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Natural purification processes
Published in Rumana Riffat, Taqsim Husnain, Fundamentals of Wastewater Treatment and Engineering, 2022
Sedimentation is a process that involves the removal of suspended solids from a water body by settling them out. The size of the solid particles plays a major role in the efficiency of sedimentation. Larger particles settle out quickly, whereas smaller particles may remain suspended for longer periods and eventually settle out. Stream characteristics, such as flow rates, bed depth, and roughness, also affect the rates of sedimentation. Excessive turbulence or flooding can cause resuspension of deposited solids. This can transfer solids deposits from one location to another.
Water Resources Engineering
Published in P.K. Jayasree, K Balan, V Rani, Practical Civil Engineering, 2021
P.K. Jayasree, K Balan, V Rani
Sedimentation is the act or process of forming or accumulating sediment in layers, including such processes as the separation of rock particles from the material from which the sediment is derived, the transportation of these particles to the site of deposition, the actual deposition or settling of the particles, the chemical and other changes occurring in the sediment, and the ultimate consolidation of the sediment into solid rock. It is the terminal end of sediment transport. It includes the termination of transport by saltation or true bedload transport.
Water Treatment Calculations
Published in Frank R. Spellman, The Science of Water, 2020
Typically, a large range of particle sizes will exist in the raw water supply. There are four types of sedimentation: Type 1—discrete particle settling (particles of various sizes, in a dilute suspension, which settle without flocculating); Type 2—flocculant settling (heavier particles coalesced with smaller and lighter particles); Type 3—hindered settling (high densities of particles in suspension resulting in an interaction of particles); Type 4—compression settling (Gregory & Zabel, 1990).
Review of stability enhanced nanofluids prepared by one-step methods—heat transfer mechanism and thermo-physical properties
Published in Chemical Engineering Communications, 2023
Annie Aureen Albert, Harris Samuel D. G., Parthasarathy V.
Despite the enhancement in thermo-physical properties, the practical application of NFs is still limited due to several factors. The thermophysical properties of the NFs are affected by the sedimentation of the dispersed phase (NPs) in the base fluid (Kong et al. 2017; Verma and Gupta 2020). Achieving stability is a major challenge in the synthesis of NFs. The suspended NPs in the base fluid collide with each other due to Brownian motion which leads to instability. During the collision, they interact with one another. The interaction may be attractive or repulsive. The attractive force between the constituent particles results in agglomeration of the NPs which is more predominantly Van der Waals force of attraction. The colliding NPs then adhere to each other due to these attractive forces and eventually lead to the coalescence of the NF. When the particles form agglomerates, they undergo sedimentation due to gravity.
Excess pore pressure generation during slurry deposition of gold tailings
Published in International Journal of Mining, Reclamation and Environment, 2021
G. Lebitsa, G. Heymann, E. Rust
In settling columns, deposited slurry undergoes both sedimentation and consolidation during the settling process. Sedimentation is taken as the settling of solid particles or groups of particles in a fluid under the influence of gravity where particle segregation forms part of the sedimentation process with particle size segregation reported to be the most prevalent mode of segregation [42]. Consolidation on the other hand emphasises the expulsion of pore water from a tailings material together with the dissipation of excess PWPs as well as the resulting settlement that takes place due to the loss of water. Figure 4 illustrates sedimentation and consolidation processes that take place in hindered settling of sandy materials with little or no clay in settling columns [43,44]. It is noted that under this scenario sedimentation is inclusive of consolidation.
Study of the sedimentation and self-weight consolidation behavior of seafloor sediments using a radioisotope densitometer
Published in Marine Georesources & Geotechnology, 2019
Rui Jia, Huayang Lei, Wenjun Zhang, Takenori Hino
Sedimentation is the process of soil particles settling in a suspension, and the suspended soil particles form sediment at the bottom of water bodies. A decrease in water content of a saturated soil is known as the process of consolidation, which is caused by an increase in effective stress in the soil (Terzaghi 1943; Shen, Xu, and Hong 2006). Self-weight consolidation is the time-dependent compaction of the soil skeleton because of its own weight. The sedimentation and self-weight consolidation processes of seafloor sediments are relevant to both land reclamation work and sediment accumulation in rivers, lakes, estuaries, and offshore. Theoretical investigations have been conducted on the sedimentation and self-weight consolidation behavior of soft clay with high water content to analyze and predict the final settlement and settlement rate (Mikasa 1963; Been and Sills 1981; Kobayashi, Yamakawa, and Ogawa 1990; Toorman 1996). Experimental investigations have also been conducted on the sedimentation and self-weight consolidation behavior of soft clay with high water content to explore the settling types and the effects of various factors on the sedimentation and self-weight consolidation behavior (Imai 1980; Been and Sills 1981; Blewett et al. 2001; Kondo and Torrance 2009; Xu et al. 2012; He et al. 2016; Zeng et al. 2016; Zhang et al. 2016).