| Turtle farming was a new special breeding industry in our country. Aquaculture was mainly based on unrestrained utilization of the fresh water and the wastewater was littlely treated,resulting in eutrophication of surface water,which was hazardous to the environment and the surrounding aquatic ecosystems.Development Of the suitable method for treating aquaculture wastewater of the scatter turtle farming was being extremely urgent.In the present study, with the field investigation,solution experiment and adsorption experiment, concentrations and loads of important pollutants in aquaculture wastewater were investigated in all the growth cycle of Taiwan turtle, alligator and red-eared turtles.The tolerance to aquaculture wastewater and nutrient uptake capacity of the selected plants were also studied.Then,the ecological maner of treating aquaculture wastewater by using selected plants.The main results obtained were as follows1.Based on the results obtained by the investigation,the concentration of the major pollutants in the Taiwan turtle,alligator and red-eared turtles wastewater were as follows,COD was 567±137mg/L,391±115 mg/L;388±128mg/L；TP was 51±37mg/L,35±21mg/L,42±26 mg/L；total nitrogen was 166±59mg/L,157±58 mg/L,154±52 mg/L；ammonia nitrogen was 88±40 mg/L,68士37 mg/L, 88±34 mg/L；nitrate was 4.06±4.75 mg/L,6.93±6.04 mg/L,2.07±3.38；pH was 7.18±0.41,6.94±O.56,7.39±0.23.COD pollutant load during the growth cycle of Taiwan turtle,alligator and red-eared turtles was 153.0±14.4g/turtle,409.3±1.30 g/turtle 716.3±56.9g/turtle；total phosphorus was 16.7±4.Og/turtle 43.6±7.21 g/turtle 70.5±O.9 g/turtle；total nitrogen was 43.5±2.5g/turtle,174.1±5.06 g/turtle 294±15.4 g/turtle；ammonia nitrogen was 24.1±1.2g/turtle,71.7±1.64 g/turtle,164.5±9.8g/turtle；nitrate was 0.8±0.1 g/turtle,8.0±0.14g/ turtle,5.0±1.4g/turtle.2.Hydroponics culture experiment showed that the tolerance of different plants in the wastewater and the uptake capacity of nitrogen and phosphorus had a significant difference.Napier 1 was able to be survived in the initial wastewater. Nitrogen and Phosphorus uptake capacity of the strongest of the two plants were as follows: Napierl,Napierl. Taking into account biomass, nitrogen and phosphorus uptake capabilities and other indictors, Napier1,Napierl were be able to directly used for breeding wastewater treatment. Other tested plants could be used in the wastewater posttreatment.3. A physical-biological technique for treating red-eared aquaculture wastewater was developed and established. All plants used in the biological filte could grow normally under the red-eared aquaculture wastewater conditions. The removal percentages of COD, total phosphorus, total nitrogen, ammonia nitrogen, nitrate nitrogen in the wastewater through the treating system were 37%,73%,74%,41%,71%, respectively. And the plant treating system was accounted for more than 70% of the removal of total phosphorus, total nitrogen, and nitrate nitrogen, implying that plants played important role on nutrient removal from wastewater. The combination with Rice -Napier - Perennial ryegrass was the most effective, and it should be recommended. |
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