||The electroplating wastewater is usually treated by chemical precipitation, and the generated sludge has loose structure to cause the difficulties in sedimentation and filtration. Moreover, the sludge is unstable and the contained heavy metals are easily leached. Solidification is one method to deal with this kind of sludge; however it cause another problem, land requirement.|
In this study, the contents of electroplating wastewater are divided into two parts organic matters and heavy metals; organic matters are treated by Fenton method and heavy metals are by Ferrite process. The purpose of this study is that through the serial Fenton-Ferrite Process treatment the effluent water and the sludge generated from the procedure could meet the standards in Taiwan.
It was well-know that the primary operation factors of Ferrite Process are pH, reaction temperature, ferrous ion concentration, time and aeration. The results showed that the proper factors of FP were pH=10, temperature= 90℃, Fe/M molar ratio= 7,reaction time=80 min and aeration rate=1.0 L air / min / L solution. However, in Fenton method, the parameters of pH, hydrogen peroxide, ferrous ion concentration, and reaction time were discussed. I had greatest efficiency under the data showed that Fenton method pH = 3, ferrous ion concentration=3000 mg/L, hydrogen peroxide = 13000 mg/L, and reaction time=2 hr.
The wastewater measured COD =1162 mg/L, Cr=70 mg/L, Zn=400 mg/L. The treatment efficiency of the procedure combining Fenton method and Ferrite Process were that COD=88.5 mg/L, Cr=1.06 mg/L, and Zn=0.98 mg/Lin effluent water and the TCLP test results of sludge were Cr=3.37 mg/L, Zn=2.46 mg/L. All the data showed that the combination of the two process can significantly treat wastewater to meet the standards. Furthermore, the sludge can be recycled as magnetic materials or other purposes due to it’s specific properties.