摘要
以KCl为钾源、新疆某地所产斜发沸石为吸附剂,研究斜发沸石对K+的动力吸附与解吸效果,并探讨吸附时间、K+初始浓度与吸附量的关系。用pH=5的HCl溶液和(Ca2++Mg2+)浓度/(mmol.L-1)为1.6,3.2,6.4,12.8,19.2,25.6的混合溶液对饱和吸附了K+的斜发沸石进行解吸,实验结果表明:沸石对K+的吸附在4min能达到最大吸附率的96%,30min内达到平衡。Langmuir吸附等温式能对吸附曲线进行很好的描述。单位质量沸石对K+的最大吸附量为44.53×10-3,以阳离子交换吸附为主。pH=5的HCl溶液对K+的解吸量最小,随解吸溶液中(Ca2++Mg2+)浓度增加,解吸滞后系数减小,解吸速率远小于吸附速率。解吸量的自然对数与解吸时间的自然对数呈现明显的线性关系,用指数方程对(Ca2++Mg2+)浓度为25.6mmol/L的解吸曲线进行拟合,R=0.998,拟合方程为qt=3.890t0.210。理论上将吸附的K+全部解吸出来需要74.4d。
The clinoptilotite occurred in Xinjiang is taken as adsorbent to study the effect of adsorption/desorption of clinoptilotite on K＋ and discuss the relation between amount of absorption and the absorption time as well as initial concentration of K^＋. Clinoptilotite adsorbed saturated K^＋ is desorbed by HCl solution（pH=5） and （Ca^2＋ ＋Mg^2＋） with concentration of 1.6,3.2,6.4, 12.8,19.2,25.6 mmol/L. It is showed that the absorption of clinoptilotite to K^＋ reaches 96% at 4 minutes,getting balanced within 30 minutes, and the amount of maximum absorption is 44.53 ）〈 10.3, dominant by cation absorption. When pH = 5, the amount of desorption of HCl to K^＋ reaches its minimum. The hysteresis coefficients decreases as the concentration of （Ca^2＋ ＋Mg^2＋） increases, and the desorption rate is much lower than absorption rate. The natural logarithm of desorption quantity is linearly proportional to desorption time. The desorption curve with a （Ca^2＋ ＋ Mg^2＋） concentration of 25.6 mmol/L is matched by exponent equation and obtain a fitting equation of q, = 3. 890t^0.210 with R = 0. 998. Theoretically, it takes 74. 4 days to desorb all adsorbed K^＋.
出处
《矿物岩石》
CAS
CSCD
北大核心
2011年第3期1-5,共5页
Mineralogy and Petrology
基金
国家自然科学基金(40502008)
关键词
斜发沸石
钾离子
动力吸附/解吸
阳离子交换
clinoptilotite
potash fertilizer
adsorbing＆ desorbing kinetics
cation exchange
