They are typically used for treatment of wastewater containing colloids suspended particles and metal ions. Flocculation,flocculation process,uses of flocculation process. Design a conventional verticalshaft rapid mix tank unit for uniformly dispersing coagulant in 10 mld of settled raw water as per design parameters given below. Civil engineering water and waste water engineering nptel. Another type of tanks combine between flocculation and sedimentation in one tank and called solid contact flocculator clarifier. In practice the coagulation process involves a rapid mixing, flocculation, sedimentation and filtration step. Hydrophobiccolloids havelittleaffinityforwater amino, carboxyl, sulfonic, hydroxyletc. Flocculation is synonymous with agglomeration and coagulation coalescence. But the phenomena are also wellknown from everyday life especially coagulation. Meanwhile, flocculation is a mixing technique that promotes agglomeration and assists in the settling of particles.
Suspended particles cannot be removed completely by plain settling. Mixing devices play an important role in through mixing of coagulant and floc. Coagulation and flocculation are used to separate the suspended solids portion from the water. Coagulation and flocculation process fundamentals 1 coagulation and flocculation. Water supply system water supply system coagulation and flocculation. Pdf coagulationflocculation process for produced water. Apr 03, 2018 what is coagulation and flocculation in water and wastewater treatment. Groundwater and surface water contain both dissolved and suspended particles. The coagulationflocculation processes facilitate the removal of ss and colloidal particles. Coagulation and flocculation tu delft opencourseware.
Flocculation or floculation is a significant process widely utilized in water treatment operations, including purification of drinking water, sewage water treatment, storm water treatment and treatment of various other industrial wastewater streams. Coagulation and flocculation are wellknown techniques within wastewater treatment. Written by aos treatment solutions on april 3, 2018. Coagulation and flocculation coagulation and flocculationconsist of adding a flocforming chemical reagent to a water to enmesh or combine with nonsettleable colloidal solids and slowsettling suspended solids to produce a rapidsettling floc. Pathogens diseasecausing organisms that include bacteria, amoebas and viruses, as well as the eggs and larvae of parasitic worms. During the coagulation process, coagulants are added to the water to aid in floc formation. Engelhardt application development manager drinking water hach company photo by author the intent of this paper is to provide cursory information about coagulation, flocculation and clarification.
Basically, coagulation is a process of addition of coagulant to destabilize a stabilized charged particle. Coagulation in water treatment destabilization using aliii and feiii salts jar test jar testing apparatus jar test procedure. The coagulation flocculation is considered the most important process in water surface treatment. After coagulation the destabilized particles can collide, aggregate so flocs can be formed. Large, heavy particles settle out readily, but smaller and lighter particles settle very slowly or in some cases do not settle at all. Some of these steps are sometimes combined in water. Solids waste disposal composting, landfill, briquetting gasification and incineration. Coagulation allows by the injection and the scattering of chemical coagulants during relatively intense mixing to destabilize naturally occurring particles and macromolecules and or to precipitate additional particles mackenzie and cornwell 1991. The process of agglomeration of the destabilized particles to such a size that separation by sedimentation and filtration is possible.
Coagulation and flocculation are an essential part of drinking water treatment as well as wastewater treatment. What is coagulation and flocculation in wastewater treatment. Its a preference in the primary purification processes due to its simplicity operation, efficient and cheap. Coagulation and flocculation electrical double layer destabilization of colloidal dispersion. Though often used interchangeably with coagulation, it is in fact a distinct process that. Pdf coagulationflocculation processes in waterwastewater. Key difference coagulation vs flocculation in water treatment water treatment is an important aspect which involves many different steps. Coagulation flocculation sedimentation chemical mixing destabilization floc formation flocs settle out aait water treatment by zerihun alemayehu rapid mixing design parameters for rapidmix units are mixing time t and velocity gradient g. The velocity gradient is a measure of the relative velocity of two particles of fluid and the distance. Optimization of the coagulationflocculation treatment. Coagulation and flocculation are essential processes in various disciplines.
Coagulationflocculation treatment is commonly used to reduce the turbidity of municipal and industrial waste water, the coagulants in question typically being divalent or trivalent metallic salts or polymers that have low solubility in the ph range used. This video lecture, part of the series water and wastewater engineering by prof. Nptel provides elearning through online web and video courses various streams. Iron and aluminium can also be removed under suitable conditions. Difference between coagulation and flocculation in water. Lecture 11 coagulation and flocculation contd youtube. Suspended particles vary in source, charge, particle size, shape. This article provides an overview of the processes and looks at the latest thinking.
Coagulationflocculationjar test marmara universitesi. Suspended particles vary in source, charge, particle size, shape, and density. Water supply system coagulation and flocculation britannica. Abstract coagulation flocculation is the most widely used process for. Coagulation, flocculation and clarification of drinking water. If you have watched this lecture and know what it is about, particularly what civil engineering topics are discussed, please help us by commenting on this video with your suggested description and title. Safe drinking water is essential coagulationflocculation. A jar test simulates the coagulation and flocculation processes fill the jars with raw water sample 500 or ml usually 6 jars adjust ph of the jars while mixing using h 2 so 4 or naohlime ph. Ligy philip, does not currently have a detailed description and video lecture title. Flocculation process of bringing destabilized colloidal particles together to allow them to aggregate to a size where they will settle by gravity. Coagulationflocculation treatment of municipal wastewater. Flocculation or gentle agitation results from velocity differences or gradients in the coagulated water, which causes the fine moving, destabilized particles to.
Ene 806 project report 2 coagulation and flocculation. One of the challenges for any water or municipal wastewater treatment plant is being able to remove the vast majority of waste particles from the water, quickly and efficiently. Coagulationflocculation followed by clarification is the most widely used process for treating the wastewater in this kind of industry. Coagulation, flocculation and clarification of drinking water terry l. This knowledge will provide a basis for understanding the needs of the. Since water treatment is a very sensitive and important process it requires the presence of both physical and chemical processes. Material for this article was largely taken from reference 1. Importance of mixing device in coagulationflocculation. These flocs are precipitates in water, wherein small par ticles are. Anaerobic and aerobic treatment biochemical kinetics, trickling filter, activated sludge and lagoons, aeration systems, sludge separation and drying. The floc is subsequently removed in most cases by sedimentation. Collodialcharacteristics classificationof collodialsolids in wateracc. Coagulation and flocculation in water and wastewater treatment provides a comprehensive account of coagulation and flocculation techniques and technologies in a single volume covering theoretical principles to practical applications.
Charge neutralization mechanism efficiency in water with. In a second experiment, river water ph was adjusted at different phs between 4. Dec 10, 2017 key difference coagulation vs flocculation in water treatment water treatment is an important aspect which involves many different steps. Analysis and optimization of coagulation and flocculation process.
Coagulation flocculation is a widelyused process in industrial wastewater treatment. Coagulation is the destabilization of colloidal particles brought about by the addition of a chemical reagent called as coagulant. Correct application of coagulation and flocculation depends. In flocculation one can make a distinction between perikinetic and. Coagulationflocculation process for produced water treatment. The process usually consists of the rapid dispersal of a coagulant into the wastewater followed by an intense agitation commonly defined as rapid mixing. Its used in the first stage of solidsliquids separation. Coagulation and flocculation are designed to remove infectious agents, remove toxic compounds that have adsorbed to the surface of particles, remove precursors to the formation of disinfection byproducts, and make the water palatable. Coagulation and flocculation video lecture by prof b. Because of this, the sedimentation step is usually preceded by a chemical process known as coagulation.
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