High requirement of aerating to increase dissolved oxygen is essential for improving the level of intensive recirculating aquaculture system (RAS). A simple, low-cost and maintainable pipeline diffused aeration (PDA) was proposed and designed for pure oxygen to increase the dissolved oxygen. It mainly consists of a diffused aeration stone, a union tee and an interior plug joint. The aim of this article was to study effects of oxygen flow rate () or inlet dissolved oxygen () combined with pipe length () on PDA performance, and to construct a referable mathematical model of outlet dissolved oxygen () with and gas-liquid contact time () for actual recirculating aquaculture water. Results indicated that the oxygen increment rate and the oxygen utilization rate increased with the increase of for tap water, and that increased with the decrease of for actual recirculating aquaculture water. PDA is mainly influenced by and thus suitably applied in the treated circulating water back flow to culture ponds, especially for RAS with long pipelines. Under the experimental conditions with of 3 L/min, of 3.92 mg/L, and of 10 m, the best oxygen increment rate was 149.02% and the best oxygen utilization rate was 11.60%. The linearly mathematical model of =3.8464+0.6237*+0.2705* (=0.97) can be referred to develop a controllable PDA system for predicting or regulating the dissolved oxygen of water in culture ponds. In particular, PDA combined with liquid oxygen supply will be further studied to promote its application in RAS.

中文翻译：

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循环水养殖系统管道扩散曝气性能评价及数学模型

增氧增溶氧的高要求是提高集约化循环水养殖系统（RAS）水平的关键。针对纯氧，提出并设计了一种简单、低成本、可维护的管道扩散曝气（PDA），以增加溶解氧。它主要由扩散曝气石、三通接头和内插接头组成。本文的目的是研究氧气流量（）或入口溶解氧（）与管道长度（）对PDA性能的影响，并构建可参考的出口溶解氧（）与气液接触的数学模型实际循环养殖水的时间()。结果表明，自来水的增氧率和氧利用率随着自来水的增加而增加，实际循环水养殖水体的增氧率和氧利用率随着实际循环水的减少而增加。PDA主要受处理后的循环水回流至养殖池的影响，因此适用于循环水回流，特别是对于长管道的RAS。在3 L/min、3.92 mg/L、10 m的实验条件下，最佳增氧率为149.02%，最佳氧利用率为11.60%。可以参考=3.8464+0.6237*+0.2705*(=0.97)的线性数学模型开发可控的PDA系统，用于预测或调节养殖池水体的溶解氧。特别是PDA结合液氧供应将进一步研究，以推动其在RAS中的应用。