CN104692612B

CN104692612B - Dehydration of papermaking sludge composite flocculation agent

Info

Publication number: CN104692612B
Application number: CN201510120077.7A
Authority: CN
Inventors: 凌伟明; 丁海明; 丁茂潮; 金鹤生; 金连平
Original assignee: Zhejiang Ai Kesai Environmental Science And Technology Limited-Liability Co
Current assignee: Zhejiang Ai Kesai Environmental Science And Technology Limited-Liability Co
Priority date: 2015-03-18
Filing date: 2015-03-18
Publication date: 2016-06-01
Anticipated expiration: 2035-03-18
Also published as: CN104692612A

Abstract

The present invention relates to a kind of flocculation agent, in particular to a kind of flocculation agent for dehydration of papermaking sludge. The present invention provides a kind of flocculation agent, and it is made up of inorganic flocculating agent, organic floculant, biological flocculant, tensio-active agent, activator and agglomerator; The paper mill sludge specific complex type flocculation agent of the present invention, it is possible to improve the dehydration property of paper mill sludge, it is to increase the activity of paper mill sludge, improve the reunion performance of paper mill sludge, reduce cost.

Description

Dehydration of papermaking sludge composite flocculation agent

Technical field

The present invention relates to technical field of sludge treatment, particularly relate to a kind of composite flocculation agent for paper mill sludge process.

Background technology

The sludge quantity of pulping wastewater treatment is big, is generally 5��10 times of equal scale municipal sewage plant. According to investigation, the sludge quantity more than 500 ten thousand tons that annual China enterprises in pulp and paper industry produces. The mud of papermaking wastewater treatment system can be divided into preliminary sludge, two grades of mud, three grades of mud and mixing sludge totally 4 kinds. Preliminary sludge, by sieving slag and high amount of inorganic filler forms, can form harder mud cake, easily dewater, and after dehydration, mass dryness fraction is higher; Two grades of mud are often called active sludge, are generally and adopt the method for biological chemistry to remove in colloidal state and the organic pollutant of dissolved state, primarily of protein composition, and more difficult dehydration; The mud that three grades of mud is mainly in Sewage advanced treatment process flocculation sediment to be produced, it is very difficult to dehydration, above mud mix after mud be called mixing sludge, mixing sludge water ratio can up to 96-99.8%.

Particle in paper mill sludge is mainly colloidal solid, has complicated structure, very strong with the bonding force of water. The form existed in mud by moisture can be divided into interstitial water, capillary water, surface adsorption water and internal combustion water. Interstitial water is the free water content that mud granule surrounds, and is not directly combined with solid, it is easy to separation, only utilizes action of gravity just can be separated; Capillary Bound moisture is the moisture acting on formation on solid particulate surface in contact due to capillary force, accounts for the 15-25% of total water content, has stronger bonding force, can remove the capillary Bound moisture of about 10% by higher mechanicals efforts; Surface adsorption water is the moisture of absorption under surface tension effects, accounts for the 2-% of total water content. Colloidal solid all with the electric charge of same nature, repels mutually, hinders the gathering of particle, grows up, and keeps steady state, by adding in flocculation agent and electric charge, particle can only be made to be unsteady state, be attached on together, finally settle down; Internal combustion water refers to the moisture in being included in paper mill sludge microorganism cells body, cannot mechanically remove.

In prior art, paper mill sludge needs to add the dewatering efficiency that chemical reagent carries out chemical conditioning and just can reach higher usually, general conventional chemical reagent comprises organic polymer coargulator and inorganic flocculating agent, conventional organic polymer coargulator has polyacrylamide, and inorganic flocculating agent has aluminum chloride, iron(ic) chloride, polymerize aluminum chloride, aluminium silicate polymer, aluminium iron polychloride etc.; But research display, adds amendment and can only improve dewatering speed, increase sludge dewatering amount is not too many; Single flocculation agent can only for the water generation effect of one or both types in paper mill sludge, and reality is limited on dehydrating amount impact; Prior art also has technology that is inorganic and organic floculant collocation use, but the technical scheme retrieved at present does not all possess the de-ability except various types of water comprehensively, the de-amount of removing of water is not increased significantly; Therefore urgently need to find new conditioning medicament to change the degree of dehydration of paper mill sludge.

