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包埋固定化海洋硅藻吸附材料的制备及其对水中铅离子的吸附特性研究 总被引:1,自引:0,他引:1
采用海藻酸钠(SA)凝胶包埋法对海洋硅藻藻粉进行固定化,考察了藻粉用量、海藻酸钠浓度、Ca Cl2质量分数、交联时间及小球粒径对固定化小球吸附铅离子性能的影响,并研究了这种吸附材料对Pb~(2+)的吸附特性.结果表明,固定化海洋硅藻生物吸附剂的最佳制备条件为:藻粉用量5.0 g/100 m L SA、海藻酸钠浓度20 g·L~(-1)、Ca Cl2质量分数0.5%、交联时间1 h、小球粒径2.8 mm左右.Langmuir等温吸附模型能够较好地描述固定化小球吸附对Pb~(2+)的等温吸附特征,R2为0.9983,最大理论吸附量为833.33 mg·g~(-1).准二级动力学模型能够较好地拟合固定化小球吸附Pb~(2+)的动力学过程,理论平衡吸附量为714.29 mg·g~(-1),与实验所得平衡吸附量706.55 mg·g~(-1)较为接近.固定化小球吸附Pb~(2+)的适宜初始p H值为4~5.Na Cl、Ca(NO3)2、Mg(NO3)2对固定化小球的吸附性能有一定的促进作用.本研究所制固定化海洋硅藻球形吸附材料对Pb~(2+)的吸附容量明显优于大部分研究所报道的固定化生物吸附剂,是一种很有潜力的生物吸附材料. 相似文献
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Xianke Lin Xiaohong Chen Sichang Li Yangmei Chen Zebin Wei Qitang Wu 《Frontiers of Environmental Science & Engineering》2021,15(2):22
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Xiaojing SHEN Junying SUN Xiaoye ZHANG Yangmei ZHANG Lu ZHANG Ruxia FAN 《Frontiers of Environmental Science & Engineering》2016,10(5):5
New particle formation (NPF) event at multi rural sites in China Identifying the characteristics of NPF event Comparing NPF event between clean and polluted conditions Quantifying contribution to the cloud condensation nuclei Implication of climate and air quality Long-term continuous measurements of particle number size distributions with mobility diameter sizes ranging from 3 to 800 nm were performed to study new particle formation (NPF) events at Shangdianzi (SDZ), Mt. Tai (TS), and Lin’an (LAN) stations representing the background atmospheric conditions in the North China Plain (NCP), Central East China (CEC), and Yangtze River Delta (YRD) regions, respectively. The mean formation rate of 3-nm particles was 6.3, 3.7, and 5.8 cm−3·s−1, and the mean particle growth rate was 3.6, 6.0, and 6.2 nm·h−1 at SDZ, TS, and LAN, respectively. The NPF event characteristics at the three sites indicate that there may be a stronger source of low volatile vapors and higher condensational sink of pre-existing particles in the YRD region. The formation rate of NPF events at these sites, as well as the condensation sink, is approximately 10 times higher than some results reported at rural/urban sites in western countries. However, the growth rates appear to be 1–2 times higher. Approximately 12%–17% of all NPF events with nucleated particles grow to a climate-relevant size (>50 nm). These kinds of NPF events were normally observed with higher growth rate than the other NPF cases. Generally, the cloud condensation nuclei (CCN) number concentration can be enhanced by approximately a factor of 2–6 on these event days. The mean value of the enhancement factor is lowest at LAN (2–3) and highest at SDZ (~4). NPF events have also been found to have greater impact on CCN production in China at the regional scale than in the other background sites worldwide. 相似文献
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Nitrification potentials of Chinese tea orchard soils and their adjacent
wasteland and forest soils 总被引:1,自引:0,他引:1
To investigate the nitrifying activities of di erent soil types, soil samples collected from 8-, 50- and 90-year old tea orchards, the
adjacent wasteland, and 90-year old forest were measured for their nitrification potentials using the conventional soil incubation and the
liquid incubation method. Among di erent soil types, the nitrification potential of soil in tea orchards was higher than that of wasteland
and forest soils. The slurry shaken liquid incubation method was confirmed to be more accurate and have reliable results than the
soil incubation. Interestingly, experimental result revealed that the generally applied pH value of 7.2 for the liquid media was not the
optimal pH for these acid soils with a strong bu er capacity. This suggested that tea orchard soils may have nitrifiers requiring pHneutral
condition for the best activity. Our data also showed that treatment with the commonly used nitrogen fertilizer urea significantly
improved nitrification potential of the soils; such enhancement e ect was stronger on all of three tea orchard soils than on wasteland
and forest soils, and also stronger on the younger (8- and 50-year old) tea orchard soils than on the older one (90-year old). 相似文献
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He Ke Zhang Junbiao Wang Xueting Zeng Yangmei Zhang Lu 《Environmental science and pollution research international》2018,25(17):16522-16532
Environmental Science and Pollution Research - Agricultural ecological compensation has drawn an increasingly broad range of interest since early 1990s. In recent years, the volume of the... 相似文献
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在探索厌氧处理制药产生的废渣和污水研究中,以中国A制药厂的药渣和中国B制药厂的污水为原料,研究制药废渣和污水的厌氧产气能力.结果表明:药渣TS产气率为205.6 mL/g~223.59 mL/g,VS产气率为221.3 mL/g~239.5 mL/g,有机物降解率为40%左右,系统中不存在产气抑制物;制药污水的TS产气率为403.9 mL/g~409.2 mL/g,VS产气率为563.4 mL/g~ 578.6 mL/g,COD降解率85%以上.药渣沼气和污水沼气的CH4浓度分别为54.6%~60.7%和52.3% ~56.8%. 相似文献
