Dynamic Adsorption Characteristics of Phosphorus Using MBCQ

Biochar is a new type of adsorption material with excellent performance, but it has some problems, such as light texture, poor sedimentation, and difficult recovery, which limits its practical application. In this study, biochar microspheres (MBCQ) were prepared by the sol–gel method using powdery biochar from Hydrocotyle vulgaris as raw material and sodium alginate as a granular carrier. Experiments were performed to investigate the dynamic adsorption characteristics of phosphorus by MBCQ in the adsorption column and the influences of particle size, initial phosphorus concentration, flow rate, and column height on the breakthrough curve. The results showed that the static adsorption properties of different particles varied and that 3-millimeter particles were optimal. The breakthrough time positively correlated with column height and negatively correlated with initial phosphorus concentration, flow rate, and particle size. Flow velocity significantly impacted breakthrough time and length of mass transfer. The bed depth/service time model accurately predicted the relationship between breakthrough times and column heights. When ct/c0 = 0.6, the average relative deviation between predicted and measured values was the lowest. The Thomas model described the MBCQ adsorption process of Ph (R2 > 0.95), which indicated that diffusion in MBCQ adsorption was not a rate-limiting step.