羟基铁覆膜硅藻土的制备及除砷实验研究

THE PREPARATION AND ADSORPTION OF HYDROXY-FE COATED DIATOMITE

利用羟基铁对硅藻土进行覆膜,探索了其制备方法并利用其处理含砷废水。制备1 g覆膜硅藻土需添加0.4 mL 1mol/L的Fe(NO3)3溶液混合均匀后加入0.05 mL 4 mol/L的NaOH溶液搅拌至混合物呈泥状,在110℃下烘干后粉碎,其用量为1 g/L。利用该方法制备覆膜硅藻土可大幅增加硅藻土的比表面积和铁含量,分别提升了76%和2134.5%,有效的增强了其吸附能力。通过实验,验证了覆膜硅藻土的除砷能力,且随砷浓度升高而升高;反应开始后1 h后可接近反应平衡,最大吸附量可达37.14 mg/g。覆膜硅藻土除砷过程受到pH值的影响,随pH值的升高除砷率将先升后降,在pH值为4~7.5时,具有较强除砷能力。

The diatomite was coated by the hydroxy-Fe and be used in the treatment of arsenic.A total of 1 g of the diatomite was mixed with 0.4 mL of 1 mol /L Fe(NO3)3and 0.05 mL of 4 mol /L NaOH.The mixture was covered loosely and heated at 110 ℃ to dryness.The specific surface area(88 m2/g) was 76% higher than that of raw diatomite(50 m2/g),and the iron content was substantially increased.Through the experiment,the absorbent for As(maximum adsorption 37.14 mg/g) was increased with the concentration of As.The adsorption process was affected by the pH,along with the increase of pH adsorption capacity will rise before pH 4.0 and for after pH 7.5.