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. The volume of sludge produced per MGD if it is collected at 2% solids. (SUVA) was calculated by the following equation: x (1) investigated by using a synthetic turbid pH 7. function of aluminum sulfate dose at pH range of 4-8. The dosage of alum, which represents least turbidity, gives Optimum Coagulant Dosage (O.C.D.). Beaker, burette, pipette. Based on what we found in … 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. Alum dose and pH control of coagulation were found to be important factors go-verning DOM removal. Flocculation and mixing speed played only a minor role in the removal efficiencies for both orthophosphates and suspended solids. Table 5. Organic coagulants include the so called poly DADMAC (polydiallydimethyl ammonium chloride) range … It was also showed that humic substances are rather more … NTU mg/L mg/L against % Alum Consumption 1. 10mg/L Alum Dose, 40.6, Addition of 10mg/l of alum dose removed 13.61% or turbid. If ferrous compounds are used, oxidation to ferric iron is needed for complete precipitation. Turbidity removal as a function of aluminium sulfate dose at pH range of 4-8 (a-f). Also, alum at 40 mg/L removed COD, turbidity, and TSS by 51.72%, 92.16%, and 85.26% respectively from the refinery wastewater. 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. The respective initial dosages were used in order to determine the optimum pH for each coagulant. Inorganic coagulants include those commonly used chemicals that relay on aluminium or iron. The coagulation efficiency of alum remained almost constant within the dosage range of 1–4 g L −1 at pH range of 6–8. 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. Now add 1 ml, 2 ml, 4 ml, 8 ml, 10 ml, 12 ml of alum respectively in each one of the beakers. Sample taken 2.5 cm below surface after 20 min settling. 3. Dosage is generally around 25 mg/L. A raw water supply is treated with an alum dosage of 25 mg/L. ^ A B C ^ 01234 01234 01234 Settling Velocity-cm/min Fig. Forms flocs of aluminum hydroxide (AlOH 3). 0 Results indicated that turbidity removal efficiency declined to some extent by increasing initial turbidity level from 100 to 200, 500, and 1000 NTU. 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). Large amounts are often required. Analysis of zeta potential vs. coagulant dosage results are used to evaluate the effectiveness of various chemicals (typical examples are alum, ferric sulfate, etc.) Repeat steps 1-10 with higher dose of alum, if necessary. 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. Turbidity meter. 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. Another ten jar tests were performed with and the average value was of the optimum dose was found to be 45 mg/L … +31. Some characteristics of observed algae 20 . Iron coagulants can be used successfully over the much broader pH range of 5.0 to 11.0. Once you feed a certain amount of alum, it essentially quits working. 2200 65 40 61.5 Table 6. 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