International Journal of Water Resources and Environmental Engineering Vol. 2(4), pp. 79-86, June 2010
Available online at http://www.academicjournals.org/ijwree
©2010 Academic Journals
Full Length Research Paper
Comparison of pollutant levels in effluent from
wastewater treatment plants in Blantyre, Malawi
Victor Chipofya
1
*, Andrzej Kraslawski
2
and Yury Avramenko
2
1
Centre for Water, Sanitation, Health and Appropriate Technology Development(WASHTED), University of Malawi – The
Polytechnic, P/Bag 303, Blantyre 3, Malawi.
2
Department of Chemical Technology, Lappeenranta University of Technology, P. O. Box 20, FI-53851, Lappeenranta,
Finland.
Accepted 19 February, 2010
In Malawi, the requirement to treat wastewater is underscored by the existing regulatory framework,
institutional arrangements, and policy guidelines. In addition, formalized national effluent standards
exist. This study was conducted to determine the pollutant levels in effluent from municipal wastewater
treatment plants in the city of Blantyre, Malawi, and to compare these with Government of Malawi
standards and World Health Organisation (WHO) guidelines. Data on physicochemical characteristics of
the effluent was collected through a desk study. This study established that Biochemical Oxygen
Demand (BOD
5
) and Total Suspended Solids (TSS) levels in effluent from the three major wastewater
treatment works in the city are in most cases above the recommended Malawi standards and WHO
guidelines. Levels for heavy metals are all lower than the recommended standards except for Cadmium,
in the dry season effluent at Limbe wastewater treatment works. In view of the pollution threat posed by
the high levels of BOD
5
from the three works, the paper recommends that the assimilative capacity of
the receiving watercourses be ascertained to determine the impact of the organic and solids loading in
the final effluent upon the aquatic flora and fauna.
Key words: aquatic flora and fauna, effluent, municipal wastewater treatment, physicochemical characteristics.
INTRODUCTION
Polluted water needs to be dully treated in order to
minimize its negative effects on people, animals, birds,
and aquatic biota. Polluted water is unsuitable for
drinking, recreation, agriculture, and industry. It dimi-
nishes the aesthetic quality of surface water sources
(Kuyeli, 2007). In order to reduce the undesirable effects
of polluted water, it is necessary to treat it to meet the
consent requirements of effluent quality set by the
environmental regulatory agency (Banda, 2007). Waste-
water treatment is the engineering process that employs
physical, biological, and chemical processes to reduce
the concentration of pollutants found in wastewater to a
harmless or near-harmless level in the effluent (Banda,
2007). The National Sanitation Policy (NSP) (Malawi
Government, 2008) stipulates the need to improve
delivery of improved sanitation services. Some of the
*Corresponding author. E-mail: vchipofya@poly.ac.mw. Tel:
+265 888 878055. Fax: +265 1 870578.
strategies for accomplishing this objective include: (1) To
provide adequate wastewater disposal facilities at all
wastewater generation points and (2) To ensure ade-
quate provision of wastewater treatment and disposal
facilities for all new piped water supply connections. One
of the specific goals in the National Water Policy (NWP)
(Malawi Government, 2005) is to ensure water of
acceptable quality for all needs in Malawi. In addition,
formalized national effluent standards exist in Malawi
(Malawi Bureau of Standards, 2005). This study looked at
the pollutant levels in effluent from the three municipal
wastewater treatment plants in the city of Blantyre,
Malawi, and compared these with Government of Malawi
and WHO guidelines.
MATERIALS AND METHODS
Study area
The study focused on the three municipal wastewater treatment
plants in the city of Blantyre, Malawi, namely: Blantyre wastewater