JP3676952B2 - Resource recovery from organic waste - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a technique for recycling a plurality of types of organic waste (eg, human waste, livestock excrement, and garbage), and relates to a resource recovery method from organic waste.
[0002]
[Prior art]
Conventionally, methods for treating organic waste such as human waste, animal manure, and garbage include biological denitrification treatment of human waste, methane fermentation of food waste, and composting of animal manure. It has been.
On the other hand, in recent years, as represented by the concept of the sludge recycling treatment center of the Ministry of Health and Welfare, attempts have been made to recycle various organic wastes such as human waste, garbage, livestock excrement, etc. in one place.
[0003]
By the way, in Japan, it is legally difficult to reduce the methane fermentation treatment solution to compost as compost, so the methane fermentation treatment solution must be denitrified and dephosphorized before being released or reused. I must.
[0004]
[Problems to be solved by the invention]
As described above, when all of the various organic wastes are mixed and digested and then the fermentation treatment liquid is denitrogenated, the organic matter is digested in one methane fermentation treatment and methane gas is taken out while the other biological waste is removed. In the denitrification treatment, the organic carbon source for denitrification is insufficient, and therefore, an unreasonable matter of adding methanol as the organic carbon source is performed. Moreover, also in the composting process of fermented sludge, since the calories which still evaporate the water | moisture content which remain | survive in the dehydrated fermented sludge do not remain in fermented sludge, it becomes necessary to supply heat from the outside.
[0005]
This invention solves the above-mentioned subject, and processes each organic waste efficiently, recovering resources in each processing process by compounding a plurality of kinds of organic waste processing processes. An object is to provide a method for recovering resources from organic waste.
[0006]
[Means for Solving the Problems]
In order to solve the above-described problems, the method for recovering resources from organic waste according to the present invention is a method for biologically denitrifying human waste and removing treated water as reused water. In the garbage treatment system that uses membrane-type methane fermentation treatment after the solubilization and generates the biogas as fuel to extract electric power in the power generation facility, and the livestock manure treatment system that separates livestock feces into solid-liquid separation and then composts them at high speed ,
Recycled water extracted from the human waste treatment system and a part of the excess sludge are supplied to the garbage treatment system to control the concentration of ammonia nitrogen in the membrane methane fermentation treatment, and the membrane treatment methane fermentation treatment of the garbage treatment system The membrane separation liquid produced in the above and the filtrate produced by the dehydration of the fermented sludge are supplied to the urine treatment system for biological denitrification , and the filtrate produced by the solid-liquid separation in the animal manure treatment system is supplied to the garbage treatment system. Surplus sludge generated by biological denitrification treatment of human waste treatment system, and surplus heat generated in the membrane-type methane fermentation treatment and supplied to the livestock manure treatment system as an auxiliary heating heat source for fast composting The dewatered cake produced by the dehydration of the fermented sludge in the treatment system is supplied to the livestock manure treatment system and is composted at high speed with the livestock manure after solid-liquid separation .
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. In FIG. 1, in the human waste treatment system 1, after removing human waste and the like in the waste removal step 2, it is directly put into a biological denitrification treatment facility 3 that performs water treatment, and organic carbon for denitrification in water treatment is obtained. Biological denitrification while using as a source. Thereby, the organic carbon source (such as methanol) for denitrification in the biological denitrification treatment facility 3 for water treatment can be saved. When the BOD source is insufficient, a part of the solubilized garbage is used as the organic carbon source. On the other hand, if there is a surplus of BOD source, a part of human waste or the like is pre-dehydrated and a part of the organic carbon source is sent to methane fermentation. The treated water subjected to biological denitrification is taken out as reused water and used in the garbage treatment system 4.
[0008]
In the garbage processing system 4, garbage (easy-degradable solid organic waste) is roughly crushed in the coarse crushing step 5, and then introduced into the solubilization step 6 to be solubilized. After removing impurities, the membrane type methane fermenter 8 is guided. In the membrane-type methane fermentation tank 8, the biogas generated by the methane fermentation process is supplied to the power generation facility 9 as a fuel, and the membrane separation liquid separated by a membrane separation device (not shown) is used as the biological denitrification treatment facility 3. To supply.
[0009]
Since the membrane separation liquid does not contain SS, it may be used as diluted water for biological denitrification or methane fermentation after ammonia stripping or granulation dephosphorization (MAP generation).
The membrane-type methane fermentation tank 8 is appropriately charged with treated water and a portion of excess sludge generated in the biological denitrification treatment facility 3, and the ammonia nitrogen concentration in the fermented sludge is controlled to a predetermined value or less. The ratio of garbage to excess sludge is preferably 1: 0.5-1.
[0010]
This makes it possible to stabilize methane fermentation, reduce the size of the methane fermentation tank, reduce heating energy, and remove organic wastes with high nitrogen content such as food waste and filtrate produced in the livestock manure treatment system 10 described below. Stable methane fermentation.
