Maji Sanjoy K, Pal Anjali, Pal Tarasankar, Adak Asok
Civil Engineering Department, Indian Institute of Technology, Kharagpur, India.
J Environ Sci Health A Tox Hazard Subst Environ Eng. 2007 Sep;42(11):1585-93. doi: 10.1080/10934520701517713.
Laterite soil, an abundant locally available natural adsorbent, has been evaluated for As(V) removal from aqueous solutions in column mode operation. The column studies were conducted using columns of 10, 20, 30 cm bed depth with 2 cm internal diameter. Initial As(V) concentration was 0.5 mg/L and flow rate was 7.75 mL/min. Bohart and Adams sorption model was employed for the determination of different parameters like height of exchange zone, adsorption rate, time required for exchange zone to move, and the adsorption capacity. Effect of flow rate and initial concentration was studied. The adsorption capacity of the laterite soil for 0.5 mg/L of As(V) was found to be 62.32 mg/L, and the adsorption rate constant was 1.0911 L/mg h for the minimum bed depth of 8.47 cm. The column was designed by the BDST model. Freundlich isotherm model was used to compare the theoretical and experimental breakthrough profile in the dynamic process. The bed saturation obtained was 36-80%. Regeneration of the exhausted column was possible with 1M NaOH.
红土是一种丰富的本地天然吸附剂，已对其在柱模式操作下从水溶液中去除五价砷（As(V)）的性能进行了评估。柱实验使用内径为2厘米、床层深度分别为10厘米、20厘米和30厘米的柱子进行。初始As(V)浓度为0.5毫克/升，流速为7.75毫升/分钟。采用博哈特和亚当斯吸附模型来确定不同参数，如交换区高度、吸附速率、交换区移动所需时间以及吸附容量。研究了流速和初始浓度的影响。对于0.5毫克/升的As(V)，发现红土的吸附容量为62.32毫克/升，对于最小床层深度8.47厘米，吸附速率常数为1.0911升/毫克·小时。该柱由BDST模型设计。在动态过程中，使用弗伦德利希等温线模型比较理论和实验突破曲线。获得的床层饱和度为36 - 80%。用1M氢氧化钠可以使耗尽的柱子再生。
