CN1202466A

CN1202466A - Complex treatment process for waste water of paper making ammonium salt process

Info

Publication number: CN1202466A
Application number: CN 98110161
Authority: CN
Inventors: 赵德志; 谢兴华
Original assignee: Individual
Current assignee: Individual
Priority date: 1998-04-17
Filing date: 1998-04-17
Publication date: 1998-12-23
Anticipated expiration: 2018-04-17
Also published as: CN1104379C

Abstract

The treatment includes the treatment of papermaking black liquor, the treatment of the middle-section water and the treatment of white water. The black liquor extruded from steam straw pulp by spiral pulp extruder is either treated through evaporation to concentrate, replenishing trace elements and pelletizing to produce solid granulated fertilizer or mixed directly with trace elements for use as liquid fertilizer supplied to farm land. The middle-section water and the white water are treated separately for irrigation or reuse.

Description

Complex treatment process for waste water of paper making ammonium salt process

The present invention relates to a kind of paper waste treatment process, specifically a kind of complex treatment process for waste water of paper making ammonium salt process.

In recent years, the development of the paper industry of developing country was rapid, and duplicate construction is also comparatively serious, and the interior water pollution of environment is increased the weight of day by day.Though various countries environmental administration has closed down the little paper mill of part in order to curb environmental pollution, still be doubled and redoubled with regard to the integral production scale.

Economic development and environmental pollution are a pair of contradiction.Developing rapidly of paper industry makes environment protection increasingly important.The primary problem of pendulum in face of various countries environmental administration is pulp and paper waste_water.Have only to have solved the paper waste handling problem, just can get rid of the heavy pollution burden of papermaking enterprise, thereby it is more developed by leaps and bounds.

Traditional chemical pulping process mainly contains alkaline process and the slurrying of ammonium method, people know that it mainly is wheat straw that present paper mill produces the used raw material of paper making pulp, the used industrial chemicals of alkaline process is that caustic soda is NaOH, the used industrial chemicals of ammonium method slurrying is an ammonium sulphite, two kinds of paper wastes that paper process produced mainly refer to three parts, and a part is the concentrated black liquid that the straw pulp after the cooking section boiling is extruded through acroll press washer; Two parts are middle section waters that pulp washing, rinsing workshop section produce; Three parts are the plain boiled water that machine hand's section produces, and three partially mixed dischargings together are the papermaking Heisui River of causing the rivers,lakes and seas severe contamination,

One, contain the NaOH that is unfavorable for crop growth in the waste water that alkaline process produced, PH＞9 can not be used for farming and irritate, thereby the key of alkaline process wastewater treatment is exactly to do alkali to reclaim.The deficiency that this alkali reclaiming method in use exists is that facility investment is big, productive expense, and highly energy-consuming is big, the paper plant that annual production is 30000 tons, alkali recycling engineering expense must need 5000～6,000 ten thousand yuan; The paper plant that annual production is 1.5000 tons, a last alkali recycling engineering also need be invested 3000～4,000 ten thousand yuan.This just equals to have declared " death sentence " concerning those middle-size and small-size paper mills.Concerning the paper mill below 15000 tons, go up the alkali recycling engineering and lose more than gain.

Two, neutral ammonium sulfite process is in the progressively test spread stage at present, sophisticated operational path is not also arranged, on quality product, through in a few years practice with grope, though reached the target level of product quality of alkaline process from quality product, but waste water treatment is a new problem, does not up to the present also have successful experience.

The purpose of this invention is to provide a kind of complex treatment process for waste water of paper making ammonium salt process.

The objective of the invention is to realize in the following manner, the concentrated black liquid that papermaking is produced to the ammonium method extrudes through acroll press washer, middle section water and plain boiled water three part waste water are divided and rule, black liquor can be made the fertile and liquid material fertilizer of particulate material, it is turned waste into wealth, middle section water and plain boiled water reach emission standard or repeated use by chemical precipitation, reach the purpose of whole utilizations.

Complex treatment process for waste water of paper making ammonium salt process of the present invention comprises the processing of black liquid, the processing of middle section water and the processing of plain boiled water.

Black liquor treatment technology is: first through evaporation concentration through the black liquor that acroll press washer is extruded, trace element supplement is produced solid particulate composite fertilizer through the tablets press granulation again, and black liquor also can add the trace element back to be used for the farmland as liquid fertilizer.

Middle section water is the pulp washing Javelle water to be filtered with oblique net filtration through cylinder send water collecting basin, squeeze into reaction settling basin by pump after adding 0.03%PAC, precipitating sludge is done fertilizer or soil improvement agent use through mummification, and supernatant liquor send high-rate filter, sealing ditch and oxidation pond to carry out making farming filling or qualified discharge behind the biochemical reaction.

Plain boiled water is handled: be to send water collecting basin to add 0.01%PAC after pump is squeezed into settling tank through the plain boiled water that paper machine gets off, and the reuse of post precipitation clear water, precipitation is sent the middle section water treatment system.

