Study on the Water Quality Characteristics of Mariculture Wastewater from Babylonia areolata in Hainan and Its Relationship with Aquaculture Models

To comprehensively understand the water quality characteristics of aquaculture wastewater in the Babylonia areolata and its relationship with aquaculture models, this study first investigated the wastewater quality from Babylonia areolata farms under different aquaculture models in Hainan Province. Subsequently, a laboratory simulation system was constructed to dynamically monitor the impact of feeding on wastewater quality under a simulated fully flow-through aquaculture model, while simultaneously analyzing the variations in wastewater quality under a simulated semi-recirculating aquaculture model. The water quality indicators were primarily evaluated according to Hainan Province's "Aquaculture Wastewater Discharge Standard" (DB46/475-2023). The results showed that for the aquaculture wastewater from Babylonia areolata farms, the compliance rates for both Level 1 and Level 2 standards under the fully flow-through model were 87.5%; under the semi-recirculating model, the compliance rate for Level 1 was 80%, and for Level 2, it was 100%. Laboratory experiments on fully flow-through aquaculture revealed that feeding led to a rapid deterioration of wastewater quality, with indicators such as Chemical Oxygen Demand (COD_Mn) quickly exceeding Level 2 standards. After "rapid drainage," the wastewater quality improved, and all indicators returned to within Level 2 standards. Laboratory experiments on the semi-recirculating aquaculture model indicated that wastewater quality gradually deteriorated over time, but most indicators remained within Level 2 standards. This study provides data and theoretical foundations for the development of wastewater treatment technologies in Babylonia areolata aquaculture, offering new insights for the future of healthy Babylonia areolata farming.