浮选光度法测定饮用水中亚硝酸根

基于亚硝酸根在弱酸性的条件下重氮化反应 ,重氮化盐再与 N,N-二甲基苯胺进行偶合反应 ,生成黄色甲基橙 ,酸化后甲基橙变成红色 ,用十二烷基硫酸钠浮选富集 ,在正丁醇中收集浮选液 ,进行分光光度测定 ,从而求得亚硝酸根的含量。摩尔吸光系数ε为 9.7× 1 0 4L/ mol· cm(正丁醇为溶剂 ) ,亚硝酸根的浓度在 0 .0 4 1～ 0 .0 0 4 1μg/ m L与吸光度有良好的线性关系。该法可检出纯净水中痕量亚硝酸根的含量     

粉煤灰对甲基橙的吸附研究

研究了粉煤灰对甲基橙的吸附性能,探讨了各种处理条件对吸附效果的影响。结果表明:对于80mL初始浓度为6.4mg·L-1的甲基橙模拟废水,采用10g·L-1粉煤灰对其进行吸附处理,当pH=3～5时,于20℃下恒温振荡1.5h,其去除率可达99.5%。     

水滑石类化合物-氧化铈催化剂的制备及其光降解甲基橙的性能研究

采用共沉淀法制备了LDHs-CeO2(LDHs为水滑石类化合物)催化剂,并将其用于光催化降解甲基橙溶液,考察了催化剂的原料配比、反应时间、甲基橙初始含量、甲基橙溶液的pH和催化剂用量对甲基橙降解率的影响;同时采用FTIR,XRD,SEM,TEM,EDS,TG等方法对催化剂进行了表征。实验结果表明,n(Mg)∶n(Al)∶n(Ce)=2∶1∶0.50的LDHs-CeO2催化剂活性最高,用该催化剂光催化降解甲基橙溶液的适宜条件为:250 mL甲基橙溶液,甲基橙初始质量浓度40 mg/L,pH=5,反应时间80 min(暗处静置20 min,光照时间60 min),催化剂用量0.3 g;在此条件下,甲基橙降解率达到98.69%。表征结果显示,LDHs-CeO2晶相单一,晶体结构一致,结晶度好,属于六方晶系,形貌为规则的片状结构,分散性较好。     

柑桔皮色素的提取及其性质研究

研究了五种溶剂对三种柑桔皮中橙黄色素的提取率，选择了提取该色素的最佳条件和工艺流程，并将所得的橙黄色素产品进行了光和热稳定性试验及理化指标检验。     

The effect of storage on the antioxidant activity of reconstituted orange juice which had been pasteurized by high pressure or heat

The effect of storage on the antioxidant activity of pasteurized reconstituted orange juice was studied. Either heat or high pressure was used for pasteurization and total antioxidant activity and ascorbic acid loss were measured during storage at different temperatures (0, 5, 10, 15 °C). The total antioxidant activity of orange juice, calculated as the sum of the activities of different antioxidant compounds, decreased during storage. This was mainly because of loss of ascorbic acid. However, rates of degradation of ascorbic acid were lower for orange juice treated with high pressure and this led to a better retention of its antioxidant activity when compared with juice pasteurized in a conventional way.     

Polyphosphate gel/methyl orange supramolecular composites

The aims of this work were to investigate theoretically the optical properties of methyl orange (MO) and the synthesis of new supramolecular composites based on the incorporation of this dye in an aluminum polyphosphate gel network. The theoretical methodology was based in semiempirical (AM1 and INDO/S-CI) and ab initio (3-21G*) methods. Our results reveal the existence of different electronic patterns for the acidic and basic forms of these molecules. Also, we present a theoretical spectroscopic study for the molecules including interactions with water molecules. MO was successfully incorporated in its acidic form within the host matrix, leading to pink–red transparent self-standing films. The dye could be converted to its basic form upon exposure to ammonia vapor. The spectrum of MO basic form within the gel network differs from its behavior in aqueous solution.     

TiO2-assisted degradation of acid orange 7 textile dye under solar light

Photocatalytic degradation of acid orange 7 (AO7) in aqueous systems was successfully achieved by the combination of TiO₂ with potassium persulphate under solar light using a photochemical reactor with recirculation. Degradation of AO7 involves color removal and mineralization. The employment of TiO₂ removed 85% of color from the 0.2 mM AO7 aqueous solution under solar light; while, 66% of color was abated using the persulphate ion as oxidant in the absence of TiO₂ under similar conditions in 2 h. However, over 90% of color removal was achieved by combining TiO₂ and the persulphate ion for the same solution under similar conditions. Color removal was faster at pH 3. Mineralization of AO7 was followed by measuring chemical oxygen demand (COD). Negligible COD abatement of the textile dye was observed in the absence of persulphate ions (S₂O₈²⁻) while over 70% of COD abatement was observed for the initial dye concentrations of 0.2–0.7 mM employing a mix of TiO₂–S₂O₈²⁻ under solar light.