Centre for Water Science, Cranfield University, Bedfordshire MK43 0AL, UK.
Water Sci Technol. 2009;60(10):2637-45. doi: 10.2166/wst.2009.686.
A new type of ion exchange media which is highly selective for phosphate, and can be easily regenerated has been investigated. The media consists of hydrated ferric oxide nanoparticles dispersed within the pore structures of polymeric anion exchanger beads. The media combines the durability and mechanical strength of ion exchange resins with the high sorption capacity of ferric oxide for phosphate. The media was trialled in fixed bed mini column experiments with real final effluent from two UK sewage treatment works, one with treatment based on chemical precipitation with iron chloride salts into an activated sludge process (population >250,000), and one based on trickling filter treatment with no specific phosphorus removal process (population <10,000). Results show that the media has high capacity for removing phosphate, reaching capacity at 4000 and 1300 bed volumes for the chemical precipitation and trickling filter works respectively, with performance greatly exceeding that of a standard anion exchanger, Amberlite IRA-410. Also trialled was the media's ability to elute the phosphorus after breakthrough, with the aim of recovering and processing it into a useful product. A one step regenerative process using a single solution containing 4% NaOH and 2% NaCl was passed through the resin bed and the phosphorus concentration of each bed volume leaving the column analysed. 80% of the phosphorus was eluted in the first bed volume. Subsequent tests investigated the performance of the media after successive partial regenerations of one bed volume of the NaOH/NaCl solution. There was no loss of performance observed after ten regeneration cycles, and levels of eluted phosphate were consistently high. These results suggest that the media has high potential for the removal and recovery of phosphate from wastewater streams. Additionally, the small volume of regenerant required translates to a very small operational footprint.
一种新型的离子交换介质，对磷酸盐具有高选择性，且易于再生，已经过研究。该介质由水合氧化铁纳米颗粒分散在聚合物阴离子交换树脂珠的孔结构中组成。该介质结合了离子交换树脂的耐用性和机械强度以及氧化铁对磷酸盐的高吸附能力。该介质在固定床小型柱实验中进行了试验，使用了来自英国两家污水处理厂的实际最终出水，一家采用基于氯化铁盐的化学沉淀进入活性污泥工艺（人口> 250000），另一家采用无特定除磷工艺的滴滤处理（人口<10000）。结果表明，该介质对磷酸盐具有高去除能力，达到 4000 和 1300 床体积的化学沉淀和滴滤工厂的容量，性能大大超过标准阴离子交换树脂 Amberlite IRA-410。还试验了该介质在突破后洗脱磷的能力，旨在回收并将其加工成有用的产品。使用含有 4% NaOH 和 2% NaCl 的单一溶液通过树脂床进行一步再生过程，分析离开柱的每床体积的磷浓度。80%的磷在第一个床体积中洗脱。随后的测试研究了连续再生一个床体积的 NaOH/NaCl 溶液后介质的性能。在十个再生循环后没有观察到性能损失，并且洗脱的磷酸盐水平一直很高。这些结果表明，该介质具有从废水中去除和回收磷酸盐的巨大潜力。此外，所需的再生剂体积非常小，因此操作占地面积也很小。
