^-］ratio,higher temperature as well as higher over-potential. Under the experimental conditions,the value of n varies from 0 to 7,while in the transitional region it is just in the range of 3 to 5. The experimental results indicate that the limiting current density or n value will increase by virtue of proper experimental conditions. However,to considerably increase the current density at lower over-potential requires a modified anode with higher activity.     

一种新型反应器——生物气射流循环厌氧流化床的启动与运行特性

A novel anaerobic reactor, jet biogas inter-loop anaerobic fluidized bed （JBILAFB）, was designed and constructed. The start-up and performance of the reactor was investigated in the Process. of .artificial glucose wastewater treatment. With the wastewater recycle ratio of 2.5 ： 1, the recycled wastewater with biogas could mix sludge and wastewater in the JBILAFB reactor completely. The start-up of the JBILAFB reactor could be completed in less than 70 d through maintenance of hydraulic retention time （HR~I＂） and stepwise increase of feed total organic carbon （TOC） concentration. After the start-up, with the volumetric TOC loadings of 14.3 kg·m ^-3·d^-1, the TOC removal ratio, the effluent pH, and the volatile fatty acids （VFA）/alkalinity of the JBILAFB reactor were more than 80%, close to 7.0 and less than 0.4, respectively. Moreover, CH4 was produced at more than 70% of the theoretical value, The reactor exhibited high stability under the condition of high volumetric TOC loading. Sludge granules in the JBILAFB reactor were developed during the start-up and their sizes were enlarged with the stepwise increase of volumetric TOC loadings from 0.8 kg.m^-3.d ^-1 to 14.3 kg.m^-3.d^-1. Granules, an offwhite color and a similar spherical shape, were mainly comprised of global-like bacteria. These had good methanogenic activity and settleability, which were formed probably through adhesion of the bacteria. Some inorganic metal compounds such as Fe, Ca, Mg, Al, etc. were advantageous to the formation of the granules.     

超短接触反应器气固快分装置的数值模拟

A gas-solids fast separator was studied for its potential application in the process of coal pyrolysis to acetylene in plasma. The CFD method was employed to simulate the flow behavior in the gas-solids fast separator based on the realizable k-ε turbulence model and the discrete particle model（DPM）.The separation efficiency and residence time of gas phase in the gas-solids fast separator could be calculated. The numerical simulations were validated by the experimental results at a low velocity of the inlet gas（e. g. ,4 m·s^-1）.With the increase of gas velocity at the inlet,the separation efficiency was increased,and the residence time of gas phase was reduced accordingly. The separation efficiency approached 100% when particle diameter was larger than 20 μm. When inlet velocity was 100 m·s^-1,the mean residence time of gas phase was about 35 ms. To be noted,the performance of the gas-solids fast separator could be improved,for example by shortening the length of the separator,with a reduced residence time of gas phase at ～20 ms. It is expected that the gas-solids fast separator can meet the stringent demand of the coal pyrolysis to acetylene process for the milliseconds reaction,quench and separation.     

回料流入口高度对循环流化床提升管流动特性的影响

The axial pressure drop profile and the radial solids distribution were measured in a circulating fluidized bed for evaluating the effects of return gas-solids stream position on the riser flow properties.The saturation carrying capacity of gas for Geldart B typed particles and the flow mode of return gas-solids stream in the bed were discussed.It was found that arranging the inlet at a higher position of the riser would make the bottom bed leaner when U₀ was high and G_s was low.When G_s increased,the longer influenced region of return particles and a small air-staging through lifting the loosening air injection position made the bottom bed become denser significantly.The deceleration and residence of return particles caused a relatively denser but asymmetrical region in the vicinity of inlet.But much more symmetrical solids distribution profile was found in the upper and lower regions far away from the inlet.The effects of inlet height on the flow properties of the riser with air-staging also were analyzed.The secondary air injection below the solids inlet could not cut off the solids exchange in the bed.The bed solids concentration increased when the particles inlet moved to a higher position of the bed when air-staging was adopted.Using CO₂ as tracer,the dispersion of the loop-seal-fluidizing air for transmitting the return particles was investigated.It was found that the loop-seal fluidizing air dispersion rate was low but can be enhanced by the secondary air injection.     

