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生物电化学系统处理难降解有机污染物研究进展 总被引:1,自引:0,他引:1
《化学工业与工程技术》2019,(1):40-45
难降解有机污染物广泛存在于水、土壤及大气等环境介质中,严重危害生态环境。生物电化学系统是一种高效处理难降解有机污染物的生物处理技术,通过电化学对微生物的刺激,增强微生物降解污染物的能力,提高污染物降解效率。介绍了生物电化学系统的工作原理,综述了生物电化学系统在处理多环芳烃类化合物、有机染料类化合物、卤代烃类化合物和其他难降解有机化合物的研究应用情况以及生物电化学系统耦合其他降解技术处理难降解有机化合物等方面的研究进展。生物电化学系统是目前去除难降解有机污染物较有前途的方法,分析了生物电化学系统处理难降解有机污染物存在的问题,提出未来可从能代谢难降解有机污染物的电极及电化学活性微生物的筛选、电子转移机制的理论分析2个方面进行深入的研究。 相似文献
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抗生素类药物是目前水环境中出现的一类新兴有机污染物,具有难自然降解、环境刺激性、生物毒性及耐药性等特点,高效去除抗生素类污染物是近年来环境工作者重点探讨的内容。掺硼金刚石(boron-doped diamond,BDD)电极由于自身优异的物理和化学性质,被认作为目前电催化氧化水中有机污染物最为理想高效的阳极材料,但关于BDD阳极在新兴抗生素类污染物的研究情况尚未进行及时的总结。本文首先论述了BDD阳极在电催化氧化有机污染物的降解过程和基于强氧化性物种的电催化氧化机理,进而分析了BDD阳极在电催化降解水中新兴抗生素类污染物的研究进展,探讨了影响抗生素类污染物电催化降解过程的关键影响因素,总结了BDD阳极材料的开发情况,同时,总结了以BDD阳极电催化氧化为基础发展而来的其他水处理联合方法,最后,进一步展望了BDD阳极在未来电催化降解抗生素类污染物存在的问题及未来的重点发展方向。 相似文献
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纳米铁强化复合技术因对难降解污染物具有较高的矿化性能,在近十几年受到广泛关注。本文简要归纳了几种主要纳米铁强化复合技术,包括纳米铁/Fenton技术、纳米铁/电化学技术、纳米铁/二氧化钛光催化技术及纳米铁/生物技术等,指出复合技术优点是可提高试剂使用率、降低反应成本,缺点是其应用于规模以上的废水处理研究还较少。同时回顾了纳米铁强化复合技术降解典型环境污染物(卤代有机物、硝基芳香化合物、染料和硝酸盐等)的最新国内外研究进展,并着重阐述了纳米铁强化复合技术去除污染物的机理、效能。复合技术的实际工程应用效果体现在,对废水中污染物的去除明显提高。改进反应试剂投加方式和开展复合技术应用于低碳卤代烃等难降解污染物的去除研究成为其在水污染治理领域的发展前景,同时要建立降解机制数据库。 相似文献
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药物和个人护理用品(PPCPs)是一类新兴的有机污染物,与常见的污染物相比,在水环境中浓度很低但化学结构复杂,种类多,性质差异大,具有毒性,常规处理技术很难完全去除。非均相催化臭氧化技术的固相催化剂可回收重复利用,二次污染少,目前此处理技术在PPCPs领域的研究已经非常广泛。文章详细描述了非均相催化臭氧化技术降解PPCPs时常遵循的表面反应机理、自由基反应机理、协同反应机理,进一步阐释了自由基反应机理中的4种途径,简要介绍了催化剂等因素对PPCPs降解的影响,归纳总结了非均相催化臭氧化在PPCPs治理领域的应用进展,提出了现今非均相催化臭氧化技术存在的问题,最后展望了非均相催化臭氧化技术的未来研究方向及应用前景。 相似文献
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电化学氧化技术去除有机物的研究进展 总被引:4,自引:0,他引:4
电化学水处理技术因其具有多功能性、高度的灵活性、易于自动化、无二次污染等特点倍受国内外研究者的重视。简单介绍了电化学氧化技术直接氧化和间接氧化的基本理论,主要总结了电化学技术在去除有机污染物和处理废水领域的研究及应用现状,并指出了该技术目前应用中所存在的一些问题,分析了其不能广泛应用的主要原因,探讨了今后的发展方向。 相似文献
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单原子催化剂(SACs)具有结构独特稳定、制备方法灵活简便以及原子利用率高等特点,其在实现高活性和高选择性的催化反应方面有巨大的潜力,并已广泛应用于水中新兴污染物处理领域。目前SACs的合成方法繁杂,其在水处理中的应用也还处于发展阶段,针对该情况,对SACs的主要合成方法及其在新兴污染物处理中的应用进行了论述。总结了SACs四类合成方法(湿化学法、原子沉积法、质量选择软着路法、热解法)的优缺点,并探讨了SACs在光催化、电催化以及类芬顿水处理技术中降解有机污染物的作用机理。SACs对污染物的良好去除依赖于自由基(1O2、·O2-、SO4·-和·OH)和非自由基途径(h+和电子转移)。最后,对SACs发展过程中的机遇和挑战进行讨论。 相似文献
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综述了国内外电化学技术去除污染物的研究现状,近几年来出现的一些新技术如电化学生成强氧化剂氢氧自由基技术、电催化降解技术、光电一体化技术、电解氯氧化技术等,探讨了电化学技术处理工业废水的发展趋势. 相似文献
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In this project, immobilized titanium dioxide photocatalysis was utilized as a post-treatment technology for the destruction of model organic contaminants found in wastewater streams produced on-board during space exploration. Phenol, a known human carcinogen, and creatinine, a human metabolite found in urine, were the compounds tested in this study. Phenol and creatinine have cyclic structures consisting of six and five