CN101580334B - Method for recovering sludge phosphorus from urban sewage treatment plant - Google Patents
Method for recovering sludge phosphorus from urban sewage treatment plant Download PDFInfo
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- CN101580334B CN101580334B CN200810106419XA CN200810106419A CN101580334B CN 101580334 B CN101580334 B CN 101580334B CN 200810106419X A CN200810106419X A CN 200810106419XA CN 200810106419 A CN200810106419 A CN 200810106419A CN 101580334 B CN101580334 B CN 101580334B
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Abstract
The invention relates to a method for recovering sludge phosphorus from an urban sewage treatment plant, belonging to the technical fields of sludge treatment and resources. The method comprises the following steps: respectively carrying out gravity thickening on sludge releasing sludge phosphorus, sludge phosphorus releasing on sludge after the gravity thickening, solid-liquid separation on sludge after the sludge phosphorus releasing, sludge phosphorus recovery on supernatant fluid rich of phosphorus after the solid-liquid separation, and the like; the sludge phosphorus releasing on sludge after the gravity thickening is realized by treating the sludge by an acidification and normal-pressure microwave radiation combination method; and the sludge phosphorus recovery on supernatant fluid rich of phosphorus after the solid-liquid separation is realized by treating the supernatant fluid rich of phosphorus by a calcium phosphate crystallization process to obtain the deposit containing calcium phosphate crystal, then filtering the deposit containing calcium phosphate crystal and finally recovering the sludge phosphorus. The method not only can efficiently recover the phosphorus in the sludge from the urban sewage treatment plant, but also can achieve the aims of reducing the sludge and improving the depositing performance of the sludge.
Description
Technical field
The invention belongs to sludge treatment and resource technology field, the method that particularly a kind of sludge phosphorus from urban sewage treatment plant reclaims.
Background technology
Phosphorus is one of all life entities essential element of depending on for existence, is playing an important role aspect cellularstructure and the cell function; Phosphorus is again a kind of Nonrenewable resources, and the Rock Phosphate (72Min BPL) reserves of occurring in nature are limited.As everyone knows, excessive phosphorus discharging is the major reason that causes body eutrophication, and when the total phosphorus concentration in the water body reached 0.02mg/L usually, the eubiosis of water surrounding will be destroyed.In order effectively to contain body eutrophication, the municipal sewage plant in the organic pollutant, also needs to remove nitrogen, phosphorus in the sewage in removing sewage.Phosphorus in the municipal effluent can be removed by chemistry and biological method.Compare with chemical dephosphorization, (Enhanced biological phosphorus removal is EBPR) because the advantage of its economy has worldwide obtained application widely to enhanced biological phosphorus removal technology.Purify through EBPR, the phosphorus in the municipal effluent has been transferred in the mud, and the mud phosphorus content that EBPR technology produces is about 4%, even up to more than 9%.It is reported that China's phosphorus ore average grade was 18.713% P in 2000
2O
5, amounting to into P% only is 8.17%.Therefore, adopt the mud of municipal sewage plant's generation of EBPR technology to be suitable as the raw material that phosphorus reclaims.In addition, municipal sewage plant's disposing sludge important means is the utilization of mud soil.Yet owing to contain organic pollutant, heavy metal and pathogenic bacteria etc. in the mud, along with the appearance of the strict gradually laws and regulations in countries in the world and the raising of common people's environmental safety consciousness, the utilization of mud soil also more and more is restricted.For example, in Sweden, ban has been issued in peasant's combination weave and foodstuffs industry, forbids that mud is applied to the farmland.So, to carry out mud phosphorus by rights and reclaim, the sludge treatment and the disposal that both can be the municipal sewage plant provide a new way, can alleviate the pressure of phosphor resource scarcity again.