A part of the fermented sludge produced in the membrane-type methane fermentation tank 8 is returned to the solubilization step 6, and the remaining one is dehydrated in the dehydration step 11 together with the excess sludge produced in the biological denitrification treatment equipment 3, and the filtrate is removed. It is supplied to the biological denitrification facility 3 together with the membrane separation liquid, biological denitrification is performed using human waste as an organic carbon source for denitrification, etc., and the dehydrated cake is supplied to the livestock excreta treatment system 9 .
[0011]
Fermented sludge is biologically denitrified without being dehydrated, and if dehydrated as excess sludge, the calories during composting will be even higher.
In the livestock manure processing system 10, pig manure and dairy cattle manure with a high water content are subjected to solid-liquid separation in the solid-liquid separation process 12, and then the solid content is input to the high-speed composting process 13. It is directly put into the high-speed composting process 13 and composted with the previous dehydrated cake, and the generated compost is taken out as a resource.
[0012]
At this time, heating energy can be reduced by supplying surplus heat generated in the power generation facility 9 to the high-speed composting process 13 as an auxiliary heating heat source. The filtrate of the solid-liquid separation step 12 is supplied to the membrane methane fermentation tank 8 and subjected to methane fermentation treatment. Thus, by mixing livestock manure and fermented sludge, the amount of heat is increased when composting the fermented sludge, and composting in the high-speed composting step 13 is facilitated.
[0013]
The organic carbon sources of various organic wastes introduced into each treatment system described above are distributed to each process of biological denitrification, methane fermentation, and high-speed composting under the following conditions for efficient To process and recycle.
1. The BOD / N ratio of the input liquid to the biological denitrification process is set to 2 to 3 kg / kg. N amount = (ammonia nitrogen amount in human waste and high water content animal droppings) + (total nitrogen amount in garbage × decomposition rate)
2. The C / W ratio of the input to the high-speed composting process is set to 2-3 kcal / kcal. C / W ratio = (total calorific value) / (water content x latent heat of vaporization)
All the remaining organic carbon sources are input into the methane fermentation process, biogas is taken out, and electricity is generated by the biogas. The generated electric power is used as in-field power such as blower power for nitrification in the biological denitrification facility 3, and the surplus is sold. The surplus heat generated in the power generation facility 9 is used as an auxiliary heating heat source for heating the membrane methane fermentation tank 8 and preventing dew condensation on the compost in the high-speed composting step 13.
[0014]
【The invention's effect】
As described above, according to the present invention, the organic carbon source in the biological denitrification treatment of water treatment can be saved by introducing human waste into the biological denitrification treatment facility, and the biological denitrification treatment Stabilization of methane fermentation, methane fermentation by controlling the ammoniacal nitrogen concentration in the fermentation sludge below a predetermined value by appropriately adding treated water and excess sludge generated in the facility to the membrane methane fermentation tank The tank can be downsized. When generating electricity using the biogas generated in the membrane methane fermenter as fuel, the surplus heat generated can be supplied to the high-speed composting process as an auxiliary heating heat source, reducing the heating energy and mixing livestock manure and garbage By doing so, when composting fermented sludge, calorie | heat amount increases and composting in a high-speed composting process can be performed easily. In this way, any organic waste can be treated and recycled regardless of the difference between the liquid and solid forms or the nitrogen content.
[Brief description of the drawings]
FIG. 1 is a flow sheet showing each processing system in an embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Human waste processing system 2 Sedimentation process 3 Biological denitrification processing equipment 4 Garbage processing system 5 Coarse crushing process 6 Solubilization process 7 Solid-liquid separation process 8 Membrane type methane fermentation tank 9 Power generation equipment 10 Livestock excrement processing system 11 Dehydration process 12 Solid-liquid separation process 13 High-speed composting process

Claims (1)

Biological denitrification treatment of human waste and removal of treated water as reused water, urine treatment system, and solubilization of raw garbage, followed by membrane-type methane fermentation treatment. In the garbage processing system to be taken out and the livestock manure processing system to take out compost by solid-liquid separation of livestock feces and later composting,
Recycled water extracted from the human waste treatment system and a part of the excess sludge are supplied to the garbage treatment system to control the concentration of ammonia nitrogen in the membrane methane fermentation treatment, and the membrane treatment methane fermentation treatment of the garbage treatment system The membrane separation liquid produced in the above and the filtrate produced by the dehydration of the fermented sludge are supplied to the urine treatment system for biological denitrification , and the filtrate produced by the solid-liquid separation in the animal manure treatment system is supplied to the garbage treatment system. Surplus sludge generated by biological denitrification treatment of human waste treatment system, and surplus heat generated in the membrane-type methane fermentation treatment and supplied to the livestock manure treatment system as an auxiliary heating heat source for fast composting A method for recovering resources from organic waste, characterized in that a dewatered cake produced by dehydration of fermented sludge in a treatment system is supplied to a livestock manure treatment system and is composted at high speed with livestock manure after solid-liquid separation .

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