member rings, respectively. In addition, creatinine is a methyl guanidine derivative, with almost 40% (w/w) nitrogen. The degradation and carbon mineralization efficiencies of the target contaminants were investigated at different initial concentrations. Their photocatalytic degradation appears to follow pseudo-first-order reaction with phenol giving higher organic carbon reduction rates than creatinine. The presence and position of the functional groups of creatinine (amine, imine and peptide bond) are primarily responsible for the significantly slower mineralization. The degradation of creatinine was also tested at different pHo values. Statistical analysis showed that there is an effect of pH on the treatment of creatinine. Besides the carbon mineralization, the extent of nitrogen mineralization and the mass balance of nitrogen were conducted for three pH values (pHo 3.0, 6.2 and 11.0). Overall, the transformation of nitrogen was low, and the total maximum conversion (<20%) occurred at basic conditions. 相似文献
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Wei Tze Mook Mohamed Kheireddine Taeib Aroua Mohammed Harun Chakrabarti Ishenny Muhammad Noor Muhammad Faisal Irfan Chee Tong John Low 《Journal of Industrial and Engineering Chemistry》2013,19(1):1-13
The main factor that determines the success of a bio-electrochemical system (BES) is the bio-electrode. This paper reviews the direct as well as mediated electron transfer mechanisms in bio-electrodes. Some discussions on their influence upon the performance of microbial fuel and electrolysis cells are considered. Factors affecting organic matter removal at bioanodes and denitrification at biocathodes are elaborated upon. Important parameters for the successful simultaneous removal of contaminants are reported. The major conclusion from this work is that BES is able to remove organic matter and nitrates simultaneously from different wastewater samples at efficiencies greater than 90%. 相似文献
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《Journal of the European Ceramic Society》2021,41(15):7498-7506
High-entropy ceramics (HEC) with a fixed composition of (VNbTaMoW)C5 were prepared by spark plasma sintering (SPS) from 1500 °C to 2200 °C. XRD, TEM, HRTEM, SAED and EDX were used to investigate effects of the sintering temperatures on compositional homogeneity, constituent phases and microstructure of the HECs. The results showed that single-phase HEC formed at a temperature as low as 1600 °C while ultimate elemental distribution homogeneity could be obtained at 2200 °C. Elemental distribution homogenization was accompanied by microstructural coarsening and oxide impurities aggregating at grain boundaries as temperature increased. SPS at 1900 °C for 12 min could yield uniform HECs (VNbTaMoW)C5 with Vickers hardness, nanohardness, fracture toughness and Young’s modulus reaching 19.6 GPa, 29.7 GPa, 5.4 MPa m1/2 and 551 GPa, respectively. The resultant HECs showed excellent wear resistance when coupled with WC at room temperature. 相似文献
