榴莲壳和不同炭材料对低汞溶液的吸附动力学

含Hg(Ⅱ)废水直接排放会对环境产生危害,目前多采用活性炭去除,而活性炭制作需要高温热解和活化,导致其使用成本较高.近年来,果皮、果渣、炉渣等废弃物也被尝试应用于直接去除水溶液中的重金属离子.本文采用榴莲壳、椰壳活性炭和活性炭纤维在不同条件下对低浓度Hg(Ⅱ)溶液进行吸附,使用原子荧光光谱法对吸附溶液中剩余的Hg(Ⅱ)...

Adsorption Kinetics of Low Mercury Solution with Durian Shell and Activated Carbon

BACKGROUND:The direct discharge of Hg(Ⅱ)is harmful to the environment.At present,activated carbon is used to remove it,but the production of activated carbon through high-temperature pyrolysis and activation is very expensive.OBJECTIVES:To investigate the adsorption difference and mechanism on low-concentration Hg(Ⅱ)for durian shell,coconut shell activated carbon and activated carbon fiber under different conditions.METHODS:The remaining Hg(Ⅱ)in the adsorption solution was determined by atomic fluorescence spectrometry.The adsorb kinetic parameters of different adsorbents were determined by Lagergren pseudo-second-order kinetic model.RESULTS:In the Lagergren pseudo-second-order kinetic model,the maximum adsorption capacity(Q_M)of the three materials was as follows:activated carbon fiber(5.61μg/g)>durian shell(1.68μg/g)>coconut shell activated carbon(0.96μg/g).The adsorption test and thermodynamic equation showed that the adsorption of Hg(Ⅱ)by the three materials was spontaneous(ΔG<0).The adsorption of Hg(Ⅱ)by coconut shell activated carbon was mainly physical adsorption(ΔH>0),while the adsorption of durian shell was an endothermic process(ΔH<0).Due to the increase of temperature,the adsorption rate and adsorption capacity were improved.CONCLUSIONS:Durian shell from a wide range of sources can be used as an effective adsorbent to treat wastewater containing Hg(Ⅱ).