基于响应面优化条件下柚皮对Pb2+的吸附

采用Plackett-Burman(P-B)法和中心复合设计(Central Composite Design,简称CCD)对影响柚皮吸附Pb2+的6个条件进行筛选优化.P-B实验设计与统计学分析表明:pH值、Pb2+初始浓度、吸附剂用量是影响吸附率的3个关键因素.以吸附率为响应目标,对3因素进行中心复合设计,并经响应面法优化分析得到影响吸附率的二阶模型,确定了Pb2+吸附实验的最优操作条件:pH值5.4.Pb2+初始浓度为265.86mg·L-1,吸附剂用量为2.56 g·L-1,实测吸附率达到92.47%,吸附量为96.01 mg·g-1;整个吸附过程吸附剂柚皮没有经过任何化学预处理.效果优于一般的天然吸附剂.研究结果表明,柚皮是一种很具潜力的环保型廉价吸附剂.

Optimization of the biosorption of Pb2+ by citron peel using response surface methodology

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.