Mud phosphorus removal process is divided into two stages: discharge and recovery, wherein primary key factor is that phosphorus discharges, and just phosphorus is discharged into liquid phase from mud (solid phase), lays the foundation thereby can be follow-up phosphorus recovery.For the phosphorus in the mud is discharged rapidly, to satisfy the needs that phosphorus reclaims, the various countries scholar has introduced multiple physics, chemical means, as Akio Kuroda, et al., A simple method to releasepolyphosphate from activated sludge for phosphorus reuse and recycling.Biotechnology and Bioengineering, 2002.78 (3): p.333～338; Reach Xue Tao, Huang Xia, Hao Wangjuan, the release characteristics of phosphorus, nitrogen and organic carbon in the excess sludge heat treatment process.China's water supply and drainage, 2006 (23): the heating method of being reported p.22～25; Saktaywin, W., et al., Advanced sewagetreatment process with excess sludge reduction and phosphorus recovery.WaterResearch, 2005.39 (5): the ozone oxidation method of being reported p.902～910; Liao, P.H., D.S.Mavinic, F.A.Koch, Release of phosphorus from biological nutrient removalsludges:A study of sludge pretreatment methods to optimize phosphorus releasefor subsequent recovery purpose
At present, struvite (MgNH
4PO
46H
2O MAP) reclaims approach with the phosphorus that calcium phosphate is considered to have most prospect, also is research and use maximum contents.Struvite is a kind of white crystal that is insoluble in water, in the time of 0 ℃, only can dissolve 0.023g in the 1L water, and under the normal temperature, the solubility product in water only is 2.5 * 10
-13For calcium phosphate, a simple clear and definite definition is not arranged as yet, it comprises multiple different form, as secondary calcium phosphate (DCPA), octocalcium phosphate (OCP), amorphous calcium phosphate (ACP), poly-hydroxy phosphatic rock (HAP), calcium phosphate (TCP) etc.Wherein the molecular formula of HAP is Ca
5(PO
4)
3OH is the most stable calcium phosphate salt of thermodynamics, and its solubility product only is 10 in the time of 25 ℃
-55.9
Therefore, the key that mud phosphorus reclaims is how economical and efficient ground discharges the phosphorus element in the mud, thereby establishes solid basis for follow-up phosphorus reclaims.
Summary of the invention
The object of the present invention is to provide the method for phosphoric in a kind of recovery sludge from wastewater treatment plant of economical and efficient, can be used as that sludge from wastewater treatment plant is handled and the technology of resource utilization.
The technical process that sludge phosphorus from urban sewage treatment plant of the present invention reclaims is as shown in Figure 1: comprise to mud mixed liquid carry out the gravity enrichment step, mud after gravity is concentrated carries out mud phosphorus release steps, mud after mud phosphorus is discharged carries out solid-liquid separation step, the rich phosphorus supernatant liquor after the solid-liquid separation is carried out mud phosphorus recycling step etc.; It is characterized in that: it is to adopt acidifying and normal pressure microwave radiation combined method that mud is handled that described mud after gravity is concentrated carries out that mud phosphorus discharges, it is described that rich phosphorus supernatant liquor after the solid-liquid separation is carried out that mud phosphorus reclaims is to adopt the calcium phosphate crystal method that rich phosphorus supernatant liquor is handled, obtain phosphoric acid calcium crystalline throw out, carry out mud phosphorus after then phosphoric acid calcium crystalline throw out being filtered and reclaim.
Described mud is carried out acidifying and normal pressure microwave radiation combined method is handled mud, be mud after gravity is concentrated at first to adopt concentration be that the sulfuric acid of 0.5～5mol/L or hydrochloric acid etc. carry out acidification as the acid of acidifying medicament to mud, the pH of the mud after the control acidifying is 1～5; Adopt microwave reactor then under normal pressure, microwave source power is 400～1000W, and the mud after the acidifying is carried out microwave radiation, and the temperature of the mud after the microwave radiation discharges the phosphorus in the mud between 70～95 ℃.
It is that concentration is concentrated to concentration less than the mud mixed liquid of 6000mg/L is 6000～8000mg/L that described gravity concentrates.Concentration time generally can reach this concentration after 1～3 hour.
