Nutrients were extracted from digester supernatant sampled from a full-scale enhanced biological phosphorus removal (EBPR) wastewater treatment plant. A four-compartment selectrodialysis setup was used to extract ammonium and phosphate in two separate compartments. The initial phosphate recovery rate was measured to be 0.072 mmol m-2s-1 and the initial ammonium recovery rate was measured to be 1.31 mmol m-2s-1. The ammonium recovery rate was 18 times higher than that for phosphate, whereas the molar concentration of ammonium in the feed was 10 times higher than that of phosphate. An average recovery of 72 ± 1% and 90 ± 10% for ammonium and phosphate was observed after 3 h of operation. A monovalent anion selective (MVA) membrane was used to avoid ammonium and reduce the concentration of monovalent anions in the phosphorus stream. The pH in the phosphorus stream was kept at 10 so phosphate did not pass the MVA membrane. A membrane area of 26 m2 per m3 digester supernatant was required to recover 70% of phosphate and ammonium for the digester supernatant that contained 6 mM phosphate and 105 mM ammonium.

中文翻译：

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选择性电渗析同时但分开的磷酸盐和铵回收

营养物质是从一个全面的强化生物除磷 (EBPR) 废水处理厂取样的消化池上清液中提取的。四室选择性透析装置用于在两个独立的室中提取铵盐和磷酸盐。测得的初始磷酸盐回收率为 0.072 mmol m-2s-1，测得的初始铵回收率为 1.31 mmol m-2s-1。铵的回收率比磷酸盐高 18 倍，而进料中铵的摩尔浓度比磷酸盐高 10 倍。运行 3 小时后，观察到铵和磷酸盐的平均回收率为 72 ± 1% 和 90 ± 10%。使用单价阴离子选择性 (MVA) 膜来避免铵并降低磷流中单价阴离子的浓度。磷流中的 pH 值保持在 10，因此磷酸盐不会通过 MVA 膜。对于含有 6 mM 磷酸盐和 105 mM 铵的消化器上清液，需要 26 m2/m3 消化器上清液的膜面积来回收 70% 的磷酸盐和铵。