In addition, in prior art, flocculation agent is of a great variety, various inorganic or organic floculant and the kind with the flocculation agent of various functional group may reach tens thousand of kinds, but these flocculation agents are when combination collocation, owing to the mechanism of the synergy between each flocculation agent or synergism is indefinite, prior art cannot provide and between flocculation agent, carry out the instruction arranging in pairs or groups or coordinate or guidance, only rely on combination repeatedly and attempt obtaining the good flocculation agent of effect with certain randomness and Unpredictability, and the probability of failure is higher; In prior art also there is the high problem of price in existing commercialization flocculation agent, result in the running cost of sludge treatment higher;

The present invention is for overcoming above-mentioned defect, propose a kind of flocculation agent that can improve sludge dewatering amount and rate of water loss completely newly, the flocculating properties of this kind of different flocculation agent kind of flocculation agent foundation, comprise molecular structure, the physico-chemical property such as electron cloud structure and the characteristic of functional group that has, work in coordination with from enhancing molecule, promote to set out in the aspects such as component electron framework optimization, consider in conjunction with the existence etc. of water in mud is many-sided, select the de-flocculant component with specific cooperation and reinforcing effect removed being suitable for all kinds of water in mud, selected composition cooperatively interacts, mutually collaborative, and it is with low cost, can greatly promote that in mud, the de-of water removes.

Summary of the invention

The present invention is directed to the defect that dehydration rate is not high, running cost is higher that in prior art, sludge flocculation agent has, it is intended to provide a kind of novel built flocculation agent. This novel papermaking mud specific complex type flocculation agent, it is possible to improve the dehydration property of paper mill sludge, it is to increase the activity of paper mill sludge, improve the reunion performance of paper mill sludge, reduce cost.

The flocculation agent of the present invention is composed of the following components: inorganic flocculating agent, organic floculant, biological flocculant, tensio-active agent, activator, agglomerator.

Wherein, inorganic flocculating agent preferably includes the inorganic salt of iron or aluminium;

Described organic floculant preferably includes the organic floculant of cation-modified group; Further organic floculant preferably includes cationic high-molecular organic floculant or Amphiphatic high polymer organic floculant; Owing to mud is usually with negative charge, therefore select the polymeric flocculant with cation group to neutralize above-mentioned negative charge, make mud granule be adsorbed on above-mentioned cation group and form big wadding body;

Described biological flocculant can be selected NOC-1 flocculation agent or cultivate biological flocculant with P.Alcaligene bacterium, filtering out the biological inoculum with good flocculence the supernatant liquor of the aerobic activated sludge that further described microbial flocculant preferably produces from paper waste, its screening method can adopt biological flocculant cultural method conventional in prior art;

The amphoterics of the preferred polymer of described tensio-active agent, it is more preferable to positively charged ion ctab surface promoting agent or palmityl trimethyl ammonium chloride; The both sexes that tensio-active agent has and solublization, the outer organism of mud born of the same parents is had good extraction effect by it, and under charge neutrality effect and Long carbon chain structure, tensio-active agent can reduce mud wadding body negative charge, and by Long carbon chain, mud is re-united, the dewatering of mud is greatly improved;

The preferred zinc salt of described activator or mantoquita, such as zinc chloride, zinc sulfate, cupric chloride etc.; Activator can increase mud space, it is to increase the size of sludge water circulation road, is conducive to surface water and the de-of interstitial water to remove, and adds salt and mud extracellular salinity can be made to improve, and what be beneficial in born of the same parents water exosmoses and de-remove;

The preferred solid slag of described agglomerator, comprise the hard particles such as flyash, quartz sand, slag, it can improve the gap between mud granule, the particle collision probability that adds when making press filtration or mechanical dehydration of hard particles increases, and extrudes further or causes breaking thus promoting that in cell, the de-of Bound moisture removes of cell;

The preferred inorganic flocculating agent 10-40% of the weight proportion of each component of above-mentioned flocculation agent, organic floculant 10-40%, biological flocculant 5-20%, tensio-active agent 5-10%, activator 5-10%, agglomerator 5-10%;

Preferred inorganic flocculating agent 25% further, organic floculant 25%, biological flocculant 20%, tensio-active agent 10%, activator 10%, agglomerator 10%;

The flocculation agent of the present invention has the following advantages:

1. the flocculation agent of the present invention utilizes the difference of the flocculation character of different sorts flocculation agent, multi-faceted, multi-angle impels the de-of all kinds of water in mud to remove, and the inorganic flocculating agent added can be used as skeleton, makes mud wadding body keep porous when dewatering, stop the collapse of wadding body, reduce the compressibility of mud cake; Add organic floculant and then improve mud granule surface charge and interfacial activity, sludge filtration speed can be increased substantially;

2. the biological flocculant added in flocculation agent of the present invention can also reduce use cost under the prerequisite ensureing flocculating effect, the environment-friendly degradable of biological flocculant own, the floc microbe contained in special utilization original inhabitants bacterium, paper mill sludge is had better adaptability by it;

