混合药物粉尘输运过程静电特性实验研

兽药制药粉尘加工工艺过程中,由于粉尘颗粒之间或颗粒与设备、管壁之间的碰撞、摩擦,导致装置内部静电荷量积聚,激发静电放电,粉尘燃烧或爆炸的事故频发。实验主要通过包括粉尘与管材摩擦的漏电电流测试和静电放电火花对粉尘云点燃敏感性测试两部分。结果表明:单一药物药粉的静电漏电电流随着管材管径的增大,管长的增长,静电漏电电流逐渐变大;随着倾斜角的增大,静电漏电电流先增大后降低;镀锌铁管的漏电电流大于PVC管,电荷逸散速度更快。单一兽药粉的粉尘云放电火花最小点燃能量随质量浓度的变化,呈现二次曲线的变化趋势。混合兽药粉与单一兽药粉的漏电电流和粉尘云放电火花最小点燃能量的测试结果的变化趋势是一致的。     

加油站油流静电在线监测技术及应用

为提高加油站安全作业水平,分析了卸油、加油过程中油流静电起电因素和常用检测方法。根据高斯定理从理论上探讨了通过测量输油管道内中心电位得到油流静电电荷密度的检测原理,并基于杆球传感器以及压电传感器技术设计开发了油品静电在线监测仪,实现了对加油枪前后、加油机内部管线及过滤器油品带电情况的在线监测。测试结果表明:基于此静电监测技术,建立加油站油流电荷监测与联锁控制措施,可有效避免油品静电燃爆事故的发生,保障加油站安全生产。     

Improved blending strategy for membrane modification by virtue of surface segregation using surface-tailored amphiphilic nanoparticles

Membrane modification is one of the most feasible and effective solutions to membrane fouling problem which tenaciously hampers the further augmentation of membrane separation technology. Blending modification with nanoparticles (NPs), owing to the convenience of being incorporated in established membrane production lines, possesses an advantageous viability in practical applications. However, the existing blending strategy suffers from a low utilization efficiency due to NP encasement by membrane matrix. The current study proposed an improved blending modification approach with amphiphilic NPs (aNPs), which were prepared through silanization using 3-(Trimethoxysilyl)propyl methacrylate (TMSPMA) as coupling agents and ZnO or SiO₂ as pristine NPs (pNPs), respectively. The Fourier transform infrared and X-ray photoelectron spectroscopy analyses revealed the presence of appropriate organic components in both the ZnO and SiO₂ aNPs, which verified the success of the silanization process. As compared with the pristine and conventional pNP-blended membranes, both the ZnO aNP-blended and SiO₂ aNP-blended membranes with proper silanization (100% and 200%w/w) achieved a significantly increased blending efficiency with more NPs scattering on the internal and external membrane surfaces under scanning electron microscope observation. This improvement contributed to the increase of membrane hydrophilicity. Nevertheless, an extra dosage of the TMSPMA led to an encasement of NPs, thereby adversely affecting the properties of the resultant membranes. On the basis of all the tests, 100% (w/w) was selected as the optimum TMSPMA dosage for blending modification for both the ZnO and SiO₂ types.

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几种捕集高比电阻粉尘的电收尘器的机理

详细论述了影响电收尘器收尘效率的主要因素,指出常规电收尘器在捕集高比电阻粉尘时产生反晕现象,从而使收尘效率大大降低,并且提出几种适用于捕集高比电阻粉尘的电除尘结构,对开发新型电收尘器有一定的指导作用。     

湿式电除尘技术及其在电厂的应用前景探讨

作为大气复合污染物控制系统的终瑞精处理技术装备,湿式电除尘器可用于控制PM2.5、酸雾、气溶胶、亚微米颗粒物、汞、重金属及二恶英等污染物的排放。论述了湿式电除尘器的工作原理、技术特点、结构及设计形式,探讨了湿式电除尘器在我国燃煤电厂的应用前景。     

海藻酸钠/锆@钙水凝胶的制备及其对磷的吸附研究

利用简便的方法制备了一种新型的海藻酸钠/锆@钙(SA/Zr@Ca)水凝胶材料,采用SEM、XRD对该材料进行了表征,并通过拟合吸附等温模型及吸附动力学模型,结合XPS和Zeta电位分析,研究了该材料对磷酸盐吸附的性能和机理.结果表明,该材料为非晶态的无定型材料.在溶液初始pH为2～7时,SA/Zr@Ca对磷酸盐(以PO...     

