Blood cockle shell: an agro-waste for N and P removal of shrimp farm effluent

Abstract

This research investigated the removal efficiency of burned (activated) blood cockle shells (BBCS) of the total nitrogen (N) and phosphorus (P) effluent from shrimp farms, in comparison with novel activated charcoal (AC) and natural (unactivated) blood cockle shell (grinding, NBCS). All shell types (BBCS, NBCS) performed well as adsorbents The removal efficiency varied with shell particle size and effluent flow rate. The shell particle size of BBCS at 0.85-2.0 millimeters had the highest removal efficiency of total N and P at 86.66% and 87.63%, respectively. The best flow rate of effluent for N and P removal efficiency through adsorbency were 300 ml/hour. Moreover, the equilibrium model study for adsorption isotherm of BBCS performed better fitted to the Langmuir model in nitrogen removal, and to both Langmuir & Freundlich model in phosphorus removal. Our findings indicated that the higher surface area and larger average pore size of the adsorbents as BBCS (Bunauer, Emmett and Teller method: BET) produced more N and P removal efficiency than the lower one as NBCS.