JP2001062494A - Treatment of waste paper sludge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method capable of inexpensively treating waste paper sludge with simple operation for the purpose of the reduction of many paper wastes, such as waste sludge liquids, recovered waste paper and used papers and further for resource recovery of the waste paper. SOLUTION: This method for treatment of the waste paper sludge includes a stage for forming an organic acid component mixture by subjecting the waste paper sludge to an enzyme anaerobic treatment, then acting photosynthesis bacteria on this organic acid component mixture. The photosynthesis bacteria are at least one kind selected from the group consisting of Rhodobacter spheroides, Rhodospirillum rubrum, Rhodobacter capsulatus, Rhodoseudomonas pslastris and Chromatium.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for treating used paper sludge. More specifically, the present invention
The present invention relates to a method of treating waste paper sludge for the purpose of reducing paper waste such as sludge waste liquid, recovered waste paper, used paper, and the like, and further recycling used paper.

[0002]

2. Description of the Related Art From the viewpoint of economic effects such as resource saving and energy saving, the effective use of waste paper as a raw material for papermaking has become increasingly important year by year.

[0003] The process of recycling used paper into a raw material for papermaking (used paper pulp) includes a process of selecting and sorting used paper, a defibration process, a dust removal process, and a deinking process.

(1) Selection and sorting process: This is an operation at a waste paper collector and a receiving factory. In the selection step, a clear grade is set for the used paper, and the paper quality is distinguished (selection of used paper) based on the fiber shape and the impurity content. At the same time, in the sorting process, non-fibrous contaminants such as earth and sand, glass, and fasteners are removed (sorted) by separation sieving or centrifugal washing, and fine crushed materials are removed by using a small aperture or a pressure with pores. Perform by sieving.

(2) Disaggregation and dust removal process: In the disaggregation process,
Using a pulper, digester, kneader, beater, etc., the used paper is defibrated, and in the dust removal process, foreign materials such as plastics such as polyethylene, styrofoam, coated films such as adhesive tape, and other low-density impurities are screened. Using a sifter and a cleaner, the sifted material is collected and separated at a spill section generated in a special sieve and a back-flow washer, and removed.

(3) Deinking step: The deinking step is
Penetration of chemicals (for example, alkalis and detergents (surfactants)) into waste paper, ink (furthermore, adhesives, dyes,
Contaminants of chemical products such as special paints and internal additives.
Flotation that breaks the bond between the fiber and ink, breaks down the ink etc. and disperses it in water, separates the dispersed ink etc. from the pulp (blows air from the bottom, attaches the ink etc. to air bubbles and floats and separates) Method or a washing method of washing with a large amount of water).

[0007] Products made from the waste paper pulp (recycled paper) thus obtained, such as lining paperboard, newsprint, box paper, printing paper, tissue paper, etc., have considerably high performance and quality. However, in terms of price, it has a high cost structure, such as manual classification work required by the collectors required before pulping, and imported wood (chips) is now available at extremely low prices. At present, it is impossible to compete with consumers if consumption is not encouraged by appealing for environmental protection, etc. Rather, the amount of recycled paper used is decreasing.

Further, in the above-mentioned method of recycling waste paper as a pulp resource, the obtained various recycled paper products suffer from contamination and drying of contaminants, aging of substances, and changes in the structure of fibers caused by the recycling process. Due to its low strength, low specific volume, and in some cases, a large average specific surface area, the inner capillary of the fiber dehydrates and decay, becomes a flat structure, sometimes the fiber is split and cut, and the average length is short. It has different physical and mechanical properties from papermaking raw materials and paper fibers.
Therefore, the production of paper and paperboard using recycled paper requires special equipment and processing. Also, once recycled paper cannot be recycled and used many times. Further, there is a problem that the deinking process is required for the regeneration, and paper containing calcium carbonate or gypsum, such as kraft paper, is not suitable for the regeneration.

Nevertheless, in order to landfill such waste paper, Japan has a narrow land area and few such places, and in most cases, there is no alternative but to incinerate it together with other general waste. However, burning such waste paper may cause adverse effects on the human body due to the generation of dioxins and increase in CO ₂ , and cause environmental pollution such as global warming (deforestation due to increased use of paper). From the viewpoint of development, the development of a new effective utilization method of waste paper is an important social issue.

[0010] In addition, the Container and Packaging Recycling Law, which requires manufacturers (makers) to collect and recycle containers and packaging materials, may be enacted soon. The development of a recovery system is urgent. At the same time, the development of an effective use method after collection has been promoted. One of the methods is to replace the conventionally used cushioning material for storage containers, such as styrofoam and air cushions made of polyvinyl chloride, with corrugated cardboard. It has been switched to cushioning materials using bulky paper such as paperboard.
In addition, the use of paper, such as office paper, has been rapidly increasing due to advanced social life and the development of the information industry (such as the introduction of personal computers to workplaces), and the amount of paper consumption tends to increase rapidly every year. As a result, the amount of used paper that greatly exceeds the demand for recycled paper, which is not so large, is collected, and the collected used paper becomes stagnant.Accordingly, sludge waste liquid from the paper industry, collected used paper, used paper, etc. A lot of paper waste is piled up. However, they cannot be easily burned due to dioxin problems, etc., and cause social problems at many recovery sites and treatment plants. Against this background, the purchase price of recycled paper manufactures (manufacturers) has fallen sharply, and now there are some collection companies who have collected them for a fee. The system is not working properly. Nevertheless, Japan is the world's second largest paper consuming country after the United States, but relies on imports for wood (chips), which is the raw material for paper. In particular, in developing countries, the afforestation after logging has been delayed, and the deforestation of fertile soil has led to the progress of desertification. . Therefore, resource saving,
From the viewpoint of economic effects such as energy saving and the protection of resources, there is a strong demand for a new effective use method of waste paper other than the use method of recycled paper.

[0011]

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a novel paper sludge treatment method.

Another object of the present invention is to reduce the amount of waste paper such as sludge waste liquid, recovered waste paper, and used paper, and to reuse waste paper sludge with a simple operation at a low cost for the purpose of recycling waste paper. It relates to a method that can be processed.

