A preliminary study on intraparticle diffusion of turbidity through nanomagnetic biocarbon composite (NBC)

Abstract

The accessibility of safe drinking water is a fundamental element of Sustainable Development Goal 6 (SDG 6). A novel nanomagnetic biocarbon composite (NBC) has been developed utilising coconut shells for purifying raw groundwater. One of the primary concerns associated with groundwater is turbidity, a condition resulting from the presence of clay, dirt, and silt particles. The presence of turbidity in untreated water has a significant effect on both the visual appeal and overall cleanliness of the water. For the purposes of comparison, commercialised activated carbon (CAC) was utilised in this study. According to the Brunauer-Emmett-Teller (BET) analysis, it was observed that the average pore diameter of NBC was smaller compared to commercially available activated carbon (CAC), despite having a higher BET surface (SBET) value of 916.189 m/g compared to CAC. Based on the results of the kinetic study, it was determined that intraparticle diffusion, specifically external film diffusion, exhibited the most suitable fit as the kinetic model for NBC and CAC. This conclusion was supported by the lowest root mean square error (RMSE) values obtained, which were 0.04 for NBC and 0.13 for CAC, surpassing the performance of alternative models. The diffusion coefficient (Di) values for NBC (7.40 x 10–15 cm2/s) and CAC (7.80 x 10–15 cm2/s) demonstrated the phenomenon of bulk diffusion from high to low concentration. Notably, the diffusion coefficient for NBC was found to be lower than that for CAC. Accordingly, it is suggested that average pore diameter played important roles in intraparticle diffusion of an absorbent.