CN1369442A

CN1369442A - Process for treating acidic sewage with high-density mud

Info

Publication number: CN1369442A
Application number: CN 01145534
Authority: CN
Inventors: 赵金标; 胡伟; 李志鸿
Original assignee: Individual
Current assignee: Individual
Priority date: 2001-12-28
Filing date: 2001-12-28
Publication date: 2002-09-18

Abstract

A high-density mud process for treating acidic sewage is disclosed. Its system is composed of two reactors, aerating pool, depositer and pressing filter. The neutralizing agent is added to make it be adsorbed by mud as carrier, which is used to neutralize the sewage, resulting in high-density big-granularity metallic hydroxides deposit. Its advantages are high precipitation efficient and short dewatering time of mud.

Description

Process for treating acidic sewage with high-density mud

The present invention is a kind of waste water treatment process, be particularly related to a kind of process for treating acidic sewage with high-density mud, can handle acidity that produces in the industry production processes such as iron and steel, mine, chemical industry, electronics, plating and the metal ion waste water that contains contaminate environment such as iron, copper, nickel, chromium, zinc, silver, make metal ion form the floc sludge precipitation of the big particle diameter of high-density, improve dehydration property, improve processing efficiency.

At present, the acid waste water of iron and steel cold rolling mill is mainly from cold-rolling pickling line and cold rolling surface treatment unit (zinc-plated unit, annealing machine, zinc-plated unit etc.), main component is acid, tensio-active agent, phosphorization agent, oil, metal ion etc., the complicated component of waste water and variation are big, and traditional processing technological flow is: waste water, neutralization, aeration, precipitation, discharging.

A little less than there is adaptive faculty to water quantity and quality in this treatment process, be difficult for precipitation, moisture percentage in sewage sludge height, sludge dewatering weak effect, neutralizing agent consumption greatly, concentration of metal ions is difficult to defectives such as up to standard.

The purpose of this invention is to provide a kind of novel acid waste water treatment process, i.e. process for treating acidic sewage with high-density mud.This processing method is to utilize neutralizing agent and acid waste water, makes the mud of its formation have higher solid content (greater than 10%), so that the metal ion content in the processed waste water is lower than the content that adopts after the traditional technology method is handled.

In conjunction with Fig. 1 this technology is described in detail, this technology is carrier-containing suspension liquid and neutralizing agent to be introduced first reactor (1) react, make the neutralizing agent particle be adsorbed on carrier surface, entering second reactor (2) then reacts, carry out the short mix reaction with needs neutral waste water, control waste water pH value is between 8.4-10.6 in second reactor (2), making most of metal ion form metallic hydrogen oxygen compound precipitation separates out, and be adsorbed on the carrier surface that first reactor (1) is discharged, form fine and close suspended sludge particle, particle can adsorbing metal ions and is stoped self in conjunction with more water.Entering settling vessel (4) through the waste water behind the secondary reaction precipitates, the clear water overflow is discharged, and the suspended sludge particle forms the higher mud of solid content through precipitation, and solid content reaches 10-50%, a part is discharged and is handled, and another part is back to first reactor (1) as sludge carrier.In order to improve sedimentation effect, before entering settling vessel, mud can add an amount of flocculation agent aids precipitation.Insoluble calcium salt is (as Ca (SO in this technology ₄) ₂) also can in second reactor (2), separate out, be adsorbed in carrier surface and form closely knit suspension precipitation particles.For the waste water that contains iron ion, in order to reach the purpose of further removal iron ion, increase an aeration tank (3) in second reactor (2) back, it is the lower ferric iron of solvability that bubbling air makes oxidation of divalent, thereby removes iron ion more completely; Waste water enters settling vessel (4) and precipitates behind aerated reaction, and the mud of post precipitation is sent into pressure filter (5), and moisture is extruded, and mud is solidified.

Processing technological flow of the present invention is: first reaction, second reaction, aeration, precipitation, dehydration, discharging.

Fig. 1 is a process structure synoptic diagram of the present invention;

1. first reactor, 2. second reactors, 3. aeration tanks, 4. settling vessels, 5. pressure filter

Fig. 2 is the mud Electronic Speculum enlarged view after traditional technology is handled;

Fig. 3 is the mud Electronic Speculum enlarged view after art breading of the present invention;

Fig. 4 is the various concentration of metal ions contrasts after technology of the present invention and traditional technology processing.

1,3,5,7,9 is respectively Cr, Ni under the traditional technology condition, Pb, Zn, Cu concentration

2,4,6,8,9 be respectively Cr, Ni under the processing condition of the present invention, Pb, Zn, Cu concentration

The difference of the present invention and traditional handicraft:

Conventional processes adopts chalkstone, NaOH etc. to carry out neutralization precipitation, makes waste water pH value and metal Ion rear discharging up to standard. For the waste water that contains many kinds of metal ions, because some metal hydroxides is both sexes Material, pH value be again dissolving in some scope. For reducing the concentration of every metal ion species, must be respectively Process, complex process, investment operating cost height are on the other hand because the sediment particle diameter that forms is little (only Be that 1 μ m is following), these particles absorption and in conjunction with a large amount of hydrones, so that the mud flco of Precipitation contains Water rate height, be difficult for precipitation, dewatering rate is low. Moisture percentage in sewage sludge through precipitation reaches more than 98%, presses through sheet frame The moisture percentage in sewage sludge of filter dehydration generally only can reach 65-70% (solid content 30-35%).

Compare with conventional processes, the present invention has the following advantages:

1. the mud particle diameter of Xing Chenging is big, is more than the 5 μ m, easily precipitation;

2. the mud solid content of post precipitation is up to 10-30%, and sludge volume reduces 10-50 doubly, and the sludge disposal expense is low;

3. dehydration property is strong, can directly send drying bed or use dehydration equipment less, reduces dewatering time 90%;

4. the metal ion content in the processed waste water is low;

5. consumption of chemical agent is few, has reduced once more and has polluted, and the waste water treatment and integral expense is cheap.

Claims

1. process for treating acidic sewage with high-density mud is made up of first reactor (1), second reactor (2), aeration tank (3), settling vessel (4), pressure filter device systems such as (5), it is characterized in that: adopt in the oxytropism waste water and add NaOH, Ca (OH) ₂Deng neutralizing agent, make the throw out of the big particle diameter of multiple metal ion formation high-density in the waste water, improve the solid content of mud.

2. process for treating acidic sewage with high-density mud according to claim 1 is characterized in that: add neutralizing agent and carrier in first reactor (1).

3. process for treating acidic sewage with high-density mud according to claim 1 is characterized in that: the waste water pH value Be Controlled in second reactor (2) prevents the dissolving once more of precipitated metal thing within the specific limits.

4. process for treating acidic sewage with high-density mud according to claim 1 is characterized in that: bubbling air in aeration tank (3), quicken the oxidation of metal ion, and aeration tank (3) can think combination with second reactor (2).

5. process for treating acidic sewage with high-density mud according to claim 1 is characterized in that: waste water enters that settling vessel (4) is preceding can to add the flocculation agent aids precipitation, in post precipitation part return of waste water to the first reactor (1) as carrier.