Some characteristics of observed algae 20 . From Table 1, it will be noted that polyaluminium … A jar test is a test used to find out the optimum dosage of coagulants like Alum. Both … S. Turbidity Alum PAC % PAC Consumption No. Once you feed a certain amount of alum, it essentially quits working. Comparative dose to bring down the turbidity to 5 NTU. That dose at which turbidity is minimum is the optimum dose for coagulation. It was also showed that humic substances are rather more … These particles are not visible but a … function of aluminum sulfate dose at pH range of 4-8. Initial turbidities of 10 and 50 NTU, 100 and 200 NTU and 500 and 1000 NTU were respectively considered as low, medium and highly turbidity levels in water, based on the applied turbidity levels. The dirtier the water, the more alum you need to feed. Large amounts are often required. 2. For the same turbidity the chemical dosage required may vary widely because of other factors such a pH, temperature, alkalinity etc also influence the dosage. dosage vs. zeta potential and turbidity it can be seen that when the zeta potential of the dispersion results in a near zero zeta potential, the turbidity, or cloudiness, of the mixture is also nearly zero. Ferric chloride and ACH were observed to obtain the highest DOC (85% and 70%, respectively) and color (98% and 97%, respectively) removals at the lowest dose concentrations (120 mg/L and 100 mg/L, respectively). Beaker, burette, pipette. High … S. Dose of Aluminium Concn. Calculate the followings: 1. Although effective, inorganic coagulants have several disadvantages, there has been a concern about the relation between aluminum residuals in treated water and Alzheimer … 6-Discussion: Coagulation units require precise dosage control in order to remain effective. Reaction between alum and natural constituents of various waters are influenced by many factors, so it is impossible to determine accurately the amount of alum that will react with a given amount of alkalinity. Initial turbidities of water samples were adjusted to be 10, 50, 100, 200, 500 and 1000 NTU. Assume that the sludge has a specific gravity of 1.011 ( at 4 °C ) 13. Finally, the turbidity removal efficiency decreased when the FCE dose was more than 2 mg/L . Turbidity vs Alum Dose It can be seen from the graph that as we increase the alum dose, turbidity decreases till a particular dose, after which if we increase the dose further, turbidity starts increasing. 10mg/L Alum Dose, 40.6, Addition of 10mg/l of alum dose removed 13.61% or turbid. To further reduce the fluoride to 1.0 mg/l, a dosage of 12 mg Al per mg fluoride removed was required. For example, to reduce fluoride from 3.6 mg/l to 1.8 mg/l, the aluminum dosage was 18 mg/l as Al, or 10 mg Al per mg fluoride removed, at an optimum pH of 6.5. In this experiment optimum doses are 20mg/l 30mg/l 3. The volume of sludge produced per MGD if it is collected at 2% solids. The performance was studied with respect to turbidity removal, concentration of residual aluminium and comparative cost of coagulants for treatment of Bhima river water. Residual Aluminium with PAC/alum. 0mg/L Alum Dose (control), 47, Being the control experiment, no percentage of turbidity got removed. 3. 150 35 25 71.4 2. Coagulation in combination with flocculation and sedimentation (SUVA) was calculated by the following equation: x (1) investigated by using a synthetic turbid pH 7. The best performance of alum in removing turbidity from water was obtained at pH 7 following by pH 6. On one hand, at a lower coagulant concentration, its long chain adsorbed on the surface of one colloid particle was adsorbed onto the surfaces of the others, and thus two or more particles aggregated by bridging flocculation. The initial dosage of the coagulants was found to be for femc chloride 7.01 mg, ferrous sulphate 8.93 mg, and for aluminum sulphate 6.54 mg. and a number of commercial brands of … The turbidity and the % solid removal were Turbidity removal as a function of aluminium sulfate dose at pH range of 4-8 (a-f). Trivalent Al charge attracts neg – particles 2. However it should be considered that coagulation with alum may … Repeat steps 1-10 with higher dose of alum, if necessary. In bulk water treatment, the jar tests are repeated with varied alum dose until the ideal dose is found. 4. +31. Alum dose and pH control of coagulation were found to be important factors go-verning DOM removal. An enhanced coagulation with alum was then conducted by standard jar test to optimize coagulation pH and alum dose. 2. Velocity gradient vs turbidity As the velocity gradient increases, … 14. In other words, results showed that alum … They found the following relationship. 550 40 35 87.5 3. Optimum removal of turbidity (98%) and dissolved organic carbon (DOC) (70%) was achieved for 100 mg alum L-1 at pH 5. Both alum and ferric chloride demonstrated excellent removal of suspended solids from initial TSS values of approximately 100–10 mg/l at a dosage of 90 mg/l. A raw water supply is treated with an alum dosage of 25 mg/L. For example, to treat muddy water like that from the Mississippi, even … However, this classification may be somewhat different in other texts. Application of higher alum dosage range may improve turbidity removal from relatively high turbidity waters. From the results, it can be seen that there is not much significant Select the optimum dosage on the basis of supernatant clarity and settleability of floc with secondary considerations to cost and sludge production. However, … Find the pH of the sample and adjust it to 6 to 8.5. Inorganic coagulants include those commonly used chemicals that relay on aluminium or iron. Optimum turbidity removal was achieved with a 60 mg/l dosage for both alum and ferric chloride. The dosage of alum, which represents least turbidity, gives Optimum Coagulant Dosage (O.C.D.). Reagents required: Alum solution (1 ml containing 10 mg of alum) Procedure : 1. Organic coagulants include the so called poly DADMAC (polydiallydimethyl ammonium chloride) range … These particles are attracted to the positive charges created by aluminum hydroxides. Experimental results suggested that turbidity removal performance varied according to the following … You cannot say that simply without knowing the characteristics of the water under consideration. Ideal pH range … Iron coagulants can be used successfully over the much broader pH range of 5.0 to 11.0. Dosage is generally around 25 mg/L. Optimum removal of turbidity (98%) and dissolved organic carbon (DOC) (70%) was achieved for 100 mg alum L-1 at pH 5. The relationship for turbidities less than 100 NTU can also be expressed as. In this technology, guidelines for dose calculation and application are lacking. dosage is comparable to 10ppm of alum dosage • This implies, dosage of PAC will be only 30% of that of alum dosage. 1. 4. The chemical reactions between the water's … Resultant pH after treatment No. Sample ID, Turbidity (FAU) and Remarks: Tap water, 0.91, Tap water is distilled hence a minimal amount of turbidity. 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