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51.
Removing large concentrations of organic pollutants from water efficiently and quickly under visible light is essential to developing photocatalytic technology and improving solar energy efficiency. This study used a simple hydrothermal method to prepare a non-metallic, S-doped NaTaO3 (S-NTO) photocatalyst, which was then loaded onto biochar (BC) to form a S-NTO/BC composite photocatalyst. After uniform loading onto BC, the S-NTO particles transformed from cubic to spherical. The photogenerated electron-hole pair recombination probability of the composite photocatalyst was significantly lower than those of the NTO particles. The light absorption range of the catalyst was effectively widened from 310 nm UV region to visible region. In addition, a dual-effect catalytic system was constructed by introducing peroxymonosulfate (PMS) into the environment of the pollution to be degraded. The Rhodamine B, Methyl Orange, Acid Orange 7, tetracycline, and ciprofloxacin degradation efficiency at 40 mg/L reached 99.6%, 99.2%, 84.5%, 67.1%, and 70.7%, respectively, after irradiation by a 40 W lamps for 90 min. The high-efficiency visible-light catalytic activity of the dual-effect catalytic system was attributed to doping with non-metallic sulfur and loading of catalysts onto BC. The development of this dual-effect catalytic system provides new ideas for quickly and efficiently solving the problem of high-concentration organic pollution in aqueous environments, rationally and fully utilizing solar energy, and expanding the application of photocatalytic technology to practice.  相似文献   
52.
Graphite carbon nitride has many excellent properties as a two-dimensional semiconductor material so that it has a wide application prospect in the field of photocatalysis. However, the traditional problems such as high recombination rate of photogenerated carriers limit its application. In this work, we introduce nitrogen deficiency into g-C3N4 to solve this problem a simple and safe in-situ reduction method. g-C3N4/CaCO3 was obtained by a simple and safe one-step calcination method with industrial-grade micron particles CaCO3. Cyano group modification was in-situ reduced during the thermal polymerization process, which would change the internal electronic structure of g-C3N4. The successful combination of g-C3N4 and CaCO3 and the introduction of cyanide have been proved by Fourier transform infrared spectroscopy and X-ray photoelectron spectrometer. The formation of the cyano group, an electron-absorbing group, promotes the effective separation of photogenic electron hole pairs and inhibits the recombination of photogenic carriers. These advantages result in the generation of more •O2 and 1O2 in the catalytic system, which increases the photocatalytic efficiency of nicotine degradation by ten times. Furthermore, the degradation process of nicotine has been studied in this work to provide a basis for the degradation of nicotine organic pollutants in the air.  相似文献   
53.
报道了胡椒基丁醚生产中5-丙基-1,3-苯并二氧杂茂的氯甲基化的废水处理,该废水经蒸馏可回收94%的盐酸,此酸吸收氯化氢后浓度在36%以上,可再用于氯甲基化反应。蒸馏残液经分油、Fenton试剂处理和五次生炭柱吸附后CODCr等项指标均可国家二类污染物的一级排放标准。  相似文献   
54.
Two types of fermented organic waste (trade and industry waste and fruit and vegetable waste) were successfully used as a sole carbon source to produce poly-3-hydroxybutyrate-co-valerate (PHBV) by Ralstonia eutrophus (formerly Alcaligenes eutrophus) via oxygen limitation.The production of PHBV could be optimized by optimizing the oxygen transfer through the fermentor. Thereby, a peak concentration of 1.1 g PHBV per liter cell suspension, 40 w% of cell dry weight, was obtained at an aeration rate of 0.24 mol O2/h·kg biomass. The yield of PHBV on the fatty acid concentration in the organic waste was 0.16 g polymer/g volatile organic matter. The process obtained, compares well with the commercial production process of PHBV based on glucose.  相似文献   
55.
结合桐柏县的实例,对县域生态功能区划分的原则和方法进行初步探讨.综合利用3S技术对县域生态敏感性和生态服务功能重要性的分析和评价,提出桐柏县生态服务功能区划的初步方案.将桐柏县划分为生态支持区,产品供给区,生态调节区.简要分析了各功能区在桐柏县经济可持续发展中的地位和作用,指出各区协调发展的方向和途征.  相似文献   
56.
