A raw water supply is treated with an alum dosage of 25 mg/L. The performance was studied with respect to turbidity removal, concentration of residual aluminium and comparative cost of coagulants for treatment of Bhima river water. 550 40 35 87.5 3. Finally, the turbidity removal efficiency decreased when the FCE dose was more than 2 mg/L . Alum- (aluminum sulfate)-particles suspended in natural, untreated water normally carry a negative electrical charge. Reagents required: Alum solution (1 ml containing 10 mg of alum) Procedure : 1. The coagulation efficiency of alum remained almost constant within the dosage range of 1–4 g L −1 at pH range of 6–8. Organic coagulants include the so called poly DADMAC (polydiallydimethyl ammonium chloride) range … Velocity gradient vs turbidity As the velocity gradient increases, … 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. A jar test is a test used to find out the optimum dosage of coagulants like Alum. By the aid of jar test apparatus, we used various alum dosages from 0 and 200 mg/L. PACl (as 100%) was required for treatment of a coloured, low turbidity water (Otway region, Victoria) compared to similar performance obtained when using an alum dose of 55 mg/L, and ♦ the increase in chloride in the treated water is much lower than the sulphate increase from alum, resulting in lower overall increases in the TDS of the treated water. 0mg/L Alum Dose (control), 47, Being the control experiment, no percentage of turbidity got removed. Large amounts are often required. Observation 0 Results indicated that turbidity removal efficiency declined to some extent by increasing initial turbidity level from 100 to 200, 500, and 1000 NTU. Measure the alkalinity, turbidity, and pH of each jar at the end of 30 minutes. Settling-Velocity Distribution Curves for an Alum Dosage of 40 mg/l and Alum-Solution Concentrations of 100, … Flocculation and mixing speed played only a minor role in the removal efficiencies for both orthophosphates and suspended solids. You cannot say that simply without knowing the characteristics of the water under consideration. The relationship for turbidities less than 100 NTU can also be expressed as. Assume that the sludge has a specific gravity of 1.011 ( at 4 °C ) 13. It was also showed that humic substances are rather more removed by alum than the other DOC compounds [4]. Conclusion: The use of M. oleifera as a natural coagulant is … 2. For example, to treat muddy water like that from the Mississippi, even … 800 80 40 50.0 4. 3. Most of the time you can go for a Jar test. 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 dirtier the water, the more alum you need to feed. Turbidity removal as a function of aluminium sulfate dose at pH range of 4-8 (a-f). Abstract: Aluminum, Lime and iron coagulants are commonly used in most industries for many decades to coagulate particles in surface water also removing turbidity from the water prior to flocculation, sedimentation or filtration. Table 5. Comparative dose to bring down the turbidity to 5 NTU. Furthermore, after determining the optimum alum dosage for natural river water, the optimum pH value for color removal was studied by varying the range from 4.5 to 8.5. It was also showed that humic substances are rather more … 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. Residual turbidity NTU Alum dose mg/L Fig 2 Effect of alum dose on turbidiy removal of high turbid water pH = 7 initial turbidity = 5 2010, Alexandria, by the turbidity meter for different samples. Another ten jar tests were performed with and the average value was of the optimum dose was found to be 45 mg/L … Beaker, burette, pipette. Turbidity Alum Model. Both … 14. ^ A B C ^ 01234 01234 01234 Settling Velocity-cm/min Fig. Dosage is generally around 25 mg/L. Keywords: Turbidity, Optimum dose, Poly Aluminum Chloride (PACL), pH. Calculate the followings: 1. This phenomenon could be attributed to a couple of reasons. Clay. An enhanced coagulation with alum was then conducted by standard jar test to optimize coagulation pH and alum dose. Moreover, when M. oleifera and alum was used together with a 2:1 dosage ratio (alum at 80 mg/L and M. oleifera at 70 mg/L), they will remove COD, turbidity, and TSS by up to 50.41%, 86.14%, and 81.52% respectively. To treat excessively dirty water, simply increasing the alum isn’t going to do anything. Plot a graph with alum dosage along x-axis and turbidity along y-axis. Take 1000 ml of given