摘要
以木薯渣为前驱物,采用持续升温限氧法制备了不同温度(350、550、750℃)的生物质炭(BC350、BC550和BC750),并对其结构和成分进行了表征。基于guideline106批量平衡法,研究了生物质炭对砖红壤中阿特拉津吸附行为的影响。结果表明,阿特拉津的吸附动力学是一个先快后慢的过程,生物质炭施用可缩短阿特拉津达到吸附平衡的时间,施入量越多,达到饱和的时间越短。施入量相同条件下,最早到达平衡的处理是BC750,BC550次之,BC350最后达到饱和。伪二级动力学方程能较好地描述生物质炭对砖红壤中阿特拉津的吸附动力学特性(R2>0.864)。阿特拉津在生物质炭土壤中的吸附等温线表现为非线性,分配作用和表面吸附作用联合是主要机制。在土壤中添加3%和5%BC750的处理用Temkin方程拟合最佳,其余处理均符合Langmuir方程和Freundlich方程。logKF值随着生物质的量增加而逐渐增大。对于不同温度制备的生物质炭,logKF的大小顺序表现为BC750>BC550>BC350,说明土壤中阿特拉津的吸附能力与生物质炭的热解温度有关。此外,阿特拉津的吸附-解吸过程存在明显的滞后现象,滞后系数HI均大于1,且表现为BC750>BC550>BC350。因此,土壤中阿特拉津的风险评价和修复需考虑滞后现象。
Three types of biochars （BC350, BC550 and BC750） were prepared by pyrolyzing manioc wastes at different temperatures （350, 550 and 750℃） under an oxygen-limited condition, the structures and compositions of BC were characterized. According to the guidelinel06 batch experiment, adsorption kinetics and isotherms of atrazine in biochar- added soil were studied. The results showed that BC could shorten balance time of atrazine, and it had positive correlation with the content of BC. For the same intake, time of reaching balance of BC750 was the shortest, as 5% BC750 only needed about 30 min. The data were fitted greatly to the pseudo-second-order model with R2 in 0.864-1.000. The isotherms of atrazine were nonlinear; the joint of partition and pore-filling was a major mechanism. Temkin equation was the best model for 3% BC750 and 5% BC750, and using Langmuir and Freundlich model to describe the other 13 treatments was perfect, logK~ was an important parameter to represent adsorption capacity, which increased with the increasing content of BC increasing. As to different types of BC, logKr was shown in order of BC750〉BC550〉BC350, which indicated that the affinity of atrazine was relative with charring temperature of BC. In addition, adsorption- desorption process of atrazine showed obvious hysteresis, all the HI values were greater than 1 with following BC750 〉 BC550 〉 BC350, which belonged to the negative lag effect and suggested that the desorption rate was greater than the adsorption rate.
出处
《广东农业科学》
CAS
CSCD
北大核心
2014年第4期79-84,F0002,共7页
Guangdong Agricultural Sciences
基金
国家自然科学基金(21367011)
海南省自然科学基金(413123)
热带作物种质资源保护与开发利用教育部重点实验室开放基金(2012hckled-5)