[0013]

Means for Solving the Problems The present inventor has conducted intensive studies in view of the above circumstances, and as a result, as for the waste paper of the organic waste which has recently attracted attention, the main component thereof is cellulose, which is similar to starch. It is focused on the fact that it is composed of sugar (glucose) and can be decomposed into the constituent sugar by the enzyme cellulase. That is, the present inventor obtains used paper sludge from a used paper recycling collector or a papermaking company, or chemically digests wastepaper discharged from a used paper recycling collector or a papermaking company into used paper sludge, loosens fibers, and removes enzymes (cellulase). )), Decomposes into sugar components, decomposes them into sugar components, organically oxidizes them by anaerobic treatment, and assimilate them into photosynthetic bacteria, thereby reducing paper waste and achieving deodorization. Thus, the present invention has been completed.

That is, the above objects are as follows:
(E) is achieved.

(A) A method for treating waste paper sludge, comprising the steps of: producing an organic acid mixed component by subjecting waste paper sludge to an enzyme / anaerobic treatment, and then allowing photosynthetic bacteria to act on the organic acid mixed component.

(A) The method according to (A), wherein the enzyme / anaerobic treatment comprises an enzyme treatment with cellulase and an anaerobic treatment using anaerobic bacteria.

(C) The method according to (a) above, wherein the enzyme / anaerobic treatment comprises a treatment using an enzyme-added microorganism preparation.

(D) The photosynthetic bacterium is Rhodobacter sphaeroides, Rhodospirillum rubrum, Rhodobacter capsulatus, Rhodopseudomonas palustri.
The method according to any one of (a) to (c) above, wherein the method is at least one selected from the group consisting of s) and chromium.

(E) The method according to any one of (a) to (d), further comprising a step of obtaining used paper sludge by digesting the used paper.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION The method for treating waste paper sludge of the present invention comprises the steps of: producing an organic acid mixed component by subjecting waste paper sludge to an enzymatic / anaerobic treatment; and then allowing a photosynthetic bacterium to act on the organic acid mixed component. It is characterized by including.

Hereinafter, the present invention will be described in detail.

The used paper sludge to be treated in the method of the present invention may be used directly from used paper sludge from a used paper collection / collection company or a papermaking company, or may be prepared from used paper by a conventionally known method. The waste paper sludge to be obtained may contain moisture or may be in a dry state. In the latter case,
For example, a waste paper collector and a waste paper collected at the receiving factory ground. A process for selecting waste paper that distinguishes paper quality according to its fiber shape and impurity content; sediment, glass, and fasteners by sorting sieving or centrifugal washing. Sorting process to remove non-fibrous contaminants and fine crushed material by pressure screening having small openings or fine pores; Disintegration process to disintegrate waste paper using pulper, digester, kneader, beater, etc. A cooking process (chemical pulp process) using an acid such as a sulfuric acid solution or an alkali such as a sodium hydroxide solution; a screen or a screen for removing contaminants such as plastics such as polyethylene, coated films such as styrene foam, adhesive tape and other low-density contaminants; Use a cleaner to collect and separate the spills in special sieves and overcurrents created in the backflow washer. Dust removal process; and penetration of chemicals (eg, alkalis and detergents (surfactants) etc.) into waste paper; ink (furthermore, contamination of chemical products such as adhesives, dyes, special paints, internal additives, etc.) Breakdown of adhesion between fiber and fiber, miniaturization of ink and dispersion in water, separation of dispersed ink and pulp (air blown from below, float ink by attaching ink to air bubbles, floatation method and large amount of water A method in which a deinking step, such as a washing method in which the ink is washed away, is appropriately selected as necessary can be used.

Further, in the present invention, waste paper is used regardless of whether it is unused paper or used paper, and is a low-gloss paper having a low degree of contamination, such as waste office paper, mixed paper and waste cardboard boxes; Printed but not in the hands of readers, such as newsprint, ledgers, new corrugated cardboard and publications with little alteration or contamination, such as cuttings; used newsprint, tissue paper, paper toweling and printing paper Properties such as the type and amount of papermaking raw materials, such as white paper waste, unprinted ledgers, unprinted newsprint, etc., without any overcoating, clean and excellent gloss, and tough paper quality, gloss and strength. Regardless. Further, the waste paper according to the present invention includes pulp as a raw material for papermaking, and also pulp residue produced as a by-product in the papermaking process. For example, newspaper web; printing paper;
Uncoated printing paper such as gravure paper, printed paper, writing paper, drawing paper, etc .; Coated printing paper such as art paper, coated paper, lightweight coated paper, etc .; Packaging of heavy duty kraft paper, pure white roll paper, etc. Paper: Glassine paper, rice paper, India paper, carbon paper base paper, typewriter paper, copy paper, condenser paper, copy base paper, etc .; tissue paper; tissue paper, kyoka paper, dust paper, toilet paper, sanitary paper, towel paper, processing Household thin paper such as base paper; photosensitive paper, statistical machine card paper, continuous voucher paper, electrical insulating paper, high-quality paper, colored string paper, calligraphy paper, shoji paper, etc .; exterior liner (craft), exterior Liner (jute), interior liner,
Corrugated base paper such as pulp and shinshin; colored paperboard paperboard such as manila balls (coated), manila balls (uncoated), white balls (coated), white balls (uncoated);
Paperboard for paper containers such as yellow paperboard, chipboard and colored paperboard, waterproof base paper; construction material base paper such as gypsum board base paper; paper tube base paper;
Products made from recycled paper such as wrapping paperboard, box paper, printing paper, tissue paper, etc .; (1) softwood pulp, hardwood pulp, softwood mixed pulp, straw pulp, etc. (2) Groundwood pulp, refined mechanical pulp (refined groundwood pulp), thermomechanical pulp, chemithermomechanical pulp, chemimechanical pulp (chemiground pulp), etc .; neutral sulfite Semi-chemical pulp such as semi-chemical pulp, acid semi-sulfite semi-chemical pulp, kraft semi-chemical pulp, etc .; chemical pulp such as sulfite pulp, soda pulp, kraft pulp (sulfate pulp); unbleached pulp; semi-bleached pulp; bleached pulp, etc. Minutes by manufacturing method ), (3) paper pulp; dissolved pulp, etc. (classification according to use), hardwood bleached neutral sulfite semichemical pulp; softwood dissolved sulphite pulp; hardwood dissolved kraft pulp; softwood broadleaf mixed bleached kraft pulp, etc. Various known papers and / or pulp such as a combination of the above can be used as the waste paper. Preferably, used paper is, for example, telephone directory, newspaper, waste paper from office, and the like, and more preferably, used paper is used, for example, shredded and collected.

