CN102964053B

CN102964053B - Domestic sludge drying treatment method

Info

Publication number: CN102964053B
Application number: CN201210450327.XA
Authority: CN
Inventors: 徐渊
Original assignee: Individual
Current assignee: Individual
Priority date: 2012-11-09
Filing date: 2012-11-09
Publication date: 2014-06-04
Anticipated expiration: 2032-11-09
Also published as: CN102964053A

Abstract

The invention relates to the technical field of sludge treatment, particularly relates to a domestic sludge drying treatment method, and solves the problems of low treatment capacity, high cost and poor effect in the existing domestic sludge dewatering and drying treatment. The method is characterized by comprising the following steps: adding an additive in the drying treatment, wherein the formula of the additive comprises the following components in percentage by mass of domestic sludge: 3-5% of slaked lime, 15-25% of sawdust, 0.5-1% of bleaching powder and 0.3-0.7% of ferrous sulfate, and the components are evenly mixed; standing the additive prepared according to the formula for more than half an hour; transferring the additive together with 2-3 ppm of polyacrylamide (by mass of the absolute dry sludge) into a press filter through a pneumatic diaphragm pump; and then, adding the domestic sludge, performing water squeezing treatment, and drying to form sludge cakes. According to the invention, the additive is wide in source and low in price; the method is simple to operate; the water content of the dried sludge is about 50%; and the dewatering effect is remarkable.

Description

The method of one way of life sludge drying processing

Technical field

The present invention relates to a kind of technical field of sludge treatment, particularly the method for one way of life sludge drying processing.

Background technology

The quantity discharged of sanitary sewage has exceeded industrial sewage quantity discharged, and mud is the final accessory products of sewage disposal, and whether mud can properly dispose the success or not that is related to whole Sewage treatment systems.The main disposal means of mud have at present: sanitary landfill, compost, burning, but sanitary landfill has secondary pollution, burning is a kind of good method, not only realize the maximization of mud decrement, and can resource again utilize, for the generating that heats, the effects such as sludge incineration ash energy brickmaking, the cost of balance sludge treatment, realizes innoxious, minimizing, the resource utilization of mud.

Moisture percentage in sewage sludge is the key issue of restriction sludge disposal and utilization, no matter be that this factor is not all walked around in sanitary landfill, compost or burning.Mummification link is the key link of sludge treatment disposal system energy consumption, and the new technology research and development of mummification are to realize the energy-saving and cost-reducing impetus of sludge treating system, and moisture percentage in sewage sludge more high heating value is lower, generally in the time that water ratio reaches 50%, is just applicable to burning.

Moisture in mud is divided into four kinds by its existence: the one, and interstitial water, is the free water content that mud granule surrounds, and generally accounts for 70% left and right of mud total water content; The 2nd, capillary water is between mud granule or particle crack in the moisture that combines due to wicking action and mud granule, account for 20% left and right of mud total water content; The 3rd, planar water, is the moisture that is adsorbed on mud granule surface due to capillary effect, has extremely strong surface adsorption power because mud granule is little; The 4th, in conjunction with water, be included in the intracellular moisture of sludge microbe, only have and destroyed microorganism cells and just can make to separate in conjunction with water.Account for altogether 10% left and right of mud total water content in conjunction with water and planar water.Analyze according to its existence, interstitial water is the most easily sloughed in theory.And in its metabolic process, secrete the extracellular polymeric in cells in vitro because mud granule surface adsorption has various charged ions and microorganism, these charged particles and extracellular polymeric have very strong water holdup, these mud granules have formed mud group, form various capillary channels, capillary water in planar water and the capillary channel that hold on mud granule surface is irreducible water, is not easy to slough; Only have destroy microorganisms cell just can become free water in conjunction with water, so the object of sludge dewatering is mainly intergranular interstitial water.

The difficulty or ease of sludge dewatering are except outside the Pass the existence form in mud has with moisture, also with the granular size of mud, sludge specific resistance is relevant with organic content, mud granule is thinner, organic content is higher, sludge specific resistance is larger, the difficulty of its dehydration is just larger, and domestic sludge particle just belongs to subparticle.

With existing technology and condition, how water ratio being dropped to 50% is a difficult problem, and in general water ratio has been difficult to continue dehydration since 80% simple mechanical external force again.Existing domestic sludge mummification means are a lot, if patent publication No. is CN2910920Y sludge drying and incineration system, adopt thermal oil as thermal medium, adopt two-step desulfurization technology.And for example patent publication No. is CN201999846U sludge drying treatment system, adopts the technical schemes such as mud and lime mixing desiccation apparatus, though there is its saving grace, but occupation of land amount is large, and disposing capacity is low, and cost of disposal is too high, dehydrating effect is undesirable, is not suitable for burning.

