Pollution-free integrated method and device for high-added-value extracellular polymeric substance recovery

Abstract

The invention relates to a pollution-free integrated method and device for high-added-value extracellular polymeric substance recovery. The method comprises the following steps: S1, conveying excess sludge into a cation exchange resin reactor, and extracting extracellular polymeric substances in the excess sludge, S2, intercepting microbial cells and residues thereof in the excess sludge through amicro-filtration membrane assembly to obtain filtrate containing extracellular polymeric substances, S3, filtering through a multistage membrane assembly, so that the high molecular weight extracellular polymeric substance and the low molecular weight extracellular polymeric substance can be concentrated and purified in sequence, and then the extracellular polymeric substances in different molecular weight ranges are separated out, and S4, conveying the filtrate generated in the step S3 to a forward osmosis membrane assembly taking a fertilizer as a driving agent for filtering to obtain a drawing solution containing the fertilizer, and the drawing solution can be directly used for water and fertilizer integrated irrigation or soilless culture. The method has the characteristics of no celldamage and no pollution.

Description

technical field [0001] The invention relates to a pollution-free integrated method and device for recycling extracellular polymers with high added value. Background technique [0002] Recycling has become an important direction and inevitable trend of future sewage treatment technology. At present, the most commonly used biological sewage treatment technology is the activated sludge method, but it is followed by a large amount of residual sludge that is difficult to treat and dispose of. Taking China as an example, according to the data released by the E20 Research Institute at the end of 2018, the sludge output (with a moisture content of 80%) reached 43.28 million tons per year in 2017. It is predicted that by 2020, my country's annual sludge output will reach 50.75 million tons, so it is necessary to stabilize, harmless and recycle sludge. [0003] Extracellular Polymeric Substances (EPS) is an important part of activated sludge, accounting for about 10% to 40% of the d...

AI Technical Summary

Problems solved by technology

[0007] At present, traditional methods are difficult to improve the extraction rate of EPS and easily cause secondary pollution

Existing research only indiscriminately extracts EPS from sludge, and the extract contains a large amount of impurities, which is difficult to apply

The excess sludge is produced in the mixed microbial treatment system of municipal sewage. In the process of extracting EPS, most of the small molecular pollutants such as heavy metal ions and antibiotics will be transferred from the excess sludge to EPS in solid phase, which has not been seen at home and abroad so far. There are studies on the detection of toxic and harmful pollutants in recycled EPS, and it is unheard of to consider removing toxic and harmful pollutants from EPS

Images