| 项目编号: | 1704472
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| 项目名称: | WRF: Experimental observation and modeling of coagulant mediated contaminant removal: flocculation, floc blankets, and sedimentation |
| 作者: | Monroe Weber-Shirk
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| 承担单位: | Cornell University
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| 批准年: | 2017
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| 开始日期: | 2017-08-15
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| 结束日期: | 2020-07-31
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| 资助金额: | 330000
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| 资助来源: | US-NSF
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| 项目类别: | Standard Grant
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| 国家: | US
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| 语种: | 英语
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| 特色学科分类: | Engineering - Chemical, Bioengineering, Environmental, and Transport Systems
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| 英文关键词: | particle
; tapered flocculation
; flocculation
; contaminant
; high rate flocculation/sedimentation
; flocculation design
; particle removal
; velocity gradient
; flocculation process
; drinking water treatment
; optimal flocculation design
; flocculation performance
; pi
; image floc
; floc blanket flocculator
; flocculation process proceeds
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| 英文摘要: | PI Name: Monroe L. Weber-Shirk
Proposal Number: 1704472
Flocculation is a core process used to convert water from rivers, streams, and reservoirs into safe drinking water. In the flocculation process, particles and some dissolved contaminants stick together and form large aggregates that can be removed by sedimentation. Although flocculation is the workhorse of surface water treatment, it is not well understood, and thus it has not been possible to optimize the design of the nation's drinking water treatment infrastructure. The PIs plan a detailed investigation of particle aggregation mechanisms that operate under decreasing mixing conditions (tapered flocculation) as a technique to enhance performance as measured by particle removal in drinking water treatment. Preliminary studies indicate that the proposed tapered flocculation design has the potential to decrease contaminant loading to filters by a factor of 10, which would significantly reduce operation and maintenance costs for drinking water treatment.
Models produced by the PIs indicate that flocculation performance as measured by settled water turbidity is the most significant limiting factor for current treatment process sequences. In flocculation the increasing separation distance between flocculating particles, as the flocculation process proceeds, limits high rate flocculation/sedimentation from producing water with particle concentrations less than a few mg/L. The primary goal of this investigation is to increase the number of particles flocculating by lowering the relative velocity of particles at the moment of collision through a stepwise decrease in mixing intensity. A decrease in velocity gradient enables aggregates that had previously reached maximum size to have successful collisions with smaller particles. Thus, each time the fluid deformation rate is decreased, the distance between growing particles is decreased, and non-settleable particles have an additional opportunity to be transformed into settleable particles. Experiments will be carried out on pilot treatment plants with differing flow rates and imaging capacities. These experimental units have the combined capacity to vary velocity gradients and image flocs to determine size distribution in both influent and effluent. This experimental design has the capability to investigate tapered flocculation in hydraulic and floc blanket flocculators with varying residence time, velocity gradients, and energy dissipation rates to determine optimal flocculation design. The research performed under this project will be integrated into Cornell?s AguaClara program, which was initiated over a decade ago for developing low-cost water treatment technologies so that communities can self-finance and sustainably operate municipal water treatment plants. The tapered flocculation technology has the potential to significantly lower the cost of high quality water treatment and enable the development of lower cost treatment plants to protect the health of the approximately two billion people who do not yet have access to safe drinking water. |
| 资源类型: | 项目
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| 标识符: | http://119.78.100.158/handle/2HF3EXSE/89417
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| Appears in Collections: | 全球变化的国际研究计划
科学计划与规划
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| Recommended Citation: | |
Monroe Weber-Shirk. WRF: Experimental observation and modeling of coagulant mediated contaminant removal: flocculation, floc blankets, and sedimentation. 2017-01-01.
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