A graphite carbon nitride(g-C_3N_4) modified Bi_4O_5I_2 composite was successfully prepared insitu via the thermal treatment of a g-C_3N_4/Bi OI precursor at 400°C for 3 hr.The as-prepared g-C_3N_4/Bi_4O_5I_2 showed high photocatalytic performance in Methyl Orange(MO) degradation under visible light.The best sample presented a degradation rate of 0.164 min~(-1),which is 3.2 and 82 times as high as that of Bi_4O_5I_2 and g-C_3N_4,respectively.The g-C_3N_4/Bi_4O_5I_2 was characterized by X-ray powder diffractometer(XRD),scanning electron microscopy(SEM),transmission electron microscopy(TEM),Raman,X-ray photoelectron spectroscopy(XPS),ultraviolet-visible diffuse reflectance spectra(DRS),electrochemical impedance spectroscopy(EIS) and transient photocurrent response in order to explain the enhanced photoactivity.Results indicated that the decoration with a small amount of g-C_3N_4 influenced the specific surface area only slightly.Nevertheless,the capability for absorbing visible light was improved measurably,which was beneficial to the MO degradation.On top of that,a strong interaction between g-C_3N_4 and Bi_4O_5I_2 was detected.This interplay promoted the formation of a favorable heterojunction structure and thereby enhanced the charge separation.Thus,the g-C_3N_4/Bi_4O_5I_2 composite presented greater charge separation efficiency and much better photocatalytic performance than Bi_4O_5I_2.Additionally,g-C_3N_4/Bi_4O_5I_2 also presented high stability.·O_2~-and holes were verified to be the main reactive species.  相似文献   
57.
盐度和pH对崇明东滩沉积物中NH+4释放的影响研究   总被引:9,自引:0,他引:9  
采集长江口下游的崇明东滩沉积物样,通过实验模拟研究盐度和pH对沉积物中NH4^ 释放的影响。结果表明,潮滩沉积物中NH4^ 的释放受盐度和pH的共同控制。NH4^ 随着盐度的变化呈明显的“M”型双峰曲线,释放量最小出现在盐度为0‰。释放峰值出现在盐度为5‰、20‰。NH4^ 随着pH的释放规律因盐度环境和沉积物类型的不同而显著不同。NH4^ 的释放量与沉积物类型有关,沙性物质含量高的低潮滩沉积物中NH4^ 的释放量明显低于沙性物质少的中潮滩。  相似文献   
58.
地聚合物是一类新型的高性能无机聚合物材料,是碱激活胶凝材料中最具前途的一类。由于其特殊的无机缩聚三维氧化物网络结构,使得地聚合物材料在众多方面具有比高分子材料、水泥、陶瓷和金属更高的高温性能和机械性能;另一方面,地聚合物材料制造过程中的能耗和三废排放量都非常低,材料对环境友好并且可以很好地被回收再年利用,是一种可持续发展的“绿色环保材料”。在比较全面地论述地聚合物材料的发展历史、生产工艺的基础上分析目前存在的问题,提出开发地聚合物材料是兼顾社会发展和减轻环境污染问题的一个较理想的对策。  相似文献   
59.
研究了对处理铝材加工含Al3+的酸性废液过程中产生的二次污染物Al(OH)3凝胶废渣的应用。含水分约90%、80%左右的Al(OH)3凝胶200g分别与14~16mL、22~24mL95%的工业浓硫酸酸反应,可制得浓度为20%~23%的Al(SO4)3溶液,经稀释可用作造纸原料。  相似文献   
60.
采用大变形弹塑性有限元理论,用DYNA3D(研究版)有限元软件,对无缝钢管局部径向模具塑性成形过程中当凸模的凹槽尺寸与凸模的圆弧半径发生变化时进行了数值模拟研究,得出了对成形钢管表面质量控制具有重要参考价值的结论,解决了成形钢管表面的压痕问题。  相似文献   
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