Influence of coexisting calcium ions during on-column phosphate adsorption and desorption with granular ferric oxide
Influence of coexisting calcium ions during on-column phosphate adsorption and desorption with granular ferric oxide
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DOI：
10.1016/j.seppur.2020.117143
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发表时间：
2020-10
影响因子：
8.6
通讯作者：
A. Sonoda;Y. Makita;Yuki Sugiura;A. Ogata;Changwon Suh;Jong Hoon Lee;K. Ooi
中科院分区：
文献类型：
--
作者：
A. Sonoda;Y. Makita;Yuki Sugiura;A. Ogata;Changwon Suh;Jong Hoon Lee;K. Ooi
研究了水合颗粒氧化铁（GFO）对磷酸盐的吸附解吸作用，并对含钙、镁离子的模型磷酸盐废水（2 mg P/dm3）进行了研究。GFO对磷酸盐的吸附等温线符合Langmuir方程。平均粒径为0.75 mm的GFO颗粒最大吸收14.2 mg P/g。磷酸盐的颗粒内表面扩散系数（Ds）为1.0 × 10−11m2/h。在含有碱土金属（Ca, Mg）和不含碱土金属的溶液中，获得了磷酸盐吸附突破曲线。比较了突破曲线，考察了共存的碱土金属离子对柱状磷酸盐吸附的影响。在相同空速（SV4.3/h）下，含Ca、Mg溶液的柱突体积（吸附床体积的3800倍）比无Ca、Mg溶液的柱突体积（860BV）大4倍以上。在Ca和Mg存在的情况下，更多的P吸收归因于GFO层中Ca盐的沉淀。由于沉淀的Ca盐溶解，酸预处理提高了NaOH中磷酸盐的解吸效率，从而再生装载磷酸盐的GFO。
Adsorption and desorption of phosphate by hydrated granular ferric oxide (GFO) were investigated using model phosphate wastewater (2 mg P/dm3) containing that also contained calcium and magnesium ions. The phosphate adsorption isotherm of GFO was fit with the Langmuir equation. GFO particles with an average size of 0.75 mm took up a maximum of 14.2 mg P/g. The intraparticle surface diffusivity (Ds) of phosphate was 1.0 × 10−11m2/h. Phosphate adsorption breakthrough curves were obtained with a solution that contained alkaline earth metals (Ca, Mg) and one that did not. The breakthrough curves were compared to examine the effects of coexisting alkaline earth metal ions on-column phosphate adsorption. The column breakthrough volume (3800 times volume of the adsorbent bed,BV) with the solution containing Ca and Mg was over four times larger than that (860BV) obtained with the Ca- and Mg-free solution at the same space velocity (SV4.3/h). Greater uptake of P in the presence of Ca and Mg was ascribed to the precipitation of Ca salts in the GFO bed. Pretreatment with acid increased the efficiency of phosphate desorption in NaOH to regenerate phosphate-loaded GFO owing to the dissolution of precipitated Ca salts.