唐古特大黄茎基生物炭吸附废水中亚甲基蓝的研究

Study on the Adsorption of Methylene Blue by Stem-Based Biochar from Tangut Rhubarb Wastewate

采用ZnCl_(2)超声浸渍和热处理的方法对废弃物唐古特大黄茎改性后制备活性炭,考查活化剂浓度、炭化时间以及炭化温度对活性炭吸附性能的影响,同时研究在最佳制备条件下制备的唐古特大黄茎基吸附剂对模拟废水中亚甲基蓝的吸附性能,考查了吸附温度、初始浓度、pH和吸附剂投加量4个因素对吸附性能的影响,并研究了唐古特大黄茎基活性炭对亚甲基蓝的吸附热力学和吸附动力学特性。结果表明,唐古特大黄茎基活性炭最佳制备条件为:活化剂浓度为25%,炭化温度为500℃,活化时间为30 min。在此条件下制备的唐古特大黄茎基活性炭对亚甲基蓝模拟废水的最佳吸附条件为:亚甲基蓝溶液初始浓度为600 mg/L,pH为7,温度为40℃,活性炭投加量为1.25 g/L,在该条件下亚甲基蓝的去除率为92%。唐古特大黄茎基活性炭对亚甲基蓝的吸附过程符合准二级动力学模型,且等温吸附曲线可用Langmuir模型关联,表明唐古特大黄茎基活性炭对亚甲基蓝的吸附是化学吸附,其中单分子层吸附占主导地位,吸附速率主要由化学吸附控制。

Activated carbon was prepared by ZnCl_(2) ultrasonic impregnation and heat treatment after modification of waste Tangu super yellow stem.The effects of activator concentration,carbonization time and carbonization temperature on the adsorption properties of activated carbon were investigated,and the adsorption properties of Tangu super yellow stem based adsorbent on methylene blue in simulated wastewater prepared under the optimal preparation conditions were studied.The effects of adsorption temperature,initial concentration,pH and dosage of adsorbent on the adsorption properties of methylene blue were investigated.The adsorption thermodynamics and kinetics of Tangut yellow stembased activated carbon were studied.The results showed that the optimum preparation conditions were as follows:activator concentration of 25%,carbonization temperature of 500℃,activation time of 30 min.The optimal adsorption conditions for the methylene blue simulated wastewater prepared by Tangu super yellow stem based activated carbon are as follows:the initial concentration of methylene blue solution is 600 mg/L,the pH is 7,the temperature is 40℃,the dosage of activated carbon is 1.25 g/L,and the removal rate of MB is 92% under this condition.The adsorption process of methylene blue on Tanggu super yellow stem based activated carbon conforms to the quasi-second-order kinetic model,and the isothermal adsorption curve can be correlated with the Langmuir model,which indicates that the adsorption of methylene blue by RAC is chemical adsorption,in which the single molecular layer adsorption is dominant.The adsorption rate is mainly controlled by chemisorption.