JPS6256392A - Manufacture of manure - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method for producing compost using human waste sludge and papermaking sludge as raw materials.

<Prior Art> Generally, human waste sludge is surplus sludge with a water content of 75 to 85% (weight %, the same applies hereinafter) that is produced as a by-product when human excrement is collected and subjected to biological treatment in a treatment facility. Septic tank sludge is sludge produced from septic tanks installed in each building, and is either treated at a human waste treatment facility or dumped into the ocean.

In this specification, the above-mentioned human waste sludge and septic tank sludge are collectively referred to as "raw sludge."

In order to compost the human waste sludge through aerobic fermentation, it is necessary to add and mix sawdust, rice husk, wood chips, etc. to the human waste sludge as a moisture regulating material, since the moisture content is high if it is left as is. to a moisture content suitable for aerobic fermentation (70
% or less) and then aerobic fermentation is known.

On the other hand, paper sludge is a waste product discharged from the pulp and paper industry. This papermaking sludge is a pulp waste liquid whose main component is low-concentration gluegenin sulfonic acid, which is not subject to concentrated combustion or wet combustion, and which is not subject to concentrated combustion or wet combustion, and is processed through primary treatment such as coagulation sedimentation or flotation separation. This is surplus sludge with a moisture content of 65 to 75% that is produced as a by-product when biological treatment is performed.

Attempts have also been made to compost such paper sludge. For example, three fertilizer elements and magnesium lime are added to papermaking sludge, passed through a rotary kiln to form a granular semi-finished product with a moisture content of about 50%, and then piled up and aged.
A method of composting is known.

<Problems to be Solved by the Invention> As mentioned above, methods of using human waste sludge or paper manufacturing sludge separately as compost raw materials have been studied, but none of these methods use human waste sludge or paper manufacturing sludge in addition to human waste sludge or paper manufacturing sludge. It requires secondary materials, and in addition, the amount that can be used as compost raw material is only a small portion compared to the amount of each waste, and most of it is disposed of by raw dumping, landfill, incineration, or drying. is the reality. However, in the case of raw dumping or landfilling, there is a risk of secondary pollution, and in the case of incineration or drying, fuel is required.

Therefore, the purpose of this invention is to provide a composting method that can effectively utilize both human waste sludge and papermaking sludge, which have conventionally been difficult to dispose of, as compost raw materials at the same time, and does not require any other auxiliary materials. It has been done.

In other words, the method for producing compost according to the present invention involves drying papermaking sludge to a moisture content of 20 to 30%, and mixing this dried papermaking sludge with human waste sludge to a moisture content of 60 to 70%. This mixture is characterized by being aerobically fermented and composted.

As mentioned above, papermaking sludge usually has a moisture content of 65 to 75%, but in the present invention, it is dried to a moisture content of 20 to 30%, and this dried papermaking sludge is used as a moisture control material for human waste. It is mixed with the sludge.

Although either natural drying or forced drying can be used to dry the papermaking sludge, it is preferable to use forced drying using a rotary kiln because it produces granular dried material.

The dry papermaking sludge thus obtained is usually 75-85%
It is added to and mixed with human waste sludge having a moisture content of . At this time, the mixing ratio of both is adjusted as appropriate so that the water content of the mixture becomes 60 to 70%, which is suitable for aerobic fermentation.

The water-adjusted mixture is subjected to aerobic fermentation in a fermenter equipped with an aeration device and a turning device.

The number of times of turning during the fermentation process may be about once a day. It is not preferable to perform the turning operation excessively because the product temperature will drop. In the early stages of fermentation (days 1 to 7), the decomposition of easily decomposable organic matter mainly progresses, and the product temperature reaches a maximum of 70 to 75 degrees Celsius.
rise to After that, the persistent organic matter gradually decomposes, and the product temperature becomes about 30 to 60'C. At this later stage, the amount of ventilation may also be lower than at the early stage. Note that after the above-mentioned initial stage of fermentation is completed, the volume of the raw material deposited in the fermenter is reduced, and the pile height is reduced. It is also possible to carry out the later fermentation stage in one fermenter, but from the point of view of efficient use of the fermenter and shortening of the fermentation period, a secondary fermenter and a secondary fermenter are prepared, and the secondary fermenter is It is preferable that unripe compost, which has undergone initial fermentation, is deposited again in a secondary fermentation tank and then subjected to late fermentation to obtain fully ripened compost.

The mature compost thus obtained generally has a moisture content of 35% or less,
It has a carbon content of 10 to 15.

Such a carbon percentage value is a preferable value for compost.

In addition, if necessary, the obtained compost may be sieved to obtain particles with a particle size of 1~
The product may be made of 5-pound granules. Ripe compost outside the above particle size range can be used as a moisture control material by mixing it back into the raw sludge-dried papermaking sludge mixture before M generation, and it can also be used as a moisture control material. This is preferable because it also serves as a seed for microorganisms.

Note that a heat source is required to perform strong drying in the papermaking sludge drying process, but in a preferred embodiment of the present invention, a part of the papermaking sludge and human waste sludge, which will be used as compost raw materials, are subjected to methane fermentation. Methane gas can be generated and used as a heat source.

