Method of economically recycling phosphor from excess sludge

An economical technology for excess sludge, applied in the field of water treatment, can solve the problems of high cost of phosphorus, and achieve the effect of stabilization and reduction

Active Publication Date: 2014-03-19
SOUTH CHINA UNIV OF TECH
View PDF5 Cites 36 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0007] The present invention solves the problem of high cost of recovering phosphorus from excess sludge, and provides a method for r

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Method of economically recycling phosphor from excess sludge
  • Method of economically recycling phosphor from excess sludge
  • Method of economically recycling phosphor from excess sludge

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0037] (2) To the alkali hydrolysis sludge, directly inject X volume of excess sludge with a concentration of 20 g / L into the reactor with a pH condition of 13.0 in step (1) to mix, and continue stirring for 1 hour to reduce the pH to 9.6 . Then centrifuge solid-liquid separation at 4000 rpm, collect the supernatant, and measure the concentrations of orthophosphate and ammonia nitrogen in the supernatant to be 70 mg / L and 65.5 mg / L, respectively. At this time, the residual TSS and VSS after centrifugation were reduced by 40% and 55% compared with the remaining sludge, which achieved a stabilization effect and was conducive to subsequent treatment and disposal.

[0038] (3) According to the molar concentration and content of orthophosphate in the supernatant, add magnesium salt with a Mg / P molar ratio of 1.4, stir and react at 100 rpm for 10 minutes until a large amount of precipitation occurs, and separate the precipitate by gravity or centrifugation. Dry naturally to obtain ...

Embodiment 2

[0043] (2) Measure the concentration of orthophosphate in the effluent 6. According to its molar concentration, add 0, 1.0, 1.4, 1.6, 1.8 and 2.0 times the molar number of magnesium salt to it, and stir at 100 rpm for 10 minutes until it appears A large amount of precipitation, gravity or centrifugation to separate the precipitate, and natural drying to obtain the crude product of magnesium ammonium phosphate. Depend on image 3 It can be seen that the amount of magnesium salt added is within the range of 0-1.4 times the molar concentration of orthophosphate, and with the increase of the amount of magnesium added, more phosphorus and nitrogen elements in the effluent are recovered to generate magnesium ammonium phosphate products; But after 1.4 times, the recovery rate of phosphorus element (orthophosphate) remains unchanged, and there is no longer magnesium ammonium phosphate, so the more suitable magnesium input amount (Mg / P ratio) is 1.4. At the same time, the concentratio...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

No PUM Login to view more

Abstract

The invention relates to a method of economically recycling phosphor from excess sludge. The method comprises the following steps: (1), pre-treating the excess sludge; (2), carrying out alkaline hydrolysis on the excess sludge, wherein the alkaline hydrolysis is carried out by a single-stage alkaline hydrolysis method or a two-stage alkaline hydrolysis method; measuring concentration of orthophosphate and ammonia nitrogen in liquid supernatant; and (3), adding magnesium salt aqueous liquor with a Mg/P molar ratio of 0.8-2, stirring and reacting for 10 minutes-120 minutes, gravitationally or centrifugally separating precipitates, naturally drying the precipitates to obtain a magnesium ammonium phosphate crude product. Organic substances remained in the liquid supernatant can be used for producing methane by anaerobic fermentation or supplementing a carbon source by a reflux wastewater treatment system, also can be used for supplementing alkalinity needed for an anaerobic unit, so that comprehensive utilization of excess sludge is facilitated. The method disclosed by the invention has the advantages that nutrient elements in the sludge are comprehensively utilized, process is simple, and phosphor can be recycled by only adding the magnesium salt; and meanwhile, ammonia nitrogen can be partly recycled without regulating pH, and the obtained magnesium ammonium phosphate crude product can be used for producing fertilizers.

Description

technical field [0001] The invention relates to a sludge treatment and resource utilization method, belonging to the field of water treatment. Specifically, it relates to an economical method for recovering phosphorus from excess sludge. [0002] Background technique [0003] With the acceleration of urbanization in my country, the discharge of urban sewage continues to increase, and the amount of sludge, especially the excess sludge, produced by sewage treatment plants is increasing. It is estimated that by 2015, the amount of municipal sludge will reach 7.594 million tons, and this value will continue to increase for a period of time. Generally, sludge treatment and disposal costs account for more than 50% of the total operating costs of sewage treatment plants, requiring huge capital investment. At the same time, sludge is also an available resource, containing nutrients such as nitrogen, phosphorus, and potassium needed for plant growth, various trace elements to main...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
IPC IPC(8): C02F11/00
Inventor 胡勇有李义勇于子淇毕薇毕琪
Owner SOUTH CHINA UNIV OF TECH
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap