| By systematic surveys, related informations of Baiyangdian aquaculture status and breeding waters were mastered. The key process of Baiyangdian aquaculture pollution was feeding.Monitorings and experiments were carried out within six typical aquaculture zonges of Baiyangdian Lake. The results of routine monitoring about water quality showed that, CODcr, TN, TP, DO were seriously exceeded and the exceeding multiple was respectively 1.19~2.88, 1.33~5.22, 4.56~5.94, and 1.40~7.55. The comprehensive trophic state index TLI(∑) was 66.5 which indicated moderate eutrophication. The results of routine monitoring about sediment showed that, the average of TN was 4027.12mg/kg, the average of TP was 634.37mg/kg. The comprehensive pollution index FF was 1.58 which indicated moderate pollution. The experiment results of deposition of suspend substance and nutrient relese of sediment showed that, the deposition velosity of TN and TP was respectively 52.43mg/(d·m2), 12.17mg/(d·m2), the release velosity of TN and TP was respectively 26.77 mg/(m2·d), 2.72 mg/(m2·d). A group of cages in waters of Shihoudian was chosen to carry out dynamic monitoring of water quality.The indicators included CODcr, TN, TP and DO. The results showed that the impact of cage culture on the surrounding water environment can extend to at least 150 meters away.SPSS-based principal component analysis method was used to analyze water monitoring data. Three principal components were extracted, characteristic value was 5.990, 3.754, 2.015, respectively and the relevant variance contribution rate was 46.078%, 28.876% and 15.498%. Cumulative variance contribution rate of the three principal components was 90.452%. The first principal component was closely related to water quality factor of nutrient. Considering the key process of Baiyangdian aquaculture pollution, comprehensive evaluation results on water environment and principal component analysis results, the key control factor of Baiyangdian aquaculture pollution was identified as CODcr, TN and TP.The annual COD pollution load of Baiyangdian aquaculture was 1211.83 t which was calculated by chemical analysis method. Nitrogen and phosphorus pollution load model were established by united method of material balance and pollution load coefficient, which were Q(x)N=0.06168x1+0.05994x2-0.04113x3 and Q(x)P=0.01555x1+0.01357x2-0.008736x3. Based on the model, the annual nitrogen and phosphorus pollution load of Baiyangdian aquaculture were estimated, which were 213.84 t and 50.46 t.Aquaculture capacity model was constructed considering the environmental, ecological and economic ability. Ultimately, the Baiyangdian aquaculture capacity was confirmed as 627 t.Baiyangdian aquaculture pollution control was researched. Bioremediation technologies such as animals, plants and microorganisms were developed and used in water fields of Shihoudian Lake, which located Datianzhuang village, Quantou town, Anxin County. The application experiment cultivated aquatic plants, built up the food chain and produced the microbial reagent. The results showed that the annual value of aquaculture was 25.45 ten thousand RMB, increased by 30% than before. The pollution load of COD, TN, TP were respectively cut by 6.27 t, 1.10 t, 0.28 t. The average concentration of COD, TN, TP during culture period was reduced by 42%, 61%, 85% than traditional aquaculture zones.Planning of Baiyangdian aquaculture pollution control was completedand regulation countermeasures of aquaculture pollution control were proposed by the research. |
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