In the present invention, in the enzyme / anaerobic treatment, the fibrous material (cellulose component) of the waste paper sludge is reduced in molecular weight and saccharified by an enzyme (cellulase), and then the sugar component is organically oxidized using anaerobic bacteria. This is a process consisting of:
At this time, organic acids such as acetic acid, propionic acid and butyric acid, and methane gas as a gas component are generated from the fibrous material (cellulose component) of the waste paper sludge by the enzyme / anaerobic treatment according to the present invention.

In one embodiment of the enzyme / anaerobic treatment method according to the present invention, the waste paper sludge obtained above is suspended at a predetermined concentration in water, and the cellulase dissolved or suspended in a buffer in this suspension is used. Is added, and then left (incubated) at an appropriate temperature for an appropriate time to hydrolyze the β-1,4-glucopyranosyl bond of cellulose to decompose it into a sugar (glucose) component (in the present specification, “ Cellulase enzyme treatment ”or simply“ enzyme treatment ”), and a saccharide component obtained by dissolving or suspending an anaerobic bacterium (group) in a buffer solution. There is a method of culturing under the condition (also referred to herein as “anaerobic treatment”).

Alternatively, in the above embodiment, the waste paper sludge obtained above is suspended in water at a concentration of 5 to 40 (w / v)%, preferably 10 to 20 (w / v)%. After adding the cellulase dissolved or suspended in the buffer and the anaerobic bacterium (group) dissolved or suspended in the buffer, respectively, or adding the solution in which the cellulase and the anaerobic bacterium (group) are dissolved in the buffer together, After addition, add 5-5
The cells may be incubated at 0 ° C., preferably 30 to 40 ° C. for 48 to 168 hours, preferably 60 to 96 hours, under anaerobic conditions by static culture or the like.

In the above embodiment, the concentration of waste paper sludge in water is 5 to 40 (w / v)%, preferably 10 to 20 (w / v)%. At this time, if the concentration of the used paper sludge is less than 5 (w / v)%, the treatment efficiency of the used paper sludge is not sufficient, which is not preferable from an industrial viewpoint, and the product concentration is undesirably reduced. On the other hand, if the concentration of the waste paper sludge exceeds 40 (w / v)%, sufficient fluidity cannot be obtained, cellulase cannot be dispersed well in the waste paper sludge, and does not act sufficiently.
The action of enzymes and cells is impaired, which is also undesirable.

The buffer used in the present invention may be any buffer having an effective pH range of 4 to 9, preferably 7 to 8. Examples of such a buffer include phosphate buffer. , Carbonate buffer, bicarbonate buffer, Tris buffer, citrate-sodium phosphate buffer, succinate-sodium hydroxide buffer, potassium phthalate-sodium hydroxide buffer, imidazole-hydrochloride buffer, Borate buffer, physiological salt solution or HEPES (N-
Good's buffer solution with 2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid), MES [2- (N-morpholino) ethanesulfonic acid] and the like.
Among these, Good's buffer such as HEPES or MES is preferably used as the buffer.

As the cellulase used in the present invention, any of a cellulase isolated from a natural microorganism and a commercially available cellulase can be used. Examples of the natural cellulase include a snail, a termite, Cytophaga, Sporocyto
Bacteria (bacteria, actinomycetes) having cellulolytic properties such as phaga, Cellulomonas, Clostridium, etc. and Trichoderma, Asper
gillus, Penicillium, Rhizopus, Fusarium, Chaetomiu
m, Alternaria, Cladosporium, Botrytis, and other celluloses derived from mold having cellulolytic ability. Examples of commercially available cellulases include those provided by Wako Pure Chemical Industries, Ltd. and Sigma. Of these, commercially available cellulases are preferably used in view of availability.

Further, according to the present invention, the amount of cellulase to be added may be an amount capable of decomposing a sufficient amount of used paper sludge, and varies depending on the type of enzyme used. For example, cellulase manufactured by Wako Pure Chemical Industries, Ltd. When used, it is usually 0.1 to 2.0% by weight, preferably 0.5 to 1.0% by weight, based on waste paper sludge.

The enzyme treatment conditions according to the present invention are appropriately selected depending on the kind of the enzyme to be used and the like, and are not particularly limited as long as the enzyme to be used can act. Specifically, the enzyme treatment temperature is 5 to 50 ° C, preferably 20 to 4 ° C.
0 ° C. Further, in the present invention, a suitable pH at which the cellulase used in the cellulase enzyme treatment exhibits an activity.
Since there is a value and fluctuation of the pH value significantly inhibits enzyme activity and affects saccharification, in the cellulase enzyme treatment according to the present invention, a buffer solution is used to control a large fluctuation of the pH value, and a regulator is added every time. It is preferable to adjust the pH value within a certain range by using this. Specifically, since the cellulase exhibits the maximum activity on the acidic side (around pH 5.0),
The pH of the cellulase enzyme-treated solution is usually 4.0 to 7.0.
0, preferably in the range of 4.5 to 6.5, the buffer solution, an aqueous alkaline solution such as sodium hydroxide, potassium hydroxide and calcium hydroxide or a low acid solution such as hydrochloric acid, carbonic acid and various organic acids. It is preferable to adjust the concentration using a concentration solution. Further, the enzyme treatment time is usually 24 to 96 hours, preferably 48 to 60 hours.

In the present invention, the anaerobic bacterium (group) decomposes by decomposing the high molecular organic component, and the decomposed product is used in the next step instead of carbon dioxide or water by the aerobic bacterium. It can be used for anaerobic treatment because it can produce organic acids and alcohols that are nutrients necessary for metabolism and growth of photosynthetic bacteria.