烧结机头电除尘灰的处理与利用

针对烧结机头除尘灰的组成和特点进行分析,探讨了目前国内钢铁企业对烧结机头除尘灰处理的现状和存在的问题,对烧结机头除尘灰固体废弃物的处理与利用技术的发展提出了一些建议和展望。     

基于鱼骨图和层次分析法的石油静电事故影响因素分析

针对石油静电事故影响因素的复杂性、多层次性和不确定性的特点,采用鱼骨图分析法,找出了引发石油静电事故的影响因素,确定出6个主因素、25个子因素的石油静电事故评价指标体系。应用层次分析法确定了各个影响因素的重要程度,分析出导致石油静电事故的重要因素。结果表明,6个主因素中,隶属于生产操作工艺和安全生产管理的操作错误、人体静电和接地故障3个主因素权重之和高达0.792,是引发石油静电事故的主导因素;子因素中预防的重点应放在喷溅式装卸油、化纤品与人体摩擦和接地线损坏方面。鱼骨图分析法和层次分析法的联合应用,合理地解决了石油静电事故影响因素分析难题,具有一定的推广应用价值。     

Effect of iron addition on the performance of anoxic-oxic membrane process and biological phosphorus removal北大核心CSCD

In order to solve the problem of poor treatment of phosphorus in membrane bioreactor (MBR) with long sludge retention time (SRT), a ferric salt was added to enhance phosphorus removal; FeCl36H2O (Fe/P = 2.0) was added to the reactor. The removal efficiency of nitrogen, organic matters, and phosphorus in the MBR was investigated systematically. Moreover, this study focused on the membrane performance, the change of active sludge flora, and the effect of adding a ferric salt on membrane fouling before and after the addition. It was seen that adding the ferric salt could not affect the removal of COD and NH4 +-N and the removal rate of COD and NH4 +-N reached over 90%. However, the average removal rate of phosphorus was 52%, while the removal rate increased by nearly 40% after adding the ferric salt. The effects of adding ferric salts on the dominant bacteria and biological phosphorus removal of activated sludge were further studied. The results showed that the addition of ferric salt (Fe/P = 2.0) decreased the diversity of active sludge flora and relative abundance of some phosphorusaccumulating organisms and had a negative effect on biological phosphorus removal. The analysis of transmembrane pressure difference (TMP) recording revealed that the concentration of iron salts did not exacerbate membrane fouling. The results showed that the concentration of iron salts entering the membrane bioreactor would reduce the relative abundance and phosphorus removal efficiency of the activated sludge in the system to a certain extent, but it had no obvious effect on membrane fouling. It allowed the effluent to attain acceptable standards, especially with respect to phosphorus removal efficiency. © 2018 Science Press. All rights reserved.     

Comparison of membrane fouling in ultrafiltration of down-flow and up-flow biological activated carbon effluents

The UF membrane fouling by down- and up-flow BAC effluents were compared. Up-flow BAC effluent fouled the membrane faster than down-flow BAC effluent. The combined effects dominated irreversible fouling. The extent of fouling exacerbated by inorganic particles was higher. The TMP, permeate flux, and normalized membrane flux during 21 days of UF of DBAC and UBAC effluents. Fouling during ultrafiltration of down- and up-flow biological activated carbon effluents was investigated to determine the roles of polysaccharides, proteins, and inorganic particles in ultrafiltration membrane fouling. During ultrafiltration of down- flow biological activated carbon effluent, the trans-membrane pressure was≤26 kPa and the permeate flux was steady at 46.7 L?m⁻²?h⁻¹. However, during ultrafiltration of up-flow biological activated carbon effluent, the highest trans-membrane pressure was almost 40 kPa and the permeate flux continuously decreased to 30 L?m⁻²?h⁻¹. At the end of the filtration period, the normalized membrane fluxes were 0.88 and 0.62 for down- and up-flow biological activated carbon effluents, respectively. The membrane removed the turbidity and polysaccharides content by 47.4% and 30.2% in down- flow biological activated effluent and 82.5% and 22.4% in up-flow biological activated carbon effluent, respectively, but retained few proteins. The retention of polysaccharides was higher on the membrane that filtered the down- flow biological activated effluent compared with that on the membrane that filtered the up-flow biological activated carbon effluent. The polysaccharides on the membranes fouled by up-flow biological activated carbon and down- flow biological activated effluents were spread continuously and clustered, respectively. These demonstrated that the up-flow biological activated carbon effluent fouled the membrane faster. Membrane fouling was associated with a portion of the polysaccharides (not the proteins) and inorganic particles in the feed water. When there was little difference in the polysaccharide concentrations between the feed waters, the fouling extent was exacerbated more by inorganic particles than by polysaccharides.