四水硝酸钙结晶动力学研究

实验考察了四水硝酸钙在实际体系即硝酸酸解磷矿后所得的酸解液中,在混合悬浮混合排出（MSMPR）结晶器里,在19 ℃条件下,不同停留时间对其结晶动力学参数的影响,得到其成核速率与悬浮密度、生长速率的关系式：B0=5.209 8×104MT1.056 3G1.109 4。此外,还考察了在实际体系中,在19 ℃、45 min停留时间条件下,不同搅拌速率对四水硝酸钙结晶动力学参数的影响,得到关联式：B0=1.732 5×103 MT1.037 1G1.021 3np0.606 6。将实际体系下得到的两式与文献中 Ca（NO₃）₂-H₂O和Ca（NO₃）₂-H₃PO₄-HNO₃-H₂O体系下的两式进行比较,比较结果对实际工业生产具有重要的指导意义。     

提高本菲尔特（脱碳）溶液质量浅析

对脱碳溶液在装置运行中影响CO2吸收效果的因素进行分析查找,找出原因,并提出相应的解决方法和措施．通过对脱碳溶液的优化操作,提高溶液质量,实现装置的最优化的节能降耗。     

Combined effects of temperature and Reynolds number on drag‐reducing characteristics of a cationic surfactant solution

The drag‐reducing characteristics in the turbulent channel flow of dilute cationic surfactant solution, cetyltrimethyl ammonium chloride (CTAC)/sodium salicylate (NaSal) aqueous solution, were experimentally investigated in a closed loop fluid flow facility at different temperatures. The mass concentrations of the surfactant solution ranged from 75 to 200 ppm, and the temperatures ranged from 15 to 55°C. The cationic surfactant solution showed a great drag‐reducing ability, which was greatly affected by concentration, temperature, and Reynolds number. It was found that there existed a critical temperature T_c in each solution at different concentrations. Above T_c, drag‐reduction level decreases and reaches the behaviour of water flow without drag‐reducing ability. A new temperature parameters T_f, was proposed, and the difference between T_c and T_f can represent the effective temperature range for the drag reduction at a certain Reynolds number. The variation tendency of T_f and T_c with Reynolds numbers can give the guidance of selecting effective drag reduction range to the practical application in the district heating systems (DHS). It was supposed that temperature and shear stress are two kind of energy applied on the surfactant microstructure, which can be helpful to the surfactant network formation or dissociation depending on their values. © 2011 Canadian Society for Chemical Engineering     

Synthesis and Polymerization of N-(2,4,5-trichlorophenyl) Acrylamide Monomer and its Thermal and Antimicrobial Properties

N-(2,4,5-trichlorophenyl) acrylamide (CPAM) new monomer was synthesized by condensing acrylic acid and 2, 4, 5-tri chloro aniline using dicyclohexyl carbodiimide as a coupling agent. The CPAM monomer was characterized by ¹HNMR, FT-IR, and mass spectroscopy. Further, the CPAM monomer was homopolymerized by solution technique in toluene using azobisisobutyronitrile (AIBN) as an initiator. The CPAM monomer and its homopolymer were employed to screen an antimicrobial activity against E. coli, S. aureus, M. luteus, and B. subtilis microorganisms, which are representative of Gram-positive and Gram-negative bacteria using ciprofloxacin and Sulphametoxazol as standards. The results showed that the CPAM monomer has good antimicrobial activity, comparable with its homopolymer. Also, the CPAM homopolymer was investigated for its thermal stability by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC).     

30%草甘膦水剂的配方研究

对几种表面活性剂在30%草甘膦水剂中的应用进行了筛选和相关性能的研究,最佳配方为草甘膦原粉30%、氨水4.0%～5.0%、AOS（α-烯基磺酸钠）4.0%、APG（烷基糖苷）6.0%、茶皂素0.50%、有机硅消泡剂0.10%~0.50%。其表面张力、起泡性、泡沫稳定性、黏度、常温热贮稳定性指标均表现优异,符合草甘膦水剂的质量标准。     