The anaerobic bacterium (group) used in the present invention is not particularly limited as long as it can assimilate glucose, which is a sugar component produced by the cellulase decomposition of the used paper sludge. Bacteria (group) can be used, in which case one kind of bacteria may be used alone or two or more kinds of bacteria may be used in a mixed form. Specific examples of the anaerobic bacteria (group) include Bacillus, Pseudonomas, and Acidgenes
Acid-producing bacteria and methane-producing bacteria. Alternatively, commercially available anaerobic sludge may be used as the anaerobic bacteria group. Examples of these are granular sludge (manufactured by Fuji Kasui Kogyo Co., Ltd.) and coagulating anaerobic sludge (Ishikawajima-Harima Heavy Industries, Ltd.) Manufactured). Among these, commercially available anaerobic sludge is preferably used in consideration of availability and the fact that a plurality of types of anaerobic bacteria can be used in combination.

In the present invention, the method and conditions for culturing (including both pre-culture and main culture) the anaerobic bacteria (group) depend on the growth range (pH, temperature, etc.) of the anaerobic bacteria (group) used in the present invention. ) And are known to those skilled in the art, but are anaerobic and do not aerate or aerate with nitrogen or carbon dioxide gas or by adding a reducing agent to the medium to reduce the redox potential. It is necessary that the cells be cultured under anaerobic conditions, for example, by lowering the concentration.

In the present invention, anaerobic bacteria (group)
Is preferably added to the enzyme-treated product after being acclimated (pre-cultured) in a glucose-containing medium in advance so that the product treated with the enzyme (cellulase) can be efficiently used. The specific acclimatization method in the above embodiment is not particularly limited as long as the enzyme-treated product can be efficiently assimilated.
Buffer containing ２０20 mM glucose, eg, HEP
ES buffer solution [10 mmol / dm ³ ; pH = 7.0
(Adjusting agent: 1N KOH, 1N HCl)], followed by stationary culture at 30 ° C. for 24 hours. The culture of the anaerobic bacterium (group) thus acclimated may be directly used as a medium in the solution obtained by the above-mentioned enzyme treatment. In this case, if necessary, vitamins may be added to the above-mentioned enzyme-treated solution. , A nitrogen source, a mineral and a phosphorus source (for example, a phosphate source) and the like may be added.

The cultivation conditions (anaerobic treatment conditions) of the anaerobic bacterium (group) according to the present invention include the range of growth of the strain used,
There is no particular limitation as long as it is appropriately selected depending on the composition of the medium and the culturing method, and is a condition under which the strain to be used can grow. Specifically, the culture temperature is 10 to 40 ° C, preferably 30 to 3 ° C.
5 ° C. In addition, there is an appropriate pH value at which the anaerobic bacterium (group) to be used has an activity, and fluctuation of the pH value significantly inhibits the activity and affects the growth of the bacterium. In the cultivation, it is preferable to use a buffer solution as described above to control large fluctuations in the pH value, and to adjust the pH value within a certain range using a regulator every time. Specifically, the pH of the medium during the cultivation of the anaerobic bacterium (group) according to the present invention is usually 6 to 9, preferably 7 to 9.
The concentration is adjusted using the above buffer solution, an aqueous alkali solution such as sodium hydroxide, potassium hydroxide and calcium hydroxide, or a low concentration solution of an acid such as hydrochloric acid, carbonic acid and various organic acids. In addition, the culture time is usually 48
１６168 hours, preferably 60-96 hours.

Further, according to the present invention, anaerobic bacteria (group)
The amount of anaerobic bacteria used may be an amount that can sufficiently assimilate sugars generated by decomposition by cellulase into organic acids, and varies depending on the type of anaerobic bacteria (group) used. For example, granule sludge (Fujikasui Industrial Co., Ltd.)
0.5 to 5.0% by weight based on waste paper sludge,
Preferably it is 1.0 to 2.0% by weight.

Alternatively, as the enzyme / anaerobic treatment method according to the present invention, the waste paper sludge obtained above is suspended at a predetermined concentration in water, and an enzyme-containing microbial preparation dissolved or suspended in a buffer in this suspension. After the addition, a method of incubating at a predetermined temperature for a predetermined time under anaerobic conditions may be used (in this specification, also referred to as “enzyme / anaerobic treatment”). In this method, since the enzyme-added microbial preparation contains one or more enzymes such as a plurality of types of anaerobic bacteria and cellulase, the enzyme treatment is carried out as in the first embodiment. In addition to the two steps of anaerobic treatment and anaerobic treatment, waste paper sludge can be decomposed (saccharified) and saccharide can be converted to organic acids in one step, and thus it is preferably used in the present invention.

The enzyme-added microbial preparation used in the above embodiment includes paper sludge (Paper Sludge) (P
S) Paper Sludge (PS) series (EN) such as 200A, 200L, 500A and 500F
BIO INC. Manufactured).

According to the present invention, the amount of the enzyme-containing microbial preparation to be added may be an amount that can sufficiently assimilate the waste paper sludge with an organic acid, and varies depending on the type of the enzyme-containing microbial preparation to be used. Is usually
It is 0.1 to 2.0% by weight, preferably 0.5 to 1.0% by weight.

The enzyme / anaerobic treatment conditions according to the present invention are appropriately selected depending on the kind of the enzyme-added microbial preparation to be used, and are not particularly limited as long as the preparation to be used can act. Specifically, the enzyme / anaerobic treatment temperature is 5
-40 ° C, preferably 30-35 ° C. In addition, in the present invention, in the enzyme / anaerobic treatment using the enzyme-added microbial preparation, an appropriate pH at which the preparation used exhibits an activity.
PH value fluctuation significantly inhibits the activity and affects the production of organic acids.Therefore, in the enzymatic / anaerobic treatment with the enzyme-added microbial preparation of the present invention, a large fluctuation of the pH value is caused by using a buffer solution. It is preferable to control the pH value and adjust the pH value within a certain range using a regulator every time. Since most of the enzyme-containing microbial preparations used in the present invention exhibit the maximum activity near neutral (pH 7), the pH of the enzyme-containing microbial preparation treatment solution is usually 5 to 8, preferably 7 to 7.
The concentration is adjusted using the above buffer solution, an aqueous alkali solution such as sodium hydroxide, potassium hydroxide and calcium hydroxide, or a low concentration solution of an acid such as hydrochloric acid, carbonic acid and various organic acids. Furthermore, the enzymatic / anaerobic treatment time is usually 24 to 96 hours, preferably 48 to 60 hours.

