Global Journal of Human-Social Science, B: Geography, Environmental Science and Disaster Management, Volume 22 Issue 3

b) Sampling Procedures Leachate: Leachate samples were collected from Saje dump site (figure 1) in Abeokuta, Ogun State during wet and dry seasons using standard methods. Samples were collected in 15 L plastic containers, transported to the laboratory and stored in a refrigerator at 4°C. The samples were removed from the refrigerator and left under room temperature for at least 2 hours. Then, the samples were thoroughly stirred to agitate settled solids before any tests were conducted on the leachate samples. Figure 2: Leachate collection point from Saje dumpsite c) Reagents In this study, Ferric Chloride (FeCl 3 .6H 2 O), Ferrous Sulphate (Fe(SO 4 ).7H 2 O) and Aluminum Chloride (Al 2 (SO 4 ) 3 .18H 2 O) were used as inorganic coagulants. Moringa oleifera Seed (MOS) was used as organic coagulant. MOS 10% Stock solution was prepared daily by dissolving 30g of MOS powder into 270ml of distilled water, and the solution was well mixed. d) Analysis Techniques The physical and chemical parameters were determined using APHA Standard Methods (2005) for testing water and waste water. pH was assessed by glass electrode method with a calibrated pH meter, while temperature EC and TDS was determined using HM Digital Meter COM-100. Total alkalinity, total hardness, Acidity, chloride, were determined by titrimetric method. A total suspended solid was determined by gravimetric method. Chemical oxygen demand (COD) was determined by open reflux method. Nitrate Phosphate and Sulphate were measured by UV-Visible spectrophotometer. The heavy metal analysis was carried out using Atomic Absorption Spectrophotometer (AAS) Model 210 VGP of the Buck Scientific AAS series. e) Experimental Procedure Chemical coagulation was performed using beakers and stirrer as Jar test apparatus. The experimental process consisted of three subsequent stages: initial rapid mixing at 160 rpm for 10 min, followed by slow mixing for 20 min at 30 rpm, the final settling time for 1 h. First, the optimum pH was determined by varying the pH of the sample using HCl and NaOH at constant coagulant concentration. The pH with the highest removal efficiency was the optimum pH. About 2L beakers of equal volume were used to examine the different coagulants at their respective optimum pH. A known mass of (1g, 2g, 3g, 4g and 5g) of each coagulants was added to a jar containing 1liter of leachate samples at optimum pH using the jar test procedure. To determine the efficiency of coagulant dose, the supernatant was withdrawn by using a pipette from a point about 2 cm below the top of liquid level of the beaker and the supernatant was assessed for TSS, COD, Mn, Pb and Cr. f) Data Analysis Data collected were evaluated for descriptive and inferential statistics using the Statistical Package for Social Sciences (SPSS) for windows version 20.The removal efficiency (RE) of the coagulants was determined for each parameter by using the equation: RE (%)= Where, C i and C t are the initial and final concentrations of the parameters. © 2022 Global Journals Volume XXII Issue III Version I 57 ( ) Global Journal of Human Social Science - Year 2022 B Abatement of Polluting Effects of Waste Dump Leachates using Different Coagulants