3. the flocculation agent of the present invention has unique ground surface activity, and it can reduce surface tension, increases solid/liquid interfaces contact angle, thus reduces capillary pressure; Flocculation agent of the present invention has positive charge simultaneously, and mud granule surface is with negative charge, by acting on mutually between electric charge, flocculation agent is made better to be adsorbed in mud granule surface, thus neutralize particle surface with negative charge, and compress colloid electrostatic double layer, mud granule surface hydration film thickness is weakened;

4. the Long carbon chain structure that the flocculation agent of the present invention has can by adsorption bridging effect, molecules a large amount of in mud is passed through throwing out, flocculate into the closely knit big floc sedimentation of diameter at 5-10mm, thus greatly reduce the quantity of kapillary in mud wadding body, and the radius making kapillary increases; The flocculation agent of the present invention considerably increases the quantity in big space in mud wadding body, make circulation passage in mud wadding body more unobstructed, also the pressure of capillary water in mud wadding body is significantly reduced so that part is difficult to the free water that the de-capillary water removed changes into easily removal;

5. the present invention adds activator and agglomerator, produces synergy with above-mentioned flocculation agent, it may be achieved the effect of dewatering synergy, is conducive to giving full play to the function and efficacy of each flocculation agent;

6. the flocculation agent of the present invention adds inorganic hard particle, utilize the extrusion and collision between particle that water in born of the same parents can be made better to discharge, and under the cooperation effect of other flocculation agent, the water deviate from is changed into free-water, thus the compound use of multiple flocculation agent can improve the dewatering of mud well.

7. surface planar water and internal combustion water can be carried out modified tempering process by the flocculation agent of the present invention, by changing its original character, destroy its connection, internal combustion water is made to turn into capillary Bound moisture, surface adsorption water turns into interstitial water, through gravity dehydration and mechanical dehydration, moisture is deviate from again, improve sludge dewatering efficiency further, test-results surface, adopt the flocculation agent process paper mill sludge of the present invention, under the dehydration means of routine, moisture percentage in sewage sludge can be reduced to 20% 30%, and adopts conventional flocculation agent water ratio generally can only be reduced to about 50-60%.

8. the flocculation agent of the present invention is with low cost, and suitability is good, and environmental protection.

Embodiment

Select water ratio be 90% paper mill sludge as subjects, configure following weight composition flocculation agent (see table 1):

Table 1

A, B, C, the D above-mentioned configuration obtained tetra-kinds of flocculation agents join in subjects by the amount of 65 kg/ton paper mill sludges, contrast with existing paper mill sludge flocculation agent, test-results following (see table 2):

Table 2

Can find out that from above test-results when selecting flocculation agent of the present invention, the water ratio of paper mill sludge is reduced to 22%, and when selecting existing paper mill sludge flocculation agent, the water ratio of paper mill sludge is only reduced to 56%.

Above-described flocculation agent; it it is only the present invention's preferably embodiment; but protection scope of the present invention is not limited to this; any it is familiar with those skilled in the art in the scope that the present invention discloses; can expecting that same or similar change or replacement mode are all in protection scope of the present invention easily, the content that the present invention does not do to state in detail belongs to the common practise of those skilled in the art.

Claims

1. a dehydration of papermaking sludge composite flocculation agent, it is made up of the component of following weight percent:

Inorganic flocculating agent 10-40%;

Organic floculant 10-40%;

Biological flocculant 5-20%;

Tensio-active agent 5-10%;

Activator 5-10%;

Agglomerator 5-10%, the biological flocculant that wherein said biological flocculant is selected NOC-1 flocculation agent or cultivated with P.Alcaligene bacterium.

2. flocculation agent as claimed in claim 1, wherein said inorganic flocculating agent comprises the inorganic salt of iron or aluminium.

3. flocculation agent as claimed in claim 1, wherein said organic floculant is the organic floculant comprising cation-modified group.

4. flocculation agent as claimed in claim 3, the wherein said organic floculant comprising cation-modified group comprises cationic high-molecular organic floculant or Amphiphatic high polymer organic floculant.

5. flocculation agent as claimed in claim 1, wherein said biological flocculant is that the biological inoculum with good flocculence filtered out from the supernatant liquor of the aerobic activated sludge of paper waste generation is cultivated into.

6. flocculation agent as claimed in claim 1, wherein said tensio-active agent is positively charged ion ctab surface promoting agent or palmityl trimethyl ammonium chloride.

7. flocculation agent as claimed in claim 1, wherein said activator is zinc salt or mantoquita.

8. flocculation agent as claimed in claim 1, wherein said agglomerator is solid slag, comprises any one in flyash, quartz sand, slag.

9. flocculation agent as claimed in claim 1, the weight percent of each component of above-mentioned flocculation agent is inorganic flocculating agent 25%, organic floculant 25%, biological flocculant 20%, tensio-active agent 10%, activator 10%, agglomerator 10%.