Described employing calcium phosphate crystal method is handled rich phosphorus supernatant liquor, can adopt among following two kinds of methods any one.A kind of is that at first to adopt concentration be that the pH value of the rich phosphorus supernatant liquor after the adjusting solid-liquid separation such as the sodium hydroxide solution of 0.5～2mol/L or potassium hydroxide solution is 7.8～11, be 1.5～2 according to calcium phosphorus mol ratio then: 1 adds calcium chloride solution, reaction times was generally 10～30 minutes, formation contains the throw out of calcium phosphate crystal, carries out mud phosphorus after then phosphoric acid calcium crystalline throw out being filtered and reclaims; Or
Another kind is to be to add aqua calcis at 1.5～2: 1 according to calcium phosphorus mol ratio in the rich phosphorus supernatant liquor after solid-liquid separation directly, and the pH that controls rich phosphorus supernatant liquor reacts between 7.8～11, and the general reaction times is 10～30 minutes; Formation contains the throw out of calcium phosphate crystal, carries out mud phosphorus after then phosphoric acid calcium crystalline throw out being filtered and reclaims.
Described solid-liquid separation is to adopt the gravity settling mode to carry out solid-liquid separation.
Described mud mixed liquid is the mud mixed liquid that the municipal sewage plant adopts activated sludge process to produce.
The supernatant liquor through after the recovery of mud phosphorus among the present invention is back in the Sewage treatment systems of municipal sewage plant.
But method of the present invention not only economical and efficient ground reclaims phosphorus in the sludge from wastewater treatment plant, and can reach mud decrement, improves the purpose of sludge settling property.
Description of drawings
Fig. 1. the process flow diagram of phosphoric in the recovery sludge from wastewater treatment plant of the present invention.
Reference numeral
I. gravity concentrates the release of II. mud phosphorus
III. solid-liquid separation IV. mud phosphorus reclaims
Embodiment
Embodiment 1.
See also Fig. 1.Gather the returned sluge mixed solution that is produced by activated sludge process in the village, Beijing side sewage work, the sludge concentration after gravity concentrates is 6800～8000mg/L, the PO of thickened sludge supernatant liquor
4 3--P and total phosphorus (TP) concentration is respectively 26.2mg/L and 28.6mg/L.In mud phosphorus release steps, under the room temperature, the mud after at first 200ml being concentrated is poured in the 500ml beaker, place on the magnetic stirring apparatus, under the certain situation of stirring intensity, (concentration is 2.5～5.0mol/L), pH=1.0～5.0 of the mud after the control acidifying to wherein adding sulfuric acid or hydrochloric acid; Then the mud after the acidifying is put into microwave reactor, microwave frequency 2.45GHz, magnetron peak power output 1kw, but step-less adjustment, cavity volume 25L has liftable whipping appts and temperature probe, and the magnetron opening time is controlled by timing device.Under normal pressure, the mud after the acidifying is carried out microwave radiation, discharge the phosphorus in the mud, about 95 ℃ of the mud terminal temperature after the microwave radiation.Mud after the radiation adopts the natural subsidence mode to carry out solid-liquid separation, the rich phosphorus supernatant liquor after the collection solid-liquid separation, the PO in the rich phosphorus supernatant liquor
4 3--P and total phosphorus (TP) concentration is respectively 53mg/L and 249mg/L.Adopting concentration is that the pH value that the sodium hydroxide solution of 0.5～2mol/L is regulated rich phosphorus supernatant liquor is 9.8, add calcium chloride solution according to calcium phosphorus mol ratio 1.5～2: 1 then, precipitin reaction takes place rapidly, has formed a large amount of throw outs such as calcium phosphate that contain, react after 30 minutes the PO in the supernatant liquor
4 3--P and total phosphorus (TP) concentration drops to 0.8mg/L and 10.3mg/L respectively, at last phosphorous throw out is filtered the back and reclaims.
Embodiment 2.