椰油丙基酰胺甜菜碱/聚乙二醇水溶液的分相研究

Phase separation behavior of cocamidopropyl betaine/water/polyethylene glycol (PEG) system was studied. The effects of concentration and molecular weight of PEG on the phase separation behavior were investigated. Clouding occurred when the con-centration of PEG was large enough in the betaine aqueous solution, and the concentration of PEG at cloud point decreased with the increase of PEG molecular weight for a constant betaine concentration. The bottom phase was the PEG-rich phase, and the upper phase was the betaine-rich phase. The volumetric ratio of PEG-rich phase to betaine-rich phase, at the same difference between the PEG concentration and the one at the cloud point, Ccp (0.1 g•ml－1), decreased as the PEG molecular weight increased and approached 1 for higher PEG molecular weight (about 20000), which was similar to the typical aqueous two-phase system. This volumetric ratio depended on the initial PEG concentration, but independent of PEG molecular weight. The concentration ratio of betaine to PEG in both phases depended on the Ccp, independent of PEG molecular weight.     

两种不同电去离子技术处理含铜金属离子废水的研究

研究了倒极电渗析技术(EDIR)和电去离子技术(EDI)过程中淡出水和浓水室的电导率、p H值、铜离子浓度和膜堆电流,以及运行后离子交换膜和树脂的表面形态。结果表明:EDIR运行15 h的淡出水的电导率为30μS/cm,16 h的铜离子去除率为97.2%。EDI过程中15 h淡出水的电导率550μS/cm,16 h的铜离子去除率为77.8%。EDIR使淡出水的电导率降低,铜离子去除率升高。EDIR淡出水的p H值长期维持碱性,EDI淡出水则由碱性变成酸性、再变成碱性。然而,EDIR和EDI过程中浓水室的电导率和p H值基本接近。EDIR降低了膜堆电流、消除了浓水室阴离子交换膜表面氢氧化铜沉淀,抑制了淡水室中混合树脂表面沉淀。本质上,EDIR通过周期性改变淡水室和浓水室的相对数量和离子迁移方向而消除了膜表面氢氧根离子富集,并缓和了树脂表面水解现象,从而改善了EDIR过程的稳定性。     

EDI用于处理含甲酸废水

在工业生产过程中,排放的废水里含有大量的甲酸。本文以含甲酸废水处理为研究对象,采用自主设计的一级一段电去离子膜堆装置,通过考察I-U、pH-U等特征曲线,研究了离子交换膜、离子交换树脂及树脂填充比例、流速等操作条件对膜堆性能的影响。结果表明：采用异相膜和凝胶型树脂、淡室填充100%阴树脂、淡水流速为2.5 L/h的操作条件,可使EDI膜堆效果最佳;不同甲酸浓度对能耗的影响比较小,淡室浓度变化情况基本相同;当淡室甲酸质量分数为1.00%时,EDI膜堆可获得较高的电流并具有较低的耗电量。总结认为该研究结果可为EDI处理甲酸废水工业装置提供设计依据。     

倒极电去离子过程浓缩分离含镍离子溶液

通过在电去离子(EDI)的淡化室和浓缩室中同时填充离子交换树脂而构成频繁倒极电去离子(EDIR)过程,用以解决处理含重金属离子溶液时EDI内部易产生金属氢氧化物结垢的关键难题。以NiSO4溶液为处理对象,采用浓缩水部分循环和浓、淡水流分步切换的运行工艺,利用EDIR单一过程,同步获得了淡化出水的高截留率和浓缩产品水的高浓缩倍数。实验条件下,倒极周期为4h可获最佳分离效果。对于含Ni2+50mg.L-1、pH为3.0的NiSO4溶液,EDIR的淡水出水和浓水出水的Ni2+浓度可分别达到1.5mg.L-1和3961mg.L-1,淡水中Ni2+的脱除率为97%,浓水的浓缩倍数则为79.2,接近理论值。实验范围内,EDIR过程运行稳定,未产生Ni(OH)结垢。     

荧光增白剂生产废水的处理

采用"曝气铁炭微电解-水解酸化-好氧生物处理-臭氧氧化"工艺对荧光增白剂生产废水进行了处理.研究了曝气铁炭微电解的铁炭质量比,反应时间和废水pH对处理效果的影响,以及水解酸化、好氧生物处理、臭氧氧化各处理阶段的处理效果,并对最终出水水质进行了分析.结果表明,采用"曝气铁炭微电解-水解酸化-好氧生物处理-臭氧氧化"工艺处理荧光增白剂生产废水,当进水COD为5 620 mg·L~(-1)左右时,出水TOC降至68.45mg·L~(-1),SS质量浓度降至25.9mg·L~(-1),浊度降至2.4NTU,色度降至0.     