According to the method of the present invention, such simple enzymatic and anaerobic treatment enables 30-70 waste paper sludge to be recovered.
% By weight, preferably 40-50% by weight, can be converted to an organic acid mixture. The organic acids contained in this organic acid mixture include acetic acid, propionic acid, butyric acid and lactic acid, especially acetic acid, propionic acid and butyric acid.

In the present invention, a step of further utilizing the mixed organic acid obtained by the above-described enzyme / anaerobic treatment with a photosynthetic bacterium is essential. That is, by adding a photosynthetic bacterium using such an organic acid as a nutrient to a solution containing the organic acid obtained in the above step, and culturing the organic acid, the organic acid is metabolized in the cells, and it has been conventionally discarded. Purifies and deodorizes waste paper or waste paper sludge, and also turns it into useful material.

The photosynthetic bacterium used in the present invention is not particularly limited as long as it can assimilate the organic acid generated by the above-mentioned enzyme / anaerobic treatment, and is a conventionally known photosynthetic bacterium belonging to the order of Rhodospirillaceae. Can be used. Specifically, the genus Rhodobacter (Rhodobacter), the genus Rhodopseudomonas (Rhodopseudomonas), the genus Rhodospirillum (Rhodospirillum), the genus Rhodocycla (Rhodocyclu
s) and Rhodospirillaceae, such as Rhodomicobium; Chromaium (Chroma)
tium), Thiocystis, Thiospillum and Thiocapsa, etc .; Chromantiaceae; Ectothiorhodospira; (Chlor
obium), genus Prostecochloris (Prosthecochloris), genus Prelodictyon (Prelodictyon) and chlorochromatium (Chlorochromatium), such as Chlorobiaceae (Chlor
obiaceae); and the genus Chloroflexu
s), Chloronema and Oscillocris
Chlorofleaceae (Chlorofle) such as (Oscillochloris)
xaceae) and the like. Among these, the genus Rhodopseudomonas rum (Rhodobacter sp.), Such as Rhodobacter sp. Rhodospirillum, Chromium sp.
atium sp.) Chromatium is preferably used as a photosynthetic bacterium. The photosynthetic bacteria may be used alone or in a mixture of two or more. Alternatively, commercially available photosynthetic bacteria (often in the form of a mixture of two or more types) may be used. Examples of such commercially available photosynthetic bacteria include PSB (produced by Nippon PSB) and photosynthetic bacteria (Kobayashi). Microbial Science Laboratory), preferably PSB
(Manufactured by Nippon PSB Co., Ltd.) is used.

In the present invention, the photosynthetic bacterium is cultured by pre-culturing the photosynthetic bacterium, and suspending the photosynthetic bacterium thus pre-cultured in a buffer solution with the mixed organic acid obtained above. It is carried out by directly adding to the solution and culturing. At this time, if necessary, furthermore, soybean and wheat hydrolysates such as meat extract, peptone, yeast extract, taste liquid, soybean powder, milk casein, casamino acid, various amino acids, corn steep liquor, other animals and plants ,
Nitrogen sources such as organic nitrogen compounds such as hydrolysates of microorganisms and ammonium salts such as ammonium sulfate [(NH ₄ ) ₂ SO ₄ ]; thiamine hydrochloride (Tiamine-HCl), nicotinic acid, p-aminobenzoic acid, biotin and vitamin solution, such as vitamin B _12; magnesium phosphate manganese, calcium, sodium, potassium, molybdenum, strontium, boron, copper, iron, tin and zinc, hydrochloride, sulfate, butyrate, propionate and An inorganic salt such as acetate may be added as a nutrient source for cell growth.

Specifically, as the pre-culture medium, MY
C (Malate-Yeast-Cazamino acid) medium (composition / 1 liter: 1.0 g DL-sodium malate)
alate), 3.0 g yeast extract, 2.0 g casamino acid; pH 6.8).
SVS (Succinate-Vitamin solution-Ammonium sulfat
e) Medium (composition / 1 liter: 100 ml mineral base, 1.0 g ammonium sulfate, 5.
4 g sodium succinate, 1.0 ml A vitamin solution was made up to a total volume of 500 ml with distilled water, to which 20 mmol / dm ³ potassium dihydrogen phosphate (KH ₂ PO ₄ ) dissolved in 500 ml distilled water was added; pH 7.2. ). At this time, the mineral base (meneral base) is 2.0 g
Magnesium chloride hexahydrate (MgCl ₂ .6H ₂ O),
2.0 g sodium chloride, 0.45 g calcium chloride dihydrate (CaCl ₂ .2H ₂ O) and 10 ml SL
-8 [composition: 1.5 g iron chloride tetrahydrate (FeCl _2.
4H ₂ O), 0.07 g zinc chloride, 0.062 g H ₂
BO _4, 0.017 g of copper chloride dihydrate (CuCl ₂ · 2
_{H 2 O), 0.034g Na 2} MoO 4 · 2H 2 O, 5.
_{2g EDTA-Na, 0.1g MnCl 2} · 4H
₂ O, 0.19 g CoCl ₂ .6H ₂ O and 0.024
g NiCl ₂ .6H ₂ O prepared with distilled water to a total volume of 1 liter] means a solution prepared by using distilled water to a total volume of 1 liter, and the vitamin solution is 0.05 g of thiamine hydrochloride, 0.1 g. 05g nicotinic acid, 0.03g p
-Aminobenzoic acid, 0.01 g biotin and 0.00
Means a solution prepared to a total volume of 1 liter 5g vitamin B ₁₂ with distilled water.

The method and conditions for culturing (including both pre-culture and main culture) of the photosynthetic bacterium performed in the present invention are based on the range of growth (pH, temperature, etc.) of the photosynthetic bacterium used in the present invention.
As is known to those skilled in the art, photosynthetic bacteria are facultatively anaerobic and do not aerate. Alternatively, the photosynthetic bacterium may be cultured under anaerobic conditions while aerating with argon or carbon dioxide gas, or reducing the oxidation-reduction potential by adding a reducing agent to the medium.

