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Semi-continuous anaerobic
treatment of fresh leachate from
municipal
solid
waste transfer station
S. M. D. Ghasimi1, A. Idris1, T. G.
Chuah1, 2 and B. T. Tey1*
1Department
of Chemical and Environmental Engineering, Faculty of
Engineering, Universiti Putra Malaysia, 43400
UPM
Serdang,
Selangor,
Malaysia.
2Institute
of Tropical Forestry and Forest Products (INTROP),
Universiti Putra Malaysia, 43400
UPM
Serdang,
Selangor,
Malaysia.
*Corresponding author.
E-mail:
btey@eng.upm.edu.my.
Tel: +
603-8946 6289. Fax: +603- 8656 7120.
Nomenclatures: BOD,
Biochemical oxygen demand; BOD5,
biochemical oxygen demand using a 5-day test; COD,
chemical oxygen demand; BOD/COD, biodegradability;
HAc, acetic acid; HBr, butyric acid; HPr,
propionic acid; MSW, municipal solid waste; NH3-N,
ammonia nitrogen; PO4-3,
phosphate; SMP, soluble microbial product; TBTS,
Taman Beringin Transfer Station; TVFA, total volatile
fatty acid; VFA, volatile fatty acid; and VSS,
volatile suspended solids.
Accepted
15 April, 2009 |
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A
semi-continuous leachate treatment process was developed in
the present study. The fresh leachate was obtained from a municipal
solid waste transfer station
and palm
oil mill effluent (POME) sludge was used as sources of
anaerobic microbial complex. The semi-continuous treatment
of leachate was operated in two phases; in Phase 1, the pH
of the bioreactor was not adjusted, and in Phase 2, the pH
of the bioreactor was adjusted by the addition of sodium
hydroxide (NaOH).
The initial
values for both chemical oxygen demand (COD) and biochemical
oxygen demand (BOD5) of fresh leachate were
extremely high compared with the stabilized landfill
leachate. COD reduction rate for the semi-continuous process
for Phase 1 and 2
were 37 and
52.7%,
respectively.
These
results clearly showed that pH adjustment is
important to enhance the
COD removal
in
leachate
treatment. In addition, we have analysed the evolution of
volatile fatty acid (VFA)
in the entire treatment process. The results indicated that
the VFA
concentration was a rapid indicator of the reactor’s
stability.
Key words:
Anaerobic treatment,
semi-continuous leachate treatment, fresh leachate, pH, COD,
VFA. |
