Department of Civil, Construction and Environmental Engineering, Marquette University, Milwaukee, Wisconsin.
Water Environ Res. 2019 Jul;91(7):606-615. doi: 10.1002/wer.1080. Epub 2019 Mar 1.
Nutrient recovery from municipal wastewater was evaluated using anion exchange media loaded with hydrated ferric oxide (HFO) and copper (Cu ) (Dow-HFO-Cu resin) to selectively capture phosphate, followed by clinoptilolite for ammonium removal and recovery. Nutrients were concentrated in the regenerants and recovered as precipitated struvite. Media exchange capacity after multiple ion exchange cycles was determined using permeate from an anaerobic membrane bioreactor (AnMBR) treating synthetic or actual municipal wastewater from a full-scale water reclamation facility. Regeneration through five ion exchange cycles using relatively low concentration regenerant solution (2% NaCl and 0.5% NaOH) resulted in the highest phosphate exchange capacity and phosphate recovery. This regenerant also provided the most consistent ammonium recovery. Column tests treating AnMBR permeate were performed over five ion exchange cycles; Dow-HFO-Cu resin exchange capacities ranged from 1.6 to 2.8 mg PO -P/g dry media. A maximum of 94% of the removed phosphate was recovered during regeneration. The rate and extent of regeneration was insensitive to regenerant salt concentrations in the range investigated. Precipitation using a mixture of the spent regeneration brines from the Dow-HFO-Cu resin and clinoptilolite columns produced low molar ratios of Mg:NH :PO , suggesting that the recovered product was not pure struvite. PRACTITIONER POINTS: Ion exchange-precipitation for the removal and recovery of and NH from AnMBR permeate is a promising technology. 2% NaCl + 0.5% NaOH regeneration solution provided the most consistent exchange performance for both phosphate and ammonium recovery. Regenerated Dow-HFO-Cu resin exchange capacity was consistently less than the virgin resin, likely due to copper leaching during regeneration. Molar ratios in the precipitates suggested that the precipitated material was not pure struvite.
采用负载水合氧化铁（HFO）和铜（Cu）的阴离子交换介质（Dow-HFO-Cu 树脂）从市政废水中回收营养物质，以选择性地捕获磷酸盐，然后用斜发沸石去除和回收铵。营养物质在再生剂中浓缩，并回收为沉淀的鸟粪石。使用处理来自全规模水回收设施的合成或实际市政废水的厌氧膜生物反应器（AnMBR）的渗透物来确定多次离子交换循环后的介质交换能力。使用相对低浓度的再生剂溶液（2%NaCl 和 0.5%NaOH）进行五次离子交换循环的再生导致最高的磷酸盐交换容量和磷酸盐回收率。这种再生剂还提供了最一致的铵回收。在五个离子交换循环中，用 AnMBR 渗透物进行的柱试验；Dow-HFO-Cu 树脂的交换容量范围为 1.6 至 2.8mg PO 4 -P/g 干介质。在再生过程中，最多可回收 94%的去除的磷酸盐。在研究范围内，再生剂盐浓度的变化对再生速率和程度没有影响。使用 Dow-HFO-Cu 树脂和斜发沸石柱的废再生盐水的混合物进行沉淀产生了 Mg:NH 4 :PO 4 的低摩尔比，表明回收的产物不是纯鸟粪石。从业者要点：用于从 AnMBR 渗透物中去除和回收 和 NH 4 的离子交换-沉淀是一种很有前途的技术。2%NaCl+0.5%NaOH 再生溶液为磷酸盐和铵回收提供了最一致的交换性能。再生的 Dow-HFO-Cu 树脂交换容量始终低于原始树脂，这可能是由于再生过程中铜浸出。沉淀物中的摩尔比表明沉淀的物质不是纯鸟粪石。
