Removal of Heavy Metals inWastewater with Polyglutamic Acid as a Flocculating Agent
田中, 智一 ,
Tanaka, Tomokazu ,
五十嵐, 雅明Igarashi, Masaaki
271 , 2015-08-06
The flocculation method with polyglutamic acid was applied in order to remove heavy metals in wastewater. Removal efficiency more than ca. 90% was obtained for metals of chromium, copper, iron and zinc, while that of manganese (Mn) was only ca. 50%. Therefore, in the present study, a combined method of flocculation and coprecipitation with iron hydroxide was attempted to increase the removal efficiency of Mn. An ion exchange method was also applied for a comparison. For the combined method of flocculation and coprecipitation, the removal efficiency of almost 100% was accomplished at the wide pH range from 7 to 12, although that value decreased negligibly at pH 6. On the other hand, for the ion exchange method, the removal efficiency became higher as pH became lower. The maximum value (93%) was obtained at pH 3. The combined method of flocculation and coprecipitation was found to be useful for removing Mn in wastewater.