Saline effluents from marine land-based aquaculture production can neither be disposed in common municipal wastewater treatment plants, nor disposed as landfill. Furthermore, stricter environmental regulations require the reduction of phosphorous and organic matter levels from marine environment discharges to minimize eutrophication. Chemical coagulation with FeCl₃ and AlSO₄ is commonly used for removing phosphorous and suspended solids in wastewater treatment. The capacity of these coagulants for creating particle aggregations depends on the characteristics and chemistry of the treated wastewater, such as the ionic strength or mixing conditions. Marine water has a higher ionic strength than fresh or brackish water, which may be beneficial when using chemical coagulants to treat the effluents from farms operated at high salinities. The following study compared the application of FeCl₃ and AlSO₄, to treat the two effluents discharged from a marine land-based recirculating aquaculture system (RAS) producing salmon (Salmo salar). The aim of the study was to determine; 1) in what effluent (sludge flow vs. exchange water overflow) at the end-of-pipe treatment the coagulant application is more efficient for the removal of PO₄³⁻-P, total suspended solids (TSS), total phosphorous (TP) and total chemical oxygen demand (TCOD); and 2) the optimal coagulant dose to apply and its associated chemical sludge production. The results show that more than 89 % removal of TCOD, TSS and TP is achieved when treating the sludge flow, arguably because the sludge flow contained the largest fraction of the target masses (P and organic matter) discharged from the system. Up to 80 % of TSS removal was achieved by simple sedimentation, and with the highest coagulant dose tested, up to 95 % of TSS could be removed from the effluent. To remove 90 % of PO₄³⁻-P, FeCl₃ and AlSO₄ need to be dosed at a molar ratio of 2.6:1 Fe:PO₄³⁻-P and 5.7:1 Al: PO₄³⁻-P, respectively. Dosing above 90 % removal efficiency did not significantly affect removal of PO₄³-P and TSS, but substantially increased the volume of chemical sludge produced. Finally, FeCl₃ is proposed as a better overall alternative for P removal at the end-of-pipe treatment in marine land-based RAS.

来自海洋陆基水产养殖产品的咸水既不能在普通的城市废水处理厂中处置，也不能作为垃圾填埋场处置。此外，更严格的环境法规要求减少海洋环境排放物中的磷和有机物含量，以最大程度地减少富营养化。FeCl ₃和AlSO _4的化学混凝通常用于去除废水处理中的磷和悬浮固体。这些凝结剂产生颗粒聚集的能力取决于处理后的废水的特性和化学性质，例如离子强度或混合条件。海水比淡水或微咸水具有更高的离子强度，这在使用化学混凝剂处理高盐度养殖场的废水时可能是有益的。以下研究比较了FeCl ₃和AlSO ₄在处理生产鲑鱼的海洋陆基循环水产养殖系统（RAS）中排放的两种废水（Salmo salar）。研究的目的是确定；1）在管道末端处理的废水中（污泥流量与交换水溢流），混凝剂的应用对去除PO ₄ ^3-更为有效-P，总悬浮固体（TSS），总磷（TP）和总化学需氧量（TCOD）；2）最佳的混凝剂用量及其相关的化学污泥产生。结果表明，处理污泥流时，TCOD，TSS和TP的去除率超过89％，这可能是因为污泥流包含了从系统排出的目标质量（P和有机物）的最大部分。通过简单的沉淀，可去除多达80％的TSS，并且以最高的混凝剂剂量测试，可从废水中去除多达95％的TSS。为了去除90％的PO ₄ ^3- P，需要以2.6：1 Fe：PO ₄ ^3- P和5.7：1 Al：PO的摩尔比添加FeCl ₃和AlSO _4。分别为₄ ^3- P。高于90％的去除效率不会明显影响PO ₄ ³ -P和TSS的去除，但是会大大增加化学污泥的产生量。最后，提出了FeCl ₃作为海洋陆基RAS管末端处理中除磷的更好的整体替代方法。