Evaluation Of Palm Kernel Shell Biochar For The Adsorption Of Bacillus Cereus

Excessive use of agrochemicals caused by the increasing demand for food is a worrying issue in the developing nations. Thus, sustainable approach of using biochar as an inoculant carrier for the plant growth promoting rhizobacteria (PGPR) is receiving a considerable amount of attention. In the present study, suitability of palm kernel shell (PKS) biochar was assessed as an inoculant carrier for Bacillus cereus. A batch experiment was conducted to determine the time taken to reach the adsorption equilibrium, the ratio of bacteria to biochar required to reach maximum adsorption, and the adsorption capacity of PKS biochar. Taken together, our findings indicate that PKS biochar is a suitable inoculant carrier for B. cereus with 90% of maximum adsorption was achieved within 60 min, where the concentration of bacteria remained at 6.5 x 10(7) CFU/mL. The highest concentration of bacteria adsorbed (9.54 x 10(7) CFU ml(-1)) was observed when the ratio of bacteria to biochar was 100:7 (vw(-1)). The Langmuir and Freundlich isotherm model showed that PKS biochar is a suitable inoculant carrier for B. cereus (Q(o) = 5 x 10(9) CFU g(-1) of biochar; K-F = 2.80 105) with high correlation coefficient (R-2) value of 0.9765 and 0.9948 respectively. Our data fitted Freundlich isotherm, indicating that the adsorption of B. cereus on PKS biochar may occur on the heterogenous surface of biochar and not limited to monolayer formation. However, kinetic study shows data conforming to Elovich model suggesting that attachment of B. cereus onto PKS biochar may be in a monolayer fashion. Finally, some considerations on the application of biochar loaded with PGPR are also highlighted.