Performance of Palm Kernel Shell as Nitrification Media for Aquaculture Wastewater at Varying Drying Time
Performance of palm kernel shell, a local (agricultural waste) material as biofilter media was investigated in comparison with a commonly used synthetic injection-moulded polypropylene bioblock. Wastewater was obtained from integrated fish culture. The biofilter media was inoculated with the wastewater and the experiment started after 24 hrs (drying time) of inoculation. The experiment was repeated for 72 and 144 hrs drying times. Water quality parameters measured were Temperature, pH, Dissolved oxygen (DO), Total ammonia-nitrogen (TAN), Nitrite-nitrogen and Nitrate-nitrogen. The efficiency of the biofilter was assessed using Percentage total ammonia-nitrogen removed (PTR) and Volumetric total ammonia nitrogen conversion rate (VTR). All the selected water quality parameters measured were within the range for fish culture and discharge to the environment. The highest PTR of 50.00±0.00% was recorded in PK at 72 hrs and the least (33.75±14.43%) was recorded in PP at 144 hrs drying time. The PK had higher VTR at all the drying time with the highest VTR of 264.76±12.53mgTAN/m3d at 72 hrs drying time while the least VTR of 120.39±104.42 mgTAN/m3d was recorded in PP also at 72 hrs drying time. The difference in VTR was significant between the two media only at 72 hrs drying time and between 24 hrs and 72 hrs drying time in PK. The two media were able to remove TAN from the effluent at all the drying time. The locally available PK is better than PP at all the drying and is also available at a cheaper cost.
