Sludge anaerobic digestion-high dryness dehydration method used for achieving adjustable high solid content based on double membrane system synchronous dehydration

Abstract

The invention discloses a sludge anaerobic digestion-high dryness dehydration method used for achieving adjustable high solid content based on double membrane system synchronous dehydration. A device of the sludge anaerobic digestion-high dryness dehydration method comprises a sludge anaerobic digestion reaction unit, a forward osmosis solid content adjusting unit, a membrane distillation draw solution concentrating unit, and a post-digestion high dryness dehydration unit. According to the sludge anaerobic digestion-high dryness dehydration method, the forward osmosis solid content adjusting unit is used for realizing sludge dehydration when sludge anaerobic digestion is carried out, so that solid content can be adjusted in sludge anaerobic digestion process, sludge anaerobic digestion process is promoted, problems that sludge water content is high and solid content is low, and digestion reactors is large in size and low in digestion efficiency are solved effectively, sludge volume is reduced, and at the same time sludge anaerobic digestion efficiency is increased. At the same time, forward osmosis high dryness dehydration technology is adopted, so that super low energy consumption quantitative reduction of sludge is realized finally. All the forward osmosis draw solution is concentrated and recycled using the membrane distillation draw solution concentrating unit, and full utilization of the temperature of anaerobic digestion solution is realized in the process.

Description

technical field [0001] The invention belongs to the technical field of sludge treatment. Background technique [0002] In recent years, with the increase in the amount of sewage treatment, the output of excess sludge has been increasing day by day. Therefore, the treatment, disposal and resource recovery of excess sludge have become the focus of research. [0003] The sludge anaerobic digestion process can stabilize excess sludge and recover energy in the form of combustible gas, so it can play an important role in municipal sludge treatment and disposal. However, the reasons for the low completion rate and lower operation rate of the conventional sludge anaerobic digestion process mainly include two aspects: one is the high moisture content of the feed sludge, and the other is the low gas production rate of the anaerobic digestion process, resulting in The volume of equipment is large, the overall investment is large, and the huge system requires high energy consumption fo...

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Problems solved by technology

[0004] However, the high solid content of sludge may have some adverse effects in the pretreatment stage. At the same time, high solid content sludge will also bring some problems in the initial stage of anaerobic digestion: (1) The concentration of the reaction substrate is high, causing Reaction intermediate products and energy are difficult to transmit and diffuse in the medium, which is easy to form feedback inhibition; (2) low water content affects cell movement or enzyme diffusion, increasing the difficulty of starting; (3) high stirring resistance and high energy consumption

Although FO was used in the concentration of industrial wastewater as early as nearly 40 years ago, it was limited to the performance of forward osmosis membrane materials and the efficiency and energy consumption of draw solution regeneration. research hotspots

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