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811.
In this work, the effects of different methods of activation on CO2 adsorption performance of activated carbon were studied. Activated carbons were prepared from biochar, obtained from fast pyrolysis of white wood, using three different activation methods of steam activation, CO2 activation and Potassium hydroxide (KOH) activation. CO2 adsorption behavior of the produced activated carbons was studied in a fixed-bed reactor set-up at atmospheric pressure, temperature range of 25–65°C and inlet CO2 concentration range of 10–30 mol% in He to determine the effects of the surface area, porosity and surface chemistry on adsorption capacity of the samples. Characterization of the micropore and mesopore texture was carried out using N2 and CO2 adsorption at 77 and 273 K, respectively. Central composite design was used to evaluate the combined effects of temperature and concentration of CO2 on the adsorption behavior of the adsorbents. The KOH activated carbon with a total micropore volume of 0.62 cm3/g and surface area of 1400 m2/g had the highest CO2 adsorption capacity of 1.8 mol/kg due to its microporous structure and high surface area under the optimized experimental conditions of 30 mol% CO2 and 25°C. The performance of the adsorbents in multi-cyclic adsorption process was also assessed and the adsorption capacity of KOH and CO2 activated carbons remained remarkably stable after 50 cycles with low temperature (160°C) regeneration. 相似文献
812.
Mei Tian Fangqing Zhao Xin Shen Kahou Chu Jinfeng Wang Shuai Chen Yan Guo Hanhu Liu 《环境科学学报(英文版)》2015,35(9):181-190
The anaerobic/anoxic/oxic (A2O) process is globally one of the widely used biological sewage treatment processes. This is the first report of a metagenomic analysis using Illumina sequencing of full-scale A2O sludge from a municipal sewage treatment plant. With more than 530,000 clean reads from different taxa and metabolic categories, the metagenome results allow us to gain insight into the functioning of the biological community of the A2O sludge. There are 51 phyla and nearly 900 genera identified from the A2O activated sludge ecosystem. Proteobacteria, Bacteroidetes, Nitrospirae and Chloroflexi are predominant phyla in the activated sludge, suggesting that these organisms play key roles in the biodegradation processes in the A2O sewage treatment system. Nitrospira, Thauera, Dechloromonas and Ignavibacterium, which have abilities to metabolize nitrogen and aromatic compounds, are most prevalent genera. The percent of nitrogen and phosphorus metabolism in the A2O sludge is 2.72% and 1.48%, respectively. In the current A2O sludge, the proportion of Candidatus Accumulibacter is 1.37%, which is several times more than that reported in a recent study of A2O sludge. Among the four processes of nitrogen metabolism, denitrification related genes had the highest number of sequences (76.74%), followed by ammonification (15.77%), nitrogen fixation (3.88%) and nitrification (3.61%). In phylum Planctomycetes, four genera (Planctomyces, Pirellula, Gemmata and Singulisphaera) are included in the top 30 abundant genera, suggesting the key role of ANAMMOX in nitrogen metabolism in the A2O sludge. 相似文献
813.
以二级出水中氨氮的吸附处理为研究对象,对活性炭吸附法和沸石吸附法去除二级出水中氨氮进行试验研究。在一定范围内,吸附剂用量对氨氮的去除效果有较大的影响,相同条件下,吸附剂投加量越大,氨氮去除率越高,但增加到一定程度后,对氨氮的吸附作用减弱,在实际应用中控制吸附剂的投加量是必要的。当吸附剂用量为15 mg时,活性炭吸附效果要明显高于沸石的;当吸附剂用量大于30 mg时,沸石的吸附效果要远远好于活性炭的。 相似文献
814.
Yingbin Hu Ning Li Jin Jiang Yanbin Xu Xiaonan Luo Jie Cao 《Frontiers of Environmental Science & Engineering》2022,16(7):90
815.
控制星湖内源性营养物质磷负荷的有效性研究 总被引:5,自引:0,他引:5
本文研究了天然沸石与石灰,铝盐,铁盐对湖水-沉积物系统中的湖水脱磷的可能性,以期在对星湖内源性营养物质磷负荷的控制方面提供科学依据。 相似文献
816.
817.
ZnCo-LDHs改性人工湿地沸石基质对城市污水的净化效果 总被引:1,自引:0,他引:1
选取常用的垂直流人工湿地沸石基质,采用金属离子物质的量比(Zn~(2+)∶Co~(3+))为2∶1在碱性环境下共沉淀生成ZnCo-LDHs,并覆膜于沸石基质表面,分析了改性前后基质的物化特性;构建模拟垂直流人工湿地基质试验柱,对改性前后2种沸石基质对城市污水的净化效果进行了研究。结果表明:Zn Co-LDHs覆膜改性沸石基质的方法是可行的;ZnCo-LDHs覆膜于基质表面,改变了原始沸石基质的物理化学特性,促进了基质对污染物的物理拦截和物化吸附作用;ZnCo-LDHs改性基质对城市污水中CODCr、氨氮、TP的净化效果均有所提高,其平均去除率分别达到了76%、63%和88%。 相似文献
818.
建立了用活性炭作吸附剂、脱芳烃石油醚萃取、紫外分光光度法测定油烟挥发组分的方法。取家用抽油烟杯内的油烟气冷凝液加热到200C的样品萃取液作标准油品,在225nm处测紫外吸光值,绘制校准曲线,相关系数在0.986~0.999之间。实验样品分析结果表明,脱芳烃石油醚对样品中油烟挥发组分萃取率可达90%以上,样品测定重现率达76.7%。红外光谱分析标准油品挥发组分初步认定为烃类、卤代烃类、醇酚醚类、醛酮类、羧酸及其衍生物类、稠环杂环类和胺类等。 相似文献
819.
Ammonium removal by modified zeolite from municipal wastewater 总被引:4,自引:0,他引:4
Ammonium removal by modified zeolite, H-form and Na-form zeolite, were examined by batch-type methods. The adsorption of ammonium on modified zeolite was exothermic process. The saturation adsorption capacity of ammonium on H-form and Na-form zeolite were 21.23 and 41.1.5 mg/g, respectively. After ten times adsorption-desorption-readsorption cycles the standard deviations of H-form and Na-form zeolite were 6.34% and 6.59%. The zeolite adsorption process has proved cost effective and practical in reducing ammonium by H-form and Na-form zeolite in municipal wastewater from concentration 27.68 mg/L to 2.80 mg/L and 5.91 mg/L. 相似文献
820.