UV+O3+H2O2法处理活性染料废水的研究

利用UV＋O3＋H2O2法对印染废水进行氧化处理。考察了处理过程中印染废水的色度、COD值及电导率的变化，使用UV＋O3＋H2O2技术对印染废水进行氧化处理，经过60min的化学氧化过程，溶液的色度去除率迭98．4％，COD去除率达67．52％，电导率不断升高。UV＋O3＋H2O2法与单一的O3和UV＋O3＋H2O2氧化法相比较，此种方法更能显著去除染料的色度和COD。     

物化-生化法处理造纸废水

本文在原有废水处理工艺的基础上利用物化-生化法对造纸废水的处理工艺进行改造.结果表明,该处理工艺效果良好,处理后出水SS、COD、BOD等各项指标均优于综合排放一级标准的要求.     

含高浓度印染废水的废水处理工程研究

以A~2/O生化法+混凝+生物滤池组合工艺处理含高浓度印染废水的污水,结果表明,出水COD通常在46~60 mg/L,对COD、NH_3-N的平均去除率分别为95%和90%,水质稳定,满足GB 18918—2002《城镇污水处理厂污染物排放标准》中的1级标准。     

O_3及O_3+AC一体化工艺深度处理印染废水对比研究

本文以印染废水二沉池的出水为研究对象,采用臭氧、臭氧+活性炭等工艺对其进行深度处理研究。对比发现,经过单独臭氧处理后,COD值去除率不足30%,且色度较高,而加入活性炭后处理效果明显改善。对活性炭加入量、活性炭预处理程度、pH值以及废水在反应器中的总停留时间等因素进行研究,结果表明:初始COD值在300~400 mg/L、pH值7.5、色度500倍的二沉池出水,在不调节pH值的情况下,按照活性炭投加量5 g/L与臭氧同时加入,在臭氧预处理15 min(浓度约4 mg/L),总水力停留5 h后,出水COD值稳定在100 mg/L以内,色度低于100倍,满足印染废水排放标准的二级排放要求。     

臭氧预氧化-混凝深度处理印染二级生化出水

采用臭氧预氧化-混凝沉淀工艺深度处理印染工业园区二级生化废水。考察了不同p H值、不同臭氧和混凝剂投加量时,深度处理出水浊度、色度和COD变化情况,分析了深度处理出水有机物特征。结果表明,臭氧预氧化和混凝相结合,有助于增强混凝效果,并降低深度处理出水中有机物浓度。混凝剂(PAC)最佳投加量为200 mg/L,臭氧最佳投加量为2.1 mgO_3/mg COD,色度去除率达到65%~75%,COD去除率20%~35%,浊度去除率20%~40%。臭氧投加量增大到2.5 mgO_3/mg COD,混凝效率下降,COD去除率降低23.3%。处理前后检出的有机物种类分别为32种和29种,经深度处理部分大分子有机物氧化成小分子。经臭氧预氧化-混凝沉淀工艺深度处理的印染工业园区二级生化废水能达到《纺织染整工业废水治理工程技术规范》(HJ 471-2009)漂洗回用标准要求。     

印染废水成分分析及净化处理技术

文章分析了不同纤维染整工艺导致印染废水成分的差异，研究测试表明各类染料所用助剂对印染废水中COD、BOD、COD／BOD，SS等所造成的影响不同，并介绍了采用聚合硫酸铁（PFS），和H2O2复合法处理印染废水的净化处理技术，该处理技术达到国家规定的排放要求。     

“A~3O+臭氧”工艺用于印染废水提标改造

纺织印染行业是工业废水排放大户。在印染废水的处理难度增加和排放标准提高的双重压力下,印染企业的发展遭遇了前所未有的环保瓶颈。以广东省某织染水处理有限公司废水站改造后工程为例,介绍了"A~3O+臭氧"工艺在印染废水处理中的应用。改造后运行情况表明,整个处理系统运行稳定,抗冲击能力高,处理效果良好,各项主要出水水质指标达到并优于《纺织染整工业水污染排放标准》(GB 4287-2012)中的直接排放标准。由此可见,A~3O工艺在印染废水处理实践中是切实可行的。     

电解脱脂废水的深度处理实例

根据电解脱脂废水的水质特性,采用常规物化方法不能使出水的COD值满足《电镀污染物排放标准》(GB21900-2008)的要求。文章通过设计向经过物化预处理的电解脱脂废水中引入生活污水,提高废水的可生化性,再采用水解酸化+MBR的工艺,使最终出水的所有指标都能够满足环保要求。     