See also Fig. 1.Gather the returned sluge mixed solution in the village, Beijing side sewage work, the sludge concentration after gravity concentrates is 6800～8000mg/L, the PO of thickened sludge supernatant liquor
4 3--P and total phosphorus (TP) concentration is respectively 26.2mg/L and 28.6mg/L.At mud phosphorus releasing unit, under the room temperature, the mud after at first 200ml being concentrated is poured in the 500ml beaker, place on the magnetic stirring apparatus, under the certain situation of stirring intensity, (concentration is 2.5～5.0mol/L), pH=1.0～5.0 of the mud after the control acidifying to wherein adding sulfuric acid or hydrochloric acid; Then the mud after the acidifying is put into microwave reactor, microwave frequency 2.45GHz, magnetron peak power output 1kw, but step-less adjustment, cavity volume 25L has liftable whipping appts and temperature probe, and the magnetron opening time is controlled by timing device.Under normal pressure, the mud after the acidifying is carried out microwave radiation, discharge the phosphorus in the mud, about 95 ℃ of the mud terminal temperature after the microwave radiation.Mud after the radiation adopts the natural subsidence mode to carry out solid-liquid separation, the rich phosphorus supernatant liquor after the collection solid-liquid separation, the PO in the rich phosphorus supernatant liquor
4 3--P and total phosphorus (TP) concentration is respectively 53mg/L and 249mg/L.In order to reach the purpose of regulating rich phosphorus supernatant liquor pH value and forming phosphoric acid calcium crystalline deposit thing simultaneously, be 1.5～2 according to calcium phosphorus mol ratio in the rich phosphorus supernatant liquor after solid-liquid separation directly: 1 adds aqua calcis, the pH that controls rich phosphorus supernatant liquor is 10.56, precipitin reaction takes place rapidly, a large amount of throw outs such as calcium phosphate that contain have been formed, react after 30 minutes the PO in the supernatant liquor
4 3--P and total phosphorus (TP) concentration drops to 0.65mg/L and 9.15mg/L respectively, at last phosphorous throw out is filtered the back and reclaims.
Claims (9)
1. the method that reclaims of a sludge phosphorus from urban sewage treatment plant, comprise to mud mixed liquid carry out the gravity enrichment step, mud after gravity is concentrated carries out mud phosphorus release steps, mud after mud phosphorus is discharged carries out solid-liquid separation step, the rich phosphorus supernatant liquor after the solid-liquid separation is carried out mud phosphorus recycling step; It is characterized in that: it is to adopt acidifying and normal pressure microwave radiation combined method that mud is handled that described mud after gravity is concentrated carries out that mud phosphorus discharges; Described rich phosphorus supernatant liquor after the solid-liquid separation is carried out that mud phosphorus reclaims is to adopt the calcium phosphate crystal method that rich phosphorus supernatant liquor is handled, and obtains phosphoric acid calcium crystalline throw out, carry out mud phosphorus after then will phosphoric acid calcium crystalline throw out filtering and reclaim.
2. method according to claim 1, it is characterized in that: described mud is carried out acidifying and normal pressure microwave radiation combined method is handled mud, be that mud after gravity is concentrated at first adopts sulfuric acid or hydrochloric acid that mud is carried out acidification, the pH of the mud after the control acidifying is 1～5; Adopt microwave reactor then under normal pressure, microwave source power is 400～1000W, and the mud after the acidifying is carried out microwave radiation, and the temperature of the mud after the microwave radiation discharges the phosphorus in the mud between 70～95 ℃.
3. method according to claim 2 is characterized in that: the concentration of described sulfuric acid or hydrochloric acid is 0.5～5mol/L.
4. method according to claim 1 and 2 is characterized in that: it is that concentration is concentrated to concentration less than the mud mixed liquid of 6000mg/L is 6000～8000mg/L that described gravity concentrates.
5. method according to claim 1 is characterized in that, described employing calcium phosphate crystal method is handled rich phosphorus supernatant liquor and is:
The pH value that employing sodium hydroxide solution or potassium hydroxide solution are regulated the rich phosphorus supernatant liquor after the solid-liquid separation is 7.8～11, be to add calcium chloride solution react at 1.5～2: 1 according to calcium phosphorus mol ratio then, formation contains the throw out of calcium phosphate crystal, carries out mud phosphorus after then phosphoric acid calcium crystalline throw out being filtered and reclaims; Or
Be to add aqua calcis at 1.5～2: 1 according to calcium phosphorus mol ratio in the rich phosphorus supernatant liquor after solid-liquid separation directly, the pH that controls rich phosphorus supernatant liquor reacts between 7.8～11; Formation contains the throw out of calcium phosphate crystal, carries out mud phosphorus after then phosphoric acid calcium crystalline throw out being filtered and reclaims.
