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Addis Ababa University Libraries Electronic Thesis and Dissertations: AAU-ETD! >
Faculty of Science >
Thesis - Environmental Sciences >
Please use this identifier to cite or link to this item:
http://hdl.handle.net/123456789/2269
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| Title: | ENVIRONMENTAL IMPACTS OF FLORICULTURE INDUSTRIES ON LAKE ZIWAY: WITH PARTICULAR REFERENCE TO WATER QUALITY |
| Authors: | Malefia, Tadele |
| Advisors: | Hammed Suliman /PhD/AAU/
Mekuria Argaw /PhD/AAU/ |
| Keywords: | Lake Ziway,
Floriculture industries,
water quality,
Farm effluent,
Water quality guidelines
waste water management |
| Copyright: | Jun-2009 |
| Date Added: | 3-May-2012 |
| Abstract: | ABSTRACT
Lake Ziway is one of the rift valley fresh water lakes. The Lake have long been used as source
of town’s water supply, small scale irrigation, bathing, animal watering, domestic water use,
fishery and eco-tourism .There is a lot of deliberation about floriculture industries located at
the shore discharging untreated effluent directly in to the lake; as a result excessive fertilizer
and pesticide residue from the farm is deteriorating the water quality as well as the aquatic
life. Therefore, this study was proposed with the objective of assessing the impact of
floriculture industries on the water quality. In order to do this, five sites were chosen on the
lake near the outlet of flower farms. The first site which was used as a control was located in
the upstream area before the effluent joins the lake water and the other four sites were at the
downstream. A total of 60 samples were tested for physicochemical, oxygen demanding,
nutrient and micronutrient parameters. The results were analyzed using SAS software to see if
there were significant differences between the control and impaired sites. In addition, the
results were also compared with water quality guidelines to check if the concentrations of
these parameters were within the permissible limits.EC,TDS,DO,BOD,COD,NO3
-,PO43-
,Na,Ca,Mg,k,Fe and Zn showed significant difference (P<0.05) between the control and
impaired sites; whereas Cu and Cr were below detection level. The result indicated higher
levels of TDS (272±9.38 to 574.5±176.5), EC (0.4164±0.044 to 1.358±6.38), PH (9.05±0.188
to 7.98±0.34), COD (92.75±3.38 to 126.8±5.79) BOD (16.8±1.11 to 22.9±7.42) NO3-
(1.68±2.524 to 50.8±18.43) andPO43-(0.5142±0.41 to 6.8±2.8) at the impaired sites where the
effluent was directly discharged without treatment. However, the concentrations of
physicochemical and micronutrient parameters were relatively low in sampling sites where
the effluent is treated by the farm to reduce the environmental impact before released in to the
lake. The levels of PH, EC, TDS, NO3-, PO43-, Na, Mg, K, Ca, BOD, COD & DO were
beyond WHO, FAO and US-EPA water quality guideline values for use as a raw public water
supply, irrigation, maintenance of fisheries and aquatic life respectively. In general, the water
quality of Lake Ziway has been threatened and becoming less suitable for the variety of
purposes being used. Actions should be taken before the once precious fresh water Lake turn
out to be seriously polluted. Environmental audit and waste water management could be
possible solutions to minimize the direct discharge of fertilizer rich effluents in to the lake. |
| URI: | http://hdl.handle.net/123456789/2269 |
| Appears in: | Thesis - Environmental Sciences
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