共查询到20条相似文献,搜索用时 250 毫秒
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以低压紫外汞灯为光源,在无光催化剂及促进剂条件下,探讨紫外光对通氧水溶液中活性染料的光降解脱色特性和主要影响因素,以及不同结构类型活性染料的紫外光脱色降解性能.结果表明,溶液pH值、染料浓度、光照时间及母体结构类型对活性黄X-R染料溶液的脱色率有较大影响;染料的光降解脱色率随溶液pH值增大而降低,酸性条件有助于染料母体结构的降解消色;活性黄X-R染料的光降解脱色率随其质量浓度增加(50 mg/L增大到120 mg/L),呈线性降低;染料的光降解脱色速率在起始阶段较快,并随一定范围内处理时间的延长,其脱色率增大;染料结构类型中,以偶氮芳环类和偶氮杂环类为母体的染料容易被紫外光直接降解脱色,但偶氮类母体中引入中心金属离子Cu(Ⅱ)后,其降解脱色率显著降低.染料重氮组分及/或偶合组分中取代基越复杂,基团越多,其光降解脱色性越差,而染料活性基则对光降解脱色影响较小. 相似文献
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采用不同剂量(0、3、6、9、12、15 kGy)60Co-γ射线对柄曲霉素(sterigmatocystin,STC)溶液进行辐照处理,研究辐照剂量、不同溶剂以及不同初始浓度对柄曲霉素辐照降解效果的影响。结果表明:60Co-γ射线可有效降解溶液中的柄曲霉素,且降解率随着辐照剂量的增大而增加。当辐照剂量为3 kGy时,STC的降解速率依次为水>氯仿>乙腈>甲醇。当辐射剂量大于6 kGy时,水、乙腈和氯仿中STC的降解率相近,且甲醇中STC降解率也相对增加。在同一辐照剂量下,柄曲霉素的初始浓度越低,其降解率越高。 相似文献
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采用自制磁化装置对蒸馏水进行处理,以紫外吸收和pH变化指标检验了水的磁化处理效果。将处理后的磁化水用于染色,用染液浓度在线监测装置测试和比较了磁化水及蒸馏水对活性染料上染棉织物上染过程和结果的差异。三个雅格素染料试验说明,磁化水对上染过程有一定影响,雅格素红BF-3B略有增深,但是三个染料固色率几乎都没有变化。 相似文献
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研究了β-环糊精(β-CD)对中性红在紫外光照射下脱色的影响.结果表明:β-环糊精能与中性红形成包合物.随着β-环糊精浓度的增加,中性红的脱色率减小;随着中性红初始浓度的增加,脱色率逐渐增大.β-环糊精对中性红紫外光脱色的抑制作用在pH为8~10时最大,该条件下β-CD/中性红包合物的脱色率仅为中性红脱色率的5.22%. 相似文献
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采用海藻酸钠、明胶和戊二醛制备固定化漆酶,并将其应用于直接染料大红4BS的脱色降解.试验结果表明,固定化漆酶脱色降解直接大红4BS的适宜条件为:酶用量10.0 U/mL,染料质量浓度50 mg/L,反应温度30℃,pH值4.0.固定化漆酶重复利用3次时,对直接大红4BS的脱色率为50%左右.采用紫外-可见光分光光谱对染料的脱色降解反应过程进行分析,证明直接大红4BS在一定程度上可被固定化漆酶降解. 相似文献
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在H2O2存在条件下,对直接墨绿染料模拟废水进行加强日光辐射处理.系统地研究了染料初始质量浓度、H2O2浓度、pH值、不同无机盐对直接墨绿染料模拟废水脱色效果的影响.结果表明,染料光降解脱色速率随H2O2浓度增加而增加,但在H2O2浓度较高时,降解速率增加不明显.在酸性媒介中直接墨绿染料能有效地光降解脱色.与SO2-4、NO-2、Cl-相比,Br-和NO-3对脱色作用抑制最显著.处理前后的UV-Vis谱图分析表明直接墨绿染料在H2O2/强化日光光降解处理中脱色是染料发生光降解作用所致. 相似文献
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采用常压等离子体对乙腈中黄曲霉毒素B_1(AFB_1)进行降解。利用单因素实验,考察了放电间距、处理电压、放电时间以及AFB_1初始浓度对AFB_1降解率的影响,在此基础上进行了BoxBehnken的实验设计,选取AFB_1降解率作为响应值,优化了AFB_1的降解条件。结果表明:各因素对AFB_1降解率的影响大小依次为处理电压放电时间AFB_1初始浓度。常压等离子降解AFB_1的最佳工艺条件为处理电压170 V、放电时间236 s、AFB_1初始浓度5 mg/L、放电间距2 cm。AFB_1的降解率高达92.45%,与预测值93.94%相接近,偏差为1.49%。 相似文献
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采用低温放电等离子体对葡萄干中赭曲霉毒素A(ochratoxin A,OTA)进行降解,研究不同时间下初始质量浓度、放电电压对葡萄干中OTA降解率的影响。结果表明,葡萄干中初始质量浓度为50?μg/mL的OTA经等离子体在放电电压75 kV时处理10 min被完全降解。利用高效液相色谱-四极杆-静电场轨道阱高分辨质谱检测并鉴定经低温放电等离子体处理的OTA降解产物,结合一级和二级质谱,推测出相对分子质量分别为m/z 426.071 5(B)和m/z 158.154 0(C)的2种主要降解产物结构及OTA可能的降解路径。等离子体处理前后葡萄干的理化品质没有发生显著变化,挥发性物质除酸类物质中3-甲基丁酸、乙酸、辛酸含量有明显的下降,甲酸、戊酸、2-乙基己酸含量有明显上升外,大部分的酸、醛、醇和酮类物质的相对含量未出现明显变化。研究结果表明低温放电等离子体可以有效地降解OTA,并对葡萄干品质没有显著影响,可为OTA污染的食品降解研究提供参考。 相似文献
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介质阻挡放电低温等离子体的产生 总被引:1,自引:1,他引:1
介绍利用介质阻挡电极放电产生低温等离子体的方法,分析了在大气压下介质阻挡电极放电的细丝模式和均匀辉光模式(APGD)的特点.通过电压-电流波形图和电压-电荷李萨育图形,比较了细丝模式和扩散模式的区别,并分析了两者在产生低温等离子体的物理机制. 相似文献
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采用雅格素BF-DR活性染料对棉织物进行轧染,研究其染色性能。结果表明,雅格素BF-DR活性染料匀染性好,固色率高,提升力优良,特别适合于染深浓颜色,并且染色牢度良好。 相似文献
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以纳米二氧化钛和纳米二氧化硅为研究对象,考察其对雅格素红BF-DS、雅格素黄BF-3R、雅格素艳蓝BF-R上染的抗皱棉织物颜色的影响规律。研究表明:添加纳米二氧化钛,对雅格素黄BF-3R染色抗皱织物的色光影响稍大,对其他2种染料的色光影响较小,同时3种染料染色织物的K/S值均没有增大;添加纳米二氧化硅,对雅格素红BF-DS染色抗皱织物的色光影响较大,对其他2种染料的色光几乎没有影响,同时3种染料染色织物的K/S值都略有减小。 相似文献
