褐煤对废水中酸性红B的吸附去除

Adsorption and removal of dye Acid Red B from wastewater by lignite

选用褐煤作为廉价吸附剂,脱除模拟废水中染料酸性红B。研究了褐煤对废水中酸性红B的吸附动力学、等温吸附模式,考察了pH、褐煤投加量以及离子强度(NaCl)对吸附效果的影响。结果表明,吸附动力学较好地符合准二级速率方程(R2=1.000),并且以化学吸附为主;吸附等温式满足Langmuir方程(R2=0.986),最大单分子层吸附量为42 mg/g;废水中染料的去除率随溶液pH的减小而明显增加,在pH=1时,去除效果最好,证实吸附过程存在静电吸引及化学键合;在一定条件下,溶液中酸性红B的去除率随褐煤投加量增加而增加;吸附效果随溶液中离子强度(NaCl)的增加而增强。说明褐煤可以作为一种廉价吸附材料,用于处理含染料废水。

Lignite was used as a cheap adsorbent to remove dye Acid Red B from simulated wastewater. Batch experiments were carried out to study the kinetics equation, isotherm, as well as the affecting parameters such as pH, dosage of lignite and ionic strength. The results indicated that the kinetics of the adsorption of Acid Red B on lignite followed the pseudo-second-order rate expression （R2 = 1. 000） , which demonstrated that sorp- tion mechanism was the formation of chemical bond. The adsorption isotherm was proven to fit the Langmuir e- quation properly （R2 = 0. 986） , and the maximum adsorption capacity reached 42 mg/g. Adsorption of Acid Red B on lignite was affected by pH significantly. The removal rate of the dye from simulates wastewater in- creased with the reduction of pH, at pH = 1, the removal rate reached the highest value （ 100% ）. This demon- strates that the adsorption may involve valence forces and electrostatic attraction between Acid Red B and lignite. The removal rate of the dye increased with the increase of the dosage of lignite under some conditions. The adsorption capacity also increased with the addition of ionic strength （NaCl）. All these show that lignite can be used as an economic adsorbent in treatment of wastewater containing dyes.