The culture vessel used for culturing the photosynthetic bacteria according to the present invention is not particularly limited as long as the photosynthetic bacteria can be sufficiently irradiated with light.
(Polyethylene terephthalate) and a reaction vessel made of an acrylic resin are used.

The conditions for culturing the photosynthetic bacterium according to the present invention are appropriately selected depending on the range of growth of the strain to be used, the composition of the culture medium and the culturing method, and are not particularly limited as long as the strain to be used can grow. Therefore, it is necessary to shine light. At this time, the light may be sunlight or artificially irradiated with a fluorescent lamp, a tungsten lamp or the like. In the latter case, the light irradiation amount is usually 5,000.
~ 50,000lux, preferably 10,000 ~ 1
5,000 lux. As the culture conditions, specifically, the culture temperature is 5 to 40 ° C, preferably 25 to 40 ° C.
35 ° C. In addition, there is an appropriate pH value at which the photosynthetic bacterium used has an activity, and fluctuations in the pH value significantly inhibit the activity and affect the growth of the bacterium. It is preferable to use a solution to control large fluctuations in the pH value, and to adjust the pH value within a certain range using a regulator every time. Specifically, the pH of the above-mentioned buffer and sodium hydroxide is adjusted so that the pH of the medium during the culturing of the photosynthetic bacterium according to the present invention is usually in the range of 6 to 8, preferably 6.5 to 7.5. , Potassium hydroxide and calcium hydroxide or a low-concentration solution of an acid such as hydrochloric acid, carbonic acid and various organic acids. Further, the culture time is usually 24 to 60 hours, preferably 36 to 48 hours.

By the treatment using such a photosynthetic bacterium, the mixed organic acid obtained by the enzyme / anaerobic treatment is further assimilated by the photosynthetic bacterium and metabolized in the cells, thereby purifying and deodorizing. Since the metabolic function of photosynthetic bacteria includes biosynthesis of physiologically active substances such as vitamins and many pigments, the culture solution of photosynthetic bacteria obtained in this way or its diluted solution is used in oligotrophic soil such as sandy soil. As a nutrient for vegetable and house cultivation areas, as a growth promoter for vegetables, fruits and plants, and as a soil conditioner, is effective for cultivation of many vegetables and fruits, and is also effective for improvement of pasture and red soil. Be expected.

[0051]

The present invention will be described below in more detail with reference to examples.

Preparation Example 1 A 10 ml autoclave (39) was placed in a glass test tube.
4.2K, 15 minutes, 98.1Kpa) High pressure The sterilized MYC medium was added to the medium, and a medium loop of Rhodobacter sphaeroides strain as a photosynthetic bacterium was inoculated into the medium, and then subjected to semi-aerobic-light conditions (5Klx, 303k)
The culture was left standing at 30 ° C. for 24 hours to prepare a preculture.

Next, 1 ml of this preculture was added to SVS medium 1
After inoculation into 20 ml, anaerobic-light conditions (15 Klx, 3
Under 03k), the cells were cultured until the late logarithmic phase where the absorbance (OD) at 660 nm was about 1.0 (20 hours, 2.83 mg dry cells / ml).

After completion of the culture, the cells were centrifuged (12,76).
(0 × g, 275 K, 7 minutes). The collected cells were placed in a HEPES buffer solution (pH 7.5; 5
0 mmol / dm ³ ), and then centrifuged (12,
760 × g, 275K, 7 minutes) to prepare a photosynthetic bacterial pellet.

Preparation Example 2 HEPES buffer solution containing 5.0 g / liter glucose and 5 g of granular sludge [10 mmol / dm ³ ;
pH = 7.0 (regulator: 1N KOH, 1N HCl)]
This was added to 300 ml, and this was cultured at 30 ° C. for 24 hours. The culture solution was subjected to suction filtration to prepare an anaerobic bacterial pellet.

Example 1 The following samples A to D were placed in a glass container having a total volume of 500 ml.
(Water content: about 70%) was charged in an amount of 100 g each.

Sample A: papermaking sludge Sample B: papermaking sludge containing 5% calcium carbonate Sample C: discarded cardboard Sample D: papermaking sludge containing 10% ink Next, 0 g was placed in a glass container charged with each sample. 0.1 g of cellulase (manufactured by Wako Pure Chemical Industries) in MES buffer solution [10 m
mol / dm ³ , pH = 5.0 (regulator: 1 NKOH,
[1N HCl)], and each sample was allowed to stand still for 190 hours (about 8 days) under anaerobic conditions in a thermostat kept at 40 ° C ± 3 ° C, whereby each specimen was Enzyme treatment with cellulase.

In the above enzyme treatment, p
H was adjusted to be around 5.0.

The enzyme-treated solution treated in this manner was separated by decantation, and the supernatant was separated from each of the samples A1 and A1.
Called B1, C1 and D1.

Example 2 Into a glass container having a total volume of 500 ml, 100 g of each of the specimens A1 to D1 treated in Example 1 was charged.
5 g of the anaerobic bacterial pellet prepared in Preparation Example 2
In advance in a HEPES buffer solution [10 mmol / dm ³ ; p
H = 7.0 (conditioning agent: 1N KOH, 1N HCl)]
Each sample was subjected to anaerobic treatment by adding the suspension in 300 ml and keeping the sample in a constant temperature bath maintained at 40 ° C. ± 3 ° C. under anaerobic conditions for 96 hours (about 4 days). did.

In the above anaerobic treatment, the pH of the processing solution was adjusted to be around 7, but the pH of the processing solution tended to be shifted to the acidic side over time. It was presumed that organic acids were being generated.

The anaerobic treatment solution thus treated was separated by decantation, and the supernatant was
2, B2, C2 and D2.

