Volume No. 2 Issue No.: 2 Page No.: 101-110 October-December 200

 

TREATMENT OF SEMI-AEROBIC LEACHATE BY COMBINED COAGULATION-FLOCCULATION AND FILTRATION METHOD

 

Zawawi Daud*1, Hamidi Abdul Aziz and Mohd Nordin Adlan2

1. Faculty of Civil and Environmental Engineering, Universiti Tun Hussein Onn Malaysia, 86400 Parit Raja, Batu Pahat, Johor, (Malaysia)
2. School of Civil Engineering, Universiti Sains Malaysia, 14300 Nibong Tebal, Penang, (Malaysia)

 

Received on : August 20, 2007

 

ABSTRACT

 

Landfill leachate is a complexed wastewater and its composition and concentration of contaminants are influenced by many factors such as the type of waste disposited and the age of landfill. To date many research works have been undertaken on leachate treatment and a lot of focus has been given on the integrated approach. An integrated technique consisted of filtration by limestone-zeolite followed by coagulation-flocculation processes was presented in this paper aiming to provide an efficient method for the treatment of semi-aerobic leachate containing high colour and COD concentrations. The landfill leachate used in this study was taken from the Pulau Burung Landfill Site (PBLS), which is located in Penang, Malaysia. The concentrations of colour and COD were 3310 Pt.Co and 2120 mg/L respectively at this site and these two parameters were among the most problematic to the landfill operators. The application of filtration by a mixture of limestone-zeolite (15:25 ratio by volume) and filtration rate = 0.0025 m3/m2.minute showed that about 45% and 35% of colour and COD were removed, respectively after 10 days of experiments. The subsequent treatment by coagulation-flocculation using polyaluminum chloride (PAC) as coagulant indicated that the removals of colour and COD of up to 93% and 56% respectively were achieved at optimum dosage of 2000 mg/L. Results indicated that the filtration by a mixture of limestone-zeolite (15:25) followed by coagulation-flocculation at optimum dosage of 800 mg/L PAC, was efficient to reduce colour and COD to 99% and 70% respectively.

 

Keywords : Semi-aerobic leachate, Landfill, Limestone, Zeolite, Coagulation, Polyaluminum chloride, Aluminum sulfate

 

 

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