印染废水分质处理及回用工程实例

嘉兴市某印染企业从产生源头对废水进行高、低分质收集并处理,高浓度印染废水采用"水解酸化+A/O处理+混凝沉淀"处理工艺,出水COD、BOD、色度和SS均值分别为171 mg/L、48 mg/L、60倍和60 mg/L,达到《纺织染整工业水污染物排放标准》(GB 4278-2012)间接排放要求。低浓度印染废水回用工程采用"水解酸化+A/O处理+超滤+反渗透"组合工艺,RO出水COD、色度和SS分别为15 mg/L、3倍和1 mg/L,各指标都符合设计回用标准。高浓度废水处理工程运行成本1.12元/m3废水,日运行费用为1 680元/d,年运行费用50.40万元,低浓度废水回用工程运行成本3.53元/m~3产水。回用率53%,年节约用水24万t,年减少支出150万余元。     

混凝-A/O法处理废纸造纸废水的工程设计与效果分析

某造纸企业采用混凝-A／O生化工艺处理废纸造纸废水,经过近120天的运行,出水达到DB4426-1989一级排放标准。运行结果表明,物化处理单元对于SS的去除率保持在90％以上,对废水中CODCr的平均去除率基本稳定在50％左右,生化处理单元对SS的去除率保持在50％左右;对CODCr的去除率保持在90％以上;每去除1kgCOD的运行费用约为0．21元。因此,采用物化-A／O生化工艺处理废纸造纸废水具有技术合理性和经济可行性。     

复合氧化剂法合成氧化玉米淀粉

以玉米淀粉为原料,过氧化氢和过硫酸钾为复合氧化剂,Fe~(2+)为催化剂,在酸性条件下以湿法工艺合成氧化玉米淀粉。以淀粉质量分数、复合氧化剂比例、复合氧化剂质量分数(占干淀粉总量)、催化剂质量分数(占干淀粉总量)、反应温度、反应时间等因素为变量,以羧基含量作为氧化度衡量指标,采用单因素试验和正交优化试验,确定制备氧化玉米淀粉最佳工艺条件为:淀粉质量分数35%、复合氧化剂质量分数8%、复合氧化剂比例[m(H_2O_2):m(K_2S_2O_8)]为4:1、体系pH 4.00、催化剂质量分数0.3%、反应温度50℃、反应时间1.5 h,在此条件下,可合成氧化度为0.118%氧化玉米淀粉。     

油脂OSI加速氧化条件下氧化机制初探

对Rancimat加速氧化试验中葵花籽油的氧化指标进行跟踪检测,测定0、1.5、3.0、4.5、6.0、7.5、9.0 h油样的酸价、过氧化值、茴香胺值及总氧化值等指标,通过与室温(25℃)、40、60、100℃的烘箱试验的氧化指标数据进行对比,从理论上确认了OSI(100℃)法对于指导油脂常温存储的可靠性。研究结果表明:油脂在OSI(100℃)、40℃烘箱、60℃烘箱与室温下氧化机制相似,即上述加速氧化方法均能准确反映室温下油脂氧化动力学特征。     

Determination of thermal oxidation and oxidation products of β-carotene in corn oil triacylglycerols

A reversed phase HPLC-DAD coupled to APCI-MS method is reported for the determination of the degradation of β-carotene and characterization of the oxidation products in corn oil. Corn oil containing β-carotene was oxidized in the Rancimat at 110 °C from 1 to 14 h. A significant degradation of β-carotene was observed in corn oil during accelerated thermal oxidation. A total of eight different oxidized products of β-carotene were identified, which includes 8′-apo-β-carotenal, 6′-apo-β-carotenal, 5,6-epoxy-8′-apo-β-carotenal, β-carotene-2,2′-dione, 13-Z-5,6,5′,6′-diepoxy-β-carotene, all-E-5,8-epoxy-β-carotene, all-E-5,6-epoxy-β-carotene, and 15-Z-5,6-epoxy-β-carotene. Corn oil triacylglycerols (TAGs) oxidation products were also identified using isocratic HPLC–ESI-MS. It was found that β-carotene promoted oxidation of TAGs especially at longer exposure times. For the first time two new classes of oxidized TAGs have been identified in corn oil, which were epidioxy bis-hydroperoxides and hydroxy bis-hydroperoxides. Other oxidation products of TAGs were mono-epoxides, mono-hydroperoxides, and epoxy hydroperoxides. It was found that complementing the HPLC-DAD method for β-carotene with ESI-MS method for TAGs oxidation provides a comprehensive set of analytical tools to characterize carotenoids and triacylglycerols oxidation and degradation in edible oils.     

