木薯淀粉-丙烯酰胺共聚物对污水的絮凝效果

实验室自制木薯淀粉-丙烯酰胺接枝共聚物（CSAAGC）作为絮凝剂处理不同来源污水。探讨了CSAAGC加入量、污水pH及絮凝时间对絮凝效果的影响。结果显示,CSAAGC的pH使用范围为3.0~10.0;对模拟污水的浊度去除率达97%;对滇池水的浊度去除率达84%;对泥浆悬浊液的30 m in浊度去除率达59%;对生活污水的浊度去除率为82%。同时测定了处理前后滇池水及生活污水的CODC r值,对滇池水CODC r去除率47.4%;对生活污水的CODC r去除率为56.4%。     

油田污水的可生化性及生化反应动力学

以油田污水为研究对象,采用电化学氧化工艺来提高污水的可生化性,考察了不同因素对除污效果的影响。利用正交实验设计确定电化学氧化最佳工艺参数为:电解电压20 V,pH值5,极板间距2.0 cm,阳极为Ti/Ir形稳电极、双向脉冲电源,在此条件下电解30 min,油田污水COD去除率达到70%。利用BOD5/CODC r比值法和微生物呼吸速率法对污水的可生化性进行了研究,2种实验方法均表明处理前油田污水的可生化性较差,而经电化学氧化工艺处理后的污水可进行生化处理,同时在微生物呼吸速率法的基础上探讨了微生物的生化反应动力学,结果表明,实验条件下微生物的呼吸速率都严格遵循一级动力学关系式。     

填料塔中氨水吸收二氧化碳的传质性能

在填料塔中对氨水吸收二氧化碳的传质性能进行了实验研究,测定了填料塔单位体积的有效传质面积aV,气相传质系数kG和体积总传质系数KGaV等,实验结果表明,随着气体流量增加,aV值略有上升,kGaV和kG值明显增大;体积总传质系数KGaV值也随着气体流量和氨水浓度的升高而增大。在总传质阻力中,气膜阻力所占比例相对较小,氨水吸收二氧化碳的过程主要受液膜阻力的控制。     

多烯多胺接枝絮凝剂处理工业废水的应用

通过实验研究了三种合成接枝絮凝剂在工业废水处理中的性能,确定三乙烯四胺接枝絮凝剂为最佳絮凝剂。实验结果表明:当保持pH值不变,废水CODC r浓度在300mg/L时三乙烯四胺接枝絮凝剂的处理效果最好,达到CODC r去除率为50.02%、透光率为97.3%的处理效果,处理后的废水可达到国家综合污水排放二级标准。     

中空纤维更新液膜在己内酰胺精制中的应用

研究了中空纤维更新液膜技术用于己内酰胺精制时的传质性能,考察了两相流速、萃取剂用量对传质的影响,并与大块液膜技术以及萃取塔技术进行了对比。在实验范围内,中空纤维更新液膜过程总传质系数随两相流速的增大而增大,且壳程流速对传质的影响较大。中空纤维更新液膜过程传质通量可达大块液膜的1．5倍,总体积传质系数可达工业萃取塔的2．3倍,萃取剂用量相比于大块液膜、工业萃取塔大幅度降低,具有很大的应用潜力。     

湿壁塔中钴氨络合物烟气脱硝的传质系数

为了研究钴氨络合物烟气脱硝的传质系数,搭建了湿壁塔反应装置。通过改变进入湿壁塔内模拟烟气的NO和SO_2浓度、钴氨络合物的浓度、反应温度等,对钴氨络合物吸收NO的传质系数进行了实验研究。实验结果表明,当烟气中NO浓度和钴氨络合物浓度增加时,NO传质系数增大;当SO_2浓度增大时,NO传质系数减小。并且发现,钴氨络合物吸收NO的最佳反应温度为55℃。可为开发钴氨络合物同时脱硫脱硝技术提供参考。     

载气增湿蒸发技术处理切削废液的研究

利用空气作为载气,采用蒸发塔进行了载气增湿蒸发浓缩切削废液的实验,探究了操作条件对蒸发过程的影响。随着载气流量的增加,容积传质系数、蒸发量和整塔压降均增大,出口载气VOC浓度减小;随着载气温度、循环流量的增加,容积传质系数、蒸发量、整塔压降和出口载气VOC浓度均增大。实验条件下容积传质系数及蒸发量最大达到了13.95 g·（m³·s）^-1和3.39 kg·h^-1;出口载气VOC浓度最大为6.2 mg·L^-1,小于《大气污染物综合排放标准》中规定值。研究结果表明载气增湿蒸发工艺能有效浓缩切削废液,为工业化应用奠定了基础。     

