Water treatment coagulation flocculation basics youtube. Pdf coagulationflocculation process for produced water. Coagulation and flocculation constitute the backbone processes in most water and advanced wastewater treatment plants. This enables their removal by sedimentation, dissolved air flotation or filtration. Advanced treatment of laundry wastewater with coagulation. The primary purpose of the coagulation and flocculation is to destabilize the charged colloidal particles in water and make them to settle so as to remove turbidity from the water. Figure 1 demonstrates the flocculation process in the clarifier by the merging horizontal lines. Coagulationflocculation processes in waterwastewater treatment. Most water treatment practices including coagulation, flocculation and clarification, date back hundreds and in some cases thousands of years.
Pdf combined coagulation flocculation pre treatment unit for. In this research, the effect of flocculant consumption rate and feed solid concentration of settling rate of layers was studied with different concentrations in iron ore. Pdf waste water treatment by coagulation and flocculation. Another type of tanks combine between flocculation and sedimentation in one tank and called solid contact flocculator clarifier. Safe drinking water is essential coagulationflocculation.
Their objective is to enhance the separation of particulate species in downstream processes such as sedimentation and filtration. Treatment processes coagulation coagulation coagulation. Combining coagulation, softening and flocculation to dispose. Coagulation and flocculation prepared by husam alnajar the islamic university of gaza environmental engineering department water treatment eenv 4331 colour in water. The addition of another reagent called flocculant or a flocculant aid may. Coagulation and flocculation consist of adding a floc forming chemical reagent to a water to enmesh or combine with nonsettleable colloidal solids and slow. Coagulation and flocculation occur in successive steps intended to overcome the forces stabilizing the suspended particles, allowing particle collision and growth of floc. Ppt coagulation and flocculation linkedin slideshare. Flocculant and coagulant market global industry analysis. In addition to removing turbidity from the water, coagulation and flocculation process removes many bacteria which are suspended in the water and can be used to. Aluminum sulfate alum, ferrous sulfate, ferric chloride and ferric chlorosulfate were commonly used as coagulants. Combined coagulation flocculation pre treatment unit for.
The theoretical mean hydraulic detention time of the tank will be 1 minute. The rapid mixing tank will have a mechanical mixer and the average alum dosage will be 30 mgl. Coagulation and flocculation play a dominant role in many water and wastewater schemes. Flocculation is the agglomeration of destabilized particles into microfloc and after into bulky floccules which can be settled called floc. Coagulation control techniques have ad vanced slowly. However, a possible link of alzheimers disease with conventional aluminium based coagulants has become an issue in wastewater treatment. The process of agglomeration of the destabilized particles to such a size that separation by sedimentation and filtration is possible. Coagulation and flocculation in water and wastewater. Flocculation, in the field of chemistry, is a process in which colloids come out of suspension in the form of floc or flake, either spontaneously or due to the addition of a clarifying agent. Iron and aluminium can also be removed under suitable conditions.
Coagulation and flocculation tu delft opencourseware. Water treatment plant waste sludge disposal is dealt with in considerable detail, in an appendix devoted to this subject. Flocculation and coagulation is a chemical cleaning treatment for the waste water generally undertaken before the sedimentation process thus aiding in enhancing the process to remove particles from the water. Coagulation and flocculation process fundamentals 1. In the flocculated system, there is no formation of. If step one is incomplete, the following step will be unsuccessful. Pdf increasing efficiency of thickener operation in. Coagulation and flocculation process fundamentals 1 coagulation and flocculation. 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. Coagulation and flocculation processes are used to separate the suspended solids portion from the water. Coagulation and flocculation practices are essential pretreatments for many water purification systems in conventional coagulationflocculationsedimentation, a coagulant is added to the source water to create an attraction among the suspended particles. Comparative study between flocculationcoagulation processes in raw wastewater treatment.
Pdf coagulation and flocculation treatment of wastewater. The salts used for coagulation form certain ions in. The floc is subsequently removed in most cases by sedimentation. 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. Many plant operators re member when dosage control was based upon a visual evaluation of the flocculation basin and the clarifier. Earthen jars used to store water it is good to keep water in copper vessels, to expose it to sunlight and. Many plant operators remember when dosage control was based upon a visual evaluation of the flocculation. Invaluble for water scientists, engineers and students of this field, coagulation and flocculation in water and wastewater treatment is a convenient reference handbook in the form of numerous examples and appended information.
The coagulation flocculation is considered the most important process in water surface treatment. Prospects and challenges of using coagulationflocculation. The mixture is slowly stirred to induce particles to clump together into flocs. Difference between coagulation and flocculation in water.
