改性木屑处理含Cr（Ⅵ）废水的研究

STUDY ON THE TREATMENT OF CHROMIUM WASTEWATER USING MODIGIED WOODFLOUR

通过正交试验选择制备改性木屑的最佳条件，水解改性后的木屑能将Ｃｒ（Ⅵ）还原成Ｃｒ￣（３＋）每克改性木屑对Ｃｒ（Ⅵ）的最大还原能力为４９０ｍｇ将其装成柱子，让ρ＿（Ｃｒ）（Ⅵ）＝８６ｍｇ／Ｌ及ｐＨ＝２的含Ｃｒ（Ⅵ）电镀废水通过柱子，其接触时间不小于６ｍｉｎ，Ｃｒ（Ⅵ）的还原率在９９．５％以上．

The best technical condilions of preparation have been obtained by factorial design experiment.The modified wcodflour increases reducibility and then it can reduce Cr(Ⅵ)to Cr￣(3+). The maximum reduclbility of medified woodflour comes up to 490 mg Cr(Ⅵ)per gram.Let chromium wastewater passeo through the column which is filled with modified woodflour,the reduction rate of Cr(Ⅵ)is more than 99.5 per cent when the contact time is over than 6min.The Cr￣(3+) can be retrieved by precipitating with Ca(OH )_2. This method is simple,cheap and has no secondary pollutant.