共查询到20条相似文献,搜索用时 31 毫秒
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采用常温饱和溶液蒸发法,一硫化四甲基秋兰姆与钻(Ⅱ)发生原位反应得到一种新型非均相Fenton催化剂单晶Co(C3H6NS2)3·C6H12N2S3;通过单晶x衍射、红外光谱和C、N和H元素分析对该单品结构进行了表征;该单晶的空间群为P-1,在不对称单元中有1个Co(Ⅲ)中心,3个新配体C3H7NS2和1个TMTM;Co(Ⅲ)呈现出稍微偏斜的八面体的配位几何构型.利用该单晶催化氧化降解了直接蓝6和直接绿28;结果显示,在酸性和碱性条件下,染料的降解率和矿化率都较高,这是因为活性中心Co(Ⅲ)提高了H2O2的效率.当投加量在1 200~1 600 mg·L-1之间时,处理90 min后,直接蓝6和直接绿28的降解效率可分别达到94.39%和94.78%.相比之下,不加该单晶光催化剂,其它条件完全相同时,处理90 min后2种染料的降解率均不到45%,降解缓慢.使用后的单晶,通过过滤,可反复使用,有利于降低处理成本.此外还研究了催化反应的动力学,反应遵从Langmuir-Hinshelwood动力学模型;2种染料降解反应速率常数k分别为3.03×102和6.25×102mg·(L·min)-1,吸附常数K分别为1.52×10-4和7.23×10-5L·mg-1. 相似文献
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Qiongfang Zhuo Xiang Li Feng Yan Bo Yang Shubo Deng Jun Huang Gang Yu 《环境科学学报(英文版)》2014,26(8):1733-1740
The 6:2 FTS was the substitute for perfluorooctane sulfonate(PFOS) in the chrome plating industry in Japan. Electrochemical oxidation of 6:2 FTS was investigated in this study. The degradabilities of PFOS and 6:2 FTS were tested on the Ti/SnO2–Sb2O5–Bi2O3anode. The effects of current density,potential,and supporting electrolyte on the degradation of 6:2 FTS were evaluated. Experimental results showed that 6:2 FTS was more easily degraded than PFOS on the Ti/SnO2–Sb2O5–Bi2O3anode. At a low current density of 1.42 mA/cm2,6:2 FTS was not degraded on Ti/SnO2–Sb2O5–Bi2O3,while the degradation ratio increased when the current density ranged from 4.25 to 6.80 mA/cm2. The degradation of 6:2 FTS at current density of 6.80 mA/cm2 followed pseudo first-order kinetics with the rate constant of 0.074 hr-1. The anodic potential played an important role in the degradation of 6:2 FTS,and the pseudo first-order rate constants increased with the potential. The surface of Ti/SnO2–Sb2O5–Bi2O3was contaminated after electrolysis at constant potential of 3 V,while the fouling phenomenon was not observed at 5 V. The fouled anode could be regenerated by incinerating at 600°C. The intermediates detected by ultra-performance liquid chromatography coupled with a triple-stage quadrupole mass spectrometer(UPLC–MS/MS) were shorter chain perfluorocarboxylic acids. The 6:2 FTS was first attacked by hydroxyl radical,and then formed perfluorinated carboxylates,which decarboxylated and removed CF2 units to yield shorter-chain perfluorocarboxylic acids. 相似文献
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污水处理厂消化沼气脱硫(H2S)实验 总被引:1,自引:0,他引:1
污泥消化池每天产生大量的沼气,主要成分为甲烷。消化沼气是一种热值很高的可燃性气体,可用于驱动发电机发电。沼气中的H2S对设备的腐蚀性严重影响了有效的能源利用。除去沼气中含有的H2S可使发电机免遭腐蚀,还可以控制SO2的排放。本论文通过对PDS法应用于某污水处理厂消化沼气脱硫的研究与试验,证明了该方法的有效性及可行性。脱硫效率高达90%以上,平均脱硫效率为95%。脱硫后消化沼气中H2S的浓度均远远低于发动机对燃气中要求的H2S的浓度不得高于1150mgm3的标准,对下一步的工程设计及工艺改进具有指导性的意义。 相似文献
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<正> 自Silverman及Epstein(1958)的早期研究以来,原油的碳同位素组成被认为主要取决于油源。有人发现在石油运移期间同位素效应较小。因此,原油中~(13)C含量已成功地应用于区别多油源盆地中的原油。Williams(1974)曾指出,~(13)C同位素与其他参数如旋光性相结合,是一个有效地对比手段。Galimov(1973)发现原油族组成中~(13)C的浓度能揭示原油的重要特性。Stahl(1977)和Fuex(1977)曾指出族组成的~(13)C同位素特征可应用于对比原油。 相似文献
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对大气降水中~3H,~(14)C放射性同位素含量的测量分析,是了解环境放射性质量及污染,特别是对大气层核污染进行监测的有效手段和项目。同时,它也是水环境尤其是对地下水污染来源、转移和污染趋势预测的一种有用的参考指标。除环境科学外,还对气象,水文、地质,水 相似文献
