Method for improving phosphorus release rate of iron phosphate-containing sludge during anaerobic fermentation

Abstract

The invention relates to a method for improving the phosphorus release rate of iron phosphate-containing sludge during anaerobic fermentation. The method comprises the following steps: placing concentrated iron phosphate-containing sludge into a reactor; adding a certain amount of Na2S into the reactor according to the total content of suspended solids in the concentrated iron phosphate-containing sludge; closing the reactor for 5-10 days' anaerobic fermentation at 30-40 DEG C, so that a large amount of phosphorus can be released from the iron phosphate-containing sludge generated during chemical phosphorus removal, and especially the release of chemical phosphorus can be promoted. Compared with the prior art, the method provided by the invention has the advantages that the phosphorus release rate of the iron phosphate-containing sludge during anaerobic fermentation can be improved, the release of organics can also be promoted, the phosphorus recovery rate in the later period can be improved, and the sludge can be further recycled and reduced. Meanwhile, the defects that the accumulated concentration of phosphorus in a surplus sludge supernatant obtained according to a pure fermentation method is low, much biological phosphorus is released during anaerobic fermentation according to a pH adjustment method, but the release of chemical phosphorus during anaerobic fermentation according to the pH adjustment method is restricted, and released phosphorus is easy to re-precipitate can be overcome. The method is higher in operability and controllability.

Description

technical field [0001] The invention belongs to the field of sludge treatment and phosphorus resource recovery, and relates to a technology for promoting the release of phosphorus by anaerobic fermentation of sludge, in particular to a method for increasing the release rate of phosphorus in the anaerobic fermentation process of iron phosphate-containing sludge. Background technique [0002] As a non-renewable resource on the earth, the shortage of phosphorus resources is becoming more and more severe. At the same time, excessive phosphorus content in water can stimulate the growth of algae and other photosynthetic microorganisms and cause eutrophication, which has become one of the main environmental problems and seriously restricts the sustainable development of society and economy. [0003] How to effectively remove phosphorus and recover phosphorus resources has always been the focus of attention. At present, the removal of phosphorus in sewage is mainly through biologic...

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Problems solved by technology

[0006] The patent application with publication number CN103204613A discloses a method for extracting phosphorus in phosphorus-containing chemical-biological mixed sludge. This method adjusts different pH values ​​to make the phosphorus release rate reach 60-80%, but the biological pollution Phosphorus release rate from mud accounts for the majority, FePO 4 The phosphorus release rate only accounts for about 10%, indicating that most of the phosphorus in the chemical precipitation is still not released

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