1. It has a high concentration of organic matter, a lot of suspended solids, and a dark color. It contains a large amount of animal feces, resulting in a very high concentration of NH3-N, and also contains a large number of pathogenic bacteria.
2. The pollutants in the wastewater mainly exist in the form of solid and dissolved carbohydrates, which makes the wastewater exhibit high levels of BOD5, CODcr, SS and color. At the same time, the wastewater has good biodegradability and contains a large amount of nutrients such as N and P.
3. The solid residue in the wastewater is primarily organic matter, necessitating intensive pretreatment and solid-liquid separation to reduce the load on subsequent treatment processes.
4. Aquaculture wastewater exhibits the typical “three highs”: high organic matter concentration (COD as high as 3000-12000 mg/L), high ammonia nitrogen concentration (800-2200 mg/L), high suspended solids (SS exceeding standards by tens of times), deep color, and high levels of bacteria, ammonia nitrogen, and organic phosphorus.
