Optimization of the biosorption of Pb2+ by citron peel using response surface methodology
基于响应面优化条件下柚皮对Pb2+的吸附

Plackett-Burman (P-B) design and Central Composite Design (CCD) were applied to optimize 6 factors for the biosorption of Pb2+ by citron peel. The P-B design and its following statistical analysis indicate that the pH, initial Pb(II) concentration, and adsorbent dosage were the 3 key factors significantly influencing Pb2+ removal. Considering biosorption as the response objective, a quadratic model was obtained by CCD for the 3 factors by analysis of response surface optimization. At the optimal biosorption conditions, i.e. pH 5.4, initial Pb2+ concentration 265.86 mg·L-1 and adsorbent dosage 2.56 g·L-1, the Pb2+ removal achieved 92.47% or 96.01 mg·g-1. Citron peel does not need any chemical pre-treatment and the effect is better than most other natural biosorbents. In this study, the results show that citron peel biosorbent is a potential environmentally-friendly material which can be applied in wastewater treatment with low cost.