Fenton试剂催化氧化降解含硝基苯废水的特性

探讨不同氧化剂和催化剂浓度下Fenton试剂氧化降解硝基苯的作用规律,用一元线性回归方程对不同氧化降解时间后硝基苯的相对残余浓度对反应时间的相关性进行了定量分析,结果发现硝基苯的Fenton试剂氧化降解符合一级反应动力学模式,通过回归求出了各反应条件下的一级速率常数.实验中还发现以Fenton反应过程中产生的铁离子的复合物代替Fe²⁺作为催化剂时Fenton反应不仅取得了较高的催化反应速率和降解效率,而且对硝基苯具有明显的专属性,硝基苯的降解速率可由原来的17.48mg/(L·min)提高到71.22mg/(L@min),反应5min的硝基苯去除率由9.74%提高到91.79%.用人造沸石为载体吸附该物质制成的非均相催化剂同样具有良好的催化性能.另外,在体系中引入紫外光可以促进废水中CODCr的进一步降解,提高有机物降解速率.     

煤油厂外排废水回用于循环水

针对炼油厂外排废水回用时存在的结垢和腐蚀问题,讨论了结垢和阻垢机理,详细介绍了水中Ca2+浓度、碱度、总溶固、悬浮物、浓缩系数五项因素对结垢的影响,并通过实验筛选出5种阻垢剂。其中Rp-88、BC-501阻垢率均在90%以上,与国外同类药剂性能相当。     

对酞内酰胺基苯甲酰氯衍生试剂合成的研究

本文对对酞内酰胺基苯甲酰氯的合成方法进行了研究，改进了溶剂的预处理方法，有效地消除了其中的有害杂质。     

浅谈纳氏试剂光度法测定水体中氨氮的影响因素及消除方法

纳氏试剂光度法是测定水体中氨氮的最标准和经典的方法。本文就其测定过程中的诸多影响因素作了详尽的论述,并进一步提出消除干扰的方法。     

总磷TNT试剂在地表水环境监测中的应用研究

为有效监控地表水环境中总磷的变化趋势,落实环境保护水污染防治行动计划.选择稳定性好、分析高效、低能耗的总磷TNT试剂对南京市的长江流域水源地、城市内河道及湖泊治理监控区的地表水环境样品进行监测.应用该试剂测定总磷的方法检出限为0.008 mg/L,相对标准偏差为2.2%~7.4%(n=6),加标回收率为91.0%~110%,有证标准样品同步验证测试的相对误差为-1.3%~1.4%.试验证实总磷TNT试剂应用结果能够满足地表水环境中总磷监测的精密度、准确度要求.     

Removement of thiocyanate from industrial wastewater by microwave-Fenton oxidation method

The microwave radiation oxidation process, Fenton as catalytic agent, was used to remove the thiocyanate from the industrial wastewater. The effects of microwave power, radiation time, pH and the feeding in ways of catalyst on the degradation rate of synthetic wastewater were investigated using the microwave radiation oxidation process by orthogonal experiment. The results show Fenton catalyst ratio was 1:20, the microwave radiation power was 900 W, the microwave radiation time was 7 min and the value of pH was 3. Under the optimum conditions, the removal of KSCN can reach over 90%. The apparent kinetics of removal was studied, which conformed to kinetics first-class reaction. In short, for the thiocyanate from the industrial wastewater, microwave-Fenton oxidation method is feasible and effective.     

