Batch studies of phosphonate adsorption on granular ferric hydroxides

Abstract

Phosphonates are widely used in various industries. It is desirable to remove them before discharging phosphonate-containing wastewater. This study describes a large number of batch experiments with adsorbents that are likely suitable for the removal of phosphonates. For this, adsorption isotherms for four different granular ferric hydroxide (GFH) adsorbents were determined at different pH values in order to identify the best performing material. Additionally, the influence of temperature was studied for this GFH. A maximum loading for nitrilotrimethylphosphonic acid (NTMP) was found to be ∼12 mg P/g with an initial concentration of 1 mg/L NTMP-P and a contact time of 7 days at room temperature. Then, the adsorption of six different phosphonates was investigated as a function of pH. It was shown that GFH could be used to remove all investigated phosphonates from water and, with an increasing pH, the adsorption capacity decreased for all six phosphonates. Finally, five adsorption–desorption cycles were carried out to check the suitability of the material for multiple re-use. Even after five cycles, the adsorption process still performed well.

Batch Studies of Phosphonate and Phosphate Adsorption on Granular Ferric Hydroxide (GFH) with Membrane Concentrate and Its Synthetic Replicas

“…A previous study comparing the adsorption of phosphonates on different granular ferric hydroxides (GFH) showed that FerroSorp RW had the highest adsorption capacity of the compared adsorbents [18]. Therefore, FerroSorp RW from HeGo Biotec GmbH was used in this study.…”

“…20 mL of the supernatant was filtered into an empty glass bottle using a two-part disposable syringe (Norm-Ject, 20 mL, Henke Sass Wolf, Tuttlingen, Germany) with an attachable 0.45 µm nylon filter (Sartorius Stedim Biotech GmbH, Göttingen, Germany). A previous study showed that the relatively long contact time of seven days was necessary to achieve equilibrium [18]. This contact time could have been reduced by grinding the adsorbent or by a higher rotation speed, which would have led to more abrasion of the adsorbent.…”

“…Due to their threshold effect, they are effective even in substoichiometric concentrations [16]. It is known that phosphonates can adsorb on granular ferric hydroxides (GFH) [4,17,18] as mono-, bi-, or tridentate complexes [19,20]. Calcium ions, whose precipitation is to be prevented by phosphonates, simultaneously have a positive influence on the adsorption of phosphonates on GFH due to the formation of ternary surface complexes [19,21].…”

“…In a previous study, Reinhardt et al [18] compared the adsorption of various phosphonates on four different GFH adsorbents. They showed that phosphonates with different properties, such as molecular size and weight, or the number of phosphonate groups, display different behaviors during adsorption.…”

Adsorption of Phosphonate Antiscalant HEDP from Reverse Osmosis Concentrates by La/FeOOH@PAC

“…XPS analysis showed that the main adsorption mechanism of the adsorbent was the ligand exchange between hydroxyl groups linked with La/Fe and HEDP. [1] 。此外，膦酸盐阻垢剂会使水 体中总磷含量增加，造成水体富营养化 [2] ，急需有 效的治理办法。目前含磷废水的主要处理工艺包括： 微生物法 [2] 、吸附法 [3] 、沉淀法 [4] 、膜分离法 [5] 、臭 氧氧化法 [6] 和离子交换法 [7] 等，在以上处理方法中， 吸附法由于具有成本低、快速安全和选择性好等优 点而被广泛地关注 [8] 。 目前对磷化物中有机磷(膦酸盐)吸附材料的 研究远少于无机磷 (磷酸盐) ， 而且已报道的吸附膦 酸盐的工作中仍存在吸附时间长和吸附性能差等 问题 [9][10] 。为了提高吸附效率，有必要开发新型膦 酸盐吸附剂。铁元素在自然界中的含量极高，同时 铁氧化物及其无定型氢氧化物尺寸一般在纳米级， 因此它们具 有 较 大 的 比 表 面 积 ， 利 于 吸 附 。 Nowack [11] 和 Zenobi [12] [14] 。复合材料对 HEDP 的吸附量 Qe(mg [15] ，在 2θ=27.30°处出现了 La(OH)3 的特征峰(JCPDS 36-1481) [16]…”