PTA精制废水处理工艺的优化

阐述了PTA精制废水处理工艺即萃取-超滤-反渗透系统的原理以及该系统的运行情况及出现的问题;分析了反渗透膜受损机理,并通过实验提出了解决方案;通过吸附操作来处理废水中少量的PX,以达到保护膜的作用,从而优化了废水处理工艺;通过实验论证了方案的可行性。     

膜生物反应器在PTA废水深度处理中的应用

在PTA废水深度处理工艺中,膜生物反应器具有较高的浊度、COD的去除率,出水水质较好,在冲击性试验中也表现出良好的工艺稳定性。通过合理设计膜组件的结构和选择恰当的运行方式,可减少膜污染,延长膜清洗周期。     

PTA装置精制单元高负荷运行技术分析

在扩容325kt／a的基础上，分析了洛阳石油化工总厂PTA装置进一步提高生产能力的可行性，并从工艺操作、设备维护、技术改造等方面，探讨影响PTA装置高负荷运行的主要因素及提高生产能力的有效途径。     

PTA精制母液余热回收技术研究

PTA在生产的过程中产生较多精制母液废水,其中含有较多附加值高的成分,对其进行回收利用能够在很大程度上提高资源的利用效率,因此主要对PTA精制母液余热回收技术进行了研究,希望能够提供一定的参考。     

PTA装置精制单元高负荷运行技术分析

分析了扬子石化公司PTA装置在600kt/a改造的设计基础上,进一步提高生产能力的可行性。并从工艺操作、设备维护、技术进步等方面,探讨影响PTA装置高负荷运行的主要因素及提高生产能力的有效途径。     

吸附法处理对苯二甲酸精制单元的废水

生产精对苯二甲酸(PTA)时,往往产生大量废水.在初步筛选实验条件的基础上,选择颗粒活性炭(GAC)作为吸附剂处理经过预处理的PTA精制废水.考察了接触时间、pH、GAC用量等因素对废水中有机污染物去除效果的影响.结果表明,吸附平衡时间为2 h,pH在3.0左右对吸附较为有利,吸附等温线符合Frendlich型,GAC的动态吸附容量为63.46 mg/g,可以用20%的NaOH溶液对GAC进行再生,浸泡5 h后的再生率接近90%.     

用HPCE法分析精制工段废水中的有机物

采用高效毛细管电泳法分析PTA精制废水中的8种有机物,考察了仪器条件、电解液组成及电解液中含有酸或碱时对有机物分离的影响;8种有机物检测的线性范围在0~30 mg/L和0~50 mg/L,分析结果最大相对偏差7.7%,最大相对标准偏差5.8%,最大相对误差10%,加标回收率91.3%~119%,8种有机物检测限在0.45~24.14 mg/L。     

压滤机在PTA行业中的应用分析

介绍在PTA生产中精制单元采用压滤机的工作情况。同传统的离心分离相比,压力过滤具有工艺设备简单、流程短、运行费用低,设备购置及检修费用便宜等优点,是传统工艺技术的重大改进。     

南京工大处理PTA废水项目效益显著

南京工业大学“膜生物反应器处理PTA废水的高效组合工艺”项目通过了江苏省科技厅组织的专家组鉴定和验收。     

消除瓶颈、提高PTA装置精制干燥系统的处理能力

PTA装置采用英国ICI专利技术,年生产能力为7.5万t,生产时间为7000h,自1995年8月试车初始,每当装置PTA部分负荷提至9t/h（设计负荷：10.7t/h）时,二级离心机（M1-1421A/B）至干燥机（M1-1423）系统就输料不畅,经常造成装置停车和产品PTA粉料浪费,这严重影响装置的正常生产。     

Evaporation-condensation derived silicon carbide membrane from silicon carbide particles with different sizes

Silicon carbide ceramic is a promising membrane material because of the high corrosive and high temperature resistance, and the excellent hydrophility. Here, a silicon carbide ceramic membrane with both substrate layer and separate layer composed of pure silicon carbide phase was successfully prepared. The effect of particle size on the microstructure and properties was investigated. The substrates were prepared from three silicon carbide particles at 2200 ℃. With the content increase of fine particle, the average pore size increased from 5.6 μm to 14.1 μm; meanwhile, the flexural strength of the substrate increased from 14.1 MPa to 24.6 MPa. The separation layers were made from particles of 3.0 μm and 0.5 μm. When sintered at 1900 ℃, the separation layer formed pore network with homogeneous structure. Such silicon ceramic membrane can be used in harsh conditions, including high temperature wastewater and strongly corrosive wastewater.     

Sol-gel derived zirconia membrane on silicon carbide substrate

To enhance the high temperature and chemical corrosion resistances of ceramics membrane, a ZrO₂/SiC ceramic membrane was prepared through sol-gel route followed by the dip-coating technique. The substrate layer was made of pure silicon carbide phase by evaporation-condensation process, and the separation layer was made of zirconia phase by solid-phase sintering process. The substrate layer was sintered at 2200 ℃ in the vacuum, and the pores were distributed in a narrow size range from 4.5–6.0 μm. When the membrane was sintered at 700 ℃, a defect-free separation layer formed on the substrate. With the increase of sintering temperature, the average pore size of the separation layer declined from 63 to 48 nm, and the water permeability declined from 355 to 273 L/(m²·h·bar). Our results indicate the ZrO₂/SiC ceramic membrane has potential applications in the separation of high temperature or chemically corrosive wastewaters.     

