Suspended particles vary in source, charge, particle size, shape, and density. Chemicals coagulants are added to the water to bring the nonsettling particles together into larger, heavier masses of solids called floc. Difference between coagulation and flocculation in water treatment. Filtration and disinfection time required 30 summary in this lesson students learn about the first three steps of a conventional surface water treatment plant. Operating within the optimum parameters will reduce the cost of treatment and will increase the quality of the water. Coagulationflocculation process for produced water. If the turbidity and colour of the raw water are not much higher than is permissible for drinking water, it should be possible to avoid chemical coagulation in the treatment of the water. Coagulation flocculation is a chemical water treatment technique typically applied prior to sedimentation and filtration e. Flocculation is the snowballing of sm all particles into larger particles called floc. The gentle stirring can be achieved using paddles or baffles to induce a rolling motion in the water, and this continues for some 2045 minutes. Coagulation, flocculation and settlement in coagulation, a liquid coaguo ooooo ooo oooo lant, such as aluminium sulfate, is added to the water to attract suspended particles. Difference between coagulation and flocculation coagulation. The process of coalescence is known as flocculation. A water treatment plant receives a 11% polymer solution.
Difference between coagulation and flocculation in water. It is an integral treatment step in the surface or underground waters treatment, indented for human consumption. Many water treatment plants use a combination of coagulation, sedimentation, filtration and disinfection to provide clean, safe drinking water to the public. Coagulation is a process used to neutralise charges and form a gelatinous mass to trap or bridge particles thus forming a mass large enough to settle or be. Water supply system coagulation and flocculation britannica. As a result, they stay dispersed and dissolved or coagulation process colloidal in the water. Aait water treatment by zerihun alemayehu rapid mixing and flocculation rapid mix 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 coagulation flocculation process can be used as a preliminary or intermediary step between other water or wastewater treatment processes like filtration and sedimentation.
The suspended particles vary considerably in source, composition charge, particle size, shape, and density. Jan 10, 2017 many water treatment plants use a combination of coagulation, sedimentation, filtration and disinfection to provide clean, safe drinking water to the public. Design of a water treatment mechanical mixer for a pre. This technique is used in treating wastewater, both industrial and treated sewage, from municipal wastewater treatment plants. The objectives of the study were, to compare the effectiveness of different coagulants, to determine. Water supply system water supply system coagulation and flocculation. This step in the pr ocess, where colloids andor destabilized par ticles react with the r eagents, takes place in basins or tanks of many shapes and sizes. Flocculation flocculation is the next step in most treatment plants inline filtration plants being the exception. Download pdf coagulation and flocculation free online. Coagulation and flocculation are an essential part of drinking water treatment as well as wastewater treatment. Flocculation flocculation is the next step in most. Coagulation and flocculation for wastewater treatment represent. Study on the factors affecting coagulation and flocculation.
After this treatment, the water is passed for sedimentation. Coagulation flocculation is used widely during water or wastewater treatment. Aluminum sulfate alum is the most common coagulant used for water purification. Principlea and design, mwh2005, isbn 04710110183 5. Coagulation and flocculation processes are used to separate the suspended solids portion from the water. But the phenomena are also wellknown from everyday life especially coagulation. Coagulation and flocculation are wellknown techniques within wastewater treatment.
Coagulation and flocculation water treatment waste water. Material for this article was largely taken from reference 1. Coagulation and flocculation water treatment chemicals are used to remove iron, suspended solids, organic color, and hardness from influent water. The impurities are mainly removed by the following process. Ppt coagulation and flocculation linkedin slideshare. 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. Figure 2 shows a typical chemical treatment process for both wastewater and drinking water settings, which usually consists of coagulation, flocculation, and sedimentation or flotation 24. Coagulation, flocculation and clarification of drinking water. 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 this new edition has been progressively modified and increased in scope to cater for the requirements of. Coagulation and flocculation can achieve the effective removal of suspended particles. Coagulationflocculation sswm find tools for sustainable.
