Fe_(3)O_(4)@SA/CTS凝胶球对亚甲基蓝及碱性品红的吸附

Adsorption of methylene blue and basic fuchsin on Fe_(3)O_(4)@SA/CTS gel ball

为解决染料对水体污染问题,本工作以海藻酸钠为骨架,结合Fe_(3)O_(4)及壳聚糖,制备了Fe_(3)O_(4)@SA/CTS凝胶球,并对制备的材料进行了微观表征。研究了不同影响因素下,吸附剂对MB及CB的吸附效果,同时研究了不同pH下对混合液的吸附性能,以及吸附剂循环利用性实验。结果表明,MB或CB初始浓度为100 mg/L、吸附剂投加量为1.0 g/L、MB的pH为11或CB的pH为8、反应时间4 h、MB和CB的去除率分别可以达到91.9%和21.5%。Langmuir模型能够更好反应对MB或CB的吸附,吸附以单分子物理吸附为主。吸附动力学符合伪二级动力学方程,吸附过程更容易受到化学吸附影响。不同pH下,Fe_(3)O_(4)@SA/CTS对混合液中的MB吸附优于CB,5次脱附循环使用后对MB保持在70%以上,对CB的去除率保持在15%以上。

As we all know,the methylene blue and basic fuchsin in the printing and dyeing wastewater are harmful to the human body.In this work,Fe_(3)O_(4)@SA/Ca adsorbents were prepared with sodium alginate as the skeleton,and Fe_(3)O_(4)was combined with chitosan and CaCl;as the cross-linking agent to remove these two pollutants.A series of microscopic characterizations of the prepared materials were carried out,such as XRD,SEM,FT-IR,VSM,etc.The effects of single factors such as pH,adsorbent dosage,reaction time,and initial concentration of substrate on the adsorption process were considered.The isotherm model and kinetic equation model were established to study the adsorption mechanism.The adsorption of methylene blue and basic fuchsin by the adsorbent at different pH was studied.Finally,the adsorption performance of the adsorbent for methylene blue or basic fuchsin for five consecutive times was investigated.The results showed that the material was successfully prepared,and the appearance was wrinkled.There were a large number of oxygen-containing functional groups on the surface of the molecular structure,and the material had strong magnetic properties.When the initial concentration of methylene blue or basic fuchsin was 100 mg/L,the dosage of adsorbent was 1.0 g/L,the pH of methylene blue was 11 or the pH of basic fuchsin was 8,and the reaction time was 4 h,the removal rate of the two kinds of pollutants by the material could reach 91.9%and 21.5%,respectively.It was obvious that the adsorption of methylene blue by the adsorbent was stronger than the adsorption of basic fuchsin.The fitting results showed that the Langmuir model can better reflect the adsorption of methylene blue or basic fuchsin,and the adsorption was dominated by a single-layer surface covering.The adsorption kinetics conforms to the pseudo-second-order kinetic equation,and the adsorption process was more susceptible to chemical adsorption.When the pH=9,the adsorption capacity for methylene blue was 82.6mg/g,and the adsorption capacity for basic fuchsin was 36.6 mg/g.Five consecutive desorption and regeneration experiments proved that the Fe_(3)O_(4)@SA/CTS adsorbent was desorbed and regenerated under 0.1 mol of HCl,and it has good reusability.