复合改性5A分子筛对水中Cr^3+的吸附研究

Adsorption of Cr^3+in water by composite modified 5A zeolite

对复合改性5A分子筛去除水中Cr^3+的效果进行了研究。采用氢氧化钠和硝酸铁为改性试剂对5A分子筛进行复合改性,考察分子筛用量、溶液pH值、Cr^3+溶液初始浓度、吸附时间对Cr^3+去除率的影响。用Langmuir和Freundlich等温吸附模型对分子筛吸附Cr^3+的吸附过程进行拟合,并探讨分子筛吸附Cr^3+过程的吸附动力学模型。结果表明,经0.4 mol/L氢氧化钠,6 mmol/L硝酸铁复合改性后效果最好,较未改性的5A分子筛的吸附容量提升了176%,改性前后分子筛的吸附均符合Langmuir吸附等温模型,吸附速率符合Lagergren准二级速率方程。

The effect of composite modified 5A zeolite on removal of Cr 3+in water was studied.The modification of 5A zeolite was carried out by sodium hydroxide and ferricnitrate solution.The influence of the amount of molecular sieve,the pH value of the solution,the initial concentration of Cr 3+solution and the adsorption time on the removal rate of Cr 3+was investigated.The Langmuir and Freundlich isotherm adsorption models were used to fit the adsorption process of Cr 3+by molecular sieves,and the adsorption kinetics models were also explored.The results showed that 5A molecular sieve treated with 0.4 mol/L sodium hydroxide and 6 mmol/L ferricnitrate solution exhibits the highest adsorption capacity,the adsorption capacity of 5A zeolite after composite modification was increased by 176%compared with that of unmodified molecular sieve.The adsorption behavior of molecular sieves before and after modification is consistent with Langmuir adsorption equation,the adsorption rate is in accordance with the Lagergren quasi-second-rate equation.