大豆秸秆生物炭对废水中Ni(II)的吸附性能

为了能以更有效更经济的方法去除废水中的Ni(Ⅱ),选用成本低廉的大豆秸秆制备生物炭作为吸附剂,研究了炭化温度、溶液pH、吸附剂投加量、溶液温度、Cd(Ⅱ)质量浓度对吸附效果的影响,得到了最佳的吸附条件,开拓了去除重金属镍的新方法,同时研究了生物炭对Ni(Ⅱ)的吸附动力学和吸附等温线。实验表明,大豆秸秆生物炭对Ni(Ⅱ)有较好的吸附性能,Ni(Ⅱ)质量浓度为20mg/L,炭化温度为500℃,pH为7,投加量为0.2g,室温为25℃,Cd(Ⅱ)质量浓度为0为最佳吸附条件。吸附反应符合准二级动力学方程。吸附等温线符合Langmuir模型,25℃时饱和吸附量为14.38mg/L。扫描电镜分析显示,炭化使得秸秆孔道结构增多,表面粗糙程度加剧,比表面积增大,从而提高了吸附性能。

Adsorption property of biochar from soybean straw for Ni(II) in wastewater

To remove Ni(Ⅱ) in wastewater more effectively and economically,soybean straw with low cost is chosen to make biochar to absorb Ni (Ⅱ).The effects of carbonization temperature,solution pH,adsorbent dosage,solution temperature and Cd(Ⅱ) concentration on the adsorption are investigated to find the optimal adsorption condition.A new method for removing heavy metal nickel is developed,and the adsorption kinetics and adsorption isotherm are studied.The experimental results show that the adsorption performance of the adsorbent is good,and when Ni (Ⅱ) concentration is 20 mg/L,carbonization temperature is 500 ℃,pH is 7,dosage is 0.2 g,temperature keeps at 25 C and the concentration of Cd (Ⅱ) is 0,the adsorption condition is the best.The adsorption reaction accords with the second-order kinetics equation.The adsorption isotherm accords with Langmuir model,and the saturated adsorption capacity is 14.38 mg/L at 25 C.Scanning electron microscope analysis shows that the pore structure of straw,the surface roughness and the specific surface area increase,which improves the adsorption performance.