The invention relates to a method for purifying the
aquaculture wastewater for prawns, and is intended to effectively filter out soluble harmful components, suspended substances and other harmful substances in the
aquaculture water. The method sequentially comprises three-stage purification of the
aquaculture wastewater: biological purification,
filtration purification and absorption purification. In the biological purification, the
algae is used for absorbing
ammonium and other soluble harmful components in the
wastewater discharged from the aquaculture pond as well as organic granules in the filter-feeding wastewater for filter-feeding
shellfish and fish; in the
filtration purification, the method allows the wastewater to pass through a sand-filtering field, so that the suspended granules and
plankton in the wastewater can be filtered out; and in the absorption purification, parts of the soluble substances in the wastewater are absorbed by the surfaces of corallites and
activated carbon, while parts of the soluble substances are absorbed and transformed by the
beneficial bacteria growing on the surfaces of the corallites and the
activated carbon. By adopting the circulation of aquaculture water, the invention can reduce the wastewater
discharge and reduce the probability of
outbreak and
prevalence of
prawn-related diseases on one hand, and by putting
algae,
shellfish and filter-feeding fish in the circulation, the invention can increase the income and the economic benefit of aquaculture on the other hand.