超临界水氧化法处理黑液

造纸黑液是一种相当难处理的高浓度工业废水,本文以工业纯氧为氧化剂,用自制的间歇式超临界水氧化系统处理造纸黑液,实验结果表明:选定最佳的实验参数后,超临界水氧化法可使黑液中COD和色度的去除率分别达到99.9%和99.5%。     

制浆黑液超临界水氧化过程的动力学研究

采用幂函数模型推导制浆黑液超临界水氧化的反应动力学方程,并利用间歇式超临界水氧化反应器进行制浆黑液超临界水氧化反应实验。通过实验发现,温度和停留时间是影响COD去除率的主要因素,在温度380～540℃,压力25～31MPa,停留时间60～150s,过氧量150%～300%的条件下,制浆黑液的COD去除率为95.0%～99.3%。对实验数据分析得到,超临界水氧化法去除高浓度黑液COD的活化能为15.171kJ/mol,COD和O2的反应级数分别为1.62和0.22,反应速率常数为0.88968。     

超临界水氧化法处理活性染料废水的研究

以过氧化氢作为氧化剂，在连续蒸腾壁式反应器内对活性染料废水进行超临界水氧化处理研究，考察了反应温度[595～704K（321．85～430．85℃）]、压力（18～30MPa）和氧化剂用量等因素对原水COD和色度去除率的影响。结果表明，当温度为704K（430．85℃）、压力为28MPa时，反应停留时间小于35s，废水COD和色度去除率分别可达到98．4％和99．9％，超临界水氧化法能有效地处理活性染料废水。     

超临界水氧化技术深度处理印染废水及污泥

采用超临界水氧化法在间歇式反应器中对印染废水及污泥进行处理试验,研究了温度和氧化系数对处理后COD(化学需氧量)的影响。当温度达到550℃,2.0倍氧化系数时,处理后废水和污泥的COD分别为20.9 mg/L和30.7 mg/L,去除率分别达到96.6%和99.9%。在该处理条件下,印染废水和污泥中的酚类和挥发酚的质量浓度均大幅降低,达到GB 8978—1996中对挥发酚的排放标准,且处理后废水及污泥中的重金属锑去除明显,达到GB 30770—2014的排放标准。     

废水处理中高级氧化技术的应用研究

本研究分析了高级氧化技术的特征及其应用范围,分别对电化学氧化技术、化学研发技术、超临界水氧化技术等的原理及应用前景进行了分析和阐述。皮革工业产生的废水中经常存在大量难以降解的有机物,采用常规的好氧生化技术处理时,处理效率低且效果差。经实验研究发现,在高级氧化技术作用下,废水经过超声波紫外线处理半小时后,能够显著提升后续生化反应速率,经8 h和24 h后COD去除率可达到经微生物处理48 h处理48%的效果,继续延长反应时间至48 h,其对废水中COD的去除率无明显提升。采用Fenton试剂强化超声波紫外线处理后,其效果要高于单独采用超声波及紫外线处理技术,预处理半小时后,在微生物条件下分别反应4 h和8 h,废水中COD的去除率可达到45%和51%,延长反应时间能够明显提升废水中COD的去除率,经过48 h反应之后,COD去除率分别能够提升64%及72%。     

超临界水氧化技术在环境治理中的应用

超临界水氧化技术在高浓度难降解有机危废处理方面具有反应迅速彻底、反应装置小、无二次污染等优点。从超临界水的性质、氧化反应特性以及基本工艺流程等方面对超临界水氧化过程进行了系统介绍,总结了现阶段超临界水氧化的研究现状,重点阐述了超临界水氧化技术在废水处理、固废处理以及水体保护方面的应用,并展望了超临界水氧化技术的发展趋势,以期为实现超临界水氧化技术的工业化提供指导。     

聚乙烯醇在超临界水氧化体系中的降解

用超临界水氧化法对聚乙烯醇(PVA)废水进行降解研究,分别考察了反应温度、反应压力、氧化剂过氧倍数以及反应时间对PVA废水降解效率的影响,并用GC/MS对液相降解产物进行表征,推测其可能降解途径.结果表明:超临界水氧化法能有效降解PVA废水,随反应温度的升高、压力的增大、反应时间的延长,COD去除率也随之提高.PVA在超临界水氧化体系中降解为烯烃、烯酮、醇和羧酸类中间产物,最终降解为小分子的饱和直链烷烃类液相产物.     

超临界水氧化法在造纸黑液治理中的应用

从超临界水的性质,超临界水氧化法的原理,动力学、工艺和优越性等方面阐述了超临界水氧化法作为一种造纸黑液治理技术具有的广阔应用前景,结合实验讨论了超临界水氧化法在造纸黑液治理中应用的可行性,并对处理过程中可能存在的一些问题及相应的改进措施进行了探讨.     

超临界水氧化技术处理造纸污泥的近况

超临界水氧化法是一种新兴且非常有效的有机废物处理方法.本文介绍了超临界水氧化技术在造纸污泥处理 研究中的应用、SCWO的流程及其特点.     

超临界水氧化技术应用探讨

超临界水氧化技术(SuPercritical Water Oxi-dation,简称SCWO)在国外近年来受到了广泛的研究和应用。目前,国内已有几家公司对该技术进行了研究及开发。超临界氧化技术是一种处理效率高,环保节能的新技术。本文着重论述超临界水氧化技术的基本原理,和其优越性以及目前超临界水氧化技术所存在的问题。     

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.     