The use of waste basic oxygen furnace slag and hydrogen peroxide to degrade 4-chlorophenol

A new treatment method is developed to degrade 4-chlorophenol (4-cp) and its oxidation intermediates. The experimental results of this research demonstrate that 4-cp and its oxidation intermediates can be decomposed completely by basic oxygen furnace slag (BOF slag) with hydrogen peroxide (H₂O₂) in an acid solution. The factors that effect the treatment efficiency were studied including initial concentration of 4-cp, pH of the solution, concentration of H₂O₂ and amount of BOF slag. The BOF slags are final waste materials in the steel making process. The major components of BOF slag are CaO, SiO₂, Fe₂O₃, FeO, MgO and MnO. As the BOF slag in an acid solution, FeO and Fe₂O₃ can be dissociated to produce ferrous ion and ferric ion. Ferrous ion reacts with hydrogen peroxide to form “Fenton's reagent” which can produce hydroxyl radicals (OH^.). Hydroxyl radical possession of high oxidation ability can oxidize organic chemicals effectively. Results show that 100 mg/l of 4-cp is decomposed completely within 30 min by 438.7 g/l BOF slag with 8.2 mM hydrogen peroxide in pH=2.8±0.2 solution. The COD value of the solution is reduced from 290 to 90 mg/l. The factors studied which affect the 4-cp decomposition efficiency were the hydrogen peroxide concentration, BOF slag concentration, pH of the solution and initial concentration of 4-cp. Because large amounts of Fe₂O₃ and FeO are present in the BOF slag, the BOF slag not only has a high treatment efficiency, but also can be used repeatedly.     

铁炭耦合Fenton试剂-混凝沉淀法预处理DMAC废水

N,N-二甲基乙酰胺(DMAC)危害大,是化纤废水中的主要污染物之一. 采用铁炭微电解-Fenton试剂-混凝沉淀工艺预处理DMAC废水. 结果表明:在海绵铁投加量为30 g/L,铁炭体积比为1,pH为2,微电解反应1 h,H₂O₂投加量为5 mL/L,pH为3,Fenton试剂反应2.0 h,混凝沉淀pH为9.0,沉淀40 min的最佳工艺条件下,COD_Cr的去除率可稳定在70%以上;紫外可见分光光计测定证明,经微电解反应后DMAC的助色基团—CH₃和CO被破坏,经过Fenton 氧化后,—NH—基团才能被破坏,废水中的大分子物质被破坏,最终转变成小分子物质,为后续处理奠定了基础.      

Study on degradation process of famotidine hydrochloride in aqueous samples

The kinetics of famotidine (FAM) transformation under the influence of various factors, important from the environmental point of view, was investigated in aqueous solutions. The degradation processes using UV, H₂O₂, UV/H₂O₂, H₂O₂/Fe²⁺, and UV/H₂O₂/Fe²⁺ were studied. Direct photolysis and H₂O₂-assisted photolysis showed a pseudo-first-order kinetics, while the Fenton and the photo-Fenton processes fit second-order kinetics. The provided experiments proved a high resistance of FAM to direct photolysis. Its stability depends highly on the pH of the reaction solutions. The rate of FAM direct photolysis in acidic solutions was almost negligible. The reaction rate of FAM photolysis at pH 8–9 was 3.7 × 10^?3 min^?1 with DT₅₀ about 3 h 7 min. It was found that the presence of H₂O₂ in the reaction environment enhances the rate of photolysis of FAM. The observed rates of reaction were 5.1 × 10^?3 min^?1 and 3.7 × 10^?3 min^?1 in acidic and basic solutions, respectively. The used Fenton systems appeared to be the most efficient in FAM removal. The rate of reaction depends on concentration of Fe²⁺ and H₂O₂. It was observed that the presence of UV-light enhances the reaction rate by two to six times in comparison to the classical Fenton system. Additionally, FAM behavior in natural water under solar irradiation was examined. The irradiation experiments were carried out in batch experiments with simulated sunlight.     

A modified steam distillation method for volatile acids determination in anaerobic digestors

A modified steam distillation method for the accurate determination of low levels of volatile acids found primarily in low rate anaerobic digestors has been developed. The interference of bicarbonate alkalinity is minimal with complete removal of carbon dioxide from the sample prior to distillation. This removal can be achieved by boiling the acidified sample for 30 min in an erlenmeyer flask with ground‐glass neck attached to a reflux condenser.