Performance of Wood Chips and Sugarcane Bagasse in Polishing Aquaculture Wastewater Using a Lab-Scale Modified Trickling Filter

Authors

  • Carolyne Ngerechi Eng
  • P. Njogu Jomo Kenyatta University of Agriculture and Technology
  • B. Karanja Jomo Kenyatta University of Agriculture and Technology
  • James Raude Jomo Kenyatta University of Agriculture and Technology

Keywords:

Waste water, Bioreactor, Hydraulic Retention Time (HRT)

Abstract

Aquaculture wastewater is characterized by high contaminant load responsible for pollution of water bodies, thus requiring quality correction. The goal of the study was to determine the most suitable substrate and optimal hydraulic retention times (HRTs) of modified trickling filters packed with wood chips and sugarcane bagasse in polishing aquaculture wastewater. Experimental research design was used to evaluate the performance of the substrates at different column heights and hydraulic retention times and a treatment capacity of batches of 12 liters. Reactor tank had perforated inlet pipes and were packed with respective substrate. The feed wastewater was fed into the system and treatment efficiency studied. Raw wastewater and Treated water Samples were sampled at different times and analyzed for Nitrates and Nitrites using a UV-VIS spectrometer (model 1800 Simadzu). The mean raw wastewater concentration was 208 ± 1.24 mg/L for Nitrates and 24.5 ± 0.4 mg/L for Nitrites. The efficiency of the bioreactors increased with increase in column height and HRT. Wood chips was the most efficient substrate at 22cm column height with a removal efficiency of 94% and an effluent concentration of 12 ± 0.5 mg/L for Nitrate at 48hours HRT, whereas sugarcane bagasse had an efficiency of 80% with effluent concentration of 24 ± 0.6 mg/L of Nitrates under similar conditions. Nitrites was easily reduced compared to Nitrates with low HRT, at 12 hours the Nitrite concentration in the effluent from the woodchip bioreactor was 2.9 ± 0.5mg/L compared to 3.4 ± 0.5 mg/L from sugarcane bagasse bioreactor. Both substrates were found to treat the effluent to acceptable levels for wastewater discharge to the environment as listed in EMCA 1999. The study thus shows that wood chips and sugarcane bagasse are appropriate for decentralized wastewater treatment.

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Published

2021-06-29

How to Cite

Ngerechi, C., Njogu, P., Karanja, B., & Raude, J. . (2021). Performance of Wood Chips and Sugarcane Bagasse in Polishing Aquaculture Wastewater Using a Lab-Scale Modified Trickling Filter. JOURNAL OF SUSTAINABLE RESEARCH IN ENGINEERING, 6(3), 100-107. Retrieved from https://jsre.jkuat.ac.ke/index.php/jsre/article/view/116