sample in 6 beakers. (SUVA) was calculated by the following equation: x (1) investigated by using a synthetic turbid pH 7. and alum dose. Ideal pH range … These particles are not visible but a … The turbidity and the % solid removal were However, this classification may be somewhat different in other texts. Two students in CEE 453 (Kim Wilson and Morgan Rog, 2005) measured the optimal alum dose for kaolin suspensions in Cornell tap water. From the results, it can be seen that there is not much significant +31. alum dose (mg/L) = a + b*log(turbidity). Also, alum at 40 mg/L removed COD, turbidity, and TSS by 51.72%, 92.16%, and 85.26% respectively from the refinery wastewater. Alum / lime 25 15 3094 94 95 30 95 Figure 3 – plot of turbidity removal efficiency Vs coagulant dosage B. pH The pH ranges from 6.4 to 7.4 as shown in table 3 which shows neutral condition of the polluted water. Residual Aluminium with PAC/alum. This may require either chlorine addition or pH adjustment. Turbidity meter. dosage is comparable to 10ppm of alum dosage • This implies, dosage of PAC will be only 30% of that of alum dosage. and a number of commercial brands of … 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. substance with different alum dosage to compare the removal efficiency of both humic substances and turbidity in either cases. The respective initial dosages were used in order to determine the optimum pH for each coagulant. Experimental results suggested that turbidity removal performance varied according to the following … 150 35 25 71.4 2. The performances of these … 4. The amount of alum required to treat a flow of 1 MGD(million gallon /day) 2. 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. Materials Tap water. Iron Salts Less … Based on what we found in … which settled very quickly. Theoretically 1 mg/L of alum reacts with 0.45 mg/L of natural alkalinity expressed as CaCo3 0.30 mg/L of 85% quicklime as CaO , and 0.35 mg/L of 95% hydrated lime as Ca(OH)3′ Alum is generally fed in … 10mg/L Alum Dose, 40.6, Addition of 10mg/l of alum dose removed 13.61% or turbid. NTU mg/L mg/L against % Alum Consumption 1. 2200 65 40 61.5 Table 6. In bulk water treatment, the jar tests are repeated with varied alum dose until the ideal dose is found. In other words, results showed that alum … Ferric sulfate was effective at DOC removal but required a higher concentration of coagulant and was the least effective coagulant at … Algal Removal by Alum Coagulation by S. D. Lin, R. L. Evans, and D. B. Beuscher SUMMARY Twenty-five samples of Illinois River water were subjected to the coagulation process using … Iron coagulants can be used successfully over the much broader pH range of 5.0 to 11.0. Alum dose and pH control of coagulation were found to be important factors governing DOM removal. Application of higher alum dosage range may improve turbidity removal from relatively high turbidity waters. The volume of sludge produced per MGD if it is collected at 2% solids. Alum dose and pH control of coagulation were found to be important factors go-verning DOM removal. Impacted by mixing, alkalinity, turbidity and temp. If ferrous compounds are used, oxidation to ferric iron is needed for complete precipitation. Some characteristics of observed algae 20 . Aluminum dosages are generally high for appreciable fluoride removals. S. Dose of Aluminium Concn. However, … Find the residual turbidity of the supernatant using nephelometer. The dosage of alum, which represents least turbidity, gives Optimum Coagulant Dosage (O.C.D.). From Table 1, it will be noted that polyaluminium … Coagulation in combination with flocculation and sedimentation Optimum turbidity removal was achieved with a 60 mg/l dosage for both alum and ferric chloride. Alum has a demand for hydroxide and alkalinity and only works within a certain pH range. Residual Turbidity vs Alum-Solution Concentration at Alum Dosages of 40, 50, and 60 mg/l A- lime added 30 s after alum; B-lime added with alum; and C-lime added 30 s before alum. Select the optimum dosage on the basis of supernatant clarity and settleability of floc with secondary considerations to cost and sludge production. Inorganic coagulants include those commonly used chemicals that relay on aluminium or iron. To further reduce the fluoride to 1.0 mg/l, a dosage of 12 mg Al per mg fluoride removed was required. Genera removal vs alum dosage 5 Algae and turbidity removal 6 Factors influencing algal removal 