反渗透膜碳酸钙污染过程模拟以及膜清洗研究

采用氯化钙和碳酸氢钙配置原水,模拟反渗透膜使用环境,测定膜污染后膜性能的变化趋势,并对膜进行了清洗,对比了不同阶段膜通量的恢复情况,并比较了不同清洗温度下膜通量的恢复情况。结果表明:在本实验条件下,膜通量随着膜污染的加剧呈现出先快后慢的下降趋势,而脱盐率呈先慢后快的下降趋势;污染的膜经过酸洗后,膜性能恢复到初始的98.6%;清洗温度越高,膜通量恢复越好。     

微波辐射法合成阴离子型聚丙烯酰胺

以丙烯酰胺（AM）和丙烯酸钠（AA-Na）为原料,过硫酸铵为引发剂,N,N-亚甲基双丙烯酰胺为交联剂,用微波辐射进行水溶液聚合制备可溶解的阴离子型聚丙烯酰胺。探讨丙烯酸中和度、单体浓度、引发剂用量、交联剂用量及温度等对相对分子质量的影响。结果表明,单体浓度为19%,中和度为80%,引发剂用量为0.05%,交联剂用量为0.002%,反应温度35℃条件下合成的聚丙烯酰胺（PAM）的相对分子质量最高。     

烧结网冒泡压力变化的原因分析

论述了单层滤网(烧结网控制层)与用单层滤网做成烧结网之间的初始冒泡压力值变化的关系,并总结了怎样的烧结网配方才能尽量减小对滤网的损伤,初始冒泡值接近单层滤网初始冒泡值的方法。     

Study on Potassium Permanganate Chemical Treatment of Discarded Reverse Osmosis Membranes Aiming their Reuse

Membrane-based industrial desalination/demineralization plants generate a considerable amount of discarded membranes. This work studies the effects of the chemical treatment with potassium permanganate solutions in combination with chemical cleaning of three years old composite polyamide/polysulfone reverse osmosis membranes (8″ modules) in order to make them reusable in other applications than reverse osmosis and to increase their life cycles. The performance of membranes with 60 cm² was evaluated in terms of water permeate flux and salt rejection, two properties that can be easily measured in industrial systems. Potassium permanganate treatment degraded the selective layer, improving the water permeate flux of at least 15% from its initial value at the expense of decreased salt rejection. The formation of a manganese oxide layer was detected which reduced subsequent oxidative treatment efficacy. Citric acid was used as a cleaning agent after the oxidation steps, removing part of the manganese oxide layer; the result was an enhanced oxidative process, which increased the permeate flux even more and decreased the loss of salt rejection. Furthermore, to verify the stability of the treatment, the membrane was submitted to a long-term oxidizing experiment.     

Effect of PVP Molecular Weights on the Properties of PVDF-TiO2 Composite Membrane for Oily Wastewater Treatment Process

Polyvinylidene fluoride (PVDF) hollow fiber ultrafiltration membranes consisted of TiO₂ and different molecular weight (M_w) of polyvinylpyrrolidone (PVP) (i.e., 10, 24, 40, and 360 kDa) were prepared to treat synthesized oily wastewater. The membrane performances were characterized in terms of pure water flux, permeate flux, and oil rejection while their morphological properties were studied using SEM, AFM, and tensile tester. Results show that the PVDF-TiO₂ composite membrane prepared from PVP40k was the best performing membrane owing to its promising water flux (72.2 L/m².h) coupled with good rejection of oil (94%) when tested with 250 ppm oily solution under submerged condition. It is also found that with increasing PVP M_w, the membrane tended to exhibit higher PVP and protein rejection, greater mechanical strength, smaller porosity, and a smoother surface layer. Regarding the effect of pH, the permeate flux of the PVDF-PVP40k membrane was reported to increase with increasing pH from 4 to 7, followed by decrease when the pH was further increased to 10. Increasing oil concentration in the feed solution was reported to negatively affect the water flux of PVDF-PVP40k membrane, owing to the formation of thicker oil layer on the membrane surface which increased water transport resistance. A simple backflushing process on the other hand could retrieve approximately 60% of the membrane original flux without affecting the oil separation efficiency. Based on the findings, the PVDF-TiO₂ membrane prepared from PVP40k can be potentially considered for oily wastewater treatment process due to its good combination of permeability and selectivity and reasonably high water recovery rate.