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A strain ZW-4 with remarkable ability to decolorize the Pigment Red 23 was isolated from aerobic sludge by the method of concentration gradient domestication. The strain was identified as Prototheca sp. according to its morphological characters and 16S rDNA sequence analysis. Experiments on the effect of decolorization conditions were carried out under aerobic conditions. The results showed that the best nutrient source was yeast powder, and the optimum conditions were 1% yeast powder, 5% inoculum, pH 7.5, temperature 35 °C, and salinity less than 4%. Under these conditions, the decolorization rate of Pigment Red 23 (initial concentration of 100 mg L?1) was more than 91% when the strain ZW-4 was cultivated for 18 h. The strain also showed better salt tolerance property, which ranged from 6 to 8%. Besides, spectrophotometric analysis demonstrated that the decolorization mechanism of Pigment Red 23 was mainly biological degradation. Furthermore, toxicity tests indicated that the toxicity of Pigment Red 23 after decolorization had reduced noticeably with the strain ZW-4. 相似文献
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综述了常压介电屏蔽放电(DBD)产生的非热等离子体在纺织整理中的应用。描述了DBD在常压织物整理和等离子体化学中的许多潜在优势。DBD(无声放电)是一种非热等离子体放电,在较宽的温度和压力范围内操作简便。常压下,许多独立的细电流丝之间会发生电击穿,这些短暂的带有电子能量的微放电具有瞬时高压辉光放电性质,非常适合背景气体原子或分子的激发和离解。 相似文献
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印染废水的复合絮凝剂脱色 总被引:2,自引:0,他引:2
研究了无机絮凝剂、有机絮凝剂及有机-无机复配絮凝剂对染料废水的脱色效果,探讨了投加量、pH值、复配比等对脱色效果的影响.结果表明,有机高分子絮凝剂与无机絮凝剂复配,可以明显提高脱色效果.用复配絮凝剂处理染料溶液时,对不同染料的脱色效果不同,最佳pH值范围也不同.复配絮凝剂对于直接红BWS和酸性红N-3BL染料的增效作用比对活性红BF-DB的大.用复配絮凝剂处理实际印染废水的优化条件为:有机絮凝剂和硫酸铝的投加量分别为120 mg/L和80 mg/L,pH值为6~7.在此条件下,实际印染废水的脱色率可达96.8%,COD去除率达80.6%. 相似文献
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Dielectric barrier discharge (DBD) plasma, lower and higher dose electron beam irradiation (EBI) are used widely in food processing. In this research, impacts of DBD plasma and EBI processing on characteristics of Tartary buckwheat whole flour were investigated in the range of parameters used most often in food industry. Cross section, small granule and reaggregation of fragments appeared after processing as well as higher values of L*, a* and WI. DBD plasma processing altered the short range crystal structure and hydrogen-containing groups, increasing oil/water absorption and freeze-thaw stability. DBD plasma and EBI processing had a mostly positive effect on hydration properties at 50 to 70 °C, with contrast to a reduction effect at higher temperature. DBD plasma and EBI processing will not affect the nutrients content indeed. TPC, TFC and antioxidant activity increased significantly after EBI processing (≤ 10 kGy) with few free radicals generated.Industrial relevanceDBD plasma and EBI processing are widely used for flour in food industry, with limited focus on physicochemical properties promotion and antioxidant activity protection. This research indicates that DBD plasma processing can affect the properties of Tartary buckwheat whole flour (TBF) significantly, but it shows negative damage to bioactive compounds and antioxidant activity. EBI processing (≤ 10 kGy) can improve physicochemical properties of TBF, which is given slightly higher TPC, TFC and antioxidant activity simultaneously. Both of DBD plasma and EBI processing are safe methods that can improve processing characteristics of the flour, while lower dose EBI processing is more suitable for development of Tartary buckwheat and functional food industry with protection to bioactive compounds and antioxidant activity. 相似文献
