关键词：
Metal -organic frameworks;Granulate adsorbent;Toxic metals;Adsorbent regeneration;Adsorption mechanism
摘要：
Developing high-efficient and easy-to-recover adsorbents for the removal of toxic metals in water is imperative, although it poses a huge challenge. In this study, a sulfur-functionalized metalorganic framework was incorporated into Ca-alginate/polyacrylic acid granulates as an effective adsorbent (abbr. CPZ-SH) for Cu2+ and Cd2+ removal. The physicochemical properties of the obtained CPZ-SH were determined by the integrated characterization techniques (e.g., FTIR, XRD, and SEM). The environmental effects of solution pH, typical background cations (K+, Na+, Mg2+, and Ca2+), and dissolved organic matter were assessed to determine the adsorption behaviors of the granulates. Time-dependent adsorption kinetics suggested that the adsorption process was dominated by an intraparticle diffusion procedure. CPZ-SH exhibited maximum adsorption capacities of 75.8 and 48.4 mg g-1 at 30 celcius, and excellent adsorption reusability with Cu2+ and Cd2+ adsorption efficiencies over 96.0% and 85.1% after 10 cycles, respectively. The extended X-ray absorption fine structure (EXAFS) demonstrated that the functional groups (thiol, carboxyl, and hydroxyl) played a crucial role in adsorption processes. The findings provided an effective strategy to construct nanostructured metal-organic frameworks (MOFs) into granulates as recyclable adsorbents and enable heavy metal removal from water.
作者机构：
[郭俊丽; 葛体达; 魏文学; 刘毅] Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha;410125, China;[王光军] College of Life Science and Engineering, Central South University of Forestry and Technology, Changsha;410004, China;[田美洁] College of Agronomy, Hunan Agricultural University, Changsha
通讯机构：
Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, China
作者机构：
[郭俊丽; 王光军] College of Life Science and Technology, Central South University of Forestry and Technology, Changsha;410004, China;[刘毅; 魏文学; 葛体达] Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha;410125, China;[郭俊丽] 410004, China<&wdkj&>Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha
通讯机构：
College of Life Science and Technology, Central South University of Forestry and Technology, Changsha, China
作者机构：
[徐珺; 王光军] College of Life Science and Technology, Central South University of Forestry and Technology, Changsha, 410004, China;[Zeng M.; 周航; 杨文弢; 辜娇峰; 廖柏寒] College of Environmental Science and Engineering, Central South University of Forestry and Technology, Changsha, 410004, China
通讯机构：
College of Environmental Science and Engineering, Central South University of Forestry and Technology, Changsha, China
作者机构：
中南林业科技大学生命科学与技术学院, 长沙, 410004;湖南会同杉木林国家重点野外科学观测研究站, 湖南会同杉木林国家重点野外科学观测研究站, 湖南, 会同, 418307;南方林业生态应用技术国家工程实验室, 南方林业生态应用技术国家工程实验室, 长沙, 410004;[赵梅芳] Faculty of Life Science and Technology, Central South University of Forestry and Technology, Changsha, 410004, China, Huitong National Field Station for Scientific Observation and Research of Chinese Fir Plantation Ecosystem in Hunan Province, Huitong,, Hunan 418307, China;[闫文德; 王光军; 玉昉永; 彭曦; 王凤琪] Faculty of Life Science and Technology, Central South University of Forestry and Technology, Changsha, 410004, China, Huitong National Field Station for Scientific Observation and Research of Chinese Fir Plantation Ecosystem in Hunan Province, Huitong,, Hunan 418307, China, National Engineering Laboratory for Applied Forest Ecological Technology in Southern China, Changsha, 410004, China
通讯机构：
[Zhao, M.-F.] F;Faculty of Life Science and Technology, China
作者机构：
[唐美玲; 王光军] College of Life Science and Engineering, Central South University of Forestry and Technology, Changsha;410004, China;[肖谋良; Yuan, Hong-Zhao; 刘守龙; 祝贞科; 葛体达; 吴金水] Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha;410125, China;[唐美玲] 410004, China<&wdkj&>Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha
摘要：
<jats:title>Abstract</jats:title><jats:p>This study provides a complete account of global warming potential (GWP) and greenhouse gas intensity (GHGI) in relation to a long-term water management experiment in Chinese double-rice cropping systems. The three strategies of water management comprised continuous (year-round) flooding (CF), flooding during the rice season but with drainage during the midseason and harvest time (F-D-F), and irrigation only for flooding during transplanting and the tillering stage (F-RF). The CH<jats:sub>4</jats:sub> and N<jats:sub>2</jats:sub>O fluxes were measured with the static chamber method. Soil organic carbon (SOC) sequestration rates were estimated based on the changes in the carbon stocks during 1998–2014. Longer periods of soil flooding led to increased CH<jats:sub>4</jats:sub> emissions, reduced N<jats:sub>2</jats:sub>O emissions, and enhanced SOC sequestration. The net GWPs were 22,497, 8,895, and 1,646 kg CO<jats:sub>2</jats:sub>-equivalent ha<jats:sup>−1</jats:sup> yr<jats:sup>−1</jats:sup> for the CF, F-D-F, and F-RF, respectively. The annual rice grain yields were comparable between the F-D-F and CF, but were reduced significantly (by 13%) in the F-RF. The GHGIs were 2.07, 0.87, and 0.18 kg CO<jats:sub>2</jats:sub>-equivalent kg<jats:sup>−1</jats:sup> grain yr<jats:sup>−1</jats:sup> for the CF, F-D-F, and F-RF, respectively. These results suggest that F-D-F could be used to maintain the grain yields and simultaneously mitigate the climatic impact of double rice-cropping systems.</jats:p>
