二氧化氯对池塘水质和浮游生物群落结构的短期影响

Short-term effects of chlorine dioxide on water quality and community structure of plankton in freshwater aquaculture ponds

监测了公安县崇湖渔场3口草鱼主养池塘施用浓度为0.375 g/m3的二氧化氯后池塘水质理化指标及浮游生物群落结构短期变化,以分析二氧化氯对池塘水环境质量的影响。结果显示,用药后水体溶解氧显著下降,亚硝态氮、活性磷和总磷降低。然而p H值显著升高,硝态氮、铵态氮和总氮也有所升高。施用二氧化氯前浮游植物共检出6门44属79种,浮游动物36属43种;用药后共检出浮游植物7门52属109种,浮游动物44属69种,用药后浮游植物消失4属12种,新增加12属42种,用药前未见金藻门种类,用药后出现分歧锥囊藻(Dinobryon divergens)。用药后原生动物消失6属7种,新出现16属24种;轮虫消失3种,增加8种;枝角类种类无变化;桡足类新增4种成体,但用药前后优势种无变化。结果表明,施用二氧化氯短期内增加了水体氨氮毒性,并导致浮游动物的种类、密度和生物量显著增加,进而导致浮游植物生物量显著下降、小型化藻类增多、优势种显著变化。建议在养殖期间慎用二氧化氯。

The short- term effects of chlorine dioxide（ common dosage,0. 0375 g / m3） on phytoplankton community structures and water quality parameters were evaluated in three ponds with grass carp（ Ctenopharyngodon idellus） as dominant species in Chonghu Lake（ Gong＇ an,Hubei）. The results showed that chlorine dioxide could redule dissolved oxygen significantly,as well as nitrite nitrogen,phosphorus and total phosphorus. Whereas p H increased significantly,nitrate nitrogen,ammonium nitrogen and total nitrogen also increased. There were 6 phyla 44 genera 79 species of phytoplankton,36 genera 43 species of zooplankton before the application of chlorine dioxide; after the application,there were 7 phyla 52 genera and 109 species of phytoplankton,44 genera 69 species of zooplankton. 4 genera 12 species disappeared,while 12 genera 42 species appeared after the application of chlorine dioxide. Dinobryon divergens was found in the experiment. There were 6 genera 7 species of protozoa disappeared,16 genera 24 species of protozoa appeared; 3 species of rotifer disappeared,8 species of rotifer appeared after the application of chlorine dioxide. Cladocera species had no change and genera4 species of Copepoda appeared. The results showed that the application of chlorine dioxide in pond might be leading to tox-icity of ammonia nitrogen easily in short time. The results suggested that chlorine dioxide should be used with caution.