Pdf coagulationflocculation processes in waterwastewater. Both flocculation and electroflocculation are readily scaled up and have an established history of largescale use in treatment of water and wastewater. Water treatment flocculation process operation youtube. Coagulation and flocculation in water and wastewater treatment. The water is then gently stirred to allow the particles to come together and form larger particles flocculation, which can then be. Coagulation is a chemical process that involves neutralization of charge whereas flocculation is a physical process and does not involve neutralization of charge.
Coagulation is an essential component in water treatment operations. Advanced treatment of laundry wastewater with coagulation. Each beaker contained 2 l of river water or humic acid spiked tap water. It is a timedependent process that directly affects clarification efficiency by providing. Pdf aeration, coagulation and flocculation processes in. Some small water treatment plants combine coagulation and sedimentation in a single prefabricated steel unit called a solidscontact tank. Coagulation is a process used to neutralise charges and form a gelatinous mass to trap or bridge particles thus forming a mass. They are typically used for treatment of wastewater containing colloids suspended particles and metal ions. In a second experiment, river water ph was adjusted at different phs between 4. Permission ranges as set by the local water and irrigation service. Certain heavy metal chelating agents can also be added during the coagulation step. The floc is subsequently removed in most cases by sedimentation. Jartest experiments are employed in order to determine the optimum conditions for the removal of surfactants, cod and turbidity in terms of effective dosage, and ph control.
Thus, we can understand the process of coagulation and flocculation with the help of examples derived from water treatment techniques. Large, heavy particles settle out readily, but smaller and lighter particles settle very slowly or in some cases do not settle at all. Coagulation, flocculation and sedimentation processes in wastewater treatment and water treatment are significant. Since water treatment is a very sensitive and important process it requires the presence of. Even after coagulation and flocculation, sedimentation does not remove enough suspended impurities from water to make it crystal. Water treatment plant waste sludge disposal is dealt with in considerable detail, in an appendix devoted to this subject. For raw water applications, polymer products help to eliminate. Some of these include screening, coagulation, flocculation, filtration etc. Apr 27, 2016 042716 water treatment 59 g value for coagulation. Coagulation and flocculation in water and wastewater.
Since, not every water requires all the treatment process smsrthurst g1979. Both these techniques are employed in the treatment of water. A water treatment plant receives a 5% polymer solution. Sep 14, 2017 example problem for designing a flocculation basin. In water treatment, coagulation flocculation involves the addition of compounds that promote the clumping of fines into larger floc so that they can be more easily separated from the water. Flocculation water treatment plants,wastewater treatment. Iron and aluminium salts are the most widely used coagulants but salts of other metals such as titanium and zirconium have been found to be highly effective as well. Groundwater and surface water contain both dissolved and suspended particles. Removal of surfactant from industrial wastewaters by. All waters, especially surface waters, contain both dissolved and suspended particles. Worldwide, a combination of coagulation, sedimentation and filtration is the most widely applied water treatment technology, and has been used since the early 20th century. Apr 03, 2018 what is coagulation and flocculation in water and wastewater treatment. Water may contain colloidal solids like nonsettleable organic matter, clay particles, bacteria, plankton, small particles of decayed plant material.
Coagulation and flocculation prepared by husam alnajar the islamic university of gaza environmental engineering department water treatment eenv 4331 colour in water. Coagulation and flocculation are used to separate the suspended solids portion from the water. After adding appropriate volume of the alum stoke solution, the water was mixed at 160 rpm for 2 min, 70 rpm for 15 min, 30 rpm for 35 min and settled for 2 hours. Coagulation and flocculation in water and wastewater treatment bratby, john download bok. Coagulation is a process to neutralize charges and then to. What is coagulation and flocculation in water and wastewater treatment. Though often used interchangeably with coagulation, it is in fact a distinct process that. Coagulation is a water treatment process that causes very small suspended particles to attract to one another and form larger. Addition of positively charged particles in the coagulation process is aimed to destabilizing the colloids. Calculate how much polymer should be mixed with 50 gallons of water to produce a 0. Ene 806 project report 2 coagulation and flocculation. Coagulation destabilises particles through chemical reaction between coagulant and colloids, and flocculation transports the destabilised particles that causes collisions with flocs.
