IJA-2018v8n19 - page 9

International Journal of Aquaculture, 2018, Vol.8, No.19, 145-150
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increased phosphate level in fresh water may due to the higher phosphorus load to the fresh water during the
nutrient mineralization process from this supplemented fish feed (Kibria, 2014). Furthermore, higher phosphorus
load to the fresh water could lead to water pollution and turned water cloudy (Sharip and Suratman, 2017). The
phosphate level in aquaponic tanks (Outdoor fish tanks with plant) is lower compare to the tank without plant. The
possible reason for phosphate level decreased in aquaponic tank with growing basil was due to the phosphorus
present in the fresh water have been taken up by plants, since phosphorus was an essential macronutrient for
enhancing plant growth and development.
Table 1 The concentration of phosphate, ammonia and chlorine of water samples (Mean ±Standard Deviation, n=3) from outdoor
tank, indoor tank and planted tanks
Water sample sources
Concentration (mg/L)
pH
Phosphate
4.0±0.5
Ammonia
1.0±0.0
Chlorine
<2.0±0.0
Outdoor fish tank
7.2±0.2
Outdoor fish tank with plant
1.0±0.5
0.2±0.0
<2.0±0.0
7.0±0.3
Indoor fish tank
4.0±0.5
1.0±0.0
<2.0±0.0
7.0±0.2
Planted tanks
0.0±0.0
0.0±0.0
<2.0±0.0
7.3±0.2
Furthermore, Phosphorus is a nutrient source for growth of aquatic plants and animals in marine ecosystem.
Excessive phosphorus concentration can lead to nutrient pollution and eventually caused eutrophication. Methods
to manage phosphate pollution in a fish pond are mechanical dredging for removal of polluted sediments and pond
aeration that facilitate the decomposition process of organic matter and prevent accumulation of excess nutrients.
Besides, by adding phosphate removal additives such as Bentonite-lanthanum clay can reduce the dissolved
phosphate concentration (Kurzbaum et al., 2017). It can react with phosphate and formed a permeable layer when
settled out at the bottom of the pond. The layer would continue to bond with phosphorus as it released from the
polluted sediment.
For ammonia concentration, both indoor and outdoor fish tanks have 1.0 ± 0.0 mg/L ammonia whereas the
ammonia concentration for planted tank is 0 mg/L (Table 1). Tanks with fishes (Indoor and outdoor) have higher
ammonia concentration. This is due to the breakdown of fish metabolism including respiration, by-products as
well as excretion of urine and faeces. There is no fish present in the planted tank so no fish feed was provided.
Most of the particulate waste from the faecal waste of fish, uneaten fish feed, some organisms such as bacteria,
fungi, and algae will be accumulated in the aquaculture system (Rakocy et al., 2006). The ammonia released from
particulate waste after decomposition by microorganisms was reported to be toxic to plants and fish in aquaculture
system (Britto et al., 2002). These particulates waste may lower dissolved oxygen levels in water, turns water
cloudy. In aquaponic system, the nutrient and water utilization efficiency were enhanced and nitrification was in
place to oxidize ammonia to nitrite and followed with nitrate. Aquaponic system has been proved as an excellent
method for recycling phosphorus by maximizing the phosphorus removal efficiency and enhancing nutrient
utilization by fish and plants while yielding a high quality crop (Cerozi and Fitzsimmons, 2017).
Chlorine is greenish-yellow gases with a strong odour that can dissolve in the water. It combined with other
chemicals as disinfectants and kills microorganisms. Most of the chlorine enters river or lake and react with other
chemicals formed more stable compounds. Basically, chlorine gets into a natural water sources due to industrial
development, agriculture activities and chemical spills. It is widely used in wastewater treatment plant, food
processing systems and paper mill systems. One of the exposures of chlorine to natural water sources is effluent
from treated water system. When treated effluent released to receiving waters, there is still some free residual
chlorine present in the water. These free residual chlorines dissipate rapidly depend on the environmental factors
(US EPA, 1999). As for chlorine concentration, all tanks have the same concentration which is less than 2 mg/L.
Chlorine present in all tanks because of the water sources. Tank that is filled with tap water to compensate water
loses through condensation, will have chlorine present in the water as disinfectants to kill the microbes. However,
the concentration is acceptable up to 4 ppm (Wiant, 2010).
1,2,3,4,5,6,7,8 10,11,12
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