Struvite (MgNH₄PO₄·6H₂O) recovered from livestock wastewater may impose a pharmacological threat to the environment, due to the extensive existence of antibiotics in the wastewater. In this study, tetracyclines (TCs) were selected as the typical antibiotics, and the individual processes of dissolved organic matters (DOM) evolution and their effects on TCs migration in struvite recovery from swine wastewater were discriminated and quantified. Results revealed that TCs transport was contributed by the adsorption of pure struvite crystals, struvite adsorbing DOM-TCs complex and DOM aggregation, which occupied 2.29–6.53%, 23.53–34.66%, and 59.09–74.19% of the total TCs migration amounts, respectively. A tangential flow filtration system was employed to divide DOM into five fractional parts on the basis of molecular weight cut-offs. Experimental results indicated that under alkaline conditions of struvite crystallization, DOMs with larger molecular weights, hydrolyzed to DOMs with smaller molecular weights, which consequently promoted TCs re-distribution in DOMs from higher molecular weights to those with lower molecular weights. Furthermore, a distribution model was developed to characterize TCs transport in struvite recovery by describing TCs distribution among various phases, including struvite adsorption, DOM-TCs complexing, DOM aggregation, and free state in the solution, respectively. These outcomes provided new understanding on DOM evolution and effects on antibiotics transport in phosphate recovery from wastewater.

鸟粪石（MgNH ₄ PO ₄ ·6H ₂O) 由于废水中广泛存在抗生素，从牲畜废水中回收可能对环境造成药理学威胁。在本研究中，选择四环素 (TCs) 作为典型抗生素，区分和量化了溶解有机物 (DOM) 演化的各个过程及其对从猪废水中鸟粪石回收中 TCs 迁移的影响。结果表明，TCs 迁移主要由纯鸟粪石晶体的吸附、鸟粪石吸附 DOM-TCs 复合物和 DOM 聚集贡献，分别占总 TCs 迁移量的 2.29-6.53%、23.53-34.66% 和 59.09-74.19% . 使用切向流过滤系统根据截留分子量将 DOM 分成五个部分。实验结果表明，在鸟粪石结晶的碱性条件下，较大分子量的DOMs水解为较小分子量的DOMs，从而促进TCs在DOMs中从较高分子量到较低分子量的重新分布。此外，通过描述不同相之间的 TC 分布，分别包括鸟粪石吸附、DOM-TC 络合、DOM 聚集和溶液中的游离态，开发了一个分布模型来表征鸟粪石回收中 TC 的传输。这些结果提供了对 DOM 演变和对从废水中回收磷酸盐中抗生素迁移的影响的新理解。因此促进了 TCs 在 DOM 中从较高分子量到较低分子量的重新分布。此外，通过描述不同相之间的 TC 分布，分别包括鸟粪石吸附、DOM-TC 络合、DOM 聚集和溶液中的游离态，开发了一个分布模型来表征鸟粪石回收中 TC 的传输。这些结果提供了对 DOM 演变和对从废水中回收磷酸盐中抗生素迁移的影响的新理解。因此促进了 TCs 在 DOM 中从较高分子量到较低分子量的重新分布。此外，通过描述不同相之间的 TC 分布，分别包括鸟粪石吸附、DOM-TC 络合、DOM 聚集和溶液中的游离态，开发了一个分布模型来表征鸟粪石回收中 TC 的传输。这些结果提供了对 DOM 演变和对从废水中回收磷酸盐中抗生素迁移的影响的新理解。和溶液中的自由状态。这些结果提供了对 DOM 演变和对从废水中回收磷酸盐中抗生素迁移的影响的新理解。和溶液中的自由状态。这些结果提供了对 DOM 演变和对从废水中回收磷酸盐中抗生素迁移的影响的新理解。