排序方式: 共有83条查询结果,搜索用时 18 毫秒
31.
Jianhua Guo Changzhou Yan Zhuanxi Luo Hongda Fang Shugang Hu Yinglan Cao 《环境科学学报(英文版)》2019,31(11):168-176
Cadmium (Cd) and arsenic (As) are two of the most toxic elements. However, the chemical behaviors of these two elements are different, making it challenging to utilize a single adsorbent with high adsorption capacity for both Cd(II) and As(V) removal. To solve this problem, we synthesized HA/Fe-Mn oxides-loaded biochar (HFMB), a novel ternary material, to perform this task, wherein scanning electron microscopy (SEM) combined with EDS (SEM-EDS) was used to characterize its morphological and physicochemical properties. The maximum adsorption capacity of HFMB was 67.11?mg/g for Cd(II) and 35.59?mg/g for As(V), which is much higher compared to pristine biochar (11.06?mg/g, 0?mg/g for Cd(II) and As(V), respectively). The adsorption characteristics were investigated by adsorption kinetics and the effects of the ionic strength and pH of solutions. X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared spectroscopy (FT-IR) revealed that chelation and deposition were the adsorption mechanisms that bound Cd(II) to HFMB, while ligand exchange was the adsorption mechanism that bound As(V). 相似文献
32.
An Assessment of U(VI) removal from groundwater using biochar produced from hydrothermal carbonization 总被引:1,自引:0,他引:1
Kumar S Loganathan VA Gupta RB Barnett MO 《Journal of environmental management》2011,92(10):2504-2512
The ever-increasing growth of biorefineries is expected to produce huge amounts of lignocellulosic biochar as a byproduct. The hydrothermal carbonization (HTC) process to produce biochar from lignocellulosic biomass is getting more attention due to its inherent advantage of using wet biomass. In the present study, biochar was produced from switchgrass at 300 °C in subcritical water and characterized using X-ray diffraction, fourier transform infra-red spectroscopy, scanning electron micrcoscopy, and thermogravimetric analysis. The physiochemical properties indicated that biochar could serve as an excellent adsorbent to remove uranium from groundwater. A batch adsorption experiment at the natural pH (~3.9) of biochar indicated an H-type isotherm. The adsorption data was fitted using a Langmuir isotherm model and the sorption capacity was estimated to be ca. 2.12 mg of U g(-1) of biochar. The adsorption process was highly dependent on the pH of the system. An increase towards circumneutral pH resulted in the maximum adsorption of ca. 4 mg U g(-1) of biochar. The adsorption mechanism of U(VI) onto biochar was strongly related to its pH-dependent aqueous speciation. The results of the column study indicate that biochar could be used as an effective adsorbent for U(VI), as a reactive barrier medium. Overall, the biochar produced via HTC is environmentally benign, carbon neutral, and efficient in removing U(VI) from groundwater. 相似文献
33.
Influence of pyrolysis temperature on production and nutrient properties of wastewater sludge biochar 总被引:12,自引:0,他引:12
Mustafa K. Hossain Vladimir Strezov K. Yin Chan Artur Ziolkowski Peter F. Nelson 《Journal of environmental management》2011
The important challenge for effective management of wastewater sludge materials in an environmentally and economically acceptable way can be addressed through pyrolytic conversion of the sludge to biochar and agricultural applications of the biochar. The aim of this work is to investigate the influence of pyrolysis temperature on production of wastewater sludge biochar and evaluate the properties required for agronomic applications. Wastewater sludge collected from an urban wastewater treatment plant was pyrolysed in a laboratory scale reactor. It was found that by increasing the pyrolysis temperature (over the range from 300 °C to 700 °C) the yield of biochar decreased. Biochar produced at low temperature was acidic whereas at high temperature it was alkaline in nature. The concentration of nitrogen was found to decrease while micronutrients increased with increasing temperature. Concentrations of trace metals present in wastewater sludge varied with temperature and were found to primarily enriched in the biochar. 相似文献
34.
Mingyi Yang Lin Shi Di Zhang Zhaohui He Aiping Liang Xiao Sun 《Frontiers of Environmental Science & Engineering》2022,16(11):144
35.
Hui Hu Lei Jiang Longli Sun Yanling Gao Tian Wang Chenguang Lv 《Frontiers of Environmental Science & Engineering》2022,16(2):21
36.
Chengjie Xue Juan Wu Kuang Wang Yunqiang Yi Zhanqiang Fang Wen Cheng Jianzhang Fang 《Frontiers of Environmental Science & Engineering》2021,15(5):101
37.
Biochar, is a low-cost material that can be used as an alternative adsorbent for the removal of heavy metals. In this study, a low-cost and efficient adsorbent synthesised from Jatropha curcas seeds was used for the uptake of Cu2+ from aqueous solutions. The as-prepared adsorbent was characterised by scanning electron microscopy and Brunauer–Emmett–Teller analysis post calcination at 500 °C, its BET surface area and total pore volume were 39.62?m2?g?1 and 0.049?m3?g?1, respectively. Subsequently, the effects of initial pH of the solution, contact time, and adsorbent material dosage on the adsorption of Cu2+ by the prepared adsorbent were investigated. The as-prepared adsorbent exhibited a high performance, with a maximum adsorption amount of 32.895?mg?g?1 for Cu2+ at pH 5.0 and 25 °C, owing to the presence of ?OH, C=O, C–O, Si-O-Si, and O-Si-O on its surface. The predominant Cu2+ adsorption mechanism was assumed to be ion exchange. Notably, the Cu2+ adsorption could attain equilibrium within 90?min. In addition, the fact that the Langmuir model was a better fit than the Freundlich model for the isotherm data of Cu2+ adsorption by the as-prepared adsorbent suggested that the adsorption of Cu2+ was a monolayer adsorption process. 相似文献
38.
通过淋溶试验分析生物炭热解温度、生物炭与尿素比例、粘结剂含量对生物炭基缓释肥缓释性能的影响,采用土壤培育试验研究生物炭基缓释肥对土壤理化性质的影响。结果表明,600 ℃下热解而成的生物炭缓释性能优于300 ℃下热解形成的生物炭;生物炭添加比例和粘结剂含量的增加能提升生物炭基缓释肥的缓释性能;生物炭基缓释肥的加入可降低培育土壤的容重,增大土壤的饱和导水率,提高土壤pH值和土壤有机质含量。 相似文献
39.
Nima Kamali Abdollah Rashidi Mehrabadi Maryam Mirabi Mohammad Ali Zahed 《Frontiers of Environmental Science & Engineering》2020,14(4):70
40.