Coagulationflocculation processes to estimate the most suitable coagulant for the treatment of the specific laundry wastes, tests were performed in small quantities of waste water 500 ml using various coagulation agents. In a first experiment, river water, or humic acid spiked tap water was treated for coagulation as explain above, with different concentrations of alum ranging from 0 to 200mgml. Correct application of coagulation and flocculation depends upon these factors. Coagulation and flocculation american water college. Coagulation and flocculation are essential processes in various disciplines. The paper identify and explain three of the most commonly use processes of enhancing the quality and purity of water treatment namely aeration which is the process that provides oxygen from the atmosphere to effect beneficial changes in the raw water. After flocculation the water flows into the sedimentation tanks. Key difference coagulation vs flocculation in water treatment water treatment is an important aspect which involves many different steps. Calculate how much polymer should be mixed with 300 gallons of water to produce a 0. Pdf waste water treatment by coagulation and flocculation.
Since water treatment is a very sensitive and important process it requires the presence of both physical. Coagulationflocculation is a chemical water treatment technique typically applied prior to sedimentation and filtration e. Earthen jars used to store water it is good to keep water in copper vessels, to expose it to sunlight and. Coagulation and flocculation in water and wastewater treatment is a readable and useful resource for the water scientist and engineer. So treatment involving coagulation and flocculation is typical of surface water. Coagulationflocculation is used widely during water or wastewater treatment. Coagulation is an indispensable mechanism that promotes the aggregation of the suspended solids. In wastewater treatment these clarification aids help with the removal of other contaminants such as oil, phosphate and heavy metals. Coagulation and rapid mixing coagulation is the process by which particles become destabilized and begin to clump together.
Download pdf coagulation and flocculation free online new. Other chemicals, such as ferric sulfate or sodium aluminate, may also be used. Evaluation and optimization of the coagulation rapid mixing step of the water treatment process includes a variety of aspects. Because of this, the sedimentation step is usually preceded by a chemical process known as coagulation. Coagulationflocculation process for produced water treatment. Evaluation and optimization of the coagulationrapid mixing step of the water treatment process includes a variety of aspects. The impurities are removed in order of size, the bigger ones being eliminated first. Suspended particles cannot be removed completely by plain settling.
The suspended particles vary considerably in source, composition charge, particle size. Most water treatment practices including coagulation, flocculation and clarification, date back hundreds and in some cases thousands of years. 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. From my course ees 3030, water treatment systems, in the department of environmental engineering and earth sciences at clemson university. Correct application of coagulation and flocculation depends. This step in the pr ocess, where colloids and or destabilized par ticles react with the r eagents, takes place in basins or tanks of many shapes and sizes. Since water treatment is a very sensitive and important process it requires the presence of both physical and chemical processes. Manual on water supply and treatment, cpheeo, ministry of moud, new delhi, 1999. Coagulations and flocculation water treatment suez. Sedimentation flocculation coagulation 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. What is coagulation and flocculation in wastewater treatment.
It is a convenient reference handbook providing numerous examples and appended information and it is a vital text for course material for undergraduate and postgraduate students. Dec 10, 2017 key difference coagulation vs flocculation in water treatment water treatment is an important aspect which involves many different steps. Written by aos treatment solutions on april 3, 2018. This article provides an overview of the processes and looks at the latest thinking. Howard, rowe, tchobanoglous, environmental engineering, 2014. 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. Example problem for designing a flocculation basin.1074 488 403 692 556 71 1403 1133 449 1034 791 249 49 985 437 457 1348 581 1092 770 40 759 128 1007 1240 579 232 717 561 846 1334 848 1075 1065 1373 537 474