JPS5898186A - Aeration in treatment of night soil - Google Patents

Abstract

PURPOSE:To accelerate the conversion of night soil into compost, by continuously operating an aerator through a controller with a signal from a detector to raise the temperature of night soil, and switching the aerator into intermittent operation during detecting the initial condition of propagating bacteria. CONSTITUTION:When an aerating cell 1 is filled with the liquid 2 of night soil, a pump 6 is driven by applying an electric current to a motor 7 to spray the liquid 2 through a nozzle in an ejector 5. Air inhaled through an air-introducing pipe 8 by vacuum pressure formed around the column of the sprayed liquid is injected together with the sprayed liquid into the liquid 2 through the ejector 5 to perform aeration. The temperature of the liquid 2 is gradually raised by heat dispatched from the motor 7 and the agitation heat of the liquid 2 derived from the continuous operation of the aerating apparatus, so that the liquid reaches the initial condition of propagation where bacteria begin to increase. Hence, a detector 3 detects it and feeds an electric signal to a controller 4. The motor 7 is intermittently operated by the output of the controller 4 to propagate bacteria while restricting the aerating air.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a composting method based on biochemical treatment of livestock human waste.

Traditionally, agriculture was usually carried out using chemical fertilizers, but chemical fertilizers alone degrade rural areas and lead to soils lacking in organic matter, so in recent years, organic fertilizers have been used instead of chemical fertilizers. Recommendations are being made about what to do. However, organic fertilizer is derived from the excreta of livestock such as cows and pigs, and if it is applied as raw manure, the nitrogen content will flow down strongly and flow into rivers and lakes, causing pollution. Also, if you apply fertilizer directly to grass, it will die. Also, from the cow's point of view, the grass has a bitter taste, and from the human's point of view, the odor is intolerable. In particular, the production of nitrified nitrogen compounds can cause diseases in cattle.

Therefore, livestock manure is fermented and turned into compost.

Various proposals have been made for composting livestock waste and manure, but fermentation using aerobic bacteria is generally used as composting. Livestock6 as a promoter of composting
The waste is divided into solids and liquid, and the liquid (hereinafter sometimes simply referred to as liquid) is stored in an aeration tank, and air is blown into the wastewater in the aeration tank to make it into compost using aerobic bacteria. It is a place where things are widely practiced. As a method of providing oxygen to this aerobic bacteria, an aeration device is installed in the aeration tank, and the liquid in the aeration tank is pumped up and sent to the ejector. This is a common method for treating livestock human waste.

Conventionally, composting using such an aeration device was carried out in an aeration tank.
During this time, human waste is being processed manually while monitoring the composting status of the human waste in the aeration tank. For this reason, the temperature and pH of the liquid in the aeration tank are measured, but the process relies mostly on sense. Because measurements are not taken continuously, when the liquid temperature does not rise during the fermentation process, aeration may cause excess oxygen supply and kill the