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A novel technique for palm oil hydrogenation with very low trans-fatty acid formation using non-thermal dielectric barrier discharge (DBD) plasma with parallel-plate configuration has been successfully demonstrated. This green technique does not require catalyst and is highly environmental-friendly. With 15% H2: 85% He mixed carrier gas concentration ratio and initial 31 °C (rising to 50 °C due to plasma), after 4 h of plasma hydrogenation, iodine value (IV) was reduced from 60.89 to 48.39 and detected trans-fat was 1.44%. This represents trans-fat generation rate of only 0.07% per % decrease in IV, which is about 6.12 times lower than a conventional method relying on high temperature, high pressure and catalyst. About 8 h was required to produce margarine with texture closest to commercial margarines. Acid value (AV) reduced from 0.47 to 0.27%, or 43% reduction, after 12–20 h of treatment, significantly indicating that plasma hydrogenation can also help extend shelf life of oil or margarine. Large portion of DBD plasma hydrogenated palm oil can, thus, be mixed with palm olein and interesterified palm oil to produce margarine with overall trans-fatty acid content no higher than regulatory requirement. Continuous production scheme was presented. This novel plasma hydrogenation technique offers promising possibility for commercial utilization by edible oils industry. 相似文献
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Although irradiation has been used to destroy bacteria and molds in spices globally, a new technology is needed to alleviate public fears of irradiation, the high cost of irradiated food, and environmental contamination at the irradiation facility. The objective of this study was to investigate the effects of dielectric barrier discharge (DBD) plasma on Eshcericah coli O157: H7 and Bacillus cereus levels in red pepper powder and the physicochemical properties of red pepper powder stored at 25 °C. RNA expression was determined by qRT-PCR. The surface of bacteria treated with DBD plasma was observed with a Field Emission Scanning Electron Microscope (FE-SEM). Red pepper powder (5 g) inoculated with E. coli O157: H7 and B. cereus was treated with DBD plasma using argon as a plasma-forming gas at 31 kW for 0, 5, 10, and 15 min. DBD plasma did not significantly decrease the bacterial concentrations with an increase in treatment time. However, DBD plasma treatment for 15 min killed E. coli O157: H7 more rapidly during storage. Expression of virulence genes of both E. coli O157: H7 and B. cereus was decreased by DBD plasma treatment for 15 min. Results of FE-SEM showed that DBD plasma damaged the bacterial cell membranes, leading to cell death. Physiochemical properties of red pepper powder were not changed for one month after treatment with DBD plasma. Thus, DBD plasma treatment for 15 min is recommended to control foodborne pathogens in red pepper powder without changing its physicochemical properties. 相似文献