Oxidation Treatment Of APMP Effluent By Activating Ammonium Persulfate With Zero-Valent Iron

It is well-known that the pulp and paper industry employs large amounts of water and produces equally large amounts of wastewater. And the effluents have the following characteristics:difficult to biodegrade, high chroma, complicated component, high concentration of refractory organic pollutants, especially for the remove of the color. High yield pulp is developing rapidly in recent years, but the effluent treatment technology and development for it is under-developed. The biological treatment technology or concentrated incorporation chemical pulp alkali recovery technology in waste liquid incineration used now all have some problems. Color problem is prominent in biological treatment process, so it is very necessary to research and develop new treatment method for high yield pulping technology.Compared with the traditional processing method, advanced oxidation technology has obvious advantages:can produce strong oxidizing free radicals, simple to operation, reaction speed is fast, degradation ability for some refracted organic pollutants is strong. Advanced oxidation technology depend on zero valent iron activation, sulfate free radical is being extensively researched in the field of wastewater treatment, especially for the colored wastewater treatment, has the remarkable superiority in the wastewater color remove.This research, with the method of zero valent iron activated ammonium sulfate oxidation treated the APMP pulping wastewater. The initial COD of the wastewater is 910 mg/L and the initial chromaticity is 2295 (C.U.), and the orthogonal test showed that:the importance of effect factors on COD is reaction time> initial pH> the amount of Fe and (NH4)2S2O8, the importance of effect factors on color is initial pH> reaction time> the amount of Fe and (NH4)2S2O8. When the initial pH is 5, the amount of zero valent iron is 1.34 g/L, the amount of ammonium persulfate dosage is 10.92 g/L, react 120 min, the removal rate of COD can reach 65.96%, the removal rate of the color can reach 98.68%, the effect of color remove is remarkable.The analysis of infrared spectrum showed that:after the oxidation degradation by zero valent iron activated persulfate, the absorption peak near 3400 cm"1 is disappeared, indicating that some aromatic substances were removed, but still containing substances that include C=C or C=O strictures. After Fenton oxidation treatment, there are absorption peaks at 3434 cm-1 shows that some aromatic hydrocarbons are still exists, the absorption peak near 1637 cm-1 represent the substances include C=C structure are still existence. But other substances were well removed.The GC-MS analysis of the extractions of wastewater showed that:the kind of organic compounds in wastewater reduced significantly after treatment. Method of zero valent iron activated persulfate oxidation was obvious on the remove of substances such as phenolic, organic acids, materials organized by nitrogen. Fenton method is obvious on the degradation of organic acids, lipids and aldehyded materials.