Coagulation flocculation is a widelyused process in industrial wastewater treatment. 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. Thickener is a main and fundamental step in modern mining separation processes. In flocculation one can make a distinction between perikinetic and. After coagulation the destabilized particles can collide, aggregate so flocs can be formed. Coagulation and flocculation are used to separate the suspended solids portion from the water. In a second experiment, river water ph was adjusted at different phs between 4. Filtration is the process of flowing a solidliquid blend through a porous media in order. Coagulation is the destabilization of colloidal particles brought about by the addition of a chemical reagent called as coagulant. Coagulation vs flocculation coagulation addition of chemical coagulant or coagulants particles destabilization reduction of electrical surface charge less than 10 s flocculation. Pdf in this study is present the advantages and disadvantages of the use of. Coagulation allows by the injection and the scattering of chemical coagulants during relatively intense mixing to destabilize naturally occurring particles and macromolecules andor to precipitate additional particles mackenzie and cornwell 1991.
However, in flocculation the clumping stops before it becomes a continuous mass, a product observed in coagulation. When these products are denser than water, they sink and may be collected. The action differs from precipitation in that, prior to flocculation, colloids are merely suspended in a liquid and not actually dissolved in a solution. Coagulation and flocculation water purification engineering. Water is clarified using the processes of coagulation and flocculation, which remove suspended solids turbidity from water by causing the suspended particles to aggregate into a slime, that settles out of the water. Coagulation the first step destabilizes the particles charges. Its a preference in the primary purification processes due to its simplicity operation, efficient and cheap. Pdf comparative study between flocculationcoagulation. Coagulation, flocculation and clarification of drinking water. Coagulation itself results in the formation of floc but flocculation is required to help the floc further aggregate and settle. Analysis and optimization of coagulation and flocculation. Coagulationflocculation process for produced water.
A key feature of flocculation and coagulation processes. Particle aggregation sticking of destabilized particles 2045 min floc separate by gravity. Coagulation vs flocculation in water treatment coagulation is an important step in water treatment which involves the addition of a coagulant to enhance the clotting of suspended particles in water. During flocculation, these small floc particles are aggregated into even larger particles through a gentle stirring of the water. Metal salts hydrolyze rapidly in waste water to form cationic species, which are adsorbed by negatively charged dirt. This module represents coagulation and flocculation. The addition of a chemical coagulant to the water causes the formation of a precipitate, or floc, which entraps these impurities. Flocculation is similar to coagulation in that both refer to smaller particles clumping together to form larger particles. The design flow for a water treatment plant wtp is 1 mgd 3. Ballast flocculation for water treatment columbus et al 2006, charles d. Coagulation is a water treatment process that causes very small suspended particles to. These properties are largely determined by coagulant type, dose, ph and mixing intensity 4, 51.
This results the collision and subsequent merger of the particles to form agglomerates flocs. Coagulation and flocculation water treatment waste. Removal of precipitates coagulation rapid chemical mix destabilization of suspended particles flocculation slow mix particle collision and growth. Various sizes of particles in raw water particle diameter mm type settling velocity 10 pebble 0. Coagulationflocculation treatment of municipal wastewater. Advanced treatment of laundry wastewater with coagulation and flocculation. Suspended particles vary in source, charge, particle size, shape, and density. The suspended particles vary considerably in source, composition charge, particle size.
The particles that form floc are often feathery in appearance. Hence, special attention has shift towards using biodegradable polymer, chitosan in treatment, which are more environmental friendly. Coagulation and flocculation are two main and important steps in drinking and. This technique is used in treating wastewater, both industrial and treated sewage, from municipal wastewater treatment plants. The coagulationflocculation process itself removes only about 60%70% of natural organic matter nom and thus, other processes like oxidation, filtration and sedimentation are necessary for complete raw water or wastewater treatment. Request pdf combining coagulation, softening and flocculation to dispose reverse osmosis retentates the concentrated stream of a reverse osmosis unit. Coagulation control techniques have advanced slowly. Coagulation and flocculation treatment of wastewater in textile industry using chitosan mohd ariffin abu hassan1, tan pei li1, zainura zainon noor1 abstract aluminum sulfate alum, ferrous sulfate, ferric chloride and ferric chlorosulfate were commonly used as coagulants. Collodialcharacteristics colloidaldispersions solidsdispersedin liquids sols e. For optimal coagulation and flocculation it is important that aggregates of certain size, strength and density are formed. 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 thoroughly revised and updated since the 1st edition it has.
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