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以凹凸棒土(ATP)作载体,硫酸氧钛、硫酸锌及碳酸铵为原料,采用化学沉淀法制备凹凸棒土负载氧化锌-二氧化钛(ATP/ZnO-TiO2)纳米复合材料,并用XRD,TEM测试手段对样品进行了表征。以其对活性大红(BES)的降解效果作为评价其光催化性能的标准,对制备条件进行了优化。结果表明:ATP与二氧化钛的质量比为20%、二氧化钛与氧化锌的物质的量比为10∶1、煅烧温度为450 ℃下制备的复合材料光催化降解活性大红的效果最佳;与凹凸棒土负载二氧化钛(ATP/TiO2)及凹凸棒土负载氧化锌(ATP/ZnO)相比,复合材料具有良好的可见光光催化性能。 相似文献
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Shijun Zhao 《Journal of the American Ceramic Society》2021,104(4):1874-1886
The idea of high-entropy alloys (HEAs) has profoundly stimulated the recent development of novel entropy-stabilized ceramics. Herein we explore the local lattice distortion, one of the core effects in HEAs responsible for their extraordinary properties, in typical high-entropy ceramic (HEC) carbides with single-phase rock salt structures. We first quantify the local distortions based on first-principles calculations, and then investigate their influences on the structural properties, lattice stability, electronic structures, mechanical deformation, defect energetics, and thermodynamic properties. Our results show that carbon generally exhibits the most substantial distortion. On average, large local distortion is found in (NbTiVZr)C and (MoNbTaVW)C. Such distortion plays a crucial role in stabilizing HECs by lowering their enthalpy of formation. The electronic structure of HECs depends strongly on the local distortion, which can enhance charge transfer between transition metals and carbon atoms. We further show that distortion makes HECs soft and ductile due to the delocalization of electronic charges. The formation energies of C vacancies decrease significantly due to local distortion, resulting in high concentrations of C vacancies. The presence of high-concentration C vacancies release distortion and helps to retain the high strength of HECs. Finally, we show that lattice distortion has a great impact on the thermodynamic quantities of HECs, such as thermal expansion coefficient and Debye temperature. 相似文献
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本文通过对碳化物粉末进行放电等离子烧结(SPS),成功制备了(Ti0.25Zr0.25Nb0.25Ta0.25)C高熵陶瓷(HECs),系统研究了HECs的微观结构演变、力学性能和氧化行为。结果表明,单相HECs的形成温度为1 800 ℃,低于已报道的HECs烧结温度。1 900 ℃烧结的陶瓷晶粒细小,平均晶粒尺寸约7.5 μm,元素分布均匀,相对密度高达99.2%。1 800 ℃和1 900 ℃烧结的HECs的室温显微硬度值分别为30.9 GPa和33.2 GPa,断裂韧性值分别为(4.6±0.24) MPa·m1/2和(4.5±0.31) MPa·m1/2,高于大多数已报道的HECs。原位高温纳米压痕试验结果表明,HECs的硬度随温度的升高而降低,当温度达到500 ℃时,1 800 ℃和1 900 ℃烧结的陶瓷硬度分别下降到21.9 GPa和22.2 GPa,具有突出的高温稳定性。此外,HECs在温度低于500 ℃时无明显氧化,当温度超过650 ℃时会发生明显氧化,氧化速率随温度升高而增加。 相似文献
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介绍纤维液膜脱硫技术的原理及处理不同种类原料油时的几种典型脱硫工艺,该技术近几年在我国轻质油脱硫及脱硫醇方面大量应用,相较于传统的氧化-脱除工艺有一定的优势。处理不同种类原料时,总硫基本可以控制在50 mg/m3以下,硫醇硫基本可以控制在10 mg/m3以下,脱除效果好。该技术易于对原工艺装置改造实现,同时具有装置运行平稳、碱耗更低、碱渣量小、能耗更低等优势。对于该技术目前存在的一些问题,提出了一些具体的改进措施,指出研究开发彻底分离碱液中二硫化物的新工艺具有一定的实际意义。 相似文献