天津地区鱼塘水、悬浮物、沉积物和鱼体中的DDT

采样测定了天津地区2典型鱼塘鲫鱼、鲢鱼、水、悬浮物、沉积物和鱼塘周边表土中的DDT及其代谢产物含量。结果发现,2鱼塘各主要介质以及鱼体肌肉和器官中都富集了较高浓度的DDT。鲫鱼和鲢鱼肌肉中DDT的含量分别为(66.4±2.7)ng·g-1和(24.3±23.4)ng·g-1。肝胰脏、肠和鱼鳃中DDT含量一般高于肌肉,其中肠的富集量最大,是肌肉的3倍以上。生物富集系数(lgBCF)分别为3.7和3.3。2鱼塘鱼体和各相含量有较大差别,鱼塘介质中悬浮物富集浓度最高。表土污染相对严重地区的鱼塘中各介质和鱼体DDT含量均高于另一污染较轻的鱼塘。污染严重鱼塘的DDE/ΣDDT含量比值也相对较高,反映早期污染残留的重要特征。尽管如此,仍然较高的DDT含量以及悬浮物中很低的DDE/ΣDDT含量比值说明很可能还有污染源存在。     

Trace metal levels in freshwater fish, sediment and water

The trace metal concentrations in water, sediment and aquatic organisms, such as fish, could indicate the level and tendency of the pollution. This is important not only for the protection of the environment, but for evaluation of the quality of fish meat either captured from natural waters or cultured in fishponds. The total trace metal concentrations in samples of fish from different regions of Hungary and from different species have been determined by using an X-ray fluorescence technique (EDXRF). Water, sediment and fish samples from fishpond systems with different feeding and stocking has also been analyzed. In the case of zinc contents, differences have been traced between the cultured and wild common carp. In the case of common carp reared under different feeding conditions, differences were also observed in the zinc concentration. The retention of the trace metals in the fish has been studied by measuring the levels in sediment, water and feed. The different retention can be explained by the different availability of zinc in the applied feeds, which can be related to the presence of different metal species in the feeds.     

浅析网箱养鱼对水质的影响

通过对千岛湖重要网箱养鱼区－坪山养殖区的调查，监测分析和对比了该水域，邻近水域及对照区的水质状况，得出了网箱养鱼对水体有较大负面影响的结论，并以此提出了网箱养鱼与环境协调发展的对策。     

稻田表面流去除鱼塘养殖水中的氮、磷效果试验研究

池塘水质对水产养殖非常重要,本研究的目的在于探索稻田面流净化池塘养殖水质的技术途径。在养殖池塘旁稻田内布置9个小区,进行田间面流试验,取水样进行分析。结果表明：在1．5—6．0m^3／h（相应的平均流速为7．5～30m／h）的水力负荷下,鱼池水经稻田表面流处理后可得到一定净化;N、P的去除率与稻田表面流的流量（流速）有关,随流量增大呈减小趋势;在抽穗一扬花期稻田可有效减少养殖水的氮磷含量,在拔节期一孕穗期可显著减少NOf—N含量,有利改善池塘养殖环境。     

太湖湖滨带的缓冲效果

在以农田．防护林．鱼塘为主的农业缓冲带一宜兴周铁太湖湖滨带内，比较和分析了不同降水时期和不同鱼塘排水时期湖滨带的缓冲效果。结果显示湖滨带的主要污染物是有机污染物、TN和Chla，尤其是有机污染物；TP污染相对较轻，NH4＋-N和BOD5污染很少。太湖湖滨带对N、P、COD等指标均有一定的缓冲效果，但对不同指标的缓冲能力不同，其中对N的缓冲效果更为明显。除COD外，湖滨带出水口基本可以达到IV类水水平。同时，强降雨导致大量污染物进入水体，导致水体污染物输出浓度显著增高，最为突出的是TN、TP和有机污染物。在垂直于太湖段，除NO3--N和NO2--N浓度略微下降外，其他水质指标均呈上升趋势。因此，该湖滨带的缓冲能力不足以净化来自地表和鱼塘的污染物质。在平行于太湖段。除NO3--N和NO2--N浓度逐步增高外，其他水质指标均呈下降趋势，说明包括河流在内的整个湖滨带的缓冲能力较高，净化作用大于湖滨带纳入的污染物质，缓冲效果好。鱼塘排水对水体的影响非常明显，这种影响大概可以持续2周左右。通过对不同时期的采样结果进行显著性分析，发现COD差异性不显著，且含量高，即有机污染物在各时期都是主要污染物。在鱼塘放水时期（已进入冬季），各指标下的采样点之间均不显著，湖滨带的缓冲作用较低。     

