摘要
选用桑蚕废弃物蚕沙为炭源,通过炭化活化的方式获得了一种高比表面的中微双孔道生物炭材料SCSE,并采用不同氧化剂对其表面氧化处理以调控材料孔径和表面积对农药噻虫嗪分子的吸附作用力,以实现SCSE材料对农药噻虫嗪的缓控释,并系统研究了氧化改性后材料的比表面积、孔径和表面基团性质的变化对材料吸附噻虫嗪的热力学和动力学平衡以及噻虫嗪的释放动力学等性能的影响。结果表明:SCSE孔隙结构发达,其BET比表面和孔容分别为1290.95 m^2/g和0.690 cm^3/g;在室温下,该材料对噻虫嗪分子的吸附容量达到560 mg/g。噻虫嗪在四种SCSE上的释放动力学可分为快速持续释放过程和慢速释放过程两个过程,其中快速持续释放过程的释放动力学常数约是慢速释放过程的29~34倍;其中硝酸改性后的SCSE-HN对噻虫嗪的释放比例最大,释放速度最快。本实验所获得的四种SCSE材料对噻虫嗪的释放均表现出长效释放效力。按照一般农作物的需药量,该吸附剂只要按照0.5 g/(d·m^2)的投入量便能很好地对农作物进行长效的虫害防治(>40 d)。
Oxidation modification of a novel silkworm excrement-based porous carbon（SCSE） with various acidic oxidants were prepared and applied for sustained release of pesticide thiamethoxam（TM）. The effects of pore size and surface properties on TM adsorption performance of SCSE and modified SCSE were investigated. The TM adsorption equilibrium/kinetics and release kinetics on four SCSE samples were systematically measured, and the corresponding kinetic parameters were estimated by using pseudo-first-order equation in two sections. The results show that： the prepared SCSE shows a micro/mesopores structure（1290.95 m^2/g and 0.690 cm^3/g） and its adsorption capacity of TM reached 560 mg/g at 298 K. The total controlled-release process for TM on the SCSE samples could be divided into two stages： fast-sustained release stage and slow release stage. The release rate for the fast-sustained release stage was about 29—34 times faster than that for the slow release stage. Among which, the SCSE-HN modified by HNO3 showed the highest release ratio and fastest release rate due to its largest pore size distribution and the weakest interaction towards TM. According to actual TM using conditions for some crops（1.0—2.0 mg/m^2）, only 0.5 g of TM loaded PCSE can efficiently control main pest of crops per square meter last for over 40 days.
作者
武煜翔
王欣辉
柴坤刚
林国友
赵祯霞
赵钟兴
WU Yuxiang, WANG Xinhui, CHAI Kungang, LIN Guoyou, ZHAO Zhcnxia, ZHAO Zhongxing(School of Chemistry ＆ Chemical Engineering~ Guangxi University, Guangxi Colleges and Universities Key Laboratory of New Chemical Application Technology in Resources, Nanning 530004, Guangxi, Chin)
出处
《化工学报》
EI
CAS
CSCD
北大核心
2018年第6期2797-2804,共8页
CIESC Journal
基金
国家自然科学基金项目(21666004
21676059
21606054)
广西自然科学基金项目(2017GXNSFFA198009
2016GXNSFAA380229)
广西大学科学研究基金(XGZ130963)~~
关键词
蚕沙基多孔生物炭
氧化改性
噻虫嗪
吸附平衡和动力学
缓控释
silkworm excrement-based porous biocarbon
oxidized modification
pesticide thiamethoxam
adsorption equilibrium/kinetics
controlled release
