Process Safety and Environmental Protection, Vol.143, 55-65, 2020
Removal of bifenthrin pesticide from aqueous solutions by treated patellidae shells using a new fixed bed column filtration technique
The Treated Patellidae Shells (TPS) packed in a fixed bed column for the removal of emerging contam-inant such as bifenthrin provides novel insights into waste valorisation, application of environmentally harmless sorbents and removal of bifenthrin pesticide with extension possibilities for larger applications. The biosorbent was characterized by XRD, FTIR, SEM-EDS, TGA-DTA, pHPZC, and BET analysis. TPS biosorbent is composed of a single phase of calcium carbonate (CaCO3) having a high specific area of 158 m(2)/g. The effects of important parameters such as flow rate, bed height, particles size and bifenthrin feed concentration were studied. The results show that the column efficiency is higher with higher flow rate, higher bed height, higher bifenthrin inlet concentration and lower TPS particles size. The optimum adsorption capacity (40.53 mg) is achieved using a flow rate of 8 mL/min, a bed depth of 4cm (1.6 g), in the TPS particles size range of 50-100 mu m and a bifenthrin feed concentration of 20 mg/L. To model the experimental data, the Bohart-Adams (B-A), Thomas (T) and Yoon-Nelson (Y-N) models were used. The mathematical formulas of these three models are equivalent, that is why the Chu logistic model was developed to fit the experimental data with a single value of both adjusted correlation coefficient (Adj. R-2) and chi-square (chi(2)), for each set. The non-linear form of Chu logistic model showed a good fit between (p)redicted and observed values with higher Adj. R-2 and smaller chi(2) values. The Chu logistic model therefore made it possible to calculate the actual parameter values of B-A, T and Y-N models. The study of the adsorption isotherm allows to show that the Langmuir isotherm is suitable for describing experimental data. This adjustment of the Langmuir model with the observed data indicates the favorable adsorption and the higher bifenthrin adsorption capacity of TPS biosorbent. The TPS regenerative power study reveals that TPS has good regenerative capacity and can be recycled to remove pesticide molecules. The TPS biosorbent is effective in removing pesticides and can be considered as an alternative to the commercial adsorbent. (C) 2020 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.