Removal of pollutants from water by biochar derived from maricultural residual bait and feces
In recent years,the rapid development of the land-based aquaculture industry has led to an increase in aquatic product production,but it has also resulted in a significant accumulation of residual bait and feces.However,the high salt content in the residual bait feces from mariculture has hindered the establishment of an effective treatment method.In this study,biochar(BC700)was synthesized from mariculture residual bait feces and modified using various methods.The removal rates,adsorption kinetics,and removal mechanisms of different biochar on PO43-,NO3-,NO2-and NH4+in water were studied.The results showed that the specific surface area of BC700 was significantly increased by alkali modification(39.8%for biochar K),acid modification(88.1%for biochar P),and metal loading modification(72.9%for biochar Fe).All biochar is characterized by the presence of-OH and/or phenol,C-O,-CH3,aromatic C=O and C=C groups.The modification significantly enhanced the biochar's ability to remove NH4+-N from water,with biochar Fe demonstrating the highest removal rates for PO43-,NO2-and NH4+.Different types of biochar adsorb PO4 and NH4 through both physical and chemical processes,while the adsorption of NO3-and NO2-by biochar is primarily driven by chemical adsorption.This study offers a novel approach to the resource utilization of residual bait and feces from mariculture,thereby contributing to the green and sustainable advancement of the aquaculture industry.
mariculturalresidual baitfecesbiocharnitrogen and phosphorus pollutantsremoval mechanism