剪切解络-超滤分离金属关键指标预测与验证

根据剪切解络-超滤过程中金属离子的动态浓度关系和质量守恒定律,采用CodeBlocks17.12软件编写程序,建立了剪切解络-超滤工艺关键指标预测模型,实现了金属离子浓度、回收率、体积稀释倍数等指标的预测,并用实验加以验证。依次在转速800 r/min、1 400 r/min、3 000 r/min下回收模拟废水中43 μg/L的Co²⁺、995 μg/L的Ni²⁺和88 μg/L的La³⁺,3种金属的回收率均达99.8%以上时,超滤过程体积稀释倍数的预测值分别为7.0、7.5、5.75,实验值分别为7.5、7.25、6.25,可见预测值与实验值基本一致。本模型对研究方案制定和调整有实际指导意义。     

空气-氧化剂联合氧化法制备聚合硫酸铁的研究

用废铁屑和H2SO4为原料,研究了空气—氧化剂联合氧化法制备聚合硫酸铁的工艺条件,如原料配比、反应温度、反应时间、溶液pH值等。结果表明,在[SO24-]∶[Fe]T=1.40~1.45∶1,反应温度为60℃,经6h的空气氧化后再用氧化剂继续氧化,可减少氧化剂用量80%,产品质量达到国家标准。     

Synthesis of Chelating Resin PETU and Its Adsorption to Ag(I)

A novel chelating resin (PETU) with thiourea groups in its main chain was synthesized by the reaction of O,O'-butane-1,4-diyl dicarbonisothiocyanatidate and triethylene tetraamine. The adsorption of Ag(I) on PETU was investigated by batch tests. The results showed that adsorption data fitted Boyd's diffusion equation of liquid film and the adsorption was controlled by liquid film diffusion. Under the temperatures between 15～60 ℃, the adsorption capacity decreased with the increase of temperature, and increased with the increase of initial concentration of Ag(I). The experimental data fitted Langmuir and Freundlich equations, and the correlation coefficients for Langmuir equation were between 0.9965～0.9998, and those for Freundlich equation were between 0.8211～0.9810, and increased with the adsorption temperature. △H, △G and △S calculated by thermodynamic formulae were all negative, which meant that the adsorption process was exothermic and spontaneous, and the entropy decreased during the process. XPS results showed that N, S and O atoms were the electron donors to coordinate with Ag.     

Modified PVA-CA blend ultrafiltration membrane by alkali metal chloride

1　INTRODUCTIONUltrafiltration(UF )isamembraneseparationprocesswhichhasfoundwideapplicationsinsuchfieldsaspetroleum ,textile ,bioseparation ,pharma cy ,food ,wastewatertreatment,preparationofdrinkingwater[13] .Manyresearchershavedevotedthemselvestoimprovingthe permeationfluxoftheUFmembraneunderthesamerejection ,andprevent ingtheformationofafoulinglayeronthesurfaceofUFmembrane .Manynovelmembranematerialsandvariousmodificationtechnologieshavebeendevel oped ,somemodificationmethods ,suchas…     

金属-聚乙烯醇-二醋酸纤维素共混复合亲水超滤膜的制备

在大孔径金属纤维毡上制备了金属-聚乙烯醇-二醋酸纤维素(金属-PVA-CA)共混复合超滤膜及金属-NaCl改性PVA-CA共混复合超滤膜。该复合超滤膜在操作压力为0.25-0.45 MPa,处理质量浓度为1000 mg/L的含油乳化液,可获得40-70 L／(m2·h)的透液通量,COD截留在90％以上。研究还表明金属-NaCl改性PVA-CA共混复合超滤膜的综合性能略优于金属-PVA-CA共混复合超滤膜。     

Synthesis of Chelating Resin PETU and Its Adsorption to Ag(I)

A novel chelating resin (PETU) with thiourea groups in its main chain was synthesized by the reaction of O,O'-butane-1,4-diyl dicarbonisothiocyanatidate and triethylene tetraamine. The adsorption of Ag(I) on PETU was investigated by batch tests. The results showed that adsorption data fitted Boyd's diffusion equation of liquid film and the adsorption was controlled by liquid film diffusion. Under the temperatures between 15~60℃, the adsorption capacity decreased with the increase of temperature, and increased with the increase of initial concentration of Ag(I). The experimental data fitted Langmuir and Freundlich equations, and the correlation coefficients for Langmuir equation were between 0.9965~0.9998, and those for Freundlich equation were between 0.8211~0.9810, and increased with the adsorption temperature. DH, DG and DS calculated by thermodynamic formulae were all negative, which meant that the adsorption process was exothermic and spontaneous, and the entropy decreased during the process. XPS results showed that N, S and O atoms were the electron donors to coordinate with Ag.     