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Mingzhi Huang Yongwen Ma Jinquan Wan Yan Wang Yangmei Chen Changkyoo Yoo 《Environmental science and pollution research international》2014,21(20):12074-12084
Due to the inherent complexity, uncertainty, and posterity in operating a biological wastewater treatment process, it is difficult to control nitrogen removal in the biological wastewater treatment process. In order to cope with this problem and perform a cost-effective operation, an integrated neural-fuzzy control system including a fuzzy neural network (FNN) predicted model for forecasting the nitrate concentration of the last anoxic zone and a FNN controller were developed to control the nitrate recirculation flow and realize nitrogen removal in an anoxic/oxic (A/O) process. In order to improve the network performance, a self-learning ability embedded in the FNN model was emphasized for improving the rule extraction performance. The results indicate that reasonable forecasting and control performances had been achieved through the developed control system. The effluent COD, TN, and the operation cost were reduced by about 14, 10.5, and 17 %, respectively. 相似文献
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Shuo Liu Sinan Zhang Xiaojing Shen Junying Sun Yangmei Zhang Xiaoye Zhang Can Xi Xinyao Hu Junting Zhong Jialing Wang 《环境科学学报(英文版)》2023,35(2):544-556
A hygroscopic tandem differential mobility analyser (H-TDMA) was used to observe the size-resolved hygroscopic characteristics of submicron particles in January and April 2018 in urban Beijing. The probability distribution of the hygroscopic growth factor (HGF-PDF) in winter and spring usually showed a bimodal pattern, with more hygroscopic mode (MH) being more dominant. The seasonal variation in particle hygroscopicity was related to the origin of air mass, which received polluted southerly air masses in spring and clean northwesterly air masses in winter. Particles showed stronger hygroscopic behaviour during heavy pollution episodes (HPEs) with elevated concentrations of secondary aerosols, especially higher mass fraction of nitrate, which were indicated using the PM2.5 (particulate matter with diameter below 2.5 µm) mass concentration normalised by CO mass concentration. The hygroscopic parameter (κ) values were calculated using H-TDMA (κhtdma) and chemical composition (κchem). The closure study showed that κchem was overestimated in winter afternoon when compared with κhtdma, because the organic particle hygroscopic parameter (κorg) was overestimated in the calculations. It was influenced by the presence of a high concentration of hydrocarbon-like organic aerosol (HOA) with a weak water uptake ability. A positive relationship was observed between κorg and the ratio of oxygenated organic aerosol (OOA) and HOA, thereby indicating that the strong oxidation state enhanced the hygroscopicity of the particles. This study revealed the effect of local emission sources and secondary aerosol formation processes on particle hygroscopicity, which is of great significance for understanding the pollution formation mechanism in the North China Plain. 相似文献
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Trace metals in atmospheric fine particles in one industrial urban city: Spatial variations, sources, and health implications 总被引:3,自引:0,他引:3
Shengzhen Zhou Qi Yuan Weijun Li Yaling Lu Yangmei Zhang Wenxing Wang 《环境科学学报(英文版)》2014,26(1):205-213
Trace metals in PM2.5were measured at one industrial site and one urban site during September, 2010 in Ji'nan, eastern China. Individual aerosol particles and PM2.5samples were collected concurrently at both sites. Mass concentrations of eleven trace metals(i.e., Al, Ti, Cr, Mn, Fe, Ni, Cu, Zn, Sr, Ba, and Pb) and one metalloid(i.e., As) were measured by inductively coupled plasma atomic emission spectroscopy(ICP-AES). The result shows that mass concentrations of PM2.5(130 μg/m3) and trace metals(4.03 μg/m3) at the industrial site were 1.3 times and 1.7 times higher than those at the urban site, respectively, indicating that industrial activities nearby the city can emit trace metals into the surrounding atmosphere. Fe concentrations were the highest among all the measured trace metals at both sites, with concentrations of 1.04 μg/m3at the urban site and 2.41 μg/m3at the industrial site, respectively. In addition, Pb showed the highest enrichment factors at both sites, suggesting the emissions from anthropogenic activities existed around the city. Correlation coefcient analysis and principal component analysis revealed that Cu, Fe, Mn, Pb, and Zn were originated from vehicular trafc and industrial emissions at both sites; As, Cr, and part of Pb from coal-fired power plant; Ba and Ti from natural soil. Based on the transmission electron microscopy analysis, we found that most of the trace metals were internally mixed with secondary sulfate/organic particles. These internally mixed trace metals in the urban air may have diferent toxic abilities compared with externally mixed trace metals. 相似文献
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