Valorization of fish and shrimp wastes to nano-hydroxyapatite/chitosan biocomposite for wastewater treatment

The conversion of the fish and shrimp wastes to produce value-added products brings economic benefits and reduces the risk of environmental pollution. This study presents a facile method for preparing nano-hydroxyapatite/chitosan biocomposites (nHCB) for wastewater treatment and bacterial immobilization. It is a novelty that hydroxyapatite nanoparticles (nHA) and chitosan (CTS) were recovered from fishbone and shrimp shell sources. The prepared nHCBs showed a high porosity, and nHA particles were well distributed in the CTS matrix. Due to these unique properties as an adsorbent for removing dyes and Cu(II) ions from wastewater, nHCBs exhibited rapid adsorption, high capacity, and easy separation for cyclic use. The maximum sorption capacity were 44.05 mg/g (methylene orange), 84.89 mg/g (methylene blue), and 236.97 mg/g (Cu(II) ions). The findings suggest a great potential fabrication of low-cost bio-composites and their application for wastewater treatment.