摘要: |
利用1991年1月用水厂照相系统和自动图象分析仪等方法获得的悬浮体絮凝现场粒径资料,并结合温度、盐度及悬浮体总量等对伊姆斯-道拉德河口的悬浮体絮凝过程及其控制因素进行了研究。结果表明,絮凝物中值粒径为74 – 13 μm;最大粒径为163 – 809 μm,随时间、地点不同而不同。在时间上,絮凝颗粒大小的变化与潮汐变化相一致,以潮相为周期呈周期性变化。在涨落潮初期稍后絮凝颗粒迅速增大,后期逐渐变小;在空间上(沿河),一般向海颗粒较大。虽然,当悬浮体浓度达到峰值时絮凝物粒径往往出现延迟,但无论描系站还是沿河飘流站絮凝颗粒大小与息浮体含量之间都呈现正相关,而与盐度、温度和有机组分的相关很差。由于受余流等的影响,水体不能完全稳定下来,在下一个潮周期来临时,絮凝颗粒并非完全沉降,部分颗粒仍停留在水体中参与下一周期的循环。这些颗粒的大小涨落潮有别,中值粒径变化在74 – 101 μm之间,最大粒径变化在163 – 382 μm之间。这反映了悬浮体絮凝和絮凝过程主要受潮流及其导致的水动力作用的控制。 |
关键词: 絮凝 悬浮体 控制因素 伊姆斯河口 |
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基金项目:中国科学院留学回国人员择优基金项目 |
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IN-SITU FLOCCULATION PROCESSES OF SUSPENDED MATTER AND FACTORS DOMINATING THESE PROCESSES IN THE EMS-DOLLARD ESTUARY |
Li Anchun,Chen Lirong,D. Eisma
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1.Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071;2.Netherlands Institute for Sea Research, 1790 AB, TEXEL
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Abstract: |
Flocculation processes of suspended matter and their controlled factors in the Ems-Dollard Estuary were studied according to floc size data which taken with an in situ suspension camera system in January of 1991 and were measured with an image analysis system, and to other data such as salinity and total suspended matter. The results indicated that at anchored stations, mean floc sizes ranged from 74 to 131 μm and maximum floc sizes from 163 to 809 μm, which varied with time and localities. Temporally, floc sizes varied with tidal cycles. They grew considerably with increase of total suspended matter shortly after the beginning of flood and ebb tides, and then decreased with reduction of the concentration. Spatially (at floating stations), floc sizes increased seaward in general and the concentration also had significant influence on the floc sizes. Floc sizes positively correlated to total suspended matter at both anchored and floating stations. However, a lag of the particle sizes often occurred when suspended matter concentrations reached their peaks. The correlation of floc sizes to temperature and organic contents were very pore. Influence of salinity on floc sizes was minor. Due to the influence of residual current and other factors, some flocs, which had the average sizes from 71 to 10l μm, for mean, and 163 to 382 μm for maxima between floods and ebbs, had kept suspending till the next tide came. The results suggest that tides or hydrodynamic condition plays an important role in flocculation or aggregation in the estuary. |
Key words: Flocculation, Suspended matter, Dominating factors, Ems-Dollard estuary |