新型气隙式膜蒸馏组件脱盐过程

利用基于聚丙烯中空纤维膜和聚丙烯中空纤维换热管的新型能量回收式膜组件(AGMD-HF),以70 g·L^-1的氯化钠溶液为研究对象,考察了膜组件长度和膜孔径大小对膜组件脱盐性能的影响。为直接衡量操作条件、组件参数以及温差、浓差极化现象对传质系数的影响,引入总传质系数,并研究进料温度和膜孔径对总传质系数的影响。实验结果表明,总传质系数随着温度的升高、膜孔径的增大而增大,提高膜孔径可有效提高总传质系数,同时可有效提高通量和造水比。通量随组件长度的增大而减小,而造水比增大,因此在应用过程中可综合考虑通量和造水比以便选择合适的组件长度。     

关联外扩散影响的合成直链烷基苯催化反应动力学

在固定床反应器内进行固体酸催化苯与直链烯烃烷基化反应实验,并将外扩散传质过程与烷基化反应相结合,确定了烯烃转化反应动力学模型方程,以及直链烷基苯、小分子烯烃和小分子烷基苯收率动力学模型方程。利用实验数据进行模型参数估值,建立了关联外扩散影响的烷基化反应动力学模型。研究结果表明,反应温度越高,各反应速率常数和外扩散传质速率常数均越大,而烷基化反应选择性越低。利用烷基化动力学模型对烯烃转化率进行预测的结果表明,随着流体空塔流速提高,烯烃转化率先增大后趋于不变,外扩散阻力对反应的影响趋于忽略不计;并且随着反应温度升高,化学反应速率增大,消除外扩散影响所要求的流体空塔流速更大。     

改良型CO2湿壁塔内气液两相流动规律及传质特性

基于Fluent软件，采用层流模型、VOF模型及非稳态类型，模拟基准湿壁塔和改良型湿壁塔的气液两相流场，分析稳定液膜边界气液两相流场对传质过程的影响。结果表明，随液相入口流量的增大，在稳定液膜边界气相涡旋运动逐渐增强，气液两相混合程度加强，利于改良型湿壁塔的气液两相传质。在一定气相入口流量范围内，随气相入口流量的增大，液膜界面涡旋运动增强，气液两相混合程度加强，利于改良型湿壁塔的气液两相传质；气相入口流量不宜过大，否则导致液相不能沿湿壁柱向下流动形成稳定的液膜，不利于传质。改良型湿壁塔的变径结构和气体挡板均利于气液两相混合，利于传质。改良型湿壁塔的传质过程在液膜边界发生，随液相入口流量的增大液膜厚度增加，液膜表面积增大，有效传质面积增大，利于气液两相传质。通过对比基准湿壁塔和改良型湿壁塔的气液两相流场，改良型湿壁塔内气液两相混合程度加强，更利于传质。     

超重力旋转填充床氧解吸过程的数值模拟

基于旋转填充床流体流动的可视化结果,建立了超重力旋转填充床气液传质过程的数学模型,模拟氮气解吸水中溶解氧的传质过程。模拟结果表明,缩短液相停留时间、提高液相扩散系数都能增大液相传质分系数k_L;总体积传质系数K_La随超重力因子的增加而增大、随温度的上升而增大、随气相流率的增加略有下降、随液相流率的增加明显增大;空腔区传质贡献率随空腔区的增大而增大,随超重力因子的增大而减小;且短暂的停留时间是超重力旋转填充床对传质过程强化的本质原因。模型较好地符合文献的实验数据,误差在±16%以内。     

含盐废水生化处理耐盐污泥驯化的研究

对两种活性污泥,即高盐环境的海边污泥和普通废水处理厂的污泥进行了耐盐污泥对比驯化研究.结果表明:经过一定时间的驯化.两种污泥都可以驯化成具有高降解性能的耐盐污泥,且都能有效地处理含盐废水.驯化后海边污泥在NaCl质量浓度为35 000 ms/L,COD_(Cr)容积负荷为1.8 kg/(m~3·d)时,出水COD_(Cr)去除率可达到97%以上;而普通污泥在NaCl质量浓度为15 000 mg/L,COD_(Cr)容积负荷为1.55 kg/(m~3·d)时,出水COD_(Cr)去除率可达到94%以上.同时对两种污泥在驯化过程中的驯化特点、生物学过程及系统的抗冲击性能进行了比较研究.与普通污泥相比,海边污泥具有驯化期短、耐冲击性能强等特点.     

Prediction of mass transfer coefficients in an asymmetric rotating disk contactor using effective diffusivity

Mass transfer characteristics have been investigated in a 113 mm diameter asymmetric rotating disk contactor of the pilot plant scale for two different liquid–liquid systems. The effects of operating parameters including rotor speed and continuous and dispersed phase velocities on the volumetric overall mass transfer coefficients are investigated. The results show that the mass transfer performance is strongly dependent on agitation rate and interfacial tension, but only slightly dependent on phase flow rates. In this study, effective diffusivity is used instead of molecular diffusivity in the Gr?ber equation for estimation of dispersed phase overall mass transfer coefficient.The enhancement factor is determined experimentally and there from an empirical expression is derived for prediction of the enhancement factor as a function of Reynolds number. The predicted results compared to the experimental data show that the proposed correlation can efficiently predict the overall mass transfer coefficients in asymmetric rotating disk contactors.     