Summary of the invention

The object of the invention is to process in order to solve existing domestic sludge dehydration and drying that the processing power existing is low, cost is high, the problem of weak effect, provide add materials cooperation science, material of one easily to get, dehydration and drying is effective, the method for the domestic sludge drying and other treatment that comprehensive cost is low.

Above-mentioned technical problem of the present invention is mainly solved by following technical proposals: the method for one way of life sludge drying processing, it is characterized in that will adding a kind of additive in drying and other treatment, described additive has following formula: do not add 3～5% white lime, 15～25% sawdust, 0.5～1% chlorinated lime and 0.3～0.7% ferrous sulfate by domestic sludge quality score, and mix; The additive obtaining by described formula is left standstill to the above time of half an hour, the polyacrylamide that adopts pneumatic diaphragm pump that additive is counted to 2～3ppm together with the quality of described over dry mud is sent in pressure filter, after adding again domestic sludge, carry out hydraulic pressure squeezing processing, after mummification, form mud cake.Pressure filter is plate and frame structure.White lime is as properties-correcting agent, its effect is the permeability coefficient that improves mud, when mud is under pressure, moisture can be discharged quickly, in mud, add appropriate white lime and can greatly shorten the time that squeezing is processed, can also make auxiliary pad for power plant's tail gas after incineration desulfurization, add dry hydrate amount to optimum by the per-cent of mud over dry quality, farthest to save time, control cost.Chlorinated lime, as sterilant, can kill the microorganism in mud, the intracellular combination water of releasing microbe.PH value in the adjustable alkaline water of ferrous sulfate, organically combines with suspended substance in water, and accelerates precipitation, has germicidal action simultaneously.Polyacrylamide with together with the mud after additive mixing of materials, squeeze into pressure filter by pneumatic diaphragm pump, after mixing completely than mud and polyacrylamide like this, squeeze into again the better effects if of pressure filter squeezing.

As preferably, the pressure of the domestic sludge adding in described pressure filter is 0.5MPa, and the hydraulic pressure that hydraulic pressure squeezes is 0.5～0.6MPa.

As preferably, described polyacrylamide is cationic polyacrylamide, ion degree 35, and molecular weight is 8,000,000.Cationic polyacrylamide is reducing the ability that is greater than the anionic polyacrylamide under same condition in domestic sludge resistivity ability, ability in reduction surface tension is also greater than the ability of the anionic polyacrylamide under same condition, therefore adopts this kind of flocculation agent.

As preferably, after during described hydraulic pressure squeezes and processes, the pressure of pressure filter rises to 10MPa gradually by zero, within the scope of 10～13MPa, regulate, pressure filter automatic compensation, squeezing is to no longer there are flowing out.The pressure rising gradually flows out the moisture squeezing out gradually mud in drainage procedure, can not produce back suction phenomenon.

As preferably, the filter plate of described pressure filter has filter cloth parcel, and filter cloth type is selected 80 object monofilament filter cloths.The present invention improves the filter cloth of pressure filter, makes its squeezing domestic sludge preferably.For the potential of hydrogen of material, the size of material particles, the viscosity of material, the adhesive of filter residue, the different situations such as the shape of filter residue, all by realizing with different canvas press cloths, each piece filter press filter board has filter cloth parcel, for the requirement of different filtering objects, determines the material that it uses filter cloth, model, filter cloth is the heart of pressure filter thus.Domestic sludge has the features such as particle is little, viscosity is large, fiber is tiny than industrial sludges such as papermaking, so filter cloth type is selected monofilament filter cloth, monofilament filter cloth has following advantage: the one, and single synthon are weaved and are formed, and intensity is large, be difficult for blocking, do not have the situation of broken yarn; The 2nd, surface is high, not yielding through heat setting type processing, stability, and aperture is even; The 3rd, the surperficial monofilament filter cloth through calender process, smooth surface, filter cloth easily peels off, easy cleaning, regeneration is easily.In material, select terylene filter cloth.What order number was larger is that the filter cloth water outlet that filter opening is little is not easy, easily stop up, and order number than 80 orders more hour material easily run away, water outlet muddiness.

As preferably, the thickness≤30mm of described mud cake.The mud cake that present method obtains, in actual production, to enter next process, be transported to and in crusher, carry out break process, then deliver to and in boiler, carry out burning disposal, if the thickness of mud cake exceedes 30mm, dehydrating effect is poor, and the larger conveying of volume requires also high, and has increased broken difficulty.

