Adsorptive removal of phosphate from aqueous solution using waste chicken bone and waste cockle shell

Abstract

The removal of phosphates from surface water is crucial to avoid water pollution problems such as eutrophication and algae blooms. There are many established methods that normally used to remove phosphates such as by chemical precipitation, biological processes and physicochemical by sedimentation. On the other hand, calcium carbonate (CaCO3) is recognised as an efficient phosphorus (P) binder in lake sediment which contribute to the permanent burial of P in the sediments. Therefore, this paper studies the potential of raw cockle shells (RCS), calcined cockle shells (CCS), raw chicken bone (RCB) and calcined chicken bone (CCB) in phosphates removal from aqueous solutions. The collected chicken bone waste and cockle shells waste were washed, boiled, sundried and oven dried for raw sample and calcinated at high temperature for calcined sample before been grinded into granular size between 1 and 2 mm. The dosage of 0.1 g, 0.2 g, 0.3 g, 0.4 g, 0.5 g, 0.6 g, 0.7 g, 0.8 g, 0.9 g and 1.0 g of the adsorbent were applied into the artificially prepared phosphate solution. The result indicated that the maximum removal of phosphate was achieved at 0.1 g (90.02% phosphate removal) for CCS, 0.2 g (58.78% phosphate removal) for RCB, 0.1 g (30.40% removal efficiency) for CCB and 0.1 g (26.69% removal efficiency) for RCS. As a general conclusion, phosphate species seem to be efficiently removed from solutions using cockle shell compared to chicken bone as natural adsorbent. In addition, the waste from the adsorption process can be recycle and used as fertilizer for acidic soils.