Memon G Zuhra, Bhanger M I, Akhtar Mubeena
National Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080, Pakistan.
J Colloid Interface Sci. 2007 Nov 1;315(1):33-40. doi: 10.1016/j.jcis.2007.06.037. Epub 2007 Jun 23.
The removal of selected pesticides such as carbofuran (CF) and methyl parathion (MP) using low-cost abundant sorbent chestnut shells from aqueous solutions has been investigated in the present study. The sorption parameters, i.e., contact time, pH, initial pesticide solution concentration and temperature have been studied. Maximum percent sorption (99+/-1%) was achieved for (0.38-3.80) x10(-4) and (0.45-4.5) x10(-4) mol dm(-3) of MP and CF pesticide solutions respectively, using 0.4 g of sorbent in 100 ml of solution for 30 min agitation time at pH 6. The Freundlich, Langmuir and Dubinin-Radushkevich (D-R) models have been applied, and their constants for methyl parathion and carbofuran, sorption intensity 1/n (0.55+/-0.02 and 0.54+/-0.04), multilayer sorption capacity C(m) (28.3+/-0.5 and 16.4+/-0.7) x10(-3) mol l(1-1/n)dm(3/n)g(-1), monolayer sorption capacity Q (22.5+/-0.5 and 10.8+/-0.3) x10(-6) mo lg(-1), binding energy, b (2.9+/-0.2 and 5.2+/-0.5) x10(4) dm(3)mol(-1), and sorption energy E (11.2+/-0.1 and 11.5+/-0.2 kJ mol(-1)) have been evaluated respectively. Lagergren, Morris-Weber and Reichenberg equations were employed to study kinetics of sorption process. Thermodynamic parameters DeltaH (-5.09+/-0.1 and 22.8+/-0.4 kJ mol(-1)), DeltaS (-4.33+/-0.0003 and 0.09+/-0.001 kJ mol(-1)K(-1)) and DeltaG((303K)) (-2.9 and -3.8 kJ mol(-1)) have been calculated for methyl parathion and carbofuran, respectively. The developed sorption procedure has been employed to environmental samples.
本研究考察了使用低成本且来源丰富的吸附剂栗壳从水溶液中去除某些农药，如克百威（CF）和甲基对硫磷（MP）的情况。研究了吸附参数，即接触时间、pH值、初始农药溶液浓度和温度。在pH值为6的条件下，使用0.4 g吸附剂于100 ml溶液中搅拌30分钟，对于浓度为(0.38 - 3.80)×10⁻⁴和(0.45 - 4.5)×10⁻⁴ mol dm⁻³的MP和CF农药溶液，分别实现了最大吸附百分比（99±1%）。应用了Freundlich、Langmuir和Dubinin - Radushkevich（D - R）模型，并分别评估了它们对于甲基对硫磷和克百威的常数，吸附强度1/n（0.55±0.02和0.54±0.04）、多层吸附容量C(m)（(28.3±0.5)和(16.4±0.7)×10⁻³ mol l⁽¹⁻¹/ⁿ⁾dm⁽³/ⁿ⁾g⁻¹）、单层吸附容量Q（(22.5±0.5)和(10.8±0.3)×10⁻⁶ mo lg⁻¹）、结合能b（(2.9±0.2)和(5.2±0.5)×10⁴ dm³mol⁻¹）以及吸附能E（(11.2±0.1)和(11.5±0.2) kJ mol⁻¹）。采用Lagergren、Morris - Weber和Reichenberg方程研究吸附过程的动力学。分别计算了甲基对硫磷和克百威吸附过程的热力学参数ΔH（(-5.09±0.1)和(22.8±0.4) kJ mol⁻¹）、ΔS（(-4.33±0.0003)和(0.09±0.001) kJ mol⁻¹K⁻¹）以及ΔG((303K))（(-2.9)和(-3.8) kJ mol⁻¹）。所开发的吸附方法已应用于环境样品。
