Determine the following: There are four main mechanisms for coagulation: double layer compression, adsorption and charge neutralization, sweep flocculation, and inter-particle bridging. Optimum retention time in pilot unit is equal to 2.5 h compared to 3.5 h for conventional chemical treatment. Design of Rapid, The design flow for a water treatment plant (WTP) is 1 MGD (3.8x103 m3/d). Coagulation and flocculation processes are used to separate the suspended solids portion from the water. The cost of coagulant and size of the plant are important factors to be considered in the design of a clariflocculator; Coagulation and flocculation play a very important role in any water treatment plant. Coagulation and flocculation are often used in combination. Coagulation and flocculation are essential processes in various disciplines. Homework #6. Flocculation Removal of TSS by flocculation Agglomeration of destabilised particles to a large size particles known as flocs , can be effectively removed by sedimentation or flotation. Typical detention time is 1 hour. first process in drinking water treatment, coagulation, is to destabilize the particles and allow them the potential to collide and stick together. Materials & Methods: This study is an applied-experimental study. It is the logical step following coagulation. Exit to the sedimentation tank entrance channel Design Considerations •The length of the flocculator channels matches the length of the sedimentation tank •Width of the flocculation channel? A common use of coagulation and flocculation for wastewater treatment is in the galvanic industry. Use the Flocculation and Sedimentation Protocol in your design. It can be manufactured with different diameters, 800 to 3000 mm. Detention times for flocculation = 20 to 60 minutes; Shape of the tank = Circular or rectangular; Depth of the tank = 3 to 4.5m; Total area of paddles = 10 to 25% of the vertical cross-sectional area of the tank; Velocity gradient, G = 20 to 75 / s Destabilization of colloids by addition of chemicals. Figure 1 depicts the coagulation process in the resident tank by the diagonal lines. The purpose of coagulation and flocculation is to remove particulate impurities, especially non-settleable solids and colour from the water being treated. Non-settleable particles in water are removed by the use of coagulating chemicals. Coagulation / flocculation is a widely-used process in the primary purification of water and in industrial wastewater treatment. 4.5 Design of Sedimentation tanks 4.5.2 Flocculent Sedimentation ( type 2 and 3): The design procedure for sedimentation tanks of type 2 and 3 are the same as type 1. The results confi rmed that the method used to design certain parameters of the tank are fairly accurate. The currents can be beneficial in that they promote flocculation of the particles. In addition, the two mixing stages for coagulation and flocculation take place within the same clarification tank. 50 -60 sec-1 in 2nd tank. Coagulation in Water Treatment Salts of Al(III) and Fe(III) are commonly used as coagulants in water and wastewater treatment. WATER TREATMENT PROCESSES – COAGULATION AND FLOCCULATION LEARNING OBJECTIVES • Analyse the chemistry of coagulation … The rapid mixing and flocculation tank together bring about aggregation and comprises the coagulation process. Design a procedure to determine the proper flocculant dose. Coagulation-Flocculation •In conventional coagulation-flocculation-sedimentation, a coagulant is added to the source water to create an attraction among the suspended particles. Most galvano companies generate wastewater containing metal ions. It is the process of slow mixing to provide inter-particle contacts. Flocculation Compute the power requirements for a 100 gallon tank mixing water at a velocity gradient of 40 fps/ft: 2 3 5 2 ft. lb. RAPID MIXING DESIGN Design parameters for rapid-mix 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 between. A jar test simulates the coagulation and flocculation processes Fill the jars with raw water sample (500 or 1000 mL) – usually 6 jars Adjust pH of the jars while mixing using H 2 SO 4 or NaOH/lime (pH: 5.0; 5.5; 6.0; 6.5; 7.0; 7.5) Add same dose of the selected coagulant (alum or iron) to each jar Although upflow units may provide more efficient sedimentation than horizontal designs, many upflow clarifiers compromise on the rapid and slow mix sequences. Key Difference – Coagulation vs Flocculation in Water Treatment Water treatment is an important aspect which involves many different steps. Coagulation and flocculation are an essential part of drinking water treatment as well as wastewater treatment. This method has a preference in the primary purification processes mainly due to the ease Sweep flocculation is the primary V W P G G = velocity gradient, sec-1 W = power imparted per unit volume of basin, N-m/s-m3 P = power imparted, N-m/s - The length of the tank was chosen