测定黑液硫含量的新方法

用离子色谱法(IC)、X射线荧光光谱法(XRFS)和电感耦合等离子体质谱法(ICP-MS)分别测定黑液中的硫含量.测定方法:30%H2O2氧化黑液用于IC分析;直接稀释黑液用于XRFS分析;加浓HNO3或30% H2O2用湿燃烧法氧化黑液用于ICP-MS分析.这3种方法分析所得结果非常接近,而传统重量分析法测定结果比上述3种方法高出4%.     

厌氧微生物的分离及对黑液降解过程的分析

从制浆黑液贮存塘的底泥中分离出厌氧微生物,将其用来处理浓度10%的制浆黑液,研究表明,黑液与菌液体积比为2∶1是厌氧降解反应的最佳反应条件之一。同时测定了厌氧生物降解过程中黑液pH值、总糖含量、糖醛酸含量、化学需氧量（COD）、酸溶木质素含量、酸不溶木质素（Klason木质素）含量随时间变化的趋势,初步研究了制浆黑液厌氧降解的过程。研究结果表明,在厌氧生物降解过程中pH值、总糖含量、糖醛酸含量、COD、酸不溶木质素含量在黑液中都呈下降趋势,而酸溶木质素含量在该过程中不断上升。     

竹浆黑液氧化-磺甲基化制备混凝土减水剂研究

对碱法竹浆黑液进行氧化-磺甲基化改性,制备了可用作混凝士减水剂的磺化木素,并研究了该产品的水溶性和表面活性,探讨了其作为减水剂在水泥浆中的应用性能.结果表明,氧化-磺甲基化处理能有效改善碱法竹浆黑液中木素的水溶性,提高其表面活性.     

Supercritical water oxidation of the PCB congener 2-chlorobiphenyl in methanol solutions: a kinetic analysis

Incineration is commonly used to destroy polychlorinated biphenyl (PCB) wastes, but this method of treatment is not ideal for all mixed liquid wastes, especially those containing radioactive materials. Therefore, other remediation technologies are needed to efficiently treat these waste forms. This study examined the supercritical water oxidation (SCWO) of 2-chlorobiphenyl (2-PCB), using hydrogen peroxide as the oxidant and methanol as a cosolvent at 2 vol %. Kinetic studies were carried out in a plug flow reactor at temperatures from 686 to 789 K and a pressure of 250 bar, with reactor residence times ranging from 1.1 to 5.8 s. Least-squares regression of the collective reaction rate data revealed that 2-PCB exhibited second-order kinetics, with an Arrhenius frequency factor, A, equal to 10(18.2+/-2.3) L x mol(-1) x s(-1) and activation energy, Ea, of 181.7 +/- 33.2 kJ/mol. The primary organic reaction products from the SCWO of 2-PCB were biphenyl at low temperatures (<700 K) and CO2 at elevated temperatures. No dioxins or chlorinated dibenzofurans were ever detected in any of the effluent samples. Additional experiments with higher organic feed concentrations (4 vol %) illustrated how the exothermic nature of the organic oxidation reactions can be used to render the process self-sustaining. Finally, SCWO destruction rates greater than 99.98% were achieved for a simulated PCB-contaminated job control waste similar to that encountered at many U.S. Department of Energy sites.     

A reliable technique to identify superior quality clones from tea germplasm

Variations in the substrate level and enzyme activity of prominent south Indian tea germplasm were studied. The content of polyphenols, catechins (substrates) and polyphenol oxidase (PPO) showed variation, which influenced the final black tea quality. The enzyme PPO occurs in tea shoots and catalyzes the reactions between catechins to form theaflavins in the presence of oxygen. The catechins mainly epicatechin (EC), epigallo catechin gallate (EGCG), epicatechin gallate (ECG) and epigallo catechin (EGC) get mixed with PPO during the oxidation process to form quality constituents like theaflavins (TF), thearubigins (TR) and high polymerized substances (HPS). Theaflavins and their fractions such as simple theaflavin, theaflavin monogallate, (TFMG), theaflavin digallate (TFDG) in black tea are the essential quality constituents that are responsible for the liquor characteristics where as TR and high polymerized substances impart colour to the liquor. As oxidation of macerated leaves proceed through different stages of tea manufacture, a decline in PPO activity, polyphenol and catechin contents were observed. Data revealed that the oxidation reaction was faster during the initial stages of oxidation. During the period, oxygen consumption was higher and declined thereafter. Ratio between the enzyme (PPO) and its substrate (catechins) were used to characterize the quality potential of tea clones. An attempt has also been made to categorize prominent tea clones as high, moderate and average quality clones based on their enzyme substrate ratio. Theaflavin content (oxidation product) of different tea clones suggests that the ratio between PPO and catechins forms an important criterion which determines black tea quality. Results obtained were compared with standard clones of known high quality (CR-6017) and moderate quality (SA-6). The study reveals that the enzyme substrate ratio can be used to identify superior quality clones from the existing tea germplasm.     

表儿茶素没食子酸酯及表没食子儿茶素没食子酸酯单体的化学氧化研究

试验对两种多酚类物质进行化学氧化，并利用高效液相色谱对其氧化产物进行了分析。同时，试验中还对来自表没食子儿茶素没食子酸酶（EGCG）的氧化产物及存在于红茶中的相应产物进行技层析，所流出的高聚合某红素成分在所用介质中的溶解性相对较差，有别于以前类似的研究报道。在相同的氧化体系中，表儿茶素没食子酸酯（ECG）的表现不同于表没食子儿茶素没食子酸酯，表明其在该试验所选定的化学氧化条件下为相对稳定。表没食子儿茶素没食子酸酷氧化产物的高效液相色谱峰十分明显，在对红茶汤的HPLC分析中，大部分色谱峰都可以找到其对应峰。因此，该试验对类黄酮化学的研究提供了一个简便的实验方法。