Chemical nitrite oxidation in acid solutions as a consequence of microbial ammonium oxidation

In long-term experiments with membrane aerated biofilm reactors we observed complete nitrite oxidation in highly concentrated ammonium nitrite solutions with a contaminant pH decrease to values below 3. The maximum initial concentration for ammonium was 42 mM and for nitrite was 41 mM. We hypothesized that (1) acid-tolerant ammonium oxidizing bacteria were responsible for the pH decrease, and (2) chemical processes caused complete nitrite oxidation at low pH values. To test this hypothesis we set up a mechanistic computer model based on kinetic data from literature and we validated the model with additional experiments. The simulations fitted the measurements very well. Additionally, an experiment with the inhibitor allylthiourea showed that ammonium-oxidizing bacteria were active at pH values far below 5.5. Experiments in a sterile reactor confirmed the chemical nitrite oxidation to nitrate. Nitrogen balances revealed that 8 +/- 4% of the initial nitrogen (ammonium, nitrite, and nitrate) were lost during the cycles. On the basis of measurements and simulations we concluded that volatilization was responsible for the significant nitrogen loss. We estimated that about half of the lost nitrogen volatilized as nitrous acid HNO2. The rest mainly volatilized as dinitrogen N2 and nitrous oxide N2O.     

蒸煮腌肉色素氧化与脂肪氧化互促效应关系的研究动态

色泽是肉及肉制品的最重要的一个品质指标,因为它是消费者用来判断其新鲜度和是否购买的一个最直观的指标.蒸煮腌肉制品在贮藏过程中会发生褪色,主要是蒸煮腌肉色素(CCMP)的降解和氧化所致,其中脂肪氧化与CCMP的氧化关系密切,许多有关脂肪氧化与肉色变化之间的关系问题还不很明确.本文主要综述了CCMP氧化与脂肪氧化之间的相互诱导和激发、促使关系研究现状,为研究蒸煮腌肉制品贮藏期间色泽变化理论以及确定有效的护色技术提供一些指导.同时,肉类研究者在发展新型稳定肉色方法的同时,需更进一步关注CCMP的化学变化理论研究.     

Supercritical water oxidation of sulfide

Supercritical water oxidation (SCWO) of sulfide wastewater with oxygen as the oxidant was investigated using ammonium sulfide solution as the model waste. The experiments, which were conducted in a bench-scale continuous SCWO installation, indicated that S2- could be completely oxidized to SO4(2-) within the residence time of less than 10 s under the supercritical water conditions at 698.2-773.2 K and 22.0 MPa-30.0 MPa. The reaction pathway of S2- in SCWO was determined to be S2- --> S2O3(2-) --> SO3(2-) --> SO4(2-). The effects of temperature, pressure, and oxygen content on SCWO of S2- were also studied. The kinetic model based on this pathway was established with the reaction rate constants and orders found by fitting the experimental data. The dependence of the rate constants on the temperature can be described with Arrhenius' law. The rate constants are dependent on the density of SCW, and the dependence is logarithmically linear.     

Kinetics of diesel nanoparticle oxidation

The technique of high-temperature oxidation tandem differential mobility analysis has been applied to the study of diesel nanoparticle oxidation. The oxidation rates in air of diesel nanoparticles sampled directly from the exhaust stream of a medium-duty diesel engine were measured over the temperature range of 800-1140 degrees C using online aerosol techniques. Three particle sizes (40, 90, and 130 nm mobility diameter) generated under engine load conditions of 10, 50, and 75% were investigated. The results show significant differences in the behavior of the 10% load particles as compared to the 50 and 75% load particles. The 10% load particles show greater size decrease at temperatures below 500 degrees C and significant size decrease at temperatures between 500 and 1000 degrees C in a non-oxidative environment, indicating release of adsorbed volatile material or thermally induced rearrangement of the agglomerate structure. Activation energies determined are 114, 109, and 108 kJ mol(-1) for the 10, 50, and 75% load particles, respectively. These activation energies are lower than for flame soot (Higgins et al. J. Phys. Chem. A 2002, 106, 96), but the preexponential factors are lower by 3 orders of magnitude, and the overall oxidation rates are slower by up to a factor of 4 over the temperature range studied. Possible reasons for the differences are discussed in the text.     

亚麻纤维的选择性氧化

采用高碘酸钠对亚麻纤维进行选择性氧化,可使纤维素链单元的2个仲羟基氧化成醛基,红外光谱图证实了活性醛基的生成。在高碘酸钠选择性氧化纤维素过程中,影响氧化程度的因素主要有高碘酸钠质量浓度、氧化时间等。研究了氧化时间和高碘酸钠质量浓度对氧化亚麻纤维醛基含量、失重率和力学性能的影响。结果表明:增加高碘酸钠质量浓度、延长氧化时间,亚麻纤维中的醛基含量增加,但亚麻纤维的失重率增加。随着氧化程度的加深,亚麻纤维的断裂强度逐渐降低。