铁负载阴离子交换树脂高效除磷研究

针对污水处理生化出水高磷酸盐浓度对水体富营养化影响的问题,采用阴离子交换树脂(AER)为基质材料,利用树脂上—NH2官能团中的N原子与Fe3+发生配位聚合,制备了除磷聚合配位交换吸附剂(Fe—PLE)。并采用Langmuir和Freundlich等温吸附方程对Fe—PLE和原AER进行了比较,发现Fe—PLE更加趋向化学吸附类型,且Fe—PLE最大吸附容量达到93.05 mg/g,比AER提高了47.98%。通过SEM、EDS、FT-IR及TGA对吸附前后Fe—PLE和AER的表征比较,认为通过配位作用形成Fe—O配位键是Fe—PLE的可溶性无机磷吸附效率提高的主要原因。通过静态吸附实验考察了吸附时间、pH和竞争性阴离子对AER和Fe—PLE吸附的影响,结果显示,Fe—PLE吸附平衡时间为1.5 h,比AER稍高;2种吸附填料都在pH 7.0时效率最高,AER的磷吸附效率对pH较为敏感,Fe—PLE能够在相对较宽的pH范围内保持高去除率;竞争性阴离子对AER磷吸附的负面影响较大,而Fe—PLE依靠其Fe—O的配位作用具有一定的抗干扰能力。通过4次循环再生实验,Fe—PLE表现出良好再生能力的同时磷有较高的回收利用率。

High-efficient adsorption of phosphate by iron ion loaded anion exchange resin

A polymeric ligand exchanger loaded with iron ion (Fe—PLE) was developed by using the reaction of the nitrogen atom on amino functional group in anion exchange resin (AER) and iron ion for phosphorous removal in wastewater treatment.Adsorption characteristics and condition optimization of phosphate removal by Fe—PLE and AER were further investigated.Resulted showed that phosphate removal by Fe—PLE was more in line with the chemical adsorption type with the maximum adsorption capacity of 93.05 mg/g (47.98% improvement than AER) by comparing Langmuir and Freundlich adsorption isotherm.The increase in adsorption efficiency of Fe—PLE was ascribed to the Fe—O, by characterization of SEM, EDS, FT-IR and TGA.Closer research about influencing factors of adsorption time, pH and competitive anions was investigated by the static adsorption experiments.Results indicated that Fe—PLE had a higher adsorption equilibrium time of 1.5 h than AER.The two adsorbing materials were most efficient at pH 7.0.AER was more sensitive to pH change, while Fe—PLE could keep the high efficiency under a relative wider pH range.In addition, Fe—PLE with high specific to phosphorous removal was more adaptable to the competition from competitive anions than AER.Finally, Fe—PLE was proved to have excellent regenerate property and high recycling rate with 4 cycles of regeneration.