Example 3 The following samples A to D were placed in a glass container having a total volume of 500 ml.
(Water content: about 70%) was charged in an amount of 100 g each. Next, 10 g of paper sludge 500F as an enzyme-added microbial preparation was placed in a glass container charged with each sample.
(ENBIO INC.) In a HEPES buffer solution [1
0 mmol / dm ³ ; pH = 7.0 (regulator: 1N K
OH, 1N HCl)], and then allowed to stand for 190 hours (about 8 days) under anaerobic conditions in a thermostat maintained at 40 ° C. ± 3 ° C. The samples were subjected to enzyme and anaerobic treatment with an enzyme-containing microbial preparation.

In the above-mentioned enzyme / anaerobic treatment, the pH of the treatment liquid was adjusted so as to be near neutral (pH 7). However, the pH of the treatment liquid tended to be shifted to the acidic side over time. From this, it was inferred that organic acids were being generated even in this treatment liquid.

The enzyme / anaerobic treatment solution thus treated is separated by decantation, and the supernatants are respectively referred to as samples A3, B3, C3 and D3.

Example 4 For the samples A2 to D2 obtained in Example 2 and the samples A3 to D3 obtained in Example 3, the chemical oxygen demand (CO
D) was simply measured using Wako Pack Test (manufactured by Wako Pure Chemical Industries) and then reanalyzed by a measuring device using the permanganate method. The results are shown in Table 1 below.

[0067]

[Table 1]

From the results shown in Table 1, the specimens A3 to D3 subjected to the enzyme / anaerobic treatment with the enzyme-added microbial preparation (paper sludge 500F) were the specimens A2 subjected to the enzyme treatment with cellulase and the anaerobic treatment with the anaerobic bacteria. ~ D
2, it was found to show a significantly higher COD value than that of
From this, it is considered that the enzyme / anaerobic treatment using the enzyme-added microbial preparation can more effectively organically oxidize waste paper sludge as compared with the case of performing the enzyme treatment and the anaerobic treatment in two steps.

Example 5 For the samples A2 to D2 obtained in Example 2 and the samples A3 to D3 obtained in Example 3, the organic acid component contained in each sample was analyzed by liquid chromatography under the following conditions. The main organic acids produced were acetic acid (retention time: about 9.8 minutes), propionic acid (retention time: about 12 minutes), and butyric acid (retention time: about 15 minutes). Therefore, these organic acids were quantified using the same liquid chromatography as described above, and the results are shown in Table 2 below. FIG. 1 shows a chart of the sample B3 by liquid chromatography.

<Analysis conditions by liquid chromatography> Detector: SHIMADZU SPD-6A UV-210 nm (manufactured by Shimadzu Corporation) Column: ULTRON PS-80H 8φ × 300 mm Carrier: HClO ₄ 22.0 mol / dm ³ pH2.
1 Column temperature: 313.2K Flow rate: 1 ml / min

[0071]

[Table 2]

From the results shown in Table 2, the enzyme treatment with cellulase and the anaerobic treatment with anaerobic bacteria (specimen A2
~ D2) and enzyme / anaerobic treatment (specimen A3 ~ D) with enzyme-containing microbial preparation (paper sludge 500F)
By organically oxidizing waste paper sludge by 3),
It can be seen that a large amount of organic acid is generated, but the amount of organic acid generated at this time is generally smaller than that of the enzyme / anaerobic treatment (samples A3 to D3) using the enzyme-added microbial preparation (paper sludge 500F). Is significantly higher than that by the enzyme treatment with cellulase and the anaerobic treatment with anaerobic bacteria (samples A2 to D2). this is,
Since the enzyme-added microbial preparation contains other enzymes and a plurality of types of dried cells in addition to cellulase, it is considered that the treatment (organic acid conversion) ability is synergistically improved.

Among the organic acids thus produced, acetic acid and propionic acid have a high uptake rate into cells and are suitable for cell growth, while butyric acid has a lower uptake rate than the above-mentioned organic acids. Since the multi-stage growth is possible by using a mixture with an organic acid having a high substrate uptake rate, the organic acid mixture obtained by the method of the present invention has a synergistic effect of the effects described above. In other words, it is expected that by culturing photosynthetic bacteria using such an organic acid mixture, it is possible to grow photosynthetic bacteria more efficiently than an organic acid alone system.

Example 6 Samples A2 and B2 obtained in Example 2 and Example 3
The specimens A3 to D3 obtained in the above were used in a HEPES buffer solution [10
mmol / dm ³ ; pH = 7.0 (conditioner: 1N KO)
H, 1N HCl)].
ml of ammonium sulfate (1.0
mmol / dm ³ ), 0.5 ml of vitamin solution and 1
0 ml of a mineral base was added as a nutrient for cell growth to prepare a culture solution for photosynthetic bacteria.

In a glass container having a total volume of 160 ml, 150 ml of the above-mentioned culture solution for photosynthetic bacteria was charged. These glass containers were inoculated with the NR3 cell pellet prepared in Preparation Example 1 so that the absorbance (OD) at 660 nm was 2.0. In this example, an absorbance (OD) at 660 nm of 1.0 corresponds to 2.83 dry cells g / liter.

Next, this culture solution was placed in a laboratory for 15,000 hours.
While irradiating 0lux light (tungsten lamp)
Under anaerobic conditions in a thermostat maintained at 30 ° C ± 3 ° C, 9
The organic acid in each specimen was metabolized by the photosynthetic bacteria by keeping it standing for 6 hours (about 4 days). At this time, the growth of the photosynthetic bacteria was examined by the absorbance (OD) at a wavelength (660 nm). As a result, the growth of the bacterial cells was stopped several days later.
This is presumed that the organic acid was taken up into the cells at the time of addition at a high rate and was consumed. In this example, the organic acid was added only at the start of the test because the batch method was used.
It is considered that by continuously adding the organic acid over time and performing continuous cultivation, the decrease in the bacterial cell concentration due to the decrease in the organic acid can be stopped, and thus the waste paper (sludge) can be continuously processed. In addition, when the pH of the culture solution was measured over time, no significant change in pH was observed due to the addition of the buffer solution, and it is considered that there is no adverse effect on the bacterial cell concentration due to the pH.

The culture solution thus treated was separated by decantation, and each supernatant was treated with an organic acid (acetic acid, acetic acid,
The decrease (assimilation) of propionic acid and butyric acid) was measured over time by liquid chromatography in the same manner as in Example 5, and the results are shown in FIG.