×Synergistic action of non-solvent induced phase separation in preparation of poly（vinyl butyral） hollow fiber membrane via thermally induced phase separation

A systematic study of air gap distance effects on the structure and properties of poly（vinyl butyral） hollow fiber membrane via thermally induced phase separation （TIPS） has been carried out. The results show that the hollow fiber membrane prepared at air gap zero has no skin layer; the pore size near the outer surface is larger than that near the inner surface; and the special pore channel-like structure near the outer surface is formed, which is quite different with the typical sponge-like structure caused by TIPS and the finger-like structure caused by non-solvent induced phase separation （NIPS）, because of the synergistic action of non-solvent induced phase separation at air gap zero. The pore size gradually decreases from outer surface layer to the intermediate layer, but increases gradually from intermediate layer to the inner surface layer. With the increase of air gap distance, the pore size near the outer surface gets smaller and a dense skin layer is formed, and the pore size gradually increases from the outer surface layer to the inner surface layer. Water permeability of the hollow fiber membrane decreases with air gap distance, the water permeability decreases sharply from 45.50× 10^-7 to 4.52× 10^-7 m^3/（m^2-s.kPa） as air gap increases from 0 to 10 mm at take-up speed of 0.236 m/s, further decreases from 4.52×10^-7 to 1.00×10 ^-8m^3/（m^2.s·kPa） as the air gap increases from 10 to 40 mm. Both the breaking strength and the elongation increase with the increase of air gap distance. The breaking strength increases from 2.25 MPa to 4.19 MPa and the elongation increases from 33.9% to 132.6% as air gap increases from 0 mm to 40 mm at take-up speed 0.236 m/s.     

Effects of coagulation bath temperature on structure and performance of poly （vinyl butyral） hollow fiber membranes via thermally induced phase separation

Poly （vinyl butyral） （PVB） hollow fiber membranes were fabricated via thermally induced phase separation （TIPS）. The effects of coagulation bath temperature （CBT） on the structure and performance of membranes were investigated in detail. The morphologies of the membranes were studied by scanning electron microscopy （SEM）, the performances of water permeability, rejection, breaking strength and elongation were measured, respectively. The results indicate that all the membranes have the asymmetric morphology and the thickness of the skin layer decreases and the pore size of the outer layer increases with the increase of CBT. The permeability of membranes prepared at air gap 1.0 cm and take-up speed 0.253 m/s increases from 1.047×10-7 to 5.909×10-7 m3/（m2·s-kPa） with the CBT increasing from 20 ℃ to 40℃, and sharply increases to 35.226×10 7 m3/（m2.s.kPa）once the CBT arrives at 50 ℃. While the carbonic ink rejections have no significant decrease, totally exceed 98%, but that of acid-maleic acid copolymer greatly decreases with the increase of CBT. Both the breaking strength and elongation decrease with the increase of CBT.     

超滤过程膜污染控制技术研究进展

探讨了超滤过程中的浓差极化和膜污染形成的机理以及影响膜污染的因素 ,综述了预防和控制膜污染的各种技术 ,包括膜材及孔径的选择、膜组件的设计、原料的预处理、膜过程的强化及膜的清洗等技术。指出开发新型实用的耐污染膜和能耗少、寿命长、抗污染的膜组件 ,对膜过程工艺进行优化控制 ,开发高效的在线清洗技术和经济便利的离线清洗技术等是尚待攻克的课题。     

金属—改性PVA复合亲水分相膜处理含油乳化废水

用一定浓度的缩醛改性聚乙烯醇作铸膜液 ,以不锈钢金属纤维烧结毡作基材 ,制备了用于处理O/W型含油废水乳化液的复合亲水分相膜 .用该金属 -改性PVA亲水分相膜处理含油乳化废水 ,具有操作压力小、处理量大和除油效果好等优点 .用该分相膜处理质量浓度为10 0 0mg/L的模拟含油乳化液 ,在 4 0 0r/min的搅拌速度下 ,当操作压力为 0 5 4kPa时 ,即可获得 2 2 38m3/(m2 ·h)的透液速率 ,除油率可达 99 5 % .研究结果还表明 ,控制一定的操作条件 ,使透液速率不超过临界透液速率是获得高效除油率的关键 ,但此分相膜用于处理含乳化剂的乳化废水时效果不佳