发酵麸皮对酸性含铬废水中Cr(Ⅵ)的吸附与解吸研究

Study on the adsorption and desorption of Cr(Ⅵ)in acidic chromium containing wastewater by fermented bran

以发酵行业产生的发酵麸皮废弃物为生物吸附剂处理酸性含铬废水中的Cr(Ⅵ),研究了pH、吸附时间、Cr(Ⅵ)初始浓度、发酵麸皮投加量对Cr(Ⅵ)吸附效果的影响,确定发酵麸皮吸附去除Cr(Ⅵ)的适宜条件。分别以NaOH、HCl、NaCl为解吸剂处理吸附饱和的发酵麸皮,利用正交实验研究解吸剂种类、解吸时间、解吸剂浓度、发酵麸皮投加量等因素对Cr(Ⅵ)解吸效果的影响。结果表明,在强酸条件下发酵麸皮对Cr(Ⅵ)的吸附效果最好,发酵麸皮吸附Cr(Ⅵ)的适宜条件为pH=1,吸附时间90min,Cr(Ⅵ)初始质量浓度20mg/L,发酵麸皮投加量0.35g。发酵麸皮解吸Cr(Ⅵ)的正交实验结果表明,最佳解吸条件为以0.20mol/L NaOH为解吸剂,发酵麸皮投加量0.50g,解吸时间60min。各因素对Cr(Ⅵ)解吸效果的影响程度排序为解吸剂种类>解吸时间>解吸剂摩尔浓度>发酵麸皮投加量。吸附饱和后的发酵麸皮可以通过解吸再生,但再生第4次已经失去了重复利用的价值。

The waste fermented bran produced in fermentation industry was used as biological adsorbent to re- move Cr（Ⅵ ） in acidic chromium containing wastewater. The effect of pH, adsorption time, initial Cr（ Ⅵ ） concentra- tion, fermented bran dosage on Cr（VI） adsorption was investigated, and the optimum adsorption conditions was ob- tained. The desorption of saturated fermented bran was performed with NaOH, HC1 and NaCI was as desorption a- gent, and orthogonal experiment was designed to investigate the influence of desorption agent type, desorption time, a- gent concentration and fermentation bran dosage on Cr （Ⅵ） desorption efficiency. The results showed that the fer- mented bran presented perfect performance of Cr （Ⅵ） adsorption in strong acid condition, the suitable adsorption con- ditions were pH = 1, adsorption time of 90 min,initial Cr（ Ⅵ ） concentration of 20 mg/L, fermented bran of 0.35 g. Orthogonal experiment showed that the optimal desorption conditions were 0.20 mol/L NaOH as desorption agent, bran fermented dosage of 0.50 g,desorption time of 60 rain. The effect of the 4 factor on Cr （Ⅵ） desorption followed the order of desorption agent type 〉 desorption time 〉 desorption agent concentration fermented bran dosage. The saturated fermented bran could be regenerated by desorption,while it lost the value of recycling after 4 times of reuse.