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1.
不同培养条件下锰过氧化物酶(MnP)的合成及其对甲基橙的降解 总被引:1,自引:0,他引:1
高效、大规模、低成本合成木质素降解酶是直接采用其降解难降解有机污染物所必须解决的问题.对锰过氧化物酶(MnP)降解甲基橙和在非灭菌的反应器中连续合成MnP的可行性进行考察.结果表明,在采用2 mmol H2O2和1.5 mmol MnSO4的降解体系中,获最大脱色效果,且100、200和300 U/L的MnP可在8h内将甲基橙分别脱色18%、23%和35%;在非灭菌的反应器水平上实现了固定化培养的P.chrysosporium连续23 d合成MnP,但MnP酶活仅为2~ 23 U/L,难以酶解甲基橙;然而,在摇瓶培养条件下固定化的P.chrysosporium合成的MnP却能达1 152 U/L.因此,直接采用MnP对污染物进行降解以及在非灭菌的反应器中持续合成MnP是可行的,但就在非灭菌条件下如何提高MnP的合成量还有待开展深入的研究. 相似文献
2.
以杨梅单宁(BT)为模板,水热法合成纳米二氧化钛(BT-NTO)。采用XRD、FTIR、SEM和TEM技术对BT-NTO的结构及形貌进行了表征。将BT-NTO用于吸附溶液中的Th~(4+),在溶液pH为3.5、温度为25℃、Th~(4+)初始浓度为0.5 mmol/L的条件下,BT-NTO对Th~(4+)的吸附量为0.905 8 mmol/g;吸附过程符合准二级动力学方程和Langmuir等温吸附方程;溶液中共存的Zn~(2+)、Ni~(2+)、Co~(2+)、Sr~(2+)、Yb~(3+)、Nd~(3+)、Sm~(3+)、Gd~(3+)、La~(3+)、Cl-、ClO4-离子对Th~(4+)吸附量影响较小;BT-NTO的重复使用性能较好。 相似文献
3.
Ali Shoaib Asem Elabasy Muhammad Waqas Lulu Lin Xinlai Cheng Qianqian Zhang 《毒物与环境化学》2018,100(1):80-91
The use of higher dosage and repeated applications of conventional pesticides have led to the rapid development of insect resistance to pesticide and adverse effects on human health and environment. Accordingly, researchers are prompted to identify an alternative entomotoxic agent for crop protection. Nanocides are being considered as alternatives to conventional insecticides because they are expected to lessen the application rate and reduce the chances of resistance development in pests. In this study, we evaluated the entomotoxic effects of nanosilica on larvae of Plutella xylostella, in a laboratory by using dust spray, larva dipping, leaf dipping, and solution spray methods. Dust treatment showed a more highly significant effect than the other three treatments. The mortality percentage increased up to 58% and 85% at 24 and 72 h after treatment, respectively, when nanosilica was applied at a rate of 1 mg cm?2. In all four bioassays, mortality rate increased with both increased time after nanosilica exposure and increased concentration. Light microscopy and scanning electron microscopy images showed that larval death was due to desiccation, body wall abrasion, and spiracle blockage. These results suggested that nanosilica can be an alternative to conventional pesticides if dust formulation would be properly used. 相似文献
4.
Spherical TiO2 nanoparticles (npTiO2) were prepared by controlled hydrolysis of tetraethoxy orthotitanate under a nitrogen atmosphere. ZnO nanoparticles (npZnO) were prepared using hydrothermal methods. The crystal structure, chemical, thermal and morphological properties of npZnO and npTiO2 were characterised using Fourier Transform Infrared Spectrometer, enery-dispersive X-ray spectroscopy, X-ray diffraction, and scanning electron microscope techniques. The short- and long-term experiments were started with neonates taken from the same culture and laboratory condition. In the acute experiments, npTiO2, npZnO, and cocktail concentrations were applied. 96h-LC50 values were 1.8, 0.7, and 0.1?mg?L?1, respectively (p?<?.05). For the chronic experiments, different npTiO2 concentrations were performed. 21d-LC50 value was 1.0?mgL?1 (p?<?.05). Morphometry became progressively worse in concentrations of more than 1?mgL?1 npTiO2. Neonate and young individuals were more sensitive to death because of their low tolerance. This result was affected by population progeny and growth rates (p?<?.05). While control and 0.5?mgL?1 npTiO2 groups were determined as growing population, 1.5 and 2?mgL?1 npTiO2 groups had decreased population size as R0 values. Consequently, the relationships between nanoparticle accumulation within Daphnia magna and its population structure and body morphometry for each concentration were important indicators. Its tolerance level to nanoparticles under laboratory conditions reflected its replacement and behaviour in the ecosystem. 相似文献
5.
