排序方式: 共有170条查询结果,搜索用时 15 毫秒
151.
针对目前室内空气污染物甲醛超标的现象,将新型碳纳米材料(石墨烯、碳纳米管)引入到气体污染物去除领域.利用石墨烯水溶液在一定条件下形成凝胶的特性,采用海绵作为骨架,构造石墨烯/碳纳米管/海绵三维气凝胶结构,并进一步采用氨基修饰提高该氨基化碳纳米管/石墨烯气凝胶(GCNTs/EDA-S)对室内空气污染物甲醛的吸附性能,研究石墨烯与碳纳米管(CNTs)对气态甲醛吸附作用机理.样品吸附实验结果对比分析表明,石墨烯和碳纳米管氨基官能团修饰后对气态甲醛均有良好的吸附性能,其中GCNTs/EDA-S在甲醛浓度为3.7ppm时,吸附实验的穿透时间可达到4024min/g,最大吸附容量为13.5mg/g. 相似文献
152.
Yu YANG Zhicheng YU Takayuki NOSAKA Kyle DOUDRICK Kiril HRISTOVSKI Pierre HERCKES Paul WESTERHOFF 《Frontiers of Environmental Science & Engineering》2015,9(5):823
Increasing production and use of carbonaceous nanomaterials (NMs) will increase their release to the sewer system and to municipal wastewater treatment plants. There is little quantitative knowledge on the removal of multi-walled carbon nanotubes (MWCNTs), graphene oxide (GO), or few-layer graphene (FLG) from wastewater into the wastewater biomass. As such, we investigated the quantification of GO and MWCNTs by UV-Vis spectrophotometry, and FLG using programmable thermal analysis (PTA), respectively. We further explored the removal of pristine and oxidized MWCNTs (O-MWCNTs), GO, and FLG in a biomass suspension. At least 96% of pristine and O-MWCNTs were removed from the water phase through aggregation and 30-min settling in presence or absence of biomass with an initial MWCNT concentration of 25 mg·L−1. Only 65% of GO was removed with biomass concentration at or above 1,000 mg·L−1 as total suspended solids (TSS) with the initial GO concentration of 25 mg·L−1. As UV-Vis spectrophotometry does not work well on quantification of FLG, we studied the removal of FLG at a lower biomass concentration (50 mg TSS·L−1) using PTA, which showed a 16% removal of FLG with an initial concentration of 1 mg·L−1. The removal data for GO and FLG were fitted using the Freundlich equation (R2 = 0.55, 0.94, respectively). The data presented in this study for carbonaceous NM removal from wastewater provides quantitative information for environmental exposure modeling and life cycle assessment. 相似文献
153.
Hongtao YU Bin MA Shuo CHEN Qian ZHAO Xie QUAN Shahzad AFZAL 《Frontiers of Environmental Science & Engineering》2014,8(2):180-187
Graphene electrodes (Ti/Gr) were prepared by depositing Gr sheets on Ti substrate, followed by an annealing process for enhancing the adhesion strength. Electrochemical impedance spectroscopies and X-ray dif- fraction patterns displayed that the electrochemical behavior of Ti/Gr electrodes can be improved due to the generation of TiO2 layer at Ti-Gr interface during the annealing process. The palladized Gr electrodes (Ti/Gr/Pd) were prepared by electrochemical depositing Pd nanoparticles on Gr sheets. The debromination ability of Ti/Gr/Pd electrodes was investigated using BDE-47 as a target pollutant with various bias potentials. The results indicated that the BDE-47 degradation rates on Ti/Gr/Pd electrodes increased with the negative bias potentials from 0V to -0.5 V (vs. SCE). Almost all of the BDE-47 was removed in the debromination reaction on the Ti/Gr/Pd electrode at - 0.5 V for 3 h, and the main product was diphenyl ethers, meaning it is promising to debrominate completely using the Ti/Gr/Pd electrode. Although the debromination rate was slightly slower at -0.3 V than that under -0.5 V, the current efficiency at -0.3 V was higher, because the electrical current acted mostly on BDE-47 rather than on water. 相似文献
154.
采用恒温搅拌法和水热法首次制备磁性三乙烯四胺氧化石墨烯(M-T-GO),并通过SEM和XPS对M-T-GO进行表征.以M-T-GO为吸附剂,分析pH值、吸附时间和初始浓度对阴离子染料酒石黄(TY)和阳离子染料亚甲基蓝(MB)吸附效果的影响.并对吸附动力学和吸附等温线进行拟合.结果表明:M-T-GO对离子型染料的吸附过程符合Langmuir吸附等温式和拟二级反应动力学描述.M-T-GO对TY和MB具有较好的吸附性能,饱和吸附量分别为157.23mg/g和169.49mg/g.与GO相比,M-T-GO对离子型染料的吸附效果更优异,同时具有快速分离和易再生的优点. 相似文献
155.
Guolong Zeng Yiyang Liu Xiaoguo Ma Yinming Fan 《Frontiers of Environmental Science & Engineering》2021,15(5):107
156.
