Coagulation and Flocculation Essay

1.0 inductionIn this lab, we are conducting two experiments on inwrought surface water. The first experiment is to conduct quiver tests to estimate an optimal dosage of iron coarseness to remove suspended solids. The seconds experiment is to observe the come in of floc formation nad depositionation.2.0 Background curdling and Flocculation clotting and flocculation are important part in water and wastewater intercession. Coagulation is the destabilization of particulate outcome matter by physical or chemical processes. Flocculation is the formation of larger instalments that will settle out of the response. They are usually the first form of treatment of water and wastewater to remove suspended matter or color. oscillate tests are apply as a control test for plant operations. aluminium or iron salts can be used to for coagulation of particles and to form flocs that can settle out. Coagulation and flocculation tests provide the optimum dosages to remove turbidity and co lor, along with secondary effects such as adjusting pH. Jar tests besides provide information on the make out of energy needed to provide the coagulation and flocculation treatments, as well as settleability of the flocs, and clarity of the water. They can also be used to study basic processes, for instance, dynamics of reactions and removal of constituents.3.0 ProcedureDetermination of Optimum coagulator DosageTo determine the optimum coagulation dosage, a series of jar tests were conducted. First, 400 mL of body and sodium bicarbonate amended DI water was calculated and poured into a 500 mL Erlenmeyer flask exploitation a graduated cylinder. The initial pH of that judge was hence measured and enter. The predetermined dose of coagulator was poured into a light speedmL graduated cylinder and DI water was added to blow over a total solution volume of 100 mL. A stir bar was added to the Erlenmeyer flask along with the coagulant dose. The flask was because located on a ma gnetic stir plate was speedily mixed for one(a) smooth.After a minute of rapid concoction, the speed was reduced to low and the solution underwent slow mixing for ten minutes. The flask was then removed from the magnetic plate and was allowed to settle. Samples were extracted from the top of the flask after five, ten, and cardinal minutes had elapsed employ a 10 mL sampling syringe. especial(a) care was taken to not disturb the sediment while sampling. The sample was transferred from the syringe to a vile, shaken, and placed in a Turbidimeter to determine the turbidity.The turbidity was recorded and the vile was emptied and rinsed between each sample. After fifteen minutes had elapsed and the last turbidity training had been recorded, the pH of the sample was measured and recorded. The sample was then dumped into a specified waste container, the flask was rinsed with stop water and DI water, and the entire experiment was repeated employ a new specified coagulant dose.4.0 R esults and treatmentAfter plotting turbidity against dosage from our results, we found that the optimum dosage of coagulant to be 1000 mg/L Fe2O3 as shown in Figure 1. Also, long-term settling times produced lower levels of turbidity, with 15 minutes being most successful. Optimum pH for a coagulant is determined empirically from laboratory interrogatory by keeping dosage constant and scrutiny a pH range for optimal coagulation. by and large after adding Fe2O3, final pH decreased. Although we did not carry out this in the lab, our samples had best success with a pH around 6.5 as seen in Table 1. blend speed is also important in coagulation and flocculation. Initially flash mixing is used, where high mixing speeds disperse the coagulant evenly throughout the container. Later, sulky mixing speeds are used to promote particle collisions, which lead to larger floc formations. The lab is performed this bureau because higher speeds will help disperse the coagulant but will break u p the flocs that form. By reducing the speed to slow after one minute, it allows for an even dispersion but also the formation of flocs.