Secondary black liquor treatment method

Abstract

The invention discloses a treatment method for secondary black liquor. The treatment method comprises the following steps: (a) regulating the pH value of the secondary black liquor to be 3-4 to obtain acidified secondary black liquor; (b) putting the acidified secondary black liquor into an anaerobic reactor, performing a biochemical treatment at normal temperature, and then regulating the pH value of the sewage generated by the biochemical treatment to be 7-8; (c) adding a coagulant into the sewage obtained in the step (b) according to a mass ratio of 1000:(0.5-1.5), stirring, primarily precipitating for 6-10 hours, and then filtering the supernatant clear liquor. The secondary black liquor is regulated to be acidic, so that a part of lignin in the secondary black liquor can be separated out; besides, by the effect of the coagulant, tiny suspension particles and colloid ions in the sewage can be aggregated, flocculated and statically precipitated; while the supernatant clear liquor is subjected to biochemical aeration treatment to generate fresh water, and the fresh water can reach emission standards after being precipitated. The treatment method for the secondary black liquor, disclosed by the invention, is simple in process, easy to control on technological condition, low in energy consumption and suitable for promotion and application in rice paper processing enterprises.

Description

technical field [0001] The invention relates to the field of rice paper processing, in particular to a method for processing secondary black liquor. Background technique [0002] Xuan paper is a traditional handicraft, and its production process includes cooking, beating, fishing, drying, paper-cutting and other processes. Among them, cooking is mainly to put sandalwood bark, the raw material of rice paper processing, in a medicinal solution to remove the lignin in the sandalwood bark. Yes, the cooking wastewater after cooking the sandalwood bark is black, which is called thick black liquor by people in the industry. In addition, the steamed sandalwood bark needs to be washed with water, and the color of the wastewater produced after washing the sandalwood bark is lighter than that of the black liquor wastewater, so It is generally referred to as sub-black liquor, which is rich in lignin and other organic wastes, so it needs to be treated in order to meet the emission standa...

AI Technical Summary

Problems solved by technology

At present, most enterprises still directly introduce secondary black liquor into the concentrated black liquor treatment system for treatment, but compared with concentrated black liquor, there are significant differences in waste components and concentrations in secondary black liquor, and the output of secondary black liquor Therefore, it is undoubtedly a waste of a large amount of processing raw material resources when using a concentrated black liquor treatment system, and the energy consumption is high. Therefore, it is very important for enterprises to actively develop and research a method that can reduce the treatment cost of secondary black liquor. important

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