<Embodiments> Preferred embodiments of the present invention will be described below with reference to flow sheets shown in the drawings. Paper sludge, which is a raw material,
(moisture content 72%) from hopper 1 to rotary kiln 2
The papermaking sludge was sent to a granular dry papermaking sludge with a moisture content of 25%. The heat source of the rotary kiln 2 was methane gas generated from a landfill 8, which will be described later, and the inlet temperature of the kiln was about 650°C, and the outlet temperature was about 150°C.

On the other hand, human waste sludge (water content 80%) is supplied from hopper 3 and mixed with dry papermaking sludge sent to hopper 4.
The mixture was charged into a primary fermenter 5 equipped with a scoop-type turning device on the top and an aeration device on the bottom, and aerobic fermentation was carried out for 7 days under aeration and stirring (turning once a day). The obtained unripe compost is transferred to a secondary fermenter 6 having the same structure as the primary fermenter,
A further 30 days under aeration and 1 stirring.

Fermented aerobically. The results of analysis of the aged compost thus obtained were as follows.

Moisture content: 35% T-C312mM a (dry) P2O319,8〃 20 1.96 u Crude fiber 164 T-N 24.3,.

Carbon rate: 12.8 Next, this compost was sieved by a sieve machine 7 to obtain particles with a particle size of 1 to 5 u.
The materials were packed into bags and made into compost products.

On the other hand, particles outside the above particle size range were returned to the primary fermenter, mixed back into the raw sludge-dried papermaking sludge mixture as compost, and used to prepare a raw material mixture with a moisture content of 60 to 70%. An example of the mixing ratio is human waste sludge (water content 80%).
): dried papermaking sludge (moisture content 25%): returned compost (moisture content 35%) = 10:4:4 (weight ratio), a raw material mixture with a water content of 57.7% was obtained.

As described above, in this example, human waste sludge and paper sludge that were not used as compost raw materials were buried in the landfill site 8. Here, these wastes were subjected to methane fermentation, and the generated methane gas was collected through a gas collection pipe 9 and stored in a gas storage tank 11 via an intermediate gas storage tank 10. By sending this methane gas to the rotary kiln 2 and using it as a heat source for drying papermaking sludge, it is possible to provide a comprehensive treatment system for human waste sludge and papermaking sludge.

Test Example A test was conducted on the application of the compost obtained above to autumn and winter vegetables.

Crop: Broccoli, cabbage (early).

Chinese cabbage, turnip, radish, spinach Area: 2,8a in each district Cultivation overview: September 2nd: Compost and chemical fertilizer base fertilizer according to the present invention, plowing with magnesium lime applied September 4th: Seedling planting (sowing on August 20th) O7 Roccoli, cabbage, Chinese cabbage) September 5th Direct sowing Chinese cabbage, turnip, radish, spinach) September 25th to 28th Top dressing, inter-tillage, soiling, herbicide application 2 thinning Fertilization amount: (per 10a) Note) *Chemical fertilizer Three element components (%) PK Chemical fertilizer A 15.00 15.00 io, o.

Chemical Fertilizer B・17.00 0 17.00 Test Results: Each crop was harvested from October to December, and the results of the yield index and quality for each crop are shown in the table below.

Note: Yield index with the yield of test plot 1 as 100.

Umbrella fist: Based on 5-level evaluation: top, bottom, middle, top, and top.

As is clear from the above table, test plots 2 and 3 to which the compost of the present invention was applied had superior yield and quality compared to test plot 1 to which no compost was applied, and no adverse effects were observed in either case due to the application of the compost.

<Effects of the Invention> As explained above, according to the present invention, human waste sludge and papermaking sludge, both of which are difficult to dispose of, can be used as compost raw materials and can be effectively applied to crops without using other auxiliary materials. It is possible to obtain aged compost.

In particular, by using methane gas generated by methane fermentation of human waste sludge and paper manufacturing sludge as a heat source for drying paper manufacturing sludge, a comprehensive treatment system for human waste sludge and paper manufacturing sludge becomes possible.

[Brief explanation of drawings]

The accompanying drawings are flow sheets illustrating preferred embodiments of the invention. 1... Paper sludge hopper, 2... Rotary kiln, 3... Human waste sludge hopper, 4... Dry paper sludge hopper, 5...-Secondary acid generation tank, 6... Secondary fermentation tank, 7... Sieving machine, 8... Landfill disposal site, 11...
・Methane gas storage tank.

Claims (1)

[Claims] 1. Dry papermaking sludge to a moisture content of 20 to 30% by weight, mix this dried papermaking sludge with human waste sludge to form a mixture with a moisture content of 60 to 70% by weight, and apply this mixture to an aerobic A method for producing compost, which is characterized by fermentation and composting. 2. The method for producing compost according to claim 1, wherein papermaking sludge is dried by forced drying using methane gas as a heat source, and the methane gas is generated by methane fermentation of human waste sludge and papermaking sludge.