Inlet zone the inlet or influent zone should provide a smooth transition from the flocculation zone. Difference between coagulation and flocculation in water. Even after coagulation and flocculation, sedimentation does not remove enough suspended impurities from water to make it crystal. Since water treatment is a very sensitive and important process it requires the presence of both physical. In light of growing concerns about the formation of nitrogenbased disinfection byproducts ndbp and the possible contribution from the use of quaternaryammoniumcontaining flocculants, there is growing interest in the alternative use of quaternary phosphonium salts, which have been reported to have a lower dbp formation potential, stronger cationic properties, lower. Flocculation is a water treatment process following coagulation, which uses gentle stirring to bring the suspended particles. Flocculation, in physical chemistry, separation of solid particles from a liquid to form loose aggregations or soft flakes. The principal factors affecting the coagulation and flocculation of water or wastewater are. There is a better appreciation for the multiple barrier approach to water treatment. The mixture is slowly stirred to induce particles to clump together into flocs. Coagulation, flocculation and clarification, followed by rapid granular media filtration, are the key steps in conventional water treatment systems. Coagulation and flocculation are important processes in water treatment with coagulation to destabilize.
Coagulation flocculation is a chemical water treatment technique typically applied prior to sedimentation and filtration e. This is a well proven technology for the significant removal of colour and particulate matter including protozoa eg, cryptosporidium oocysts and giardia cysts, viruses, bacteria, and other. This article provides an overview of the processes and looks at the latest thinking. Download coagulation flocculation process for produced water treatment book pdf free download link or read online here in pdf. In dispersed clay slurries, flocculation occurs after mechanical agitation ceases and the dispersed clay platelets spontaneously form flocs because of attractions between negative face charges and positive edge charges. A common use of coagulation and flocculation for wastewater treatment is in the galvanic industry. Cataloginginpublication data is on file with the library of congress. Ec sought the assistance of clean water technology inc. Water treatment plant wtp processes that are commonly used in getting clean potable water to your household. After this treatment, the water is passed for sedimentation.
Correct application of coagulation and flocculation depends. It is an integral treatment step in the surface or underground waters treatment, indented for human consumption. This knowledge will provide a basis for understanding the needs of the. In recent years, due to vast oil and gas resources in the. Coagulation, particles will be ready to a tract and agglomerate and form flocs. Most water treatment practices including coagulation, flocculation and clarification, date back hundreds and in some cases thousands of years. Common water treatment processes intended to remove suspended solids and reduce turbidity include. What is coagulation and flocculation in water and wastewater treatment. What is coagulation and flocculation in wastewater treatment.
Difference between coagulation and flocculation in water treatment. Coagulation and flocculation in water and wastewater treatment bratby, john on. Coagulation and flocculation in water treatment prepared by. Typical treatment processes consist of grates, coagulation, flocculation, sedimentation, granular filtration and disinfection. Pdf coagulationflocculation processes in waterwastewater. A water treatment plant receives a 11% polymer solution. In water treatment, coagulation flocculation involves the addition of compounds that promote. Most water treatment practices including coagulation, flocculation and. Correct application of coagulation and flocculation depends upon these factors. Coagulation and flocculation are used to separate the suspended solids portion from the water. The scientific principles behind water treatment are better understood. 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.
Bantcheva department of chemical engineering, university of durban westville, south africa abstract the introduction of wastewater treatments increases the plant cost. Coagulation is extensively utilized in several water treatment plants and has been found to be desirable in the treatment of wastewaters from petroleum refineries and industrial treatment plant 7, 8. In this research, the applications of electrocoagulation were investigated in raw water treatment and wastewater applications. Apr 27, 2016 coagulation and flocculation in water treatment prepared by. Cwt in order to improve their wastewater treatment system. A treatment plant consists of many processes, which can generally be subdivided into pre treatment, and treatment. Waste water treatment by coagulation and flocculation. Optimization of coagulationflocculation for treatment of. Calculate how much polymer should be mixed with 300 gallons of water to produce a 0. American water works association american society of civil engineers. You will recall that we discussed a similar process in estuaries, with solids separating from the water. Coagulation and flocculation in water and wastewater. Apr 03, 2018 what is coagulation and flocculation in water and wastewater treatment. 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.