碳化硅陶瓷膜处理采油污水的中试试验

用0.02μm的多通道非对称性碳化硅陶瓷膜对采油污水进行了现场中试。在各种运行条件下,陶瓷膜出水SS<1.0 mg/L,油<10 mg/L,粒径中值<1.0μm。还考察了不同运行条件下陶瓷膜膜通量和跨膜压差的变化,以及强化混凝过滤对膜通量的影响。根据试验结果对陶瓷膜在采油污水处理中的进一步研究提出了建议,并对其工程应用前景进行了展望。     

具备雷达吸波功能的碳化硅纤维的研究进展

概述了雷达吸波材料的特点、应用领域,以及碳化硅纤维作为雷达结构吸波材料的吸收剂和增强剂的要求和应用。综述了赋予碳化硅纤维雷达波吸收功能的4种方法(即高温处理法、表面处理法、掺杂异元素法和改变纤维截面形状法)的研究进展,比较了这4种方法的优缺点,并指出了今后的研究方向。     

Growth of silicon carbide nanotubes in arc plasma treated silicon carbide grains and their microstructural characterizations

Silicon carbide nanotubes were found to grow in straight as well as curved configurations by treating silicon carbide grains in an arc plasma reactor/furnace followed by 3 h of cooling (in air). By increasing the plasma treatment time from 16 min to 20 min, multi-wall tubes were found to change to single wall tubes with reduction in diameter from few nm to sub-nm. Typical in situ grown nanotubes were characterized by XRD, TEM, SAED, HRTEM, EDS and micro Raman spectroscopy, and it is established from these evaluations that the nanotubes are made up of silicon carbide and not carbon. A possible mechanism, involving reaction between the plasma dissociated carbon (solid) forming carbon nanotube and the left-out silicon (existing in vapour state) during the cooling period (3000–2680 °C), is suggested to be responsible for silicon carbide nanotube formation in the plasma assisted process.     

Processing and properties of glass-bonded silicon carbide membrane supports

Porous SiC membrane supports were fabricated from SiC and glass frit at a temperature as low as 850 °C in air by a simple pressing and heat-treatment process. The effects of the initial SiC particle size and frit content on the porosity, flexural strength, and air permeation of the membrane supports were investigated. During heat-treatment, the glass frit transformed to a viscous glass phase, which acted as a bonding material between SiC particles and as a protecting layer for severe oxidation of SiC particles. The porosity of the porous SiC membrane supports could be controlled within a range of 37–46% with the present set of processing conditions. The typical flexural strength, permeability, and specific air flow rate of the porous membrane supports fabricated using 23 μm SiC particles with 15 wt% glass frit were 75 MPa, 4.2 × 10⁻¹³ m², and 32.4 L/min/cm², respectively.     

Microstructures and properties of solid-state-sintered silicon carbide membrane supports

Porous solid-state-sintered SiC (S–SiC) membrane supports were successfully fabricated by pressureless sintering at 2150 °C in argon, using fine and coarse graded SiC powders as the main starting material. There were uniformly distributed and fully interconnected pores in as-acquired S–SiC membrane supports, accompanied with similar apparent porosities for all of them. When increasing the size of coarse SiC powder, their average pore sizes were distinctly enlarged from ∼1.6 μm to ∼2.3 μm, which significantly enhanced their nitrogen permeability from 0.9 × 10⁻¹³ m² to 2.6 × 10⁻¹³ m². Moreover, S–SiC membrane supports possessed outstanding flexure strengths of 134.1 ± 21.3 MPa at room temperature and 88.7 ± 8.4 MPa at 1000 °C owing to strong interface bonding between SiC grains. Compared with the traditional SiO₂ -bonded and mullite-bonded SiC supports, S–SiC membrane supports presented their great superiority in high-temperature flexure strength as well as acid and alkali corrosion resistance, which permitted them to be potentially applied in high-temperature and strongly corrosive environments.     

反应与分离相耦合的钢铁酸洗液处理研究

采用反应与分离相耦合的途径,用19通道陶瓷膜元件构建了5L气升式膜反应器,并就其用于钢铁酸洗液的处理进行了研究.结果表明:在0.5～2.5 m~3/h曝气量范围内,稳定膜通量能维持在60L/(m~2·h)以上,且提高曝气量有利于提高循环液体流速.在稳定操作条件下,料液中氢氧化铁悬浮物浓度、温度(1～45℃)和膜两侧压差(0.025～0.1MPa)均与膜通量呈线性关系.当处理Fe~(2+)质量浓度为400ms/L的酸洗废液时,在溶氧度>70%、压差0.1 MPa、18～25℃、pH为6-9、HRT=2h条件下,出水浊度<2 NTU,pH符合国家排放标准.     

炼化污水抗污染反渗透膜回用处理中试研究

采用氧化混凝-复合过滤-反渗透组合工艺处理大庆炼化公司外排污水，考察了预处理系统的操作参数和抗污染反渗透膜组件性能的变化规律，为工程设计提供了基本参数。结果表明，预处理出水水质主要受过滤速度和絮凝剂加药量的影响，而膜污染是影响反渗透系统运行的主要因素。系统出水水质符合工业用水软化除盐设计规范。     

反应烧结碳化硅高温性能的研究进展

反应烧结碳化硅具有优良的力学性能、抗侵蚀性能和抗氧化性能等优点,是一种高致密度、低成本和净尺寸成型的材料.但由于反应烧结法的特殊工艺,反应烧结碳化硅中常含有较多游离硅,严重损害了材料的高温性能.主要阐述了反应烧结碳化硅高温力学性能、抗氧化性能、导热性能和抗热震性能的研究现状,并总结了近年来降低游离硅含量、提高反应烧结碳...