8 References 9 Appendix A. Algal counts for runs 1 through 25 11 Appendix B. Activated carbon. Sample taken 2.5 cm below surface after 20 min settling. The study on the performance of different coagulants in water treatment was carried out using coagulants such as alum(C1), Poly aluminium chloride(PAC)(C2) and sodium aluminate(C3). pH and coagulant dose were developed and evaluated. S. Turbidity Alum PAC % PAC Consumption No. Introduction Turbidity is one of the important physical parameters of water that representing the amount of suspended solids, (Kawamura, 2000; Daneshvar, 2009). Download our Water Treatment Plant Diagram … They found the following relationship. Sample ID, Turbidity (FAU) and Remarks: Tap water, 0.91, Tap water is distilled hence a minimal amount of turbidity. The chemical reactions between the water's … The turbidity value is proportional to the amount of colloid and suspended solids in water that cannot be deposited in usual ways. Initial turbidities of water samples were adjusted to be 10, 50, 100, 200, 500 and 1000 NTU. 3. 1. Find the pH of the sample and adjust it to 6 to 8.5. Analysis of zeta potential vs. coagulant dosage results are used to evaluate the effectiveness of various chemicals (typical examples are alum, ferric sulfate, etc.) The fractionation and measurement of residual aluminum was conducted during the treatment of humic (HA)-kaolin synthetic water with Al(2)(SO(4))(3), AlCl(3) and polyaluminum chloride (PAC) in order to investigate the effect of pH on the coagulation performance as well as residual aluminum speciation. The optimum alum dosage was lower (1 g L −1) which was the lowest required dosage obtained the highest turbidity removal. … Resultant pH after treatment No. function of aluminum sulfate dose at pH range of 4-8. In this technology, guidelines for dose calculation and application are lacking. Coagulants are classified as being inorganic or organic. Now add 1 ml, 2 ml, 4 ml, 8 ml, 10 ml, 12 ml of alum respectively in each one of the beakers. In this experiment optimum doses are 20mg/l 30mg/l 3. 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. The best performance of alum in removing turbidity from water was obtained at pH 7 following by pH 6. Optimum removal of turbidity (98%) and dissolved organic carbon (DOC) (70%) was achieved for 100 mg alum L-1 at pH 5. Trivalent Al charge attracts neg – particles 2. Through charge neutralization and flocculation in raw water, alum removes: Turbidity; Suspended solids; Total organic carbon (TOC) Biochemical oxygen demand (BOD) Aluminum Sulfate easily hydrolyzes to form insoluble precipitates which aid in removal of tiny particles that cannot be easily filtered and/or are too small to settle via gravity in a useful period of time. Repeat steps 1-10 with higher dose of alum, if necessary. 3. 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. Once you feed a certain amount of alum, it essentially quits working. As these are critical to drinking water treatment, … 6-Discussion: Coagulation units require precise dosage control in order to remain effective. Although effective, inorganic coagulants have several disadvantages, there has been a concern about the relation between aluminum residuals in treated water and Alzheimer … 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. These particles are attracted to the positive charges created by aluminum hydroxides. That dose at which turbidity is minimum is the optimum dose for coagulation. 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). High … However it should be considered that coagulation with alum may … 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. Optimum removal of turbidity (98%) and dissolved organic carbon (DOC) (70%) was achieved for 100 mg alum L-1 at pH 5. The amount of natural alkalinity required to react with the alum added in terms of CaCO 3 3. 2. With aluminum sulfate, optimum coagulation efficiency and minimum floc solubility normally occur at pH 6.0 to 7.0. 2. 0 2 4 6 8 10 12 14 0 20 40 60 80 100 120 140 160 180 Turbidity variations vs Alum coagulant dosage Alum coagulant A Alum coagulant B Coagulant (mg/l) Turbidity (NTU) Figure 2: Variation of turbidity in different jars for both sample, A and B using Alum coagulant. In-line coagulant injection facility is an innovative application technology in restoring Eutrophic lakes. 4. Forms flocs of aluminum hydroxide (AlOH 3). 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