Publication: Coagulation-flocculation process by tin tetrachloride (sncl4), rubber seed, polyacrylamide (pam) and sedifloc in landfill leachate treatment
Loading...
Date
2023-09-01
Authors
Siti Fatihah Binti Ramli
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
The goal of this study is to assess the effectiveness of tin tetrachloride (SnCl4), rubber seed (RS), polyacrylamide (PAM), and Sedifloc as coagulants/coagulant aids for the removal of colour, COD, suspended solids (SS), and UV254 from high strength leachate. Divalent and trivalent metal-based coagulants were the primary focus of earlier research on leachate treatment. Tetravalent coagulants have not yet been extensively studied for application in leachate treatment. The same case goes for RS, PAM and Sedifloc. There are no reported studies to date on the use of RS for the treatment of high-strength leachate. The leachate samples in this study were collected from the aged Alor Pongsu landfill site located in Alor Pongsu, Perak, Malaysia and multi-series of coagulation-flocculation experiments were conducted in standard jar test procedures. The results found that, the optimum condition for SnCl4, RS, PAM and Sedifloc when used alone was rapid mixing of 220rpm-4 minutes, 120 rpm-10 minutes, 180 rpm-8 minutes,220 rpm-8 minutes; slow mixing of 60 rpm-30 minutes, 60 rpm-20 minutes, 60 rpm-30 minutes, 60 rpm-20 minutes; settlement time of 40-45 minutes; optimum dosage (10,000 mg/L, 6000 mg/L, 1000 mg/L, 500 mg/L); optimum pH (pH 8, pH 3, pH 2, pH 2), respectively. When SnCl4 was used alone, the removals obtained for colour, SS, COD and UV254 were 98.9%, 100%, 74.5%, and 95.7%, respectively. However, RS, PAM and Sedifloc were found ineffective when used alone. When used as the coagulant aid, the obtained removal percentages were comparable to SnCl4 alone. The dosage of SnCl4 was reduced from 10,000 mg/L to 8,000 mg/L when RS was used as a coagulant aid and to 6000 mg/L with the usage of PAM and Sedifloc. Characteristics of the sludge supported that the main mechanism involved for SnCl4 was charge neutralization and bridging for RS, PAM and Sedifloc. It was also found that the functional groups such as amine, carboxyl and hydroxyl are the active functional groups components that are responsible for the effective coagulation and flocculation activities. It was found from the study that 6000 mg/L SnCl4 in the presence of 100 mg/L Sedifloc is the best option in removing pollutants in leachate and also improves the characteristics of sludge after the treatment. Therefore, SnCl4 use in conjunction with Sedifloc was chosen as the best condition for the treatment of Alor Pongsu and other equivalent leachates.