6. method according to claim 5 is characterized in that: the concentration of described sodium hydroxide solution or potassium hydroxide solution is 0.5～2mol/L.
7. method according to claim 1 or 5, it is characterized in that: described solid-liquid separation is to adopt the gravity settling mode to carry out solid-liquid separation.
8. method according to claim 1 is characterized in that: described mud mixed liquid is the mud mixed liquid that the municipal sewage plant adopts activated sludge process to produce.
9. method according to claim 1 or 5, it is characterized in that: the supernatant liquor after reclaiming through mud phosphorus is back in the Sewage treatment systems of municipal sewage plant.
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Families Citing this family (17)
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| CN101962255B (en) * | 2010-09-14 | 2012-07-04 | 长沙洁湘环保工程有限公司 | Method for effective sterilization and efficient hydration of primary sludge |
| CN101948225B (en) * | 2010-09-14 | 2012-03-28 | 长沙洁湘环保工程有限公司 | Method for quickly dewatering and effectively removing heavy metals from primary sludge |
| CN102774978A (en) * | 2011-05-09 | 2012-11-14 | 上海丰信环保科技有限公司 | Treatment method for waste water with high content of nitrogen and phosphorus |
| JP5997145B2 (en) * | 2011-06-21 | 2016-09-28 | 水ｉｎｇ株式会社 | Method and apparatus for treating organic wastewater and organic sludge |
| CN103204611A (en) * | 2012-01-16 | 2013-07-17 | 中国科学院生态环境研究中心 | Method and apparatus for source sludge reduction based on microwave sludge pretreatment |
| CN102643005A (en) * | 2012-05-09 | 2012-08-22 | 哈尔滨工业大学 | Excess sludge dewatering method based on microwave radiation technology |
| CN102815824B (en) * | 2012-08-30 | 2013-11-06 | 北京世纪国瑞环境工程技术有限公司 | Method for extracting phosphorus from urban excrement |
| CN102849705B (en) * | 2012-09-29 | 2014-07-02 | 东莞新长桥塑料有限公司 | Method for recycling tricalcium phosphate from expandable polystyrene industrial wastewater |
| CN103896401A (en) * | 2014-04-17 | 2014-07-02 | 中国科学院生态环境研究中心 | Water treatment device for remaining sludge decrement and enhanced biological denitrification and dephosphorization and method |
| CN105084686B (en) * | 2015-08-12 | 2017-05-03 | 广东石油化工学院 | Sanitary production method for recycling residual activated sludge in sewage treatment plant |
| CN105000766B (en) * | 2015-08-12 | 2017-05-17 | 广东石油化工学院 | Cleaner production method for increasing nitrogen and phosphorus recovery rate of residual activated sludge |
| JP6197095B1 (en) * | 2016-12-14 | 2017-09-13 | 新日鉄住金エンジニアリング株式会社 | Method for recovering phosphorus in treated water |
| CN109354003A (en) * | 2018-09-20 | 2019-02-19 | 江苏理工学院 | The recovery method of phosphorus in a kind of cyanobacteria |
| CN110950314B (en) * | 2019-11-25 | 2021-04-23 | 中南民族大学 | Artificial struvite, preparation method thereof and citrate soluble fertilizer |
| CN111548197A (en) * | 2020-05-20 | 2020-08-18 | 四川大学 | Method for recovering calcium phosphate fertilizer from sludge incineration bottom ash |
| CN113087325B (en) * | 2021-03-27 | 2022-06-24 | 同济大学 | Targeted cleaning extraction method for sludge phosphorus recovery |
| CN113526811B (en) * | 2021-08-10 | 2022-08-23 | 南通固润环保科技有限公司 | Excess sludge treatment system of municipal sewage treatment plant |
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