As preferably, the granularity of described sawdust powder is 20～30 orders, water ratio≤50%, thermal value >=1700Cal/g.Granularity is controlled at the sawdust between 20～30 orders, dehydrating effect the best of mud.The effect of sawdust is to help mud to reduce than resistance as auxiliary agent, and sludge specific resistance value is lower, and dehydrating effect is better.Sawdust is meticulous is greater than 30 orders as granularity, and the meticulous unfavorable reduction of fiber is than resistance, and dehydrating effect is just poor; Sawdust is crossed thick as granularity and is less than 20 orders, affects charging, can damage the barrier film of filter in expressing process.

As preferably, described mud is domestic sludge, from sewage work, and water ratio≤80%.

The invention has the beneficial effects as follows: known by following table data, through the dosage comparison of additive, add sawdust powder, ferrous sulfate, the chlorinated lime of the technical program, the amount of white lime can increase dehydrating effect and shorten the squeezing treatment time; Additive source is sufficient, and cheap, simple to operate, after mummification, sludge moisture content is in 50% left and right, and dehydrating effect is obvious, and production unit, without particular requirement, is easily promoted to the extensive domestic sludge of processing.

Following table is that relation between time, water ratio is squeezed in the each composition of additive and domestic sludge mummification.

Embodiment

Below by embodiment, technical scheme of the present invention is described in further detail.

The method of the present embodiment one way of life sludge drying processing, in agitated pool, putting into 40Kg water ratio is 75% domestic sludge, 400Kg adds water, adding order number is that 30 orders, water ratio are 48%, the 6Kg sawdust powder of thermal value 1778Cal/g, add 0.2Kg ferrous sulfate, 1.5Kg dry hydrate and 0.3Kg chlorinated lime, stir.Getting polyacrylamide ready is cationic polyacrylamide, ion degree 35, and molecular weight is 8,000,000, and polyacrylamide solution is 3Kg, and concentration is 0.26%, and polyacrylamide is 7.8g.

After sampling, recording mud solid content is 9.7%, then with pneumatic diaphragm pump, mud is squeezed into pressure filter together with the polyacrylamide solution preparing, and the filter plate of pressure filter all adopts 80 object monofilament filter cloth parcels; The pressure of sending into of material is 0.5MPa, after one hour feeding complete, open booster water pump, increase gradually hydraulic pressure, finally remain on 0.6MPa; The pressure of pressure filter remains on 11MPa after rising to gradually 10MPa by zero, and pressure filter adopts automatic compensation, till squeezing always extremely no longer there are flowing out; Close booster water pump, squeezing finishes, and it is one hour that whole hydraulic pressure squeezes the treatment time.

Obtain the mud cake of 55KG, after testing, its water ratio is 47.24%, and thermal value is 1275Cal/g, and hmc is 30mm, and mud cake physical dimension size is 1500mm × 1500mm × 30mm.

Following table is the actual mummification comparison of adding by the each composition of additive, one group of data of the squeezing time obtaining, water ratio, thermal value.

As seen from the above table, through the dosage comparison of additive, add the amount of sawdust powder, ferrous sulfate and chlorinated lime that the present invention sets can increase dehydrating effect, add white lime can shorten the squeezing treatment time.In addition, add polyacrylamide can shorten into the mud time.

Above-described embodiment is to explanation of the present invention, is not limitation of the invention, any method after simple transformation of the present invention is all belonged to protection scope of the present invention.

Claims

1. the method for one way of life sludge drying processing, it is characterized in that will adding a kind of additive in drying and other treatment, described additive has following formula: do not add 3～5% white lime, 15～25% sawdust, 0.5～1% chlorinated lime and 0.3～0.7% ferrous sulfate by domestic sludge quality score, and mix; The additive obtaining by described formula is left standstill to the above time of half an hour, the polyacrylamide that adopts pneumatic diaphragm pump that additive is counted to 2～3ppm together with the quality of over dry mud is sent in pressure filter, after adding again domestic sludge, carry out hydraulic pressure squeezing processing, after mummification, form mud cake; The pressure of the domestic sludge adding in pressure filter is 0.5MPa, and the hydraulic pressure that hydraulic pressure squeezes is 0.5～0.6MPa; Described polyacrylamide is cationic polyacrylamide, ion degree 35, and molecular weight is 8,000,000; After during described hydraulic pressure squeezes and processes, the pressure of pressure filter rises to 10MPa gradually by zero, within the scope of 10～13MPa, regulate, pressure filter automatic compensation, squeezing is to no longer there are flowing out; The filter plate of described pressure filter has filter cloth parcel, and filter cloth type is selected 80 object monofilament filter cloths; Thickness≤the 30mm of described mud cake; The granularity of described sawdust is 20～30 orders, water ratio≤50%, thermal value >=1700cal/g; Described domestic sludge is from sewage work, water ratio≤80%.