Growth And Physiological Responses Of Chaetoceros Mulleri And Dunaliella Salina To Different Aquaculture Wastewater

Over the last decade, the mariculture in China has developed so quickly that the production now reached the top in the world. Because aquaculture wastewater emission Standard has not been promulgated, most of the wastewater produced by mariculture is discharged directly into seawater without any treatment. It is well known that intensive mariculture give off excessive amounts of nutrients into the environment, thus encourages eutrophication and red tide in the coastal region. By now, there is no a perfect treatment technology to remove nutrition from this kind of wastewater. On the basis of the research advance about maricultural wastewater treatment technology, in this study, researchs on the nutritional condition about the algae's reproduction and the processes and characteristics of absorbing nutrition and purifying aquaculture wastewater, and it will give theoretical bases and technology support to the healthy mairculture.Chaetoceros mulleri and Dunaliella salina are used to culture with aquaculture wastewater after culturing Paralichthys olivaceus, and set different proportions of aquaculture wastewater and seawater, and research of the purification of the two algaes on aquaculture wastewater. The results are as follows: Chaetoceros mulleri and Dunaliella salina grew very well in different concentrations of aquaculture wastewater, and the pH value and dissolve oxygen both behave as first increase then decrease and last level off, the metabolism of chemical oxygen demanded has no obvious changes, the uptake ratio of ammonia of all the controls reach to 100%, the highest uptake ratio of nitrate, nitrite and phosphate up to 100%.Both Chaetoceros mulleri and Dunaliella salina grew well in the aquaculture wastewater after culturing clam, while the pH value and dissolve oxygen both appeared to as first increase then decrease and last level off, the metabolism of chemical oxygen demanded has no evident changes, and the content of total nitrogen increase in the exponential growth phase while the content of total phosphorus remain decreasing.The nutrition is lack in the aquaculture waster after culturing sea cucumber. Study the...