磁化聚合硫酸铁混凝处理造纸废水的余铁和pH值变化研究

The Changes of Residual Iron and pH Value in Papermaking Waste Water Treated with Magnetized PFS

中文关键词:  造纸废水  聚合硫酸铁  变频磁场  余铁  pH值

Key Words:papermaking wastewater  polymeric ferric sulfate  variable frequency magnetic field  residual iron  pH value

中文摘要:

      利用自制磁化装置对聚合硫酸铁（PFS）进行预磁化，再进行混凝处理废水实验，从而降低出水余铁和亚铁含量。分别考察了有无磁场磁化作用条件下，PFS投加量、磁化强度、磁化时间等因素对出水余铁含量和pH值的影响。结果表明，磁化组出水的余铁和亚铁含量比未磁化组分别降低了47.6%和53.0%，且pH值低于未磁化组； 在PFS投加量1000 mg/L、磁化强度12 mT、磁化频率130 Hz、磁化时间5 min的条件下，最终出水的余铁和亚铁含量分别为0.688 mg/L和 0.202 mg/L，pH值呈弱酸性；磁化组出水的COD_Cr和色度的去除率分别较未磁化组提高了5.5个百分点和7.1个百分点。

Abstract:

      Papermaking waste water treatment using iron coagulant may increase iron ion concentration in the effluent， which causes secondary pollution. Homemade magnetizing device was used for pre magnetization of PFS using as coagulant in order to reduce the iron content in effluent. The effects of magnetization intensity， PFS dosage， magnetization time on the iron content and pH value of papermaking wastewater were investigated. The experimental results showed that the total iron and ferrous iron contents of the waste water treated with the magnetized PFS were decreased by 47.6% and 53.0% respectively compared with that treated with conventional PFS， and the pH value of the waste water treated with magnetized PFS was lower. When the PFS dosage was 1000 mg/L， the magnetization intensity was 12 mT， the magnetic frequency was 130 Hz， magnetization time was 5 min， the contents of the total iron and ferrous iron in final effluent were 0.688 mg/L and 0.202 mg/L， respectively， pH was slightly acidic；when magnetized PFS was used， the removal rates of COD_Cr and chromaticity of the effluent were increased by 5.5 percentage points and 7.1 percentage points respectively in comparison with that without using magnetized PFS．