Pretreatment method of promoting anaerobic fermentation of high-density sludge through alkaline-hydrolysis coupling ultrasonic processing

Abstract

A disclosed pretreatment method of promoting anaerobic fermentation of high-density sludge through alkaline-hydrolysis coupling ultrasonic processing comprises preparing sludge with the solid concentration TS of 7%-9% from dewatered sludge, adding calcium oxide powder according to the concentration of 0.01 g/g-TS, and stirring uniformly; and then pouring into a trough type ultrasonic generator for ultrasonic processing, and controlling the ultrasonic frequency to be 20 KHz, the power density to be 0.15 KW/L and the processing time to be 30 min. The dissolvable COD concentration and the dissolvable polysaccharide concentration of the sludge subjected to the above processing process are both substantially increased compared with those of sludge not subjected to pretreatment, the pH value is about 7.6, and the processed sludge can be directly poured for anaerobic reaction for fermentation and generating methane, and after the anaerobic fermentation reaction is performed for 25 d, the methane accumulated yield is improved by 55.1% compared with that of unprocessed sludge. The method is simple in operation, saves reagent usage amount and energy consumption, and does not influence subsequent processing and disposal, also the gas production performance of the sludge is improved and the anaerobic reaction period is shortened.

Description

technical field [0001] The invention relates to the field of high-concentration sludge anaerobic fermentation for methane production, and in particular relates to a high-concentration sludge enhanced pretreatment method which is combined with low alkali input and low power density ultrasound. Background technique [0002] Anaerobic fermentation technology is an effective way to realize sludge reduction, stabilization, harmlessness and resource utilization and has been widely used. The sludge concentration in the traditional sludge anaerobic fermentation process is generally 2% to 4%. In the high concentration anaerobic fermentation process, the sludge concentration can be increased to 8% to 12%, which can effectively solve the problem of the large volume of the fermentation facility and the unit volume. Problems such as low gas production have become an important trend in the development of current sludge anaerobic fermentation technology. Studies on anaerobic fermentation ...

AI Technical Summary

Problems solved by technology

[0005] The present invention aims at the problem of low organic matter degradation rate existing in the existing high-concentration sludge anaerobic fermentation, and provides a kind of direct action on high-concentration sludge (TS=7%~9%), which has obvious decomposing effect on sludge, A combined enhanced pretreatment method that can improve the gas production performance of sludge anaerobic fermentation, shorten the reaction cycle, and has low energy consumption and easy operation