铁对反硝化脱硫运行效能影响

研究基于Fe2+可以刺激硫酸盐还原菌的活性,氢气又可以作为电子供体促进反硝化脱氮理论,考察了铁粉对同步反硝化脱硫运行技能的影响.在混养(主)、自养和异养(辅)条件下对比加入铁粉前后各种底物的代谢规律,结果表明:混养条件下加入铁粉前后,硫化物去除率均在99％以上,硝酸盐和乙酸盐的去除率分别为80％,90％和88％,62％.铁粉不影响碳、氮、硫的同步脱除,而且可以强化硫酸盐还原作用和反硝化作用,却使硫化物的去除时间延长2倍.经分析得知,铁粉的加入可以提高自养菌群的活性,进而提供氢气这种更容易被自养菌利用的电子供体将硝酸盐还原为氮气,使硫化物剩余.而且,Fe和H2O发生化学反应生成的Fe2+和氢气均能提高硫酸盐还原菌的活性,硫酸盐还原菌群和自养菌群之间可能存在一定的共生关系,Fe的加入会破坏这种共生关系.     

刘铁男：要加快推进铝工业的优化升级

8月25日,由国务院参事室和中国有色金属工业协会共同举办的＂促进铝应用高层论坛＂在北京钓鱼台国宾馆召开。国家发改委刘铁男副主任出席论坛并致辞。     

纳米材料对斑马鱼的氧化损伤及应激效应研究

以斑马鱼(Daniorerio)为受试动物,研究了纳米及常规TiO2、ZnO悬浮液对其鳃、消化道及肝脏的氧化损伤及应激效应,同时对纳米及常规TiO2、ZnO悬浮液中的颗粒形貌特征及·OH生成量进行了测定.结果发现,虽然纳米TiO2、ZnO颗粒与其常规颗粒在溶液中的粒径分布接近,但50mg/L纳米TiO2、ZnO悬浮液中·OH产生量(96h光照下,分别为2.17mmol/L、0.72mmol/L)远远高于50mg/L常规颗粒(未检测到).50mg/L纳米TiO2处理下,斑马鱼肝脏中超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、还原型谷胱甘肽(GSH)、蛋白质羰基含量分别为对照的70.2%、65.4%、53%、178.1%;消化道中SOD活性及GSH、丙二醛(MDA)含量分别为对照的149.6%、212.9%、217.2%;鳃中MDA含量为对照的160.9%.而50mg/L常规TiO2悬浮液对斑马鱼没有产生毒理效应.5mg/L纳米及常规ZnO对斑马鱼肝脏的氧化伤害最强,其中5mg/L纳米ZnO处理组中SOD、CAT活性及GSH、MDA含量分别为对照的62.9%、53.1%、45.2%、204.2%,5mg/L常规ZnO处理组中SOD、CAT活性及GSH、MDA含量分别为对照组48.3%、51.8%、34.6%、289.6%;虽然斑马鱼鳃及消化道也受到明显氧化应激效应(p0.05),但并没有受到氧化损伤.研究表明,团聚作用对不同化学组成纳米颗粒的毒性影响程度不同;且不同化学组成纳米颗粒在生物体内可能通过不同机制产生了不同种类的ROS,从而对不同细胞组分产生的氧化损伤及应激效应是其重要的毒理机制.     

铁氧化物改性黏土对Cr(Ⅵ)的吸附性能研究

利用铁氧化物对黏土进行了包覆改性,采用静态吸附法对该改性黏土吸附Cr(Ⅵ)的特性进行了研究,并考虑了反应时间、pH、浓度、温度对吸附的影响。实验结果表明,整个吸附过程基本在3h内完成;改性黏土对Cr(Ⅵ)的吸附量随溶液初始pH的增大而明显减小;随着溶液初始浓度和温度的增大而增大。同时,在初始pH为3.0的条件下,研究了改性黏土吸附Cr(Ⅵ)的动力学和热力学特性,结果表明,改性黏土对Cr(Ⅵ)吸附能较好地符合准二级动力学方程和Langmuir等温式。由Langmuir等温式得出,在293K、初始pH为3.0条件下的单层饱和吸附量为12.91 mg•g-1。确定了改性黏土吸附Cr(Ⅵ)的热力学参数,表明该吸附过程是一个吸热的自发过程。与原土的对比实验表明,改性黏土对Cr(Ⅵ)的吸附能力大大增强。     

己内酰胺生产废水的铁碳微电解深度处理与机理研究

采用铁碳微电解方法对己内酰胺生产废水进行深度处理,探讨了pH值、停留时间、铁碳质量比对处理效果的影响。在pH为4、停留时间为120 min、铁碳质量比为4的最佳处理条件下,COD去除率可达57.8%,色度去除率可达68.4%。微电解对己内酰胺废水的作用主要通过铁的絮凝作用,处理过程中的酸性条件、微电解的氧化还原和电场作用,从而提高其去除效率。     