Shu-Yii Wu Yong-Fang Liu Ya-Chieh Li Chun-Min Liu 《International Journal of Green Energy》2015,12(10):1025-1030
The CO2 absorption capacities of potassium glycinate, potassium sarcosinate (choline, proline), mono-ethanolamine (MEA), and tri-ethanolamine were evaluated to find the optimal absorbent for separating CO2 from gaseous products by a CO2 purification process. The absorption loading, desorption efficiency, cost, and environmental tolerance were assessed to select the optimal absorbent. MEA was found to be the optimum absorbent for separating the CO2 and H2 mixture in gaseous product. The maximum absorption loading rate was 0.77 mol CO2 per mol MEA at temperature of 20°C and absorbent concentration of 2.5 mol/L, whereas desorption efficiency was 90% by heating for 3 h at 130°C. MEA was found to be an optimal absorbent for the purification process of CO2 during gaseous production. 相似文献
6.
利用废气中本身含有的CO催化还原烟气中的NOx,可以实现以废治废。采用TiO2纳米管负载CeO2,制备CeO2/TiO2纳米管催化剂,并对其进行了SEM表征及影响因素实验。实验结果表明:在n(Ce)∶n(Ti)=3∶7、焙烧温度500 ℃、焙烧时间3 h时制备的CeO2/TiO2纳米管催化剂形貌较好,表面颗粒分布相对均匀;反应温度400~600 ℃时NO脱除率达98%;该催化剂具有一定的抗氧性能;当n(SO2)∶n(NO)=(1∶2)~(2∶1)时,NO脱除率仍然在95%以上。 相似文献
7.
Francisco M. Baena-Moreno Mónica Rodríguez-Galán Fernando Vega Luis F. Vilches Benito Navarrete 《International Journal of Green Energy》2019,16(5):401-412
Biomethane production through biogas upgrading is a promising renewable energy for some industries which could be part of the equilibrium needed with fossil fuels consumption to achieve a sustainable society. This paper presents a comprehensive list of biogas upgrading technologies focused on carbon dioxide removal as well as recent advances reported by researcher with wide expertise in this topic. Additionally, an extensive costs–performance comparison among the technologies studied is discussed. Among the different alternatives, chemical scrubbing stood out to achieve high biomethane purities while cryogenic technologies proved to be effective against methane losses. Regarding the different costs, water scrubbing and membrane separation seem to be the most affordable techniques. 相似文献
8.
四环素光催化降解特性与选择性研究 总被引:3,自引:1,他引:2
研究了盐酸四环素的光催化降解行为,结果表明四环素光催化降解反应符合一级反应动力学方程,吸附过程为整个光催化降解的控制步骤,推断四环素的主要降解途径是吸附在二氧化钛(TiO2)表面发生光催化氧化反应.同时,通过对四环素与磺胺甲唑或阿莫西林混合样品的降解实验表明,改变pH、TiO2投加量等因素,两种抗生素的降解表现出了明显的选择性. 相似文献
9.
皮革在激光烧蚀过程中会产生大量具有恶臭气味的有机废气,严重影响空气质量。为了评估该类型气体危害,分别利用紫外可见分光光度计和气相色谱-质谱联用仪,检测了天然皮革和人造革在激光烧蚀过程中的废气成分。结果显示烧蚀天然皮革所产生的废气中含有NO、NO2、SO2、二氨基丙烷和丙烯酸甲酯,烧蚀人造革所产生的废气中含有NO、NO2、甲硫醇、二硫化碳、乙二醇、二甲基二硫醚、丙二醇、乙二醇二甲醚和硫代乙酸甲酯。其中,甲硫醇、二硫化碳、二甲基二硫醚和乙二醇二甲醚都是产生恶臭的有机成分。研究为该类型废气的治理提供了基础数据和依据。 相似文献
10.