摘要
应用同位素示踪技术,简要地研究了63Ni在泥煤中的静态吸附行为。结果表明,5 min后泥煤对63Ni的吸附率可达69%,60min后达到吸附平衡;第1吸附阶段内镍吸附量随时间的延长而增加,不易解吸;从泥煤-水液固体系中泥煤的电离平衡和镍离子-氢离子之间离子交换平衡,以及物料平衡关系推导出泥煤平衡时63Ni的吸附量和氢离子的浓度、平衡时镍离子的浓度有关。溶液的pH值对镍的吸附和解吸有很大影响,随着溶液pH值增大,63Ni由水分室向泥煤分室转移的速率常数也逐渐增大,而由泥煤分室向水分室转移的速率常数逐渐减小,二者比值逐渐增大,pH=4.624 6时,2种可逆传递速率常数相等,为2.51。即适宜pH值范围内的pH值升高吸附量增大,低pH值不利于吸附。63Ni在泥煤-水体系中的动态变化可用封闭二分室进行描述,经拟合后的理论值与实验数据点具有较好的一致性。
We show that peat can enrich nickel under static conditions by means of Liquid Scintillation Counting. It was found that the adsorption of ^63Ni on peat reached 69% in 5 min, and equilibrium. It was deduced from ionisation equilibrium of peat, ion exchange equilibrium between hydrogen ion and nickel ion, and mass balance among peat-water system that the adsorption amount of ^63 Ni depended on concentration of hydrogen ion and nickel ion in equilibrium state. The pH value showed great influence on the adsorption of nickel onto peat. Along with the increase of aqueous pH value, the transfer rate constant from water compartment to peat compartment increases gradually while the transfer rate constant from peat compartment to water compartment decreases progressively. The ratio between two of rate constants increases with pH. At pH = 4. 624 6, the two reversible transfer rate constants both equal 2. 51. The ability of peat to bind Ni increases with the increase in pH. The adsorption kinetics of nickel on peat can be described by a closed two-compartment model. Theoretical data were in good agreement with experimental data after fitting.
出处
《应用化学》
CAS
CSCD
北大核心
2007年第4期420-424,共5页
Chinese Journal of Applied Chemistry
基金
国家留学基金管理委员会资助项目(22307S05)
东华理工学院博士基金资助项目(DHB0504)
东华理工学院核资源与环境工程技术中心开放测试基金资助项目(051104)
关键词
镍-63
泥煤
吸附
同位素示踪法
封闭二分室
nickel-63
peat
adsorption
isotopic tracer technique
closed two-compartment model