Effect of platinum on the photocatalytic degradation of chlorinated organic compound

TiO2 nanoparticles, doped with di erent Pt contents, were prepared by a modified photodeposition method using Degussa P-25 TiO2, H2PtCl6 6H2O and methanol as the solvents. The physicochemical properties of Pt/TiO2 were investigated by the nitrogen adsorption and desorption isotherm measurement technique, X-ray di raction analysis and photoluminescence spectra, respectively. Reaction rates from photocatalytic removal of dichloromethane over Degussa P-25 TiO2 and Pt/TiO2 were evaluated. The average diameter and BET surface area of the TiO2 catalyst particles were 300 nm and 50 m2/g, respectively. The degradation e ciency was 99.0%, 82.7%, 55.2%, and 57.9% with TiO2 at inlet concentrations of 50, 100, 200, and 300 ppm, respectively. And the degradation e ciency was 99.3%, 79.7%, 76.5%, and 73.4% with a 0.005 wt.% Pt/TiO2 at inlet concentrations of 50, 100, 200, and 300 ppm, respectively. In addition, we found that the photoluminescence emission peak intensities decreased with increases in the doping amount of Pt, which indicates that the irradiative recombination was weakened. Furthermore, the results showed that the UV/0.005 wt.% Pt/TiO2 process was capable of e ciently decomposing gaseous DCM in air.     

Preparation and coagulation efficiency of polyaluminium ferric silicate chloride composite coagulant from wastewater of high-purity graphite production

The aim of the present work was to produce a polyaluminium ferric silicate chloride (PAFSiC) coagulant from acidic and alkaline wastewater of purifying graphite by roasting, and subsequently to evaluate coagulation efficiency of the reagent by treating surface water from the Yellow River as well as municipal wastewater in comparison with the conventional coagulant polyaluminium chloride (PAC). The PAFSiC coagulant was prepared by co-polymerization. The effects of (Al+Fe)/Si molar ratio, OH/(Al+Fe) molar ratio (i.e., value), coagulant dosage and pH value of test suspension on the coagulation behavior of FAFSiC and the stability of the PAFSiC were also examined. Results showed that PAFSiC performed more efficiently than PAC in removing turbidity, chemical oxygen demand (COD), and total phosphate (TP). The PAFSiC with a value of 2.0 and (Al+Fe)/Si ratio of 5 (PAFSiC 2.0/5) showed excellent coagulation effect for both turbidity and COD, while PAFSiC 1.0/5 was the best for TP. The optimum coagulation pH range of PAFSiC 2.0/5 was 5.0–9.0, slightly wider than that of PAC (6.0–8.0). The process can be easily incorporated into high-purity graphite production plants, thereby reducing wastewater pollution and producing a valuable coagulant.     

吸附树脂负载铁酞菁催化降解硝基苯的研究

在可见光照射下,采用吸附树脂负载铁酞菁催化过氧化氢降解硝基苯.考察了光照、催化剂投加量、双氧水投加量、温度及pH值等因素对催化效果的影响.结果表明,在功率为50W卤钨灯照射下,硝基苯溶液初始质量浓度为200 mg/L,初始pH值为3,催化剂投加量为1.5 g/L,双氧水投加量为1.0 mL/L,温度为35℃下反应10h,硝基苯去除率可达到79.9％.     

快速高效去除微囊藻的GO/QPEI复合纳米材料

本研究合成了一种新型高效的去除铜绿微囊藻(Microcystis aeruginosa)的氧化石墨烯/季铵盐聚乙烯亚胺(GO/QPEI)纳米复合材料.GO/QPEI在pH为4~10的条件下都具有高效去除M.aeruginosa的能力,其去除能力在2 min内可达96%以上.GO/QPEI对微囊藻的吸附更符合Freundlich方程,最大吸附量为5.58×1011cells·mg-1.吸附动力学表明GO/QPEI的假二级吸附反应.GO纳米片和QPEI的协同效应是其高效去除微囊藻的主要机制.     

废旧线路板中主要有价金属的生物反应器浸出研究

为探讨可供实际生物浸出应用的反应器规模废旧线路板中有价金属浸出特性和工艺条件,通过设计序批式生物浸出反应器,采用分离到的氧化亚铁硫杆菌Z1作为菌种资源,在考察废旧线路板中有价金属的浸出特性的基础上,确定了反应器运行的最佳工艺条件.结果表明,反应器运行的最佳工艺条件为曝气量1L/min、停留时间30h、搅拌速率300r/min以及粉末投加量12g/L.在此条件下,经过101h可以浸出90.24%的铜.同时,经197h的浸出,可以溶出93.06%的镁、92.00%的锌、85.59%的铝和64.51%的镍.因此,生物浸出反应器能有效回收废旧线路板中的有价金属,为该技术的实际应用提供了实验证据.