Sludge chemical conditioning deep dewatering method

A technology of deep dehydration and chemical conditioning, applied in chemical instruments and methods, sludge treatment, water/sludge/sewage treatment, etc., can solve the problem of increasing sludge subsequent transportation costs, sludge disposal costs, inability to use compost, land Use and landscaping, sludge pH value changes and other problems, to achieve the effect of safe and convenient dosing method, low dosage of chemicals, and small environmental impact

Inactive Publication Date: 2018-08-03
SHANGHAI TECHASE ENVIRONMENT PROTECTION
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In addition, cationic polyacrylamide is difficult to degrade under natural conditions, and the acrylamide monomer produced by its degradation is also a highly toxic substance with neurotoxicity, and a large amount of surfactants used in the synthesis of cationic polyacrylamide, etc. Organic solvents can also pollute the environment
Adding "ferric chloride + lime" scheme, because the addition of ferric chloride will introduce chloride ions into the s...

Method used

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  • Sludge chemical conditioning deep dewatering method

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Effect test

Embodiment 1

[0049] A large urban sewage plant in Shenzhen actually treats about 350,000 tons of sewage per day, and produces 54 tons of dry sludge (secondary sedimentation tank sludge) with a moisture content of 99.0%. The sludge is pumped into the thickener with a delivery pump, and polyacrylamide (PAM) is added according to 0.3% of the absolute dry sludge amount, and the sludge is concentrated. The moisture content of the sludge after concentration treatment is 95.6%. First, pump the concentrated sludge into the sludge fast reactor 1, add PFSS according to 1.5% of the sludge dry basis (that is, the amount of absolute dry sludge), and mix and stir for 5 minutes at a speed of 40r / min. Carry out a conditioning; then pump the sludge after the first conditioning into the sludge fast reactor 2, add PDADMA according to 2% of the dry basis of the sludge, mix and stir for 5 minutes at a speed of 10r / min, and perform a second conditioning ; After that, pump the sludge after secondary conditioning...

Embodiment 2

[0051] A large urban sewage plant in Zhangzhou actually treats about 130,000 tons of sewage per day, and produces 48 tons of dry sludge (secondary sedimentation tank sludge) with a moisture content of 98.0%. The sludge is pumped into the thickener with a delivery pump, and polyacrylamide (PAM) is added according to 0.1% of the absolute dry sludge amount, and the sludge is concentrated. The moisture content of the sludge after concentration treatment is 95.4%. First, pump the concentrated sludge into sludge fast reactor 1 with a transfer pump, add PFSS according to 1% of the sludge dry basis (that is, the amount of absolute dry sludge), and stir for 10 minutes at a speed of 30r / min. Carry out a conditioner; then pump the sludge after the first conditioner into the sludge fast reactor 2, add PDADMA at 1.5% of the dry basis of the sludge, stir for 3 minutes at a speed of 20r / min, and perform a second conditioner ; After that, pump the sludge after secondary conditioning into an u...

Embodiment 3

[0053] A large urban sewage plant in Qinhuangdao actually treats about 100,000 tons of sewage per day, and produces 60 tons of dry sludge (secondary sedimentation tank sludge) with a water content of 99.9%. The sludge is pumped into the thickener with a delivery pump, and polyacrylamide (PAM) is added according to 0.6% of the absolute dry sludge amount, and the sludge is concentrated. The moisture content of the sludge after concentration treatment is 96.3%. First, pump the concentrated sludge into sludge fast reactor 1 with a transfer pump, add PFSS at 2% of the sludge dry basis (that is, the amount of absolute dry sludge), mix and stir at 40r / min for 10min, and carry out Primary conditioning; then pump the sludge after primary conditioning into sludge fast reactor 2, add PDADMA according to 3% of the dry basis of sludge, stir for 5 minutes at a speed of 20r / min, and perform secondary conditioning; Afterwards, pump the sludge after secondary conditioning into the diaphragm pl...

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Abstract

The invention discloses a sludge chemical conditioning deep dewatering method, which comprises the following steps that after sludge in a sewage plant is subjected to concentration treatment, polyferric silicate sulfate (PFSS) is added according to 1 to 2 percent of the dry sludge quantity for primary conditioning; then, PDADMA (poly dimethyl diallyl ammonium chloride) is added according to 1.5 to3 percent of the absolute dry sludge quantity for secondary conditioning; after the two kinds of chemicals are added, and the reaction is completed, the conditioned sludge is pumped into a high-pressure elastic extraction machine or a diaphragm plate frame press filtering machine for press filtering deep dewatering; the water content of mud cake after the press filtering is lowered to a value being 60 percent or below. The sludge chemical conditioning deep dewatering method has the advantages that only two kinds of chemicals FPFSS and PDADMA are added; in addition, the total adding quantity of the two kinds of two chemicals does not exceed 5 percent of the absolute dry sludge quantity; the chemical adding quantity is obviously reduced; no dry powder chemical is added; the pH value changeon the sludge is small, so that the organic matter and heat value content of the sludge after the dewatering is higher; the method is favorable for various purposes such as various kinds of compost, land utilization and garden greening.

Description

technical field [0001] The invention belongs to the technical field of deep dewatering of sludge, and relates to a method for chemically conditioning deep dehydration of sludge. Background technique [0002] Sludge from urban sewage plants is a by-product of sewage treatment. With the continuous improvement of sewage treatment capacity and discharge standards, the sludge output is increasing day by day. The moisture content of sludge after concentration and pressing in conventional methods is usually 78% to 83%. It is difficult to meet the deep dehydration requirements of the subsequent treatment device (subsequent sewage treatment system) with a moisture content of 55% to 65%. Therefore, deep dehydration of sewage plant sludge has become the main trend of sludge treatment. Among the various sludge deep dewatering technologies at present, chemical conditioning deep dehydration has been widely used because of its simple process and good dehydration effect. Among them, "cation...

Claims

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Application Information

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IPC IPC(8): C02F11/14C02F11/12
CPCC02F11/12C02F11/122C02F11/14
Inventor 宋玉刘道广李亚攀王兆晖
Owner SHANGHAI TECHASE ENVIRONMENT PROTECTION
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