Many small and medium-sized pig farms do not have the necessary environmental protection measures, such as wastewater discharged wantonly, dung piled randomly, polluting river water and polluting the environment. The solid-liquid mixture of aquaculture wastewater contains suspended matter, high concentration of organic matter, high content of ammonia nitrogen and phosphorus, and high odor. With the increase of labor and feed costs, the treatment of aquaculture wastewater should also reduce costs as much as possible. The common treatment methods of aquaculture wastewater are filtration, precipitation and solid-liquid separation. Equipment such as grille, air flotation, solid-liquid separator and 2-3 sedimentation tanks need to be built. However, the cost of such investment does not say that the water content of mud cake after solid-liquid separation is too high, and the content of COD and ammonia nitrogen in water still exceeds the standard, which can not meet the requirements of environmental protection.

Anaerobic and aerobic wastewater pretreatment is usually used in the prophase of a certain scale farm. The difficulties in the treatment of aquaculture wastewater lie in its deep color, strong odor and high content of organic matter, which can be solved by snail-stacking sludge dewaterer. After flocculation treatment, the organic matter and suspended matter in the wastewater will flocculate into alum flower. After concentrated and dewatered treatment by the snail-stacking sludge dewaterer, solid-liquid separation is realized. The mud cake with low water content can be used as organic fertilizer, and the filtrate basically becomes colorless and odorless clean water, which meets the secondary discharge standard.

Using the snail-folding sludge dewaterer to treat aquaculture wastewater can reduce the cost of soil construction without air flotation and sludge sedimentation tank. The snail-folding machine has high automation and can run continuously and smoothly. The whole dewatering process does not need manual intervention, thus realizing the separation of mud. Sewage is dehydrated in a closed space, and odor does not volatilize.