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在实验室模拟研究中,丙烷和丙烯在Pt-Rh型汽车尾气催化剂表面的催化氧化性能的差异,会对催化剂的起燃特性表现造成影响。由于丙烯在催化剂表面存在较严重的自中毒作用,使得CO和NOx的低温起燃特性变差。在低温下,由于丙烷相对丙烯催化燃烧速率较慢,剩余的氧气和NOx发生竞争反应,导致NOx的温度一转化率曲线出现S型的起伏。 相似文献
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铁氧体法处理含Zn~(2 )、Cr~(6 )电镀废水工业性试验研究 总被引:2,自引:0,他引:2
以冷镀锌为主的乡镇企业,环境保护治理措施一般比较简陋,采用简单中和处理后就外排,排放的废水Zn2 、Cr6 经常出现超标现象。我们先后对徐州源园涂装有限公司、徐州方园电镀厂含Zn2 、Cr6 废水进行试验研究,在试验研究的基础上建设了污水处理设施,运行正常,能够稳定达标排放。1含Zn2 、Cr6 电镀废水工艺特性锌的氢氧化合物是两性化合物,pH值过高或过低,排放的废水都不能稳定达标排放;废水中Cr6 必须首先还原成Cr3 ,再调节PH值,以Cr(OH)3沉淀去除;废水水质不稳定,锌、铬含量波动大,加药量保持不变的情况下,出水经常超标排放。鉴于锌、铬氢氧化物的沉淀化合特性,利用铁氧体共沉淀工艺,可以较好地克服两性氧化物沉淀的特性和水质波动而带来水质超标。2处理原理铁氧体即为铁离子与其它金属离子组成的氧化物固溶体,该工艺最初由日本电气公司研制使用。铁氧体固溶体具有较高稳定性且具有磁性,易于实现固液分离,在处理两性氧化物和重金属废水中具有自己独到优点。根据铁氧化体形成工艺,可以分为氧化法和中和法。氧化法是将加入亚铁离子废水在加热和通气情况下,部分氧化为铁离子;中和法是通过按照一定浓度比例向废水投加亚铁离子和铁离子而... 相似文献
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Zidan Yuan Xu M Xing Wu Guoqing Zhang Xin Wang Shaofeng Wang Yongfeng Jia 《环境科学学报(英文版)》2020,32(4):205-215
Tooeleite(Fe6(As03)4 SO4(OH)4·4 H_2 O) is widely precipitated for direct As(III) removal from sulfate-rich industrial effluents.However,whether or not Fe(III)-As(III)-Cl(-I) precipitate is produced in chloridizing leaching media for As immobilization is almost unknown.This work founded the existence of ferric arsenite(hydroxy)chloride as a new mineral for As(III)removal.Its chemical composition and solid characterization were subsequently studied by using scanning electron microscope with an energy dispersive spectrometer(SEM-EDS),X-ray diffraction(XRD),infrared(FT-IR),Raman spectroscopy and thermogravimetric(TG)curve.The results showed the formation of a yellow precipitate after 3-days reaction of Fe(III)/As(III) with molar ratio≈1.7 in chloride solution at pH 2.3 neutralized with NaOH.Compared with tooeleite,chemical analysis and solid characterization indicated that Cl(-I)replaces S04(-II) producing ferric arsenite hydroxychloride with formula Fe5(As03)_3-Cl_2(OH)4·5 H_2 O.This new plate shaped solid showed better crytallinity than tooeleite,although it has similar morphology and characteristic bands to tooeleite.The FT-IR bands at 628,964 cm-1 and the Raman bands at 448,610,961 cm-1 were assigned to Fe-O or As(Ⅲ)-O-Fe or As(Ⅲ)-O bending/stretching vibration,indicating that both arsenite and chloride substituted for the position of sulfate for ferric arsenite hydro xychloride produced due to the lack of the SO_4~(2-) vibrations.Cl-(I) also contributed to increase As removal efficiency in aqueous sulfate media under acidic pH conditions via the probable formation of sulfatechloride ferric arsenite. 相似文献
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以TiO2P25(TIO-P25)及Fe(NO3)3为前驱物制备TiO2负载Fe3+多相催化剂Fe/TIO-P25,研究Fe/TIO-P25可见光催化H2O2降解扑草净的协同效应.XRD、XPS、EDS及SEM结果表明,Fe元素以Fe2O3形式高度分散于TiO2表面,负载量约1.5%(wt%),未对TIO-P25的粒径及形貌产生明显影响,Fe/TIO-P25的粒径约20~40nm;光催化结果表明,Fe/TIO-P25能可见光催化H2O2降解扑草净,反应30min降解率达100%,远大于TIO-P25的催化活性,负载Fe与TIO-P25之间存在明显的协同效应;通过对反应体系的荧光光谱分析显示,扑草净的降解涉及较单纯羟基自由基(·OH)过程更为复杂的反应机理. 相似文献
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1 斜楔式冲模设计 1.4 斜楔滑板的表面压力与行程的求法从楔块上传来的力(P)和作用于楔形滑板运动方向所需要的加工力(F),与楔形滑板行程(S)以及作用于楔块表面的表 相似文献
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