Treatment of Waste Liquor from Gallic Acid Roughing Production by Combination of Catalyzed Oxidation, Neutralization and Bio-degradation

摘要

Waste liquor from gallic acid roughing production is a kind of organic wastewaters with high concentration and poor biodegradability, and it is difficult to treat only by single process. Combination of catalyzed oxidation, neutralization and biological processes to treat waste liquor from gallic acid roughing production was studied in this paper. The catalyzed oxidation consisted of hydrogen peroxide and ferrous iron is also called Fenton's reaction. The effect of the molar ratio of n(H2O2) :n(Fe2+), amount of H2O2, reaction time, initial pH value, and reaction temperature on CODcr removal efficiency of waste liquor was investigated respectively, and optimum condition of catalyzed oxidation was obtained. After catalyzed oxidation, the CODcr of waste liquor was dropped from about 54,352 mg/L to about 33,004 mg/L, and its removal efficiency reached about 39.28%. Then the CODcr of waste liquor was dropped to about 1,6921 mg/L after being neutralized by CaO, and its removal efficiency reached about 48.73%. At last the waste liquor was diluted and treated by aerobic biological process, the CODcr of wastewater was dropped from 1,990 mg/L to 928 mg/L, and its removal efficiency reached 53.33%, and the wastewater discharged finally could meet the National 3 standard for the discharge of waste water from pharmaceutical raw materials production (CODCr≤1,000 mg/L).