Akhtar Mubeena, Hasany Syed Moosa, Bhanger M I, Iqbal Shahid
National Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080, Pakistan.
Chemosphere. 2007 Jan;66(10):1829-38. doi: 10.1016/j.chemosphere.2006.09.006. Epub 2006 Nov 15.
Sorptive potential of selected agricultural waste materials i.e. rice (Oryza sativa) bran (RB), bagasse fly ash (BFA) of sugarcane (Saccharum officinarum), Moringa oleifera pods (MOP) and rice husk (RH) for the removal of methyl parathion pesticide (MP) from surface and ground waters has been investigated. Optimization of operating parameters of sorption process, i.e. sorbent dose, agitation time, pH, initial concentration of sorbate, and temperature have been studied. The sorption data fitted to Freundlich, Langmuir and Dubinin-Radushkevich (D-R) sorption isotherms. The maximum capacities of RB, BFA, MOP and RH for MP were calculated to be 3.6+/-0.8, 5.3+/-1.4, 5.2+/-1.5 and 4.7+/-1.0 mmolg(-1) by Freundlich, 0.39+/-0.009, 0.39+/-0.005, 0.36+/-0.004 and 0.35+/-0.008 mmolg(-1) by Langmuir and 0.9+/-0.08, 1.0+/-0.10, 1.0+/-0.10 and 0.9+/-0.07 mmolg(-1) by D-R isotherms respectively, employing 0.1g of each sorbent, at pH 6, 90 min agitation time and at 303 K. Application of first order Lagergren and Morris-Weber equations to the kinetic data yielded correlation coefficients, close to unity. Thermodynamic parameters of sorption process, i.e. DeltaH, DeltaS and DeltaG were computed and their negative values indicated the exothermic and spontaneous nature of sorption process. The pesticide may be stripped by sonication with methanol, making the regeneration and reutilization of sorbents promising. The sorbents investigated exhibited their potential applications in water decontamination, treatment of industrial and agricultural waste waters.
研究了几种选定的农业废料，即米糠（RB）、甘蔗（Saccharum officinarum）的蔗渣飞灰（BFA）、辣木（Moringa oleifera）豆荚（MOP）和稻壳（RH）从地表水和地下水中去除甲基对硫磷农药（MP）的吸附潜力。研究了吸附过程操作参数的优化，即吸附剂剂量、搅拌时间、pH值、吸附质初始浓度和温度。吸附数据符合Freundlich、Langmuir和Dubinin-Radushkevich（D-R）吸附等温线。在pH值为6、搅拌时间90分钟和温度为303K的条件下，使用0.1g每种吸附剂，通过Freundlich方程计算得出RB、BFA、MOP和RH对MP的最大吸附量分别为3.6±0.8、5.3±1.4、5.2±1.5和4.7±1.0 mmol g⁻¹；通过Langmuir方程分别为0.39±0.009、0.39±0.005、0.36±0.004和0.35±0.008 mmol g⁻¹；通过D-R等温线分别为0.9±0.08、1.0±0.10、1.0±0.10和0.9±0.07 mmol g⁻¹。将一级Lagergren和Morris-Weber方程应用于动力学数据，得到的相关系数接近1。计算了吸附过程的热力学参数，即ΔH、ΔS和ΔG，其负值表明吸附过程是放热的且自发的。通过甲醇超声处理可以解吸农药，这使得吸附剂的再生和再利用具有前景。所研究的吸附剂在水净化、工农业废水处理中显示出潜在的应用价值。