Material for this article was largely taken from reference 1. Evaluation and optimization of the coagulationrapid mixing step of the water treatment process includes a variety of aspects. But this agglomeration is slow and they need help to accelerate this agglomeration. It is a timedependent process that directly affects clarification efficiency by providing. Both flocculation and electroflocculation are readily scaled up and have an established history of largescale use in treatment of water and wastewater. This help is called flocculation which is the slow stirring or gentle agitation to aggregate the destabilized particles and form a rapid settling floc. That is not possible for most types of water treatment plants. Flocculantdisinfectant powder the safe water system cdc. Some of these include screening, coagulation, flocculation, filtration etc. In filtration treatment plants treating surface water to removes flocculated solids. These flocculates are easily disrupted, being held together only by a force analogous to the surface tension of a liquid. The separation method for removing of colloidal particles from raw water pdf. Coagulation and flocculation involves the removal of suspended solids and turbidity from water to prepare it for use or for further treatment.
Removal of turbidity by coagulation depends on the type of colloids in. Coagulation and flocculation in water and wastewater treatment. Coagulation and flocculation practices are essential pretreatments for many water purification systems in conventional coagulation flocculation sedimentation, a coagulant is added to the source water to create an attraction among the suspended particles. The requirement of water quality is increasing during the time, therefore the aesthetic quality of water should be improved by water treatment plant before being used. Energy use head loss in flocculation controls velocity gradient head loss high head loss results in a taller building for the water treatment plant high head loss. Coagulation and flocculation for wastewater treatment represent. Another type of tanks combine between flocculation and sedimentation in one tank and called solid contact flocculator clarifier. Coagulationflocculation process for produced water treatment.
Modern measurement tools permit identification of process variation whereby. 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. Flocculation flocculation is the next step in most treatment plants inline filtration plants being the exception. Flocculation flocculation is the next step in most. Coagulationflocculation process for produced water. Pathogens diseasecausing organisms that include bacteria, amoebas and viruses, as well as the eggs and larvae of parasitic worms. Introduction the need to clarify water aesthetics and health colloids impart color and turbidity to water aesthetical acceptability microbes are colloids too 042716 water treatment 2. A condition in which clays, polymers or other small charged particles become attached and form a fragile structure, a floc.
The most widely used coagulants in water treatment are aluminum sulfate and iron salts. Water treatment flocculation process operation youtube. Fracking wastewater treatment at collection facility. Some small water treatment plants combine coagulation and sedimentation in a single prefabricated steel unit called a solidscontact tank. The addition and rapid mixing of coagulants the destabilization of colloidal and fine particles the initial aggregation of destabilized particles aait water treatment by zerihun alemayehu colloid stability. Flocculation, in the field of chemistry, is a process in which colloids come out of suspension in. The sedimentation tank comes after the flocculation tank. Flocculantcoagulant water purification calcium hydroxide. A new way to treat the waste water 105 2sulfoethyl methacrylate is of limited commercial value owing to the hydrolytic instability of the ester linkage. Example problem for designing a flocculation basin.
A combination of mixing and stirring or agitation that produces aggregation is called flocculation. It is a timedependent process that directly affects clarification efficiency by providing multiple opportunities for particles suspended in water to collide through gentle and prolonged agitation. Mixing is specific blending, mingling, or commingling of coagulating chemicals with water in. After flocculation the water flows into the sedimentation tanks. 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.
Suspended settle able solids will settle out of water over time, though this may be so slow that it is impractical to merely allow the particles to settle out in a water treatment plant. Pdf waste water treatment by coagulation and flocculation. This paper will address several topics that will help the water treatment plant operator select the most appropriate chemical. The process of coalescence is known as flocculation. Calculate how much polymer should be mixed with 50 gallons of water to produce a 0. Coagulation and flocculation water treatment waste water. The coagulation is the most important process during the water treatment, which includes the removal of species. Aait water treatment by zerihun alemayehu coagulation coagulation is a chemical process in which charged particles colloids are destabilized. Since water treatment is a very sensitive and important process it requires the presence of. The impurities are removed in order of size, the bigger ones being eliminated first. In water treatment it is used to remove solids from waters which are high in sediment content, and also to remove particles rendered settleable by coagulation and flocculation.
