| Aquaculture is the fastest growing food production industry in the world. Along with the amount of natural fish approaching the bionomic maximum, intensive aquaculture will certainly play an unsubstitute important role in the aquatic product supply. As the intensive aquaculture system is a kind of manual ecology system, the ecologic balance of the system is mainly maintained by manpower, in order to pursue high yield, some biology factors are intensified factitiously, which leads to the increasing cumulation of waste concentration. The waste water letted without treatment will burthen the nutrient in the nearby waterbody, which is one of the eutrophicated pollute fountainhead.As a system engineering in the field of modern environment, aquacultural engineering and technology is faced to many limits, especially on technologies of integrated utilization and environment-kind discharge of aquacultural wastewater, which will have a great value and a wide application. The wastewater treatment technologies in developed countries are complicated, high-technology and high-cost, which seriously restrict applications in developing countries. On the other hand, organic masses, the main waste in aquacultural wastewaters, are necessary materials for the growth of plants. Using plants as bio-medias to treat organic masses and then make out products, can not only protect the environment, but also bring economic profit, which is especially welcome in our country. Considering the characteristic of aquaculture waste water and the particularity in treatment equipment, to develop an aquaculture waste water treatment eco-engineering technology which suited for our country are being extremely urgentIn this project, treatment of intensive aquaculture wastewater by pasture bio-filter eco-engineering system", main compounds in the effluents from a turtle-production system were analyzed; The physiological toxicity of the wastewater to ryegrass (Loliwn perenne L) was studied using COO as an evaluation standard. The physiological mechanism under the stress on turtle effluent in pasture is researched from the changes of protective enzymes activity. A soilless sod-production system was set up to treat wastewater. Dynamic change of nitrogen compounds in water and plant was investigated during the process of bio-filtration, and it was used to decide parameters in the development of treatment systems. To meet the requirements of control of recircukting strategy, a multi-function timer upon support of MCU was developed. Details were listed as followed:(1) In intensive turtle-production wastewaters, total nitrogen (TN) and total phosphorus (TP) are far higher than the first level of rich-nutrient wastewater standard. The main nitrogen compounds was ammonia nitrogen, mostly in un-ionized style, and relatively low level of nitrate nitrogen. Chemical oxygen demands (COD) of turtle-production wastewaters were usually ten times as high a normal aquacultural waters. Additionally, dissolved oxygen (DO) level was very low.(2) The result of physiological toxicity test under the treatment of turtle effluent indicates that when [COD]>1009.1 lmg/L, it'll cause long-time serious damage to ryegrass, restraining the growth of the root, reducing the chlorophyll content The CAT activity changes from initially activation to be destroyed. So the natural function of the enzyme can not exert While 581.36mg/L<[COD]<1009.11mg/L,the waste water causes short-time toxicity function on the growth of the plant. But through some time of adaptation, the community can resume. While [COD]<581.36mg/L, the waste water has no toxicity function on the growth of the plant It turns out that [COD]<581.36mg/L is the best control condition for ryegrass dealing with the turtle effluent, and [COD]=189.74mg/L is the best deal concentration.(3) Effects of turtle effluents stress on pasture physiology activity were studied. As for ryegrass, in terms of plant height, the fresh weight and dry weight in above-ground and under-ground, the treatment of low concentration showed si...
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