【作者】 刘环宇；

【导师】 杨春平；

【作者基本信息】 湖南大学 ， 环境工程， 2010， 硕士

【摘要】 香精香料、苯酚等工业产生的有机废水化学需氧量高(CODCr>4000mg/L),含生化法不能降解的化合物(如氨氮、多环芳烃、致癌物苯等),是高浓度、有毒有害、难降解的有机废水,危害非常大。若不经处理就排入水体会使水生物中毒,农作物减产,引发各种疾病。传统的水处理技术对高浓度难降解废水的处理有限,研究有效的方法解决污水处理的问题十分有意义。Fenton试剂通过H2O2和Fe2+作用产生·OH,使其具有极强的氧化能力,特别适用于难降解有机废水的氧化处理,因此Fenton试剂法是废水处理技术的主要发展方向之一。由于吸附、混凝、萃取等方法对废水的处理效果不明显,因此采用Fenton试剂氧化降解香精香料废水。经过一系列的实验,探讨了不同pH值、H202(30%)、FeSO4·7H2O用量和反应时间等因素对CODcr去除率的影响。结果表明：在pH值为3、H202投加量为40mL/L、FeSO4·7H2O投加量为4.0 g／L、反应时间为3.0 h时,CODcr去除率为75%,色度去除率达到最高值82%。Fenton试剂对于香精香料生产废水的CODcr和色度都有较好处理效果。电Fenton作为类Fenton试剂比传统的Fenton试剂有较好的处理效果,本研究采用电-Fenton氧化降解苯酚模拟废水,采用双石墨为电极中间填充活性炭颗粒的反应器对100 mg／L的苯酚模拟废水进行处理研究,重点考察该方法降解率、CODcr和反应体系矿化能力的影响,并探讨了双石墨电极法对苯酚的降解行为。结果表明,常温条件下(25℃±1℃),反应过程中使溶液的pH值为3.0(±0.01)；电流为0.3 A；亚铁离子投加量为0.1 mmol/L;活性炭颗粒投加量为100 g的情况下电解60 min,苯酚的去除率达到93%；CODcr去除率达到65%。随着电解时间的加长当反应时间到达6h以上其苯酚基本矿化完全。加入·OH清除剂Na2CO3发现苯酚的降解效率明显下降,表明在反应过程中会产生高活性的·OH和H2O2,体系中苯酚的电催化氧化是由直接氧化和间接氧化的协同作用共同去除,从而决定了其有较高的矿化能力。更多还原

【Abstract】 The organic wastewater of fragrance and flavor production and phenol industry contains high CODCr (CODCr>4000 mg/L) or the compound (ammonia nitrogen, polycyclica romatich ydrocarbons, Bap,et.al) that could not be degraded by conventional biological wastewater treatment methods.The organic wastewater is harmful because it is high concentration, poisonous and difficult to degrade.It will poison the creature in the water, reduce the corps production and cause serious sickness if it is let out into the rivers without treatment.Traditional water treatment technology for highdensity refractory wastewater treatment is limited.So look for effective ways to solve the problem of sewage treatment, it is extremely meaningful. Fenton reagent by the role of H2O2 and Fe2+ generated OH,it has strong oxidation ability for the oxidation of refractory organic wastewater treatment.So Fenton reagent is the main wastewater treatment technology development directions.As adsorption,coagulation,extraction,methods in wastewater treatment effect was not obvious,therefore Fenton reaction was used to treat wastewater from fragrance and flavor production.After a series of experiments,effects of factors including pH value,dosage of H2O2 and FeSO4·7H2O,and reaction time to the CODCr removal efficiency were evaluated.Results showed that the CODcr and color of the wastewater were effectively removed by Fenton.The optimal operating conditions determined were at a pH value of 3,a dosage of H2O2 of 40 mL/L, a dosage of FeSO4·7H2O of 4.0 g/L,and the time of reaction of 3.0 h. The corresponding CODCr removal efficiency was 75%,color removal efficiency was 82%.The Fenton reaction was found to be effective for the treatment of wastewater from fragrance and flavor production.Electro-Fenton reagent as a class than the traditional Fenton reagent has good treatment effect.Oxidation of phenol in aqueous solution by electro-Fenton reactions has been studied using bipolar graphite electrodes filled with activated carbon.Effects of reaction parameters including pH value of the solution,dosages of ferrous ion, current of solution,and reaction time on phenol and CODCr removal were evaluated for the treatment of wastewater containing phenol of 100 mg/L at 25±1℃.Removal mechanisms were also investigated by analyzing the intermediate products using HPLC and GC-MS.Results showed that removal efficiencies of phenol and CODCr were 93%and 65% respectively at pH of 3.0 (±0.01),current of 0.30A,plate distance of 4 cm,a dosage of ferrous ion of 0.1 mmol/L,a dosage of granular activated carbon of 100 g, an reaction duration of 60 min, and an air flow rate of 10 L/min.When the reaction time was increased to 180 min,phenol in the wastewater was not below detection limit.Phenol removal efficiency decreased significantly when Na2CO3,a hydroxide radical scavenger, was added in the reactor, which indicates that both electro catalytic oxidation and radical oxidation contributed to the degradation of phenol.更多还原