PAC is a water conditioner, is commercially available industrial chemicals.

Concrete technology is as follows:

One, the treatment process of black liquor:

Two, middle section water treatment process: 0.03%PAC

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Pulp washing Javelle water-cylinder filtration-oblique net filtration-middle section water water collecting basin-pump house-

Three, plain boiled water is handled; 0.01%PAC

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Paper machine-plain boiled water-water collecting basin-pump house-settling tank-precipitation is sent the middle section water treatment system

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Supernatant water gives each workshop section's reuse

By above three technologies, realize the comprehensive regulation of paper waste.

The feasibility of this technology:

One, advantage.Utilize imonium to make steaming-boiling agent, utilize ammoniacal liquor, bicarbonate of ammonia or urea to make buffer reagent, boiling wheat straw under high-temperature and high-pressure conditions makes the fibrocyte in the wheat straw separate with other organism, inorganics, and fiber is used for papermaking.2.2 tons of pure wheat straws produce one ton of paper pulp fiber in the practice, other organism in the wheat straw except that Mierocrystalline cellulose and inorganics, the needed trace element of wheat growth, also has the nitrogen in the imonium, nitrogen rope in the buffer reagent, enter together in the waste liquid, come the irrigated farmland, for the farmland provides a large amount of organic and inorganic fertilizer as a kind of multi-component composite fertilizer based on nitrogenous fertilizer, realize returning crop stocks to the field with liquid form (or making solid composite fertilizer), the structure of improving the soil, the agricultural that promotes circulate benignly.

Two, fertilizer efficiency.In the imonium pulping process, though consumed 10% ammonium sulphite, still have 90% ammonium sulphite in the black digestion liquid, and the nitrogen of wheat straw itself is dissolved in also among the black liquor, other also are mixed in wherein as inorganicss such as phosphorus, potassium, sulphur and large amount of organic.Through chemical examination: nitrogenous 10% in the black digestion liquid, contain potassium 5%, phosphorous ten thousand/, contain organism 10%, sulfur-bearing 1%.The ammonium sulphite black liquor is used for grain, Cotton Production, can increase production 20%, is used for vegetables production and can increases production 30-50%, and Dezhou China official form for filing a lawsuit industry group is positioned at the Dezhou City suburb, and 4000 mu of good farmlands are arranged on every side.After the said firm's middle section water processing is up to standard, can all be used for farming and irritates, compound fertilizer making and feed after the concentrated black liquid evaporation concentration have reached the unification of environmental benefit and economic benefit, social benefit.

Above scheme all is applicable to the waste water treatment in the paper mill of pulping with ammonium sulfite method, and does not resemble alkaline process, and alkali reclaims and is subjected to production-scale restriction like that, can fundamentally solve the pollution problem in paper mill.

Through research, exploration in a few years, we have summed up " an ammonium sulphite pulp-making waste-water comprehensive treatment scheme " that overlaps successfully, and this formula investing is few, comprehensive utilization ratio is high.The paper mill effluent in 30000 tons of paper/years is administered 1,000 ten thousand yuan of investments, compare than the alkaline process of identical scale and will economize 4000～5,000 ten thousand yuan, general paper mill can sustain, the water that this method is treated, fertilizer efficiency height, PH=7 is fit to farming and irritates, be a kind of water resources, and the water after the alkaline process processing is alkalescence, is not suitable for farming and irritates, compare with prior art alkali paper-making technology, the waste water treatment and integral utilization of ammonium method papermaking is as far apart as heaven and earth.

Complex treatment process for waste water of paper making ammonium salt process of the present invention is compared with prior art, have technological design rationally, less investment instant effect, easy to implement, characteristics such as economic results in society are remarkable, thereby, have good value for applications.

Claims

1. complex treatment process for waste water of paper making ammonium salt process; comprise the processing of black liquid, the processing of middle section water and the processing of plain boiled water; it is characterized in that straw pulp after the boiling is through the acroll press washer extruding black liquor; black liquor is through the evaporation concentration trace element supplement; produce solid particulate composite fertilizer through the tablets press granulation again; black liquor also can directly add the trace element back to be used for the farmland as liquid fertilizer, is used for farming after middle section water and plain boiled water are handled respectively and irritates and reuse.

2. complex treatment process for waste water of paper making ammonium salt process according to claim 1, it is characterized in that middle section water is the pulp washing Javelle water to be filtered with oblique net filtration through cylinder send water collecting basin, squeeze into reaction settling basin by pump after adding 0.03%PAC, precipitating sludge is done fertilizer and soil improvement agent use through mummification, and supernatant liquor send high-rate filter, sealing ditch and oxidation pond to carry out making farming filling or qualified discharge behind the biochemical reaction.

3. complex treatment process for waste water of paper making ammonium salt process according to claim 1, it is characterized in that the plain boiled water processing: be to send water collecting basin to add 0.01%PAC after pump is squeezed into settling tank through the plain boiled water that paper machine gets off, the reuse of post precipitation clear water, precipitation is sent the middle section water treatment system.