摘要
采用化学反应的合成方法向蔗渣中引入巯基官能团,并进行电镜扫描和红外光谱分析。在此基础上,通过土壤培养试验和生物盆栽试验,研究了蔗渣和改性蔗渣对模拟镉(Cd)污染农田土壤中镉的赋存形态和生物有效性的影响。结果表明,采用该合成方法,成功地向蔗渣中引入了巯基官能团。在土壤培养试验中,有机物对土壤Cd赋存形态的转化与土壤pH的相关性不明显,但与土壤中胡敏酸(HA)和富里酸(FA)含量的变化具有一定的相关性:土壤中HA含量随培养时间的延长而逐渐升高,各处理土壤弱酸提取态Cd含量相应减少,而土壤残余态Cd含量则逐渐增加,且巯基蔗渣的作用效果均强于未改性蔗渣。在生物盆栽试验研究中,外加5 mg·kg-1Cd显著降低了小白菜的生物量,而施用有机物料对小白菜均有显著的增产效果,研究结果同时表明蔗渣和巯基蔗渣都不同程度降低了土壤有效态Cd的含量以及小白菜地上部分的镉含量,且巯基蔗渣的作用效果较为显著。另外,小白菜地上部分镉含量与小白菜生物量呈现显著负相关,与土壤有效镉含量呈显著正相关。
To investigate the effect of bagasse on speciation and bioavailability of Cd in agricultural soil, the unmodified and thiol-modified bagasse were used as soil ameliorants in pot experiments and soil culture experiments, and the surface of thiol-modified bagasse was further characterized by SEM and FTIR. The results showed that about 0.96% of thiol was grafted onto the bagasse fibers. No significant correlation was found between the chemical speciation of Cd and pH in the soil, but the concentration of humic acid（HA ） and fulvic acid（FA ） in soils was found to correlate with that of Cd： The concentration of HA in the soil decreased with the incubation time, and the exchangeable Cd de- creased, while the residual Cd increased in the soil, and the chemically thiol-modified sugarcane bagasse was more effective than the un- modified one. In the pot experiment, Brassica Chinensis biomass was decreased significantly by the addition of Cd（5 mg kg-1） compared with uncontaminated soil. The two amendments significantly improved biomass, and remarkably decreased Cd content in Brassiea Chinertsis and the content of DTPA extractable Cd in the Cd-contaminated soil, and the effect of thiol-modified bagasse was more remarkable than unmodified one. It was also found that the concentration of Cd in Brassica Chinensis has a significant negative correlation with the biomass, whereas it has a significant positive correlation with the content of DTPA extractable Cd.
出处
《农业环境科学学报》
CAS
CSCD
北大核心
2013年第9期1793-1799,共7页
Journal of Agro-Environment Science
关键词
蔗渣
镉
生物有效性
bagasse
cadmium
bioavailability
