Appraising the Performance of Oil Palm Fiber Biochar for Low Concentration Ammoniacal Nitrogen Recovery from Aquaculture Wastewater

Abstract

ABSTRACT Oil palm fiber is a type of solid waste generated from the palm oil processing plant. At present, there is no proper utilization of this abundant waste. Ammoniacal nitrogen (NH3-N) has received a lot of attention as a water pollutant due to its toxicity, which has an impact on both the environment and human health. In aquaculture wastewater (AQW), NH3-N presents in low concentrations (<10 ppm) and removing low concentrations of NH3-N is tedious. Thus, this study focuses on the potential of oil palm fiber biochar (OPFB) for sustainable low concentration NH3-N recovery from AQW and the recovered spent adsorbent to be used as a bio-fertilizer. The Physico-chemical properties of OPFB show a positive correlation with NH3-N recovery. Significant reduction of value-added metals in OPFB has confirmed the recovery of NH3-N through the ion exchange process. The adsorption isotherms and kinetics of NH3-N recovery had good correlation coefficients under the Freundlich and pseudo-second-order kinetic model confirming a multilayer heterogeneous and chemical adsorption respectively. Thermodynamic parameters indicated that the recovery process via adsorption was exothermic and had physio-chemical mechanism. At optimum conditions OPFB could recover up to 66% recovery of NH3-N actual AQW. The properties of spent OPFB showed potential reutilization as a soil amendment agent or biofertilizer which could be easily degraded.