Phytosynthetic bacteria (PSB) as a water quality improvement mechanism in saline-alkali wetland ponds

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Shallow groundwater nitrogen responses to different land use managements in the riparian zone of Yuqiao Reservoir in North China

This field study investigated the nitrogen concentrations in the shallow groundwater from an ephemeral stream and four land uses:cropland,two-year restored (2yr) and five-years restored (5yr) woodlands,fishponds,and the nitrogen flux in the riparian zone of Yuqiao Reservoir.The groundwater nitrate-N concentrations in cropland were the highest among the four land uses.Total dissolved nitrogen (TDN) and nitrate-N concentrations in the 2yr woodland were significantly (p<0.05) higher than in 5yr woodland.The lowest nitrogen concentrations were detected in fishponds.Nitrate-N was the main form in cropland and 2yr woodland,whereas both nitrate-N and diSSolved organic nitrogen (DON) were the main species in 5yr woodland and fishponds.But,ammonium-N was the main form in the ephemeral stream.During the rainy season,the groundwater flow wim dissolved nitrogen drains from upland into the reservoir along the hydraulic gradient.The woodland between the cropland and reservoir could act as a buffer to retain shallow groundwater nitrogen.The dominant form of ammonium-N in the groundwater TDN pool in ephemeral stream indicated that nitrogen from the village and orchard in upland flowed into the reservoir via subsurface flow.The fishpond Was not an important pollution source for nitrogen transfer via shallow groundwater.     

围滩鱼塘中藻类生物量与水体养分关系的研究

通过大塘试验和围格试验,研究了围滩鱼塘生态系统中藻类的种群分布、变化及其与环境因子的关系。结果表明:鱼塘藻类共有7门127种,年平均(4月～10月)数量11939×106个L、平均生物量9060mgL;藻类种群数量、生物量等存在动态变化;组成、生物量都以蓝、绿、硅藻门为主;影响藻类种群的主要水环境因子是氮磷比和总磷。在本试验范围内,藻类生物量与氮磷比呈极显著负相关关系。     

复合光合细菌对鱼塘水氨态氮H2S的去除效应

采用厌氧光照富集法培养光能有机异养型光合细菌A液和光能无机自养型光合细菌B液,将A液和B液配合成复合光合细菌,将其投放到鱼塘水中,结果表明按2%投放复合光合细菌对鱼塘水净化效果最佳,其中对NH3—N去除率88.89%;对H2S去除率91.67%。     

Shallow groundwater nitrogen responses to di erent land use managements in the riparian zone of Yuqiao Reservoir in North China

This field study investigated the nitrogen concentrations in the shallow groundwater from an ephemeral stream and four land uses： cropland, two-year restored （2yr） and five-years restored （Syr） woodlands, fishponds, and the nitrogen flux in the riparian zone of Yuqiao Reservoir. The groundwater nitrate-N concentrations in cropland were the highest among the four land uses. Total dissolved nitrogen （TDN） and nitrate-N concentrations in the 2yr woodland were significantly （p 〈 0.05） higher than in 5yr woodland. The lowest nitrogen concentrations were detected in fishponds. Nitrate-N was the main form in cropland and 2yr woodland, whereas both nitrate-N and dissolved organic nitrogen （DON） were the main species in 5yr woodland and fishponds. But, ammonium-N was the main form in the ephemeral stream. During the rainy season, the groundwater flow with dissolved nitrogen drains from upland into the reservoir along the hydraulic gradient. The woodland between the cropland and reservoir could act as a buffer to retain shallow groundwater nitrogen. The dominant form of ammonium-N in the groundwater TDN pool in ephemeral stream indicated that nitrogen from the village and orchard in upland flowed into the reservoir via subsurface flow. The fishpond was not an important pollution source for nitrogen transfer via shallow groundwater.