研究氧化石墨烯(GO)的遗传毒性,考察其致突变作用,为GO在生物领域的安全应用提供依据。采用Ames试验、体外CHL细胞染色体畸变试验和小鼠体内染色体畸变试验,分别在细菌水平、细胞水平及整体动物水平研究GO的遗传毒性。GO各剂量组的Ames试验结果为阴性。CHL试验中,CHL细胞染色体畸变率随GO浓度的增加而升高,其中1.000 mg·mL~(-1)剂量组(+S_9)和0.500 mg·mL~(-1)剂量组(-S_9)畸变率显著升高(P 0.05)。小鼠骨髓细胞染色体畸变试验中,骨髓细胞染色体畸变率同样随GO浓度的增加而升高,1.000和0.500 mg·kg~(-1)剂量组的畸变率显著提高(P 0.05)。虽然Ames试验结果没有反映出GO的遗传毒性,但在体外及体内染色体畸变试验中,GO均表现出对哺乳动物细胞染色体有潜在的遗传毒性。 相似文献
157.
Xiaoyan Guo Chunyu Li Chenghao Li Tingting Wei Lin Tong Huaiqi Shao Qixing Zhou Lan Wang Yuan Liao 《Frontiers of Environmental Science & Engineering》2019,13(6):81
158.
Motivated by the recent realization of graphene sensor to detect gas molecules that are harmful to the environment, the ammonia adsorption on graphene or graphene oxide (GO) was investigated using first-principles calculation. The optimal adsorption and orientation of the NH3 molecules on the graphene surfaces were determined, and the adsorption energies (E b) as well as the Mulliken charge transfers of NH3 were calculated. The E b for the graphene are small and seem to be independent of the sites and orientations. The surface epoxy or hydroxyl groups can promote the adsorption of NH3 on the GO; the enhancement of the E b for the hydroxyl groups is greater than that for the epoxy groups on the surface. The charge transfers from the molecule to the surfaces also exhibit the same trend. The Brönsted acid sites and Lewis acid sites could stably exist on the GO with surface hydroxyl groups and on the basal, respectively. 相似文献
159.
采用动态光散射技术研究了不同价态阳离子、富里酸(FA)等对两种功能化石墨烯(FG)悬浮凝聚行为的影响机制.结果表明:FG分别在含不同浓度Na+、Ca2+和La3+的电解质溶液中,其临界聚集浓度(CCC)值范围为221~263,3~4,0.05~0.07mmol/L,符合经典的DLVO理论与Schulze-Hardy法则.5种FA亚组分均可显著抑制FG在水体中的凝聚,加入5mg/L的FA亚组分后,在不同浓度的Ca2+和La3+的电解质溶液中,FG-OH (FG-COOH)的CCC值分别增大12.5%~37.5%(3.2%~4.5%)和4.2%~25.7%(10%~46%).FG的CCC值与FA亚组分的C、H含量和H/C比显著正相关(P<0.05),与O含量、O/C比和羧基C含量显著负相关(P<0.05).差分荧光光谱研究表明随着FG的加入,FA的荧光强度逐渐降低,二者发生相互作用. 相似文献
160.
Billie Yan Zhang Hiew Wan Ting Tee Nicholas Yung Li Loh Kar Chiew Lai Svenja Hanson Suyin Gan Suchithra Thangalazhy-Gopakumar Lai Yee Lee 《环境科学学报(英文版)》2022,34(8):194-203
Water contamination by non-steroidal anti-inflammatory drugs, such as acetaminophen, is an emerging ecological concern. In this study, a new three-dimensional manganese dioxide-engrafted reduced graphene oxide (3D MnO2/rGO) hybrid aerogel was developed for acetaminophen sequestration. The synthesis involved firstly the self-assembly of GO aerogel, followed by thermal reduction and in-situ MnO2 growth by redox-reaction. The aerogel demonstrated interlinked planes with smooth surfaces deposited with MnO2 nanospheres and pores of 138.4 – 235.3 µm width. The influences of adsorbent dosage, initial pH, acetaminophen concentration, temperature and contact time were investigated. It was determined that the adsorption of acetaminophen occurred on uniform sorption sites in the aerogel, as suggested by the best fit of data to the Langmuir isotherm, yielding a maximum adsorption capacity of 252.87 mg/g. This highest adsorption performance of the 3D MnO2/rGO aerogel was attained at a dosage of 0.6 g/L, initial pH of 6.2 and temperature of 40°C. The process kinetics were in-line with the pseudo-first-order and pseudo-second-order kinetics at 10 and 20 – 500 mg/L concentrations, respectively. Thermodynamic assay showed the spontaneity and endothermicity features of the 3D MnO2/rGO-acetaminophen system. The acetaminophen adsorption mechanisms were mainly hydrogen bonding and pore entrapment. Moreover, the as-synthesised aerogel was effectively regenerated using acetone and re-utilised in four adsorption-desorption cycles. Overall, the results highly recommend the implementation of the 3D MnO2/rGO hybrid aerogel for purification of wastewater polluted by acetaminophen residue. 相似文献