as 1 m and the corresponding depth to provide a volume of 5.70 m3 was determined to be 3.00 m. The depth was checked to be between 1.1-1.6 times the width of the tank, as per normal design standards. The rapid mixing tank will have a mechanical mixer and the average alum dosage will be 30 mg/L. You should have at least 4 different samples that can range in dose from 0 mL to 5 mL of alum solution. The theoretical mean hydraulic detention time of the tank will be 1 minute. In the coagulation process, chemicals are added which will Material for this article was largely taken from reference 1. View 3 Coag+Flocc 1.pdf from CIVE 4407 at Carleton University. •Minimum? However, water currents also tend to distribute the floc unevenly throughout the tank; as a result, it does not settle out at an even rate. _____ •Material limitations (polycarbonate or concrete) •Vary to optimize flocculation … A combined unit in which process of coagulation, flocculation and sedimentation, has been designed and operated utilizing hydraulic mixing. The coagulation and flocculation process requires a great amount of attention to detail along the way. Design criteria for Mechanical flocculator are furnished below. as adsorption , flocculation, electro-coagulation and flotation (Zouboulis, et al., 2000). When a salt of Al(III) and Fe(III) is added to water, it dissociates to yield trivalent ions, which hydrate to form aquometal complexes Al(H 2 O) 6 3+ and Fe(H 2 O) 6 3+ . Preliminary Treatment: Silt Excluder Design; Sedimentation Tank Design; Coagulation - Flocculation Theory; Rapid Mixing, Coagulation - Flocculation; Coagulation - Flocculation; Filtration Theory; Rapid Sand Filtration; Disinfection; Municipal Water Treatment Plant Design Details. •The mixture is slowly stirred to induce particles to clump together into “flocs.” •The water is then moved into a quiet sedimentation basin to settle out the 20-30 sec-1 in 3rd tank Design Considerations of Flocculation: The aim of coagulation is to destabilise a colloidal solution, so that polluting matter can bunch together to form floccules. tank. Therefore, it is perfect when managing very delicate applications, where the fluid needs to be handled very gently and carefully. The gentle mixing is usually done mechanically although hydraulic mixing is sometimes required. Flocculation. - Two baffles were chosen … Some of the water current problems can be reduced by the proper design of the tank… s ft. = 40 2 10 100 s ft. ft. 7.48 P gallons gallon P =0.427lbf s = 0.58 watts 1.355818 =0.427 P lbf watts s lbf s CIVL 1112 Water Treatment - Coagulation and Flocculation 6/7 A. Since water treatment is a very sensitive and important process it requires the presence of both physical and chemical processes. In some cases, the use of a coagulant or flocculant is sufficient to form settleable and floating floccules. Consider the following in your design: 1. 3. 1.2.1. This article provides an overview of the processes and looks at the latest thinking. Coagulation and Flocculation Cost NCF 4.8 or 5 units Project 1 – Treatment Cost The total yearly cost of the coagulation and flocculation system for 20 MGD is: $25,000 5 CF year Cost 7 9.462×10-5 kg 2 10 gal 365 days $0.25 gal day year kg Coagulation and Flocculation Cost $297,691 Project 1 – Treatment Cost Sedimentation System Cost 544 9 Coagulation and Flocculation the coagulation and flocculation processes. Academia.edu is a platform for academics to share research papers. efficiency of coagulation and flocculation process along with chemical sequestration in the removal of organic and inorganic pollutants from automotive industry sewage. Coagulation, Flocculation, Sedimentation 1. When coagulants are added, the stabilised colloidal system of water is disturbed and the coagulant forms primary flocculation particles. Coagulation Removal of TSS by coagulation Removal of TSS, (total suspended solids) from waste water. tank. By the use of coagulation and flocculation these ions can be precipitated and settled in a sedimentation tank or … Basic principle of flocculation: The flocculation step can only operate on a water/wastewater where the particles are already destabilized. View Design of Coagulation Rapid Mixing System(1).pdf from AA 1Design of Coagulation & Flocculation Processes Rapid Mixing System Draft Lecture Notes Contents Prelim. Coagulation uses salts such as aluminum sulfate (alum) or ferrous of ferric (iron) salts, which bond to the suspended particles, making them less stable in suspension, i.e., more likely to settle out. In case of tapered flocculation, which is often a preferred option in efficient and energy-saving flocculation process, G values can be set as follows: 100 sec-1 in 1st tank. 2. That is why Premium is specific for flocculation. This design is aimed to prevent the fluid coming out from one blade to immediately meet the second blade. 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