Mass transfer behavior of liquid–liquid slug flow in circular cross-section microchannel

An alkaline hydrolysis reaction was used as the model reaction to investigate the performance of liquid–liquid slug flow microchannel. The specific interfacial area was determined through the photographic snapshot method physically by means of measuring the lengths of relevant slugs. The overall volumetric mass transfer coefficients were calculated through the Danckwerts’ model chemically. The influences of various operating conditions on the slug length, the overall volumetric extraction rate and the mass transfer coefficient were investigated quantitatively. A decreasing trend of volumetric mass transfer coefficients along the channel length was found. The linear dependence of the volumetric extraction rate on the volumetric mass transfer coefficient indicates that the overall rate of the process is determined by the mass transfer process. In addition, the volumetric mass transfer coefficients were correlated for different channel lengths.     

Mass transfer intensification in the process of membrane cleaning using supercritical fluids

Mechanisms of mass transfer intensification in the process of membrane cleaning using supercritical fluids were investigated. Transport properties, hydrodynamics of the solvent flow, mutual solubility of the solvent and the oil contaminant, and capillary effects occurring inside the porous membrane as factors affecting the overall process performance were studied. The analysis was performed using empirical correlations for the transport property coefficients and a model of the process implemented to CFD code developed using the OpenFOAM environment. Supercritical carbon dioxide exhibits favourable transport properties, which are highly tunable with process parameters and contribute to low mass transfer resistance. The investigated process is controlled by diffusive mass transfer inside the membrane pores, so increasing solvent flow rate has limited impact on the overall process rate. Mutual solubility of the oil and solvent phase leads to the effect of swelling of the oil phase, which promotes faster completion of cleaning. Capillary effects inside the pores may be another factor of process acceleration which requires further investigation.     

二氧化钛粉体光催化降解印染废水的研究

采用溶胶-凝胶法制备TiO2粉体,研究TiO2粉体光催化降解印染废水的可行性和影响因素。结果表明,CODC r为268 mg/L的印染废水,用125 W荧光灯照射2 h,脱色率为96%,CODC r去除率为86%。酸度、TiO2用量、光照距离、光照时间等多种因素对光催化降解印染废水效果均有一定影响。同时做了TiO2回收试验,结果表明,TiO2催化性能比较稳定,可重复使用,且脱色率及COD去除率较高。     

活性炭吸附法处理麦麸膳食纤维废水的研究

采用活性炭吸附的方法来处理麦麸膳食纤维废水。实验结果表明,当活性炭的投入量为160 g/L,接触时间为20 m in,温度为55℃,pH值在小于5的条件下能有效处理该废水,CODC r的去除率最高达96.89%,BOD5的去除率最高达96.61%。     

中空纤维更新液膜传质性能的研究

研究了中空纤维更新液膜(HFRLM)技术的传质性能.以CuCl2水溶液-10%P204 煤油-盐酸为实验体系,研究结果表明,中空纤维更新液膜技术可以实现同级萃取-反萃,且总传质系数随料液相流速的增大而增大,在实验条件下,总传质系数受反萃相流速的影响较小.实验研究探讨了混合方式(料液与萃取剂混合和反萃剂与萃取剂混合)和体系分配系数对传质性能的影响.实验结果表明,由于相间分配系数的不同,总传质系数受混合方式的影响较大,以分配系数较大的一相与萃取相混合流经管程的方式对传质过程有利.     

Use of axial dispersion model for determination of Sherwood number and mass transfer coefficients in a perforated rotating disc contactor

The mass transfer process in a perforated rotating disk contactor (PRDC) using a toluene-acetone-water system was investigated.The volumetric overall mass transfer coefficients are calculated in a PRDC column.Both mass transfer directions are considered in experiments.The influences of operating variables containing agitation rate,dispersed and continuous phase flow rates and mass transfer in the extraction column are studied.According to obtained results,mass transfer is significantly dependent on agitation rate,while the dispersed and continuous phase flow rates have a minor effect on mass transfer in the extraction column.Furthermore,a novel empirical correlation is developed for prediction of overall continuous phase Sherwood number based on dispersed phase holdup,Reynolds number and mass transfer direction.There has been great agreement between experimental data and predicted values using a proposed correlation for all operating conditions.     

高固多相生物反应工程

以木质纤维素高固酶解发酵为例,高固形物及其复杂的理化性质会导致体系出现“固体效应”和“水束缚效应”,形成传质速度较低的固液气和微生物复杂多相体系,影响木质纤维素生物转化速率;同时,固形物增加及由此产生的高固酶解发酵流变学特性使以剪切力为主导的机械搅拌在高固多相体系下具有不适应性(会导致酶或微生物活性降低),从而对搅拌方式、反应器及过程设计放大等提出新的要求. 本工作基于课题组多年的研究,提出高固多相生物反应工程的理念,从固体基质特性入手剖析影响高固多相生物反应速率的关键因素,提出了以周期法向力为动力源的过程强化方法,开发出周期蠕动高固多相生物反应系统,以期为高固多相生物反应工程研究提供理论和技术支持.