黑碳吸附亚甲基蓝染料废水的行为研究

文章研究了黑碳吸附亚甲基蓝的动力学和热力学特性,探讨了温度、初始浓度、溶液pH值及转速等因素对吸附过程的影响。结果表明,吸附过程符合二级动力吸附方程,颗粒内扩散过程是影响吸附速率的主要控制步骤。用Freundlich方程能够更好地对吸附等温线进行拟合;吸附热力学研究表明:△H>0,说明吸附为吸热过程;△G<0,说明吸附质倾向于从溶液中吸附到吸附剂表面,反应过程是自发进行的;△S>0,说明固/液相界面上分子运动更为混乱。     

Kinetics of aniline oxidation with chlorine dioxide

For the first time, kinetics of aniline oxidation with chlorine dioxide(ClO2) were investigated systematically by detecting concentration of aniline with HPLC at regular intervals. Results showed that the reaction was first-order both in ClO2 and in aniline, and the oxidation reaction could be described as second-order reaction. Stoichiometric factor η was experimentally determined to be 2.44. The second-order-reaction rate constant k was 0.11L/(mol.s)under condition of pH 6.86 and water temperature(Tw) 287K. Reaction activation energy was 72.31 kJ/mol, indicating that the reaction could take place under usual water treatment conditions. The reaction rate constants in acidic and alkali media were greater than that in neutral medium. Chlorite ion could slightly increase reaction rate in acidic medium. p-aminophenol and azobenzene were detected by GC-MS as intermediates.     

Photocatalytic degradation of dye effluent by titanium dioxide pillar pellets in aqueous solution

Photocatalytic oxidation (PCO) process is an effective way to deal with organic pollutants in wastewater which could be difficult to be degraded by conventional biological treatment methods. Normally the TiO2 powder in nanometre size range was directly used as photocatalyst for dye degradation in wastewater. However the titanium dioxide powder was arduous to be recovered from the solution after treatment. In this application, a new form of TiO2(i. e. pillar pellets ranging from 2.5 to 5.3 mm long and with a diameter of 3.7 mm) was used and investigated for photocatalytic degradation of textile dye effluent. A test system was built with a flat plate reactor(FPR) and UV light source(blacklight and solar simulator as light source respectively) for investigating the effectiveness of the new form of TiO2. It was found that the photocatalytic process under this configuration could efficiently remove colours from textile dyeing effluent. Comparing with the TiO2 powder, the pellet was very easy to recovered from the treated solution and can be reused in multiple times without the significant change on the photocatalytic property. The results also showed that to achieve the same photocatalytic performance, the FPR area by pellets was about 91% smaller than required by TiO2 powder. At least TiO2 pellet could be used as an alternative form of photocatalyst in applications for textile effluent treatment process, also other wastewater treatment processes.     

食油假单胞菌DT4菌株对四氢呋喃(THF)的降解特性

对某医药厂废水池的活性污泥进行长期驯化,分离筛选到1株在好氧条件下能以四氢呋喃(tetrahydrofuran,THF)为唯一碳源和能源生长的食油假单胞菌DT4(Pseudomonas oleovorans DT4).研究发现在初始pH值7.2、温度30℃、初始菌体浓度3.2 mg/L的条件下,P.oleovorans...     

臭氧氧化降解水中四丁基锡效能及动力学研究

对水中臭氧氧化降解四丁基锡(TeBT)的反应动力学、效能及影响因素进行了实验研究.结果表明,温度从12℃升到22℃,TeBT的去除率可从36％升高到43％,但当温度升到32℃时其去除率有所下降.pH升高有利于TeBT的氧化降解,在pH =5.9的缓冲溶液中,前10 min TeBT的去除率为30％;在pH=8.0的缓冲溶液中,前10 min TeBT的去除率提高到42％.原因可能是pH的升高会使臭氧在水中的分解速率加快,臭氧向水相转移率也提高.·OH抑制剂叔丁醇和重碳酸盐对臭氧氧化去除TeBT具有明显的抑制作用,说明在臭氧氧化去除TeBT的过程主要受到·OH产率的影响.通过拟一级反应动力学,计算出单独臭氧(即臭氧分子)与TeBT的直接反应速率常数ko3=435.79 L·mol-1·s-1,·OH与TeBT的间接反应速率常数k.oH=1.4 ×109 L·mol-1·s-1.     

流化床光催化反应器动力学模式

提出二相流化床光催化反应器的理论计算数学模式,并通过试验对其进行了验证和分析．结果表明,理论计算值与试验值一致该数学模式可用于流化床光催化反应器的设计计算,相对误差小于0.15％．     

N_2/CO_2/H_2O抑制甲烷爆炸化学动力学机理分析

应用敏感性分析方法对N2,CO2和H2O抑制甲烷爆炸的化学动力学机理进行了理论分析,结果表明:在N2,CO2和H2O的抑制作用下,在甲烷氧化链式反应进程中起关键"桥梁"作用的自由基——CH3和HCO的生成受到强烈抑制,从而使得甲烷氧化链式反应进程受到影响和破坏;CO2和H2O除了具有N2所具有的抑燃、抑爆特性外,还会参与甲烷氧化链式反应,并对CH4氧化放热产生阻碍作用。     

基于维纳过程的MEMS陀螺仪贮存寿命评估

目的 针对MEMS陀螺仪在步进应力加速试验条件下获取的性能退化数据,提出基于维纳过程的贮存寿命评估方法及其模型准确度检验方法。方法 首先,确定温度为影响MEMS陀螺仪性能退化的主要环境因素,采用步进温度应力加速试验的方式获取其性能退化数据。其次,分析各项性能参数的演变规律,确定标度因数为表征产品性能退化的特征性能参数。最后,采用漂移维纳过程对标度因数退化轨迹进行建模,并外推得到常温条件下的贮存寿命。结果 采用留一法对模型精度进行验证,模型准确度最低为86.44%。可靠度水平为0.95时,常温贮存(25 ℃)条件下的寿命评估结果为50.02 a。结论 基于维纳过程建立的性能退化模型的准确度在85%以上,该模型可应用于指定贮存条件下MEMS陀螺仪的性能退化预测及贮存寿命评估。     

硝酸盐对矿化垃圾中兼/厌氧甲烷氧化的影响

设计全因子实验研究了NO-3-N对填埋10~12 a的矿化垃圾中兼/厌氧甲烷氧化作用的影响.结果表明,兼/厌氧条件下,NO-3-N能促进矿化垃圾中CH4的去除.初始CH4和NO-3-N对CH4去除和N2产生有明显影响,且两者具有交互作用(P<0.05).CH4去除量随着初始CH4体积分数的增加而增加,添加一定含量的NO-3-N能促进CH4去除,同时通入一定体积分数CH4可以明显促进反硝化作用,说明矿化垃圾中NO-3-N还原能与兼/厌氧甲烷氧化耦合.本实验条件下,初始CH4体积分数为30%,NO-3-N含量为110 mg·kg-1时耦合效应较好.     

南京市经济发展与环境污染关系的实证研究

根据南京市1991～2003年经济与环境数据,分析经济发展与环境污染的相互关系,建立了南京市经济增长与环境污染水平的计量模型,进而评价了南京市的环境保护政策。研究表明：作为一个重化工业城市,南京市自20世纪90年代以来,在经济高速发展的情况下,其环境恶化程度逐步得到遏制,部分环境指标与人均GDP演替轨迹呈现显著的环境库兹涅茨曲线特征。这主要归功于南京市政府近年来有效的环境政策和巨额的环境投资。