Submerged plant-biochar composite system exhibits effective control over residual organic pollutants in the benthic organisms of aquaculture ponds

This study assesses a submerged plant-biochar system's efficacy in removing HOCs from simulated freshwater aquaculture ponds. Vallisneria natans was planted in sediment with varying levels of wheat straw biochar, while Corbicula fluminea served as the targeted benthic organism. The bioaccumulation experiment identified the optimal biochar ratio for the Vallisneria natans-biochar system in controlling HOCs in aquaculture products. Analyses included final accumulation concentrations in benthic organisms, changes in freely-dissolved concentrations in aquaculture sediment, and a mass balance calculation to explore key factors in their removal from the system. Results indicated that the Vallisneria natans-1.5% biochar composite system achieved optimal control of HOCs in sediment and aquaculture products. Biochar addition to the sediment in the composite system demonstrated a "promotion with low addition, inhibition with high addition" effect on Vallisneria natans growth. Notably, the addition of 1.5% biochar (VN1.5 group) significantly promoted the growth of Vallisneria natans leaves and roots. Comparing the final pollutant proportions in different environmental media, concentrations in water (0.20%∼1.8%), clam accumulation (0.032%∼0.11%), and plant absorption (0.10%∼0.44%) constituted a minimal portion of the overall pollutant load in the system. The majority of pollutants (24%∼65%) were degraded in the aquaculture environment, with microbial degradation likely playing a ...
Source: Environmental Pollution - Category: Environmental Health Authors: Source Type: research