Relating climatic parameters with leachate chemistry and its association with river water quality
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Date
2015
Journal Title
Journal ISSN
Volume Title
Publisher
Uva Wellassa University of Sri Lanka
Abstract
Increased solid waste generation due to rapid urbanization and industrialization is a major problem
in the world (Golomeova et al. 2013). .Landfilling is the most common disposal method of
municipal solid waste (MSW) in developing countries, even though majority of these landfills are
not properly managed, and pose a serious threat to the environment due to leachate run-off which
contaminates the nearby ground water and surface water bodies (Kjeldsen 1993).
The quantity and quality of leachate is influenced by various factors and climatic conditions are
one of these governing factors (Chu et al. 1994; Johansen & Carlson 1976). Hence this study was
carried out focusing on the impact of climatic parameters on leachate quality and its association
with the Mahaweli river water quality which has not yet been further studied. Meantime two main
objectives were fulfilled during the process of reaching the main target. They were, investigating
seasonal variation of leachate chemistry and Mahaweli river water quality and developing
correlation between climatic parameters, leachate chemistry and Mahaweli river water quality.
Materials and methods
Landfill leachate ,river water samples and ground water samples were collected from the leachate
drain of the Gohagoda landfill, four locations along the Mahaweli river- two upstream and two
downstream points from where leachate drain to the river and from two wells within the landfill.
Weekly sampling was carried out for a period of two months and sample preservation, storage and
analysis were performed according to Standard Methods (APHA, 1999). Daily temperature and
rainfall data were collected from Horticultural Crop Research and Development Institute
(HORDI) Gannoruwa and the statistical computations were performed with MINITAB version
17.0.
Results and Discussion
All the measured leachate and water quality data are summarized in Table 1.As the first step,
primary leachate characteristic values were being compared with the past studies (Wijesekara et
al.) and with the recommended standards of tolerance limits for discharge of effluent for inland
surface waters by the Central Environmental Authority (CEA). Alkaline pH value represented the
methanogenic stage of the landfill(More than 10y of operation) and exceed the CEA value. TDS
and EC values of the leachate were very high (1.33× 10 mg/L & 2.05×10 µs/cm) compared to
other sites. Dissolved Oxygen showed a very low value (0.09 mg/L) at the leachate drain owing
to the anaerobic conditions and oxidisable organic matter related components are measured as
BOD and COD. Both of these components were exceeding the CEA values. BOD:COD ratio was
stated as 0.911 representing acidogenic condition which contrast with the above results. It is
obvious that the uncontrolled dumping of the waste can produce leachate with various ages due to
the irregular degradation pattern of the refuse material.(Wijesekara et al).
Description
Keywords
Mineral Sciences, Materials Sciences, Science and Technology, Water quality, Climate, Chemistry