Physical Chemical Treatment Of Stabilized Leachate Using Limestone, Activated Carbon And Zeolite
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Date
2007-04
Authors
Ahmed El-Arabi Mohammed Abu Foul
Journal Title
Journal ISSN
Volume Title
Publisher
Universiti Sains Malaysia
Abstract
Leachate generated from Larut Matang landfill in Taiping was characterized.
Colour, COD, iron and ammoniacal nitrogen were found to be high. The
potential use of activated carbon, limestone and zeolite and their possible
mixtures as an adsorbent was investigated in this research. Influence of shaking
speed and contact time was studied. The adsorption isotherms and the kinetics
constants were determined. The batch experiments demonstrated that both
combine mixtures of activated carbon with zeolite at 15:25 (by volume) and
activated carbon with limestone and zeolite at 15:10:15 (by volume) gave the
best results with removal efficiencies more than 90% for colour and ironi 85%
for COD, 80% for ammoniacal nitrogen at shaking speed of 350 rpm and
contact time of 4 hours. Both Langmuir and Freundlich isotherms fitted well to
the experimental data with correlation coefficient more than 93%. The mixtures
yielded adsorption capacity of 522.19, 232.56, 52.63, 21.01 (mg/g) and SOO,
200, 50, 20.20 (mg/g) for colour, COD, iron and ammoniacal nitrogen,
respectively. The kinetic results showed that the data fitted well with the pseudo
second order equation with correlation approaching unity for all parameters in
all experiments implying that the rate limiting step may be chemisorption. The
regeneration experiments showed that 0.2 M HN03 can be used to regenerate
activate carbon and 0.2 M HCI and NaCI mixture and regenerate zeolite, with
regeneration more than 80% in most cases. Results of the continuous flow
experiments for both mixtures indicated that removal can reach up to 50-90% of colour. 70-90% of COD. 85-90% of iron and 50-90% of ammoniacal nitrogen in
the first 10 days of the experiments. The results indicated that the arrangement
of layers of adsorption media inside the column is not significant. The results
also showed that it was possible to treat about 800 m3 of leachate at flow rate of
15.92 Umin for 35 days. before the ratio C/Co exceeded 0.1. by using four filters
connected in series each with an area of 6.25 m2• and a height of 3 m. It can be
concluded from the research that the activated carbon-limestone-zeolite and
activated carbon-zeolite mixtures media exhibited better results for all
parameters as compared with the use of individual media.
Description
Keywords
Engineering