Natural Cellulosic Adsorbent for Recovery of Nitrate from Aquaculture Effluent

Abstract

Abstract Nitrogen based nutrients are among the main components in aquaculture effluent to cause eutrophication condition, as it may cause algal bloom and depletion in oxygen once its concentration reaches the threshold. Nitrogen based nutrients are released into water in a form of nitrate after going through nitrification and denitrification. Cellulose based adsorbent are increasingly gaining attention due to its adsorption capability which comes in useful for recovery of nitrogen based nutrients. This study aims to evaluate the efficiency of powder cellulose as a potential natural cellulosic adsorbent for the recovery of nitrate ions in water under a constant pH 6.6. The uptake of nitrate by natural cellulosic adsorbent was investigated with variation of parameters such as initial concentration of 5.0 mg L−1 and 30.0 mg L−1, adsorbent dosage of 5.0 mg and 40.0 mg, temperature of 25.0 °C and 45.0 °C, and contact time of 10 minutes and 60 minutes. The experiment was conducted based on the experiment design by Design Expert Version 11 software in order to observe the recovery percentage of powder cellulose in different condition. The best recovery percentage was achieved at the condition of 5.0 mg L−1, 5.0 mg, 25.0 °C and 10 minutes with 96.50 % of recovery. This shows that the electrostatic force of attraction between powdered cellulose and nitrate anion nutrients have the potential to occur without heat and vacant pores around powdered cellulose was filled by nitrate anions in a limited amount of time. The model for the experiment which is most suited in this experiment is a natural log with a significant R2 value of 0.9982. This indicates that the adsorption of nitrate anion nutrients using natural cellulose adsorbent is indeed feasible. Therefore, there are potential of using cellulose extracted from biomasses in Malaysia, which will expand its product-value.