ZH型重金属螯合纤维对水溶液中Sr2+的吸附行为

研究了ZH型重金属螯合纤维对水溶液中Sr~(2+)的吸附行为,考察了pH值、纤维加入量、Sr~(2+)初始浓度、作用时间等对吸附行为的影响,并采用SEM、EDS和FTIR等现代分析测试手段探讨了ZH型重金属螯合纤维对Sr~(2+)的吸附机制。结果表明,在pH值为7.0、纤维加入量为2.0 g/L、Sr~(2+)初始质量浓度为50 mg/L的条件下,纤维对Sr~(2+)的吸附在4 h左右基本达到平衡。实验条件下ZH型重金属螯合纤维对Sr~(2+)的最大吸附量可达26.22 mg/g。等温吸附拟合结果表明,ZH型重金属螯合纤维对Sr~(2+)的吸附可能是以单分子层为主的单分子层和多分子层吸附共同作用的结果。纤维对Sr~(2+)的动力学吸附过程符合准二级动力学模型。红外光谱分析表明Sr~(2+)与纤维上—NH_2和—COOH等基团进行配位络合从而吸附在纤维表面,—CH_2—和C=CH_2等基团参与此吸附过程。能谱分析表明Sr~(2+)与纤维上Na~+和Ca~(2+)还存在着离子交换作用。

Adsorption behavior of Sr2+ by ZH heavy metal chelating fiber in aqueous solution

The adsorption of strontium from aqueous solution with heavy metal chelate fiber was studied. The effects of several experimental parameters such as pH, dosage, temperature, contact time and initial concentration of strontium on adsorption efficiency of strontium were investigated. The adsorption mechanism of strontium ions by ZH heavy metal chelating fiber was discussed by contemporary analytical testing methods such as SEM, SEM-EDS and FTIR analysis. The results indicated that, under the conditions pH=7.0, biomass dose=2.0 g/L, the initial concentration of strontium ions=50.0 mg/L, and adsorption time=4 h, the fibers exhibited the best biosorption capacities. The biosorption equilibrium indicated that the process was mainly based on monolayer adsorption combined with multi-molecular layer adsorption. The results indicated that the maximum adsorption capacity of Sr²⁺ by ZH heavy metal chelating fiber was 26.22 mg/g. The equilibrium sorption capacity of strontium was determined from the Langmuir equation, and the dynamic adsorption process conformed to the secondary dynamic model. FTIR analysis found that Sr²⁺ was coordinated to -NH₂ and -COOH on the surface of fibers, and -CH₂- and C=CH₂ were involved in the adsorption. DES analysis indicated that there was ion exchange between Sr²⁺and Na⁺, Ca²⁺ on fibers.