微电解-SBR组合处理对硝基苯酚研究

以微电解为预处理,与生化处理直接结合,考察了该工艺对对硝基苯酚的处理效果.结果表明,微生物经过合理的驯化后,在短期内获得对对硝基苯酚较好的适应性与处理效果,不同质量浓度负荷下微生物都能够将对硝基苯酚的质量浓度降低到1～2mg·L~(-1),只是随着负荷的提高,降解的时间也不断延长.组合工况在对硝基苯酚含量较高时,系统运行稳定,能够较好提高整体去除效率,出水对硝基苯酚的质量浓度在5mg·L~(-1)左右,COD不超过40mg·L~(-1),并具有一定的抗冲击负荷能力.     

曝气生物滤池在印染废水回用处理中的应用

采用曝气生物滤池(BAF)工艺对经兼氧-好氧生化预处理后的印染废水进行中试规模的深度处理试验研究.结果表明,在进水COD约为100～250mg·L~(-1)、SS质量浓度约为80～120mg·L~(-1)、色度约为30～50倍的条件下,当BAF水力负荷为1.0m~3·m~(-2)·h~(-1),气水体积比4:1时,出水COD≤50 mg·L~(-1),ρ(SS)≤20 mg·L~(-1),色度≤20倍,出水水质可满足生产工艺对回用水的水质要求.     

不同类型离子交换树脂对填充床电渗析中L-Lac-和L-Glu-分离的影响

通过树脂静态吸附、常规电渗析及填充床电渗析的对比实验,考察了带有不同离子交换基团的树脂对发酵废液中L-Lac-和L-Glu-分离的影响. 结果表明,碱性树脂201′7和WA30对2种组分的静态吸附量、L-Lac-/L-Glu-选择吸附比例均比酸性树脂001′1.1和WK10大. 与常规电渗析相比,填充001′1.1(强酸型)、WK10(弱酸型)的填充床电渗析体系中L-Lac-和L-Glu-的跨膜迁移量及分离比例均有明显增加,填充001′1.1时分离比例最大可达22.22. 填充201′7(强碱型)时两组分跨膜迁移量及分离比例均比常规电渗析小,最大分离比例分别为5.74和8.28. 填充不同离子交换树脂体系的能耗对比表明,填充床淡室中填充树脂001′1.1和WK10时可促进L-Lac-和L-Glu-的迁移传递、提高二者的分离比例.     

CAF气浮-水解酸化-SBR处理羊剪绒水洗废水

介绍了CAF气浮-水解酸化-SBR工艺处理羊剪绒水洗废水的工艺设计和运行效果.该工艺具有处理效果好、能耗低、易管理等特点.在进水COD为1 800mg·L~(-1),BOD5为300mg·L~(-1),SS质量浓度为1 200mg·L~(-1)的条件下,经过本系统处理,平均出水COD保持在200 mg·L~(-1)以下,BOD_5保持在60 mg·L~(-1)以下,SS质量浓度保持在150mg·L~(-1)以下,出水水质达到GB 8978-1996污水综合排放标准的Ⅱ级标准.     

泥渣回流强化混凝沉淀再生水处理工艺条件优化

以北方某城市再生水厂原水为研究对象,通过泥渣回流强化混凝沉淀工艺进行再生水处理,研究了泥渣回流浓度、泥渣回流量、助凝剂投加量、泥渣回流位置、搅拌强度等参数对该工艺的运行效果影响.结果表明,经泥渣回流强化混凝沉淀后,再生水处理效果良好.在进水流量为200L·h~(-1)时,优化后工艺运行参数分别为:PAc投加量10mg·L~(-1),PAM投加量0.3 mg·L~(-1),泥渣回流质量浓度10 000～16 000 mg·L~(-1),泥渣回流量200 mg·L~(-1),混合池搅拌强度G=328 S~(-1),絮凝池搅拌强度G=22 S~(-1),泥渣回流位置在混合池.在最佳工艺运行条件下,出水水质达到了景观环境用水水质(GB/T 18921-2002)的要求.     

应用电解絮凝-UASB-MBR组合工艺处理萘普生废水的中试研究

采用电解絮凝-UASB-MBR组合工艺处理萘普生混合废水,研究结果表明,控制电压4.1 V,电解过程使COD在15 000 mg·L-1以上的废水,实现约20%左右的去除率,同时使废水的BOD有较大幅度的提高,增大了废水的可生化性;使聚铁混凝剂和PAM的投加浓度比为500:2,絮凝过程对COD约有20%的去除率;UASB单元对有机污染物有较大幅度地削减,去除率约75.8%～80%,将废水中的COD降至2 000 mg·L-1;而MBR单元则进一步将最终出水的COD降至100mg·L-1以下.