From FIG. 2, it can be seen that the organic acid is efficiently assimilated (metabolized) by photosynthetic bacteria by the method of the present invention. In other words, the waste paper (sludge) can be efficiently treated by using the method of the present invention. Show.

Example 7 In a PET container having a total volume of 400 ml, 300 ml of a photosynthetic bacteria culture solution prepared in the same manner as in Example 4 was charged. These PET containers were inoculated with 10 ml of PSB (produced by Nippon PSB Co., Ltd.).

Next, the culture solution was allowed to stand still under anaerobic conditions for 120 hours (about 5 days) while irradiating sunlight outdoors, whereby the organic acids in each sample were metabolized by the photosynthetic bacteria. Was. In this example, since the sunlight was used, the irradiation amount of light was affected by the weather, and in fact, there were all weathers of sunny, cloudy, and rainy during the experiment. The light irradiation dose during this experiment was as follows: day 1: 110,000 lux (fine), day 2: 112,
000 lux (sunny), day 3; 8,190 lux (cloudy), day 4; 4,000 lux (rain), and day 5;
33,000lux (fine).

At this time, the growth of the photosynthetic bacterium was measured at a wavelength (660).
As a result, the growth of the bacterial cells was stopped several days later. This is presumed that the organic acid was taken up into the cells at the time of addition at a high rate and was consumed. Further, in this example, the organic acid was added only at the start of the test because the batch method was used. It is considered that the waste paper (sludge) can be continuously processed. In addition, when the pH of the culture solution was measured over time, no significant change in pH was observed due to the addition of the buffer solution, and it is considered that there is no adverse effect on the bacterial cell concentration due to the pH.

The culture solution thus treated was separated by decantation, and each supernatant was treated with an organic acid (acetic acid, acetic acid,
The decrease (assimilation) of propionic acid and butyric acid) was measured over time by liquid chromatography in the same manner as in Example 5, and the results are shown in FIG.

FIG. 3 shows that the organic acid is efficiently assimilated (metabolized) by the photosynthetic bacteria by the method of the present invention. In other words, the waste paper (sludge) can be efficiently treated by using the method of the present invention. Show.

[0084]

As described above, the method for treating waste paper sludge of the present invention is characterized in that the waste paper sludge is treated with a combination of cellulase and anaerobic bacteria or with an enzyme-anaerobic treatment using an enzyme-added microbial preparation to reduce waste paper sludge. After the cellulose is finally converted to the organic acid mixed component,
The method includes a step of causing a photosynthetic bacterium to act on the organic acid mixed component. Therefore, the sludge waste liquid can be obtained by a simple and environmentally friendly operation such as depolymerization of waste paper sludge by the enzyme cellulase (decomposition into sugar components), organic oxidation of the sugar components by anaerobic treatment, and metabolism of the organic acids by photosynthetic bacteria. Many paper wastes that presently have a problem in processing, such as collected waste paper and used paper, are reduced and assimilated. Can deodorize. In addition, all of the above steps do not require special equipment or equipment, so that waste paper sludge can be processed at low cost.

Further, by performing the enzyme / anaerobic treatment using the enzyme-added microbial preparation in the method of the present invention, the number of the above steps can be reduced by one step, and the enzyme treatment and the anaerobic treatment are separately performed in two steps. A higher treatment (organic acid conversion) ability can be exhibited as compared with the case where the above is performed.

The enzyme / anaerobic treatment solution thus obtained has a high organic acid concentration, and the converted organic acid mixture is mainly composed of acetic acid, propionic acid and butyric acid. Of the components, acetic acid and propionic acid have a high uptake rate into cells and are suitable for cell growth, and butyric acid has a lower uptake rate than the above-mentioned organic acids but is mixed with other organic acids having a higher substrate uptake rate. Since multi-stage growth is possible by using the organic acid mixture obtained by the method of the present invention, the above-mentioned effects can be expected to be synergistic, that is, using such an organic acid mixture By culturing the photosynthetic bacterium, the photosynthetic bacterium can grow more efficiently as compared with a conventional culture system using only an organic acid.

As described above, the method of the present invention greatly expects the practical use of the treatment of waste paper or papermaking sludge and the efficient culture of photosynthetic bacteria.

Further, since the metabolic function of the photosynthetic bacterium includes the biosynthetic system of physiologically active substances such as vitamins and many pigments, the metabolic function of the photosynthetic bacterium is obtained through the enzyme / anaerobic treatment and the culturing treatment with the photosynthetic bacterium according to the method of the present invention. The photosynthetic bacterium culture solution or its diluted solution can be used as a nutrient for oligotrophic soil lands such as sandy lands and house cultivation lands, as a growth promoter for vegetables, fruits and plants, and as a soil conditioner for many vegetables and fruits. It can be expected to be effective, and can also be expected to be effective in improving pasture and red soil.

[Brief description of the drawings]

FIG. 1 is a chart of a sample B3 of Example 5 by liquid chromatography.

FIG. 2 is a graph showing changes in various organic acid concentrations and bacterial cell concentrations (OD) with respect to culture time in Example 6 (indoor experiment).

FIG. 3 is a graph showing changes in various organic acid concentrations and bacterial cell concentrations (OD) with respect to culture time in Example 7 (outdoor experiment).

Claims (5)

[Claims] 1. A method for treating waste paper sludge, comprising the steps of: producing an organic acid mixed component by subjecting waste paper sludge to an enzyme / anaerobic treatment, and then allowing photosynthetic bacteria to act on the organic acid mixed component. 2. The enzyme / anaerobic treatment comprises enzyme treatment with cellulase and anaerobic treatment using anaerobic bacteria.
The method of claim 1. 3. The method according to claim 1, wherein the enzyme / anaerobic treatment comprises a treatment using an enzyme-added microbial preparation. 4. The photosynthetic bacterium is Rhodobacter sphaeroides, Rhodospirillum rubrum, Rhodobacter
The method according to any one of claims 1 to 3, wherein the method is at least one selected from the group consisting of Rhodobacter capsulatus, Rhodopseudomonas palustris, and Chromatium. 5. The method according to claim 1, further comprising a step of obtaining waste paper sludge by digesting the waste paper.