Environmental microbiology water treatment process. Design of a water treatment mechanical mixer for a pre. A water treatment plant receives a 5% polymer solution. Electrocoagulation in the treatment of industrial waters and. Coagulation and flocculation are an essential part of drinking water treatment as well as wastewater treatment. Harmful chemicals from human activities industrial wastes, pesticides, fertilizers. I use a chemical called calcium hydroxide and i even show how to make it. In addition to this main reaction, several side reactions, such as hydrogen bubble formation and the reduction of metals on cathodes, also take place in the cell. Coagulation and flocculation american water college. This technique is used in treating wastewater, both industrial and treated sewage, from municipal wastewater treatment plants. 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. Pdf pure water is an essential requirement for the survival of human beings. Coagulationflocculation processes in waterwastewater treatment. Groundwater and surface water contain both dissolved and suspended particles.
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. Ec was in need of advanced primary treatment, flocculation flotation technology. Key difference coagulation vs flocculation in water treatment water treatment is an important aspect which involves many different steps. This step typically uses the difference in density between the water and the suspended material for separation.
Civil engineers are vital in the treatment and delivery of water to your household. The color of water is an indication of the organic content, including humic and fulvic acids, the presence of natural metallic ions such as iron and manganese, and turbidity. Coagulation and flocculation process may be used as a pretreatment step prior to biological treatment in order to enhance the biodegradability of organic compounds amuda and amoo, 2007 or to increase the efficiency of removal of colloidal particles colla et al. Study on the factors affecting coagulation and flocculation in treatment of industrial effluents i. Individuals using the measurement tools and treatment processes are better educated and trained. Coagulation, flocculation and clarification of drinking water terry l. 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.
Written by aos treatment solutions on april 3, 2018. Water treatment step tostep to conventional water treatment dr. 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. Coagulation, flocculation and sedimentation processes in wastewater treatment and water treatment are significant. Flocculation is the snowballing of sm all particles into larger particles called floc. No pdf files stored in this site but only links from search engines and other sites. By the use of coagulation and flocculation these ions can be precipitated and settled in a sedimentation tank or filtrated through sand filters. Coagulation and flocculation play a dominant role in many water and wastewater treatment, schemes.
Coagulation, flocculation, and sedimentation subject areas environmental systems, chemistry associated unit drinking water treatment process lesson title drinking water treatment. Civil engineers design, monitor and maintain water treatment plants and water supplies. Sustainable municipal drinking water treatment monroe webershirk 1 flocculator design overview analysis of hydraulic flocculators ratio of maximum to average energy dissipation rate inefficiency of energy use due to nonuniformity of energy dissipation rate. Earthen jars used to store water it is good to keep water in copper vessels, to expose it to sunlight and. Flocculation and sedimentation cannot occur without coagulation, and some of veolias patented hydrex water treatment chemicals are used to facilitate all of these processes. Most galvano companies generate wastewater containing metal ions. Coagulation flocculation is used widely during water or wastewater treatment. Ec currently operates a water treatment facility for their clients in myton, utah. Coagulation and flocculation in water and wastewater treatment is a readable and useful resource for the water scientist and engineer. Ene 806 project report 2 coagulation and flocculation. The treatment efficiencies of coagulants have been compared for maximum removal of impurities under optimum ph and optimum dosage of. Coagulation, flocculation and clarification of drinking water. Terminology of polymers and polymerization processes in dispersed systems iupac recommendations 2011 pdf.
Safe drinking water is essential coagulationflocculation. Electrocoagulation in the treatment of industrial waters. Flocculation water treatment plants,wastewater treatment. Flocculation and sedimentation are widely employed in the purification of drinking water as well as in sewage treatment, storm water treatment and treatment of industrial wastewater streams. Most sedimentation tanks are divided into these separate zones.