可见光/H2 O2/海藻酸铁非均相催化降解吖啶橙的研究

由海藻酸钠和氯化铁反应制备了海藻酸铁凝胶小球催化剂,考察了该催化剂的吸附和可见光下催化降解吖啶橙的性能.结果表明催化剂的吸附能力随pH升高而提高,且催化剂用量为40个凝胶小球时,可见光下吖啶橙能够在较宽pH值范围内脱色,脱色速率随H2O2的用量增加而增加,该反应符合Arrhenius规律,其表观活化能为49.6 kJ/mol.自由基清除剂的加入不会降低脱色速率,表明催化反应不是羟基自由基的机理,而与高活性的类{ Fe(Ⅳ)=O}高价铁中间产物有关.     

Local circulation and aerosol water-soluble ions--a case study in Taiwan during Mei-yu season

The Mei-yu (plum rain) season is a short but important period when the weather changes from spring to summer in Taiwan. In this study, size-segregated aerosols were collected alternately at 5 sampling sites in northwestern Taiwan from June 16 to 24, 1994. For the first time in Taiwan, this study revealed the aerosol mass spectra and water-soluble ions in the Mei-yu season. For all samples, a bi-modal aerosol mass spectra was found with modal diameters at 3.2 and 0.32 microm, respectively. The aerosol samples were able to be divided into different groups to show their mass and ion spectra according to the calculated 5-hr backward air trajectory. The utilization of enrichment factors showed that aerosol Cl-, Na+, and Mg2+ for all sizes, and super-micron SO4(2-) were related to the sea. Both the scheme of "chlorine loss" (Ohta and Okita, 1990) and a multivariate analysis (Thurston and Spengler, 1985) for categorizing water-soluble ions showed that sea-salts were major contributors in the prevalence of a sea breeze. In contrast, the secondary salts were significant for land breeze and a mix of land-sea breeze. In conclusion, the influence of local circulation on the distribution of aerosol mass and ionic species was found to be prominent.     

混凝辅助电化学法处理橙黄G染料废水

以石墨板为阳极,研究了电化学氧化法对橙黄G染料废水的降解效果。比较了在NaCl、Na2 SO4以及NaCl与FeSO4·7H2O组合的支持电解质体系中的处理效果,同时考察了电压、初始pH、电解质浓度、电极间距和电解时间等因素对废水中橙黄G脱色率及COD去除率的影响。研究结果表明,橙黄G的脱色主要是活性氯的氧化作用,橙黄G分子的矿化可能主要是电解过程中产生的·OH的作用,FeSO4·7H2O的加入增加了混凝作用,使得处理效果进一步提高。最佳脱色条件下橙黄G脱色率和COD的去除率分别为97．6％和56．3％,B／C（BOD／COD）由0．09提高至0．41,可生化性有较大改善,并且随着降解时间的增加,COD去除率逐渐升高。此结果表明,橙黄G废水COD的去除相对于脱色存在滞后性。     

微米Cu／Fe对污染土壤洗脱液中有机氯农药的降解

以表面活性剂TritonX-100（TX-100）为洗脱剂,某有机氯农药（organochlorinepesticides,OCPs）污染场地土壤为对象,七氯、氯丹和灭蚁灵为目标污染物,研究微米Cu／Fe双金属对污染土壤洗脱液中OCPs的降解效果。考察了洗脱液中OCPs初始浓度、洗脱液pH值、微米零价铁加入量和cu负载量对Cu／Fe去除OCPs效果的影响。结果表明,微米Cu／Fe可以有效的去除土壤洗脱液中目标污染物。当微米零价铁加入量为1．0g（25g／L）,cu负载量为1．0％,洗脱液pH值为6．89时,Cu／Fe对2号土壤洗脱液中七氯、γ-氯丹、α-氯丹和灭蚁灵的去除效果最好,去除率分别为100．0％、99．3％、80．8％和71．1％。洗脱液中OCPs初始浓度越低,微米零价铁加入量越大,Cu／Fe对OCPs去除率越高;偏酸性条件有利于Cu／Fe对γ-氯丹和灭蚁灵的去除,而α-氯丹在中性条件下去除效果最好;1号土壤和2号土壤洗脱液的最佳铜负载量分别为2．O％和1．0％。     

臭氧氧化污泥的试验研究

采用接触反应柱对污泥臭氧氧化过程中污泥性质的变化进行了研究。结果表明,在相同臭氧投量下,低浓度臭氧分解污泥的效率较高;在臭氧投量为0．1gO3／gss、臭氧浓度为16．8mg／L时,臭氧化使污泥溶液中的溶解性TOC从114．9mg／L增加到803．7mg／L;臭氧氧化后溶解性IC(无机碳)从2．63mg／L减少到1．02mg／L;臭氧氧化显著提高了污泥沉淀性能,氧化后污泥的SV和SVI相当于氧化前28．9％和58％。臭氧氧化使污泥的pH从初始的7．13降低到投量增加到0．44gO3／gss时的4．40。污泥臭氧化的最佳投量点为0．1gO3／gSS。     

生化黄腐酸对污染水体生物修复的强化作用

研究了生化黄腐酸（BFA）对污染水体生物修复的强化作用。生化黄腐酸能提高水体中微生物活性,加快微生物对目标污染物的降解。在污染水体生物修复强化作用的试验中,投加生化黄腐酸,CODCr、NH3-N、TP和浊度的去除率分别增加了29．47％、20．61％、35％和19．86％,同时有利于水体DO的提升。     

Influences of metals on kinetics of methyl tert-butyl ether biodegradation by Ochrobactrum cytisi

The influence of zinc, manganese, and nickel on the degradation of MTBE (methyl tert-butyl ether), by an aerobic MTBE-degrading strain, Ochrobactrum cytisi, were investigated. The result showed that unlike previous findings, O. cytisi was able to degrade MTBE through direct metabolism when MTBE was present as the only carbon source. The degradation rate of MTBE was rapid, completed within 80 h. MTBE biodegradation by this strain was stimulated at low concentrations of Zn(2+) (1-5 mg l(-1)) and Mn(2+) (1-5 mg l(-1)) but inhibited at high concentrations of Zn(2+) (20 mg l(-1)) and Mn(2+) (20 mg l(-1)), and at low concentration of Ni(2+) (1-4 mg l(-1)). Kinetic parameters for MTBE degradation in the presence or absence of metals were obtained through nonlinear regression and a least-square minimization procedure. In all cases, a good agreement was achieved between kinetic simulations and experimental results.     

Life cycle assessment of fuel selection for power generation in Taiwan

Life cycle assessment (LCA) was applied to performance data from 1997-2002 to evaluate the environmental impacts of the energy input, airborne emission, waterborne emission, and solid waste inventories for Taiwan's electric power plants. Eco-indicator 95 was used to compare the differences among the generation processes and fuel purification. To better understand the environmental trends related to Taiwan's electric power industry, three fuel scenarios were selected for LCA system analysis. Results indicate that there are differences in characteristic environmental impact among the 13 power plants. Scenario simulation provided a basis for minimizing environmental impacts from fuel selection targets. Fuel selection priority should be a gas-fired combined cycle substituted for a coal-fired steam turbine to be more environmentally friendly, particularly in the areas of the greenhouse effect, acidification, winter smog, and solid waste. Furthermore, based purely on economic and environmental criteria, it is recommended that the gas-fired combined cycle be substituted for the oil-fired steam turbine.     

热解析-固相微萃取-气相色谱法测定空气样品中挥发性有机化合物

建立了热解析-固相微萃取-气相色谱法测定空气样品中挥发性有机化合物的分析方法,并对色谱分离条件、玻璃针筒保存样品的稳定性、固相微萃取萃取纤维、萃取时间、色谱进样时间等条件进行了优化,9种挥发性有机化合物的峰面积与其质量浓度在所测范围内有较好的线性关系,相对标准偏差＜8.8%,检出限为0.05～0.75 μg/100 mL,满足实际空气样品测定需要。     

ClO2三相催化氧化处理硝基苯生产废水的试验

硝基苯(NB)生产废水中含有大量NB及其衍生物,对生物具有毒性,属难生物降解物质.采用ClO2三相催化氧化工艺对NB废水进行处理.结果表明,每升废水投加280、350 mg ClO2,废水在活性炭加载含铜复合金属氧化物的催化剂床层停留56min,NB和色度的去除率均达到95%以上,COD去除率达到90%以上.吨废水处理成本约为10.5元.