MnO2@ Graphite电极类电Fenton降解有毒有机污染物

制备了二氧化锰复合石墨(MnO2@graphite)电极,通过XRD,TEM对电极材料进行表征,并通过电化学工作系统(循环伏安法,线性扫描伏安法,计时电量法)对MnO2@graphite电极的电催化机理进行了研究.以有机染料罗丹明B( RhodamineB,RhB)和2,4-二氯苯酚(2,4-DCP)为对象,探讨了 p...     

Effects of relative humidity on the characterization of a photochemical smog chamber

A linear relationship between k_NO2→HONO and relative humidity in smog chamber is found in this work.     

阿替洛尔在模拟太阳光照射下的光解

以1000W氙灯为光源,研究了阿替洛尔在模拟太阳光照射下的光降解行为,采用HPLC和SPE-LC-MS技术鉴定了阿替洛尔在250～600nm波长照射下的主要光解产物并提出了可能的光解途径.探讨了溶液pH值、硝酸根离子浓度、腐殖质和碳酸氢根离子等因素对阿替洛尔在模拟太阳光照射下光解的影响.结果表明,阿替洛尔在模拟太阳光下的直接光解很难发生,且改变溶液pH值不能促进直接光解.而在250～600nm波长照射下,阿替洛尔4h光解率达42%,光解途径主要有母体羟基化和支链的断裂反应.在模拟太阳光照下,NO3-对阿替洛尔光解有显著的光敏化作用,而富里酸(SRFA)光敏化作用微弱.HCO3-抑制了模拟太阳光照下阿替洛尔在NO3-溶液中的光解,腐殖质则通过自由基淬灭和内滤机制抑制了阿替洛尔在NO3-溶液中的光解.     

汽车尾气中NO_X再燃烧过程的动力学

为了阐明汽车尾气中 NOX再燃烧的动力学进程 ,以甲醛和 NO2 作为探针分子 ,通过 FT-IR跟踪研究了反应体系中所产生的 HCO自由基与 NO2 反应的动力学。结果表明 ,反应的主要产物中包括 CO、CO2 、NO、HONO和 H2 O等分子 ,经长时间的反应 ,当体系中的 NO2 基本耗尽时 ,才有少量的 N2 O生成。这些产物分子分别是在几个不同途径的连串反应中形成的。从体系中 CO和 CO2 的生成量 ,测定了主反应的歧化反应速率比 ,并对相应的动力学机理进行了讨论。     

碱催化H2O2氧化法预处理奶牛养殖废水的试验研究

采用碱催化H2O2氧化法对奶牛养殖废水进行预处理试验,研究了温度、pH、H2O2投加量、反应时间等参数对COD去除效果的影响,确定了反应最佳运行条件。试验结果表明,碱催化H2O2氧化法在pH7~12时,对COD的去除率为40%~60%;当反应温度50℃,pH值9,H2O2投加量2.72 g/L,反应时间20 min时,COD的去除率为66.3%。     

Cu~(2+)/UV/H_2O_2去除水中盐酸四环素及动力学研究

对比了UV、Cu~(2+)/H_2O_2、UV/H_2O_2、Cu~(2+)/UV/H_2O_2体系对盐酸四环素(TC)的降解效果,考察了Cu~(2+)/UV/H_2O_2体系降解TC的影响因素,并进行了动力学分析。实验结果表明:Cu~(2+)的加入明显增强了UV/H_2O_2体系对TC的降解效果,反应60 min时,Cu~(2+)/UV/H_2O_2体系对TC的降解率相比UV/H_2O_2体系提高了24.82%;Cu~(2+)的最佳投加量为120μmol/L;pH对TC的降解影响较小;H_2O_2投加量、温度、紫外灯功率的增加均会增加TC的降解率。Cu~(2+)/UV/H_2O_2体系中TC的降解可用拟二级动力学方程描述,TC降解的活化能为15.56 kJ。     

Mechanism study of electrochemical oxidation in the terylene diaphragm cell

Introduction T he dem and for new technologies to rem ove or to detoxify organics, especially those that are toxic to biological treatm ent processes from aqueous effluents, is w idely recognized. T he electrochem ical m ethod for treatm ent of such kinds of w astew ater has attracted a great deal of attention recently, m ainly because of its ease of control, am enability to autom ation, high efficiency and environm ental com patibility(C om ninel- lis and N erini, 1995). A t present, dim ens…     

Radiation-induced reduction of chromium(Ⅵ) in aqueous solution by γ-irradiation in a laboratory-scale

Radiation-induced reduction of chromium(Ⅵ)(Cr(Ⅵ) by γ-irradiation was studied with an initial concentration of 42 mg/L in aqueous solutions. Several factors which might affect the reduction of Cr(Ⅵ) to Cr(Ⅲ) were examined. pH of aqueous solution affects the reduction efficiency significantly. Acidic condition of aqueous solution accelerates the process. At pH 2, a reduction of 86.2%was achieved with the absorbed dose of 15 kGy, while, with the same dose, at pH 5 and 7, the reduction of Cr (Ⅵ) were only 36.3%and 22.2%, respectively. Ethanol (0.1% in V:V) and sodium carbonate (1 mmol/L) were added into the solution respectively as relatively non-toxic hydroxyl radical scavengers. Reduction rate increased greatly in the presence of ethanol at each pH. Reduction efficiency of Cr(Ⅵ) was enhanced in neutral condition with the addition of sodium carbonate, however, no enhancement was found in acidic condition. The reduction of Cr(Ⅵ) was restrained when the solution was saturated with oxygen; however, the restraint was not significant.     

臭氧氧化水中壬基酚的反应机理研究

采用臭氧氧化浓度为20 mg/L的壬基酚溶液,研究了臭氧氧化去除壬基酚的效果及氧化过程中中间产物的变化情况,探讨了臭氧氧化壬基酚的反应机理.结果表明,臭氧氧化涉及2种氧化方式,臭氧分子的单独反应和臭氧/羟基自由基的联合氧化.2种氧化方式在18 min内均能完全去除壬基酚,联合氧化方式在4 min内即能达到96％的去除率,而单独臭氧分子氧化需要12 min.氧化过程中检测到甲醛的产生,单独臭氧氧化下甲醛产生量在8 min左右达到稳定,而混合氧化方式下甲醛量逐步增加.     

光照下高岭土悬浮液中产生羟基自由基的测定

对高岭土悬浮水溶液在光照过程中产生的羟基自由基(·OH)进行了测定.在pH2.0,苯浓度为7.0mmol·l-1的条件下,经过250W金属卤素灯(λ≥365nm)光照5h,高岭土浓度为20.0g·l-1的悬浮液中,·OH的产生量为21.6μmol·l-1.在pH 2.0-10.0范围内,·OH产生量随pH值的降低而增加.高岭土浓度在0-20.0g·l-1的范围内,·OH产生量随高岭土浓度的升高而增加,高岭土浓度增加到25.0g·l-1时,·OH产生量反而减少.高岭土中的铁是·OH产生的重要因素.