氯化物熔盐体系共电沉积法制备Al-Li-Gd合金的研究

在773K时,采用循环伏安法、方波伏安法和计时电位法研究了Gd(III)和Al(III)在LiCl-KCl-AlCl3-GdCl3熔盐体系中的电化学行为及共电沉积制备Al-Li-Gd合金,并借助XRD,SEM-EDS对所得合金进行表征.结果表明,Gd(III)在预先沉积的Al上欠电位沉积形成了两种Al-Gd金属间化合物,当电流密度超过-279.5 mA/cm2时,Al,Gd和Li能同时析出.通过调节熔盐中AlCl3的含量可以获得不同相的Al-Li-Gd合金.Al-Li-Gd合金含有Al2Gd和Al2Gd3,Gd在合金中分布不均匀,而Al的分布相对均匀.     

纳米TiO2颗粒与腐殖酸和SDBS的相互作用机制

为保障水环境生态安全性及纳米技术的可持续发展,研究了纳米Ti O2颗粒与腐殖酸(HA)和十二烷基苯磺酸钠(SDBS)的相互作用,考察了p H、离子浓度对其相互作用的影响.结果表明,腐殖酸和十二烷基苯磺酸钠均会抑制纳米颗粒的聚集,增强颗粒的迁移能力.p H和离子浓度对相互作用有显著的影响.当溶液的p H接近等电点时,纳米颗粒表面带正电荷,因电荷屏蔽效应,HA和SDBS在颗粒表面的吸附量增大;随着IS的增加,由于双电层压缩作用,HA及SDBS在纳米Ti O2表面的吸附量也不断增加.最后,讨论了纳米Ti O2颗粒与HA及SDBS的相互作用机制,即可分为聚集、接近和强相互作用3个步骤.同时比较了HA和SDBS与纳米Ti O2颗粒相互作用机制的不同.     

Effects of temperature on the degradation pathway of domestic sewage in upfiow anaerobic sludge blanked reactor

To understand the anaerobic degradation pathway of domestic sewage,three lab-scale upflow anaerobic sludge blanked reactors(UASB)were employed to study the degradation pathway of different particle size and the effect of temperature on this process.Under the operation conditions of the hydraulic retention time of 24 h,the MI,VSS of approximate 11200 mg· L-1 and the water temperature at 10,15 and 20℃,the overall degradation pathway of soluble fraction was characterized according to zero-order kinetics.As for the colloidal fraction(between 0.45 and 4.5 μm),the degradation processes followed a first-order kinetic,and should firstly disintegrated into soluble fraction before finally degrading.In contrast,suspended solids(bigger than 4.5 μm)degraded to soluble and colloidal fractions according to first-order kinetics,and the colloidal fraction originating from suspended solids further degraded into soluble fraction which had the same degradation kinetics as the original soluble fraction.There existed the difference of temperature effect on different fraction degradation.Under the temperature at 20,15 and 10 ℃,the first-order rate constant of suspended solids depredating into collide was 4.97,3.01 and 1.01 d-1 respectively.Whereas the degradation of collide to soluble fraction was slightly affected by the temperature change.On the other hand,the zero-order degradation rate constant of soluble fraction was 0.26,0.18 g and 0.12 gCOD · gVSS-1d-1,respectively.     

浅述微型计算机直流稳压电源

本文阐述了目前微型计算机广泛采用的脉冲宽度调制式直流稳压电源的工作原理和特点，并介绍维修经验。     

温度对复合式A/O工艺的影响研究

针对温度因素对污水处理效果的影响,造成冬季北方大多数污水处理厂运行效果变差的问题,在中试试验的基础上,以城市污水为处理对象,进行了温度对复合式A/O工艺处理效能和微生物特性的影响研究。研究结果表明,系统对于温度的变化较为敏感,当温度由20℃下降到6℃时,系统对COD_(Cr)的去除率下降到60%,对NH_3—N、TN的去除率下降到40%以下;6℃时的吸附性能和沉降速率仅为20℃时的85%和40%;活性污泥和生物膜的SOUR下降到46mgO_2/(mgMLVSS·min)和33mgO_2/(mgMLVSS·min),SOUR下降的程度要比VSS/SS大。研究结果对于理解温度对处理效能的影响和本质原因具有重要的意义,特别对污水处理厂运行具有借鉴意义。     

Effects of temperature on the degradation pathway of domestic sewage in upflow anaerobic sludge blanked reactor

To understand the anaerobic degradation pathway of domestic sewage,three lab-scale upflow anaerobic sludge blanked reactors (UASB) were employed to study the degradation pathway of different particle size and the effect of temperature on this process.Under the operation conditions of the hydraulic retention time of 24 h,the MLVSS of approximate 11200 mg·L-1 and the water temperature at 10,15 and 20℃,the overall degradation pathway of soluble fraction was characterized according to zero-order kinetics.As for the colloidal fraction (between 0.45 and 4.5 μm),the degradation processes followed a first-order kinetic,and should firstly disintegrated into soluble fraction before finally degrading.In contrast,suspended solids (bigger than 4.5 μm) degraded to soluble and colloidal fractions according to first-order kinetics,and the colloidal fraction originating from suspended solids further degraded into soluble fraction which had the same degradation kinetics as the original soluble fraction.There existed the difference of temperature effect on different fraction degradation.Under the temperature at 20,15 and 10 ℃,the first-order rate constant of suspended solids depredating into collide was 4.97,3.01 and 1.01 d-1 respectively.Whereas the degradation of collide to soluble fraction was slightly affected by the temperature change.On the other hand,the zero-order degradation rate constant of soluble fraction was 0.26,0.18 g and 0.12 gCOD·gVSS-1d-1,respectively.     

碳源对低温A2O工艺反硝化除磷的影响

为丰富低温污水脱氮除磷途径并了解碳源对A2O工艺反硝化除磷的影响程度,采用单独的乙酸钠、丙酸钠及其混合物对A2O工艺处理低温污水时厌氧释磷与缺氧反硝化吸磷过程进行研究.结果表明,在水温为10～12℃、HRT为8 h、污泥回流比为50%和硝化液回流比为150%～250%的条件下,不同碳源时厌氧释磷与缺氧吸磷速率差异较大....     

污泥回流比对复合式生物膜-活性污泥工艺的影响研究

在中试的基础上进行了污泥回流比(R)对复合式生物膜-活性污泥工艺处理城市污水的效能和微生物特性的影响研究.结果表明R对COD的去除效果影响不大,系统去除率始终在80%以上,R的增加有利于氨氮的去除,当R超过200%时,氨氮的呈下降趋势,总氮的去除与氨氮一致.对微生物特性分析表明,R的增加能够提高系统内的污泥浓度,但会降低微生物的活性.复合式生物膜-活性污泥工艺合理的R为150%～200%.     

LiCl–KCl熔盐中共沉积直接电化学形成不同相Al–Y合金

本文在773K的LiCl–KCl–AlCl3–Y2O3熔盐体系中,采用循环伏安、方波伏安、开路计时电位和稳态极化研究了不同相的Al–Y合金的电化学制备过程。电化学研究表明钇在预先沉积的铝上欠电位沉积形成了两种铝钇金属间化合物。X-射线衍射研究表明：这两种Al–Y金属间化合物为Al2Y和α-Al3Y。通过金相显微镜和电子扫描显微镜对合金样品进行了表征,结果显示钇元素主要分布于块状析出物上。通过调节熔盐中AlCl3的含量可以获得不同相的Al–Y合金。