Optimization of process parameters of chemically modified orange peel for Pb~(2+) removal from aqueous solution

摘要

The aim of this work was to chemically modify orange peel with ethyl alcohol, sodium hydroxide and calcium chloride, and optimize the modified process parameters through the orthogonal experimental design. The effects of various parameters on the removal efficiency of Pb~(2+) were investigated detailedly, including ethyl alcohol volume, NaOH solution volume, NaOH solution concentration and CaCl_2 solution volume. According to the results of the orthogonal experiments, the best levels for this four factors were obtained through a L_9(3~4) matrix analysis, as follows: ethyl alcohol volume was 20 mL, NaOH solution volume was 20 mL, NaOH solution concentration was 30 g/L and CaCl_2 solution volume was 5 mL. The results were researched by the range analysis and showed that the NaOH solution concentration had the most significant impact on the removal efficiency of Pb~(2+), whereas the ethyl alcohol volume had the least impact. The removal efficiency of Pb~(2+) of chemically modified orange peel from aqueous solution had reached up to 93.41% in the optimum levels, which showed this chemical modification of orange peel had enhanced effectively its removal capacity of Pb~(2+) from aqueous solution.