Fenton-like technology for pretreatment of papermaking wastewater

Abstract

The invention discloses a Fenton-like technology for pretreatment of papermaking wastewater. The Fenton-like technology includes the following process steps of 1) collecting acid pickling waste liquor and preparing hydrogen peroxide; 2) feeding the acid pickling waste liquor and the hydrogen peroxide into the papermaking wastewater, wherein the mixed liquor of the acid pickling waste liquor, the hydrogen peroxide and the papermaking wastewater undergoes Fenton-like reaction; broken bonds and open loops of lignin macromolecular organisms in the papermaking wastewater form small macromolecular organisms, and part of COD (chemical oxygen demand) in the wastewater is subjected to oxygenolysis to form colloid suspended matters; 3) adding flocculants into the wastewater treated in the step 2) and enabling the colloid suspended matters generated in the step 2) to be mixed and solidified into large granular alumen ustum; 4) precipitating the wastewater treated in the step 3), performing secondary biochemical treatment on supernate generated through precipitation, and dehydrating sludge generated through precipitation. The Fenton-like technology for pretreatment of the papermaking wastewater has the advantages that the papermaking wastewater is treated by the acid pickling waste liquor, and accordingly the Fenton-like technology is good in treatment effect and capable of avoiding waste of acid and iron resources.

Description

technical field [0001] The invention relates to a refractory wastewater pretreatment process, in particular to a Fenton-like process for papermaking wastewater pretreatment. Background technique [0002] Papermaking wastewater contains a large amount of refractory lignin substances, which have the characteristics of high chroma, high alkalinity, high organic matter content, etc., and basically have no biodegradability. The five-day biochemical oxygen demand (BOD for short) 5 ) / Chemical Oxygen Demand (COD for short) is usually 0.1 to 0.2. It is difficult to effectively remove its refractory COD or improve its biodegradability through general coagulation and sedimentation treatment, and it is also difficult to make the effluent COD reach the standard after secondary biochemical treatment. Generally, effluent COD Cr At about 80mg / L, the dilution factor of the chroma is more than 130 times, which is the same as the COD specified in the first-class A standard in the "Pollutant D...

AI Technical Summary

Problems solved by technology

If this kind of waste liquid is not recycled effectively, it will cause serious environmental pollution.

The traditional treatment method generally uses lime, calcium carbide slag, etc. for neutralization reaction. Although the pH value can reach the discharge standard after neutralization, the remaining indicators are still difficult to meet the standard, and the sludge generated is difficult to dehydrate, difficult to dry, and post-treatment. It is difficult, and in most cases, it is piled up for treatment, which takes up a lot of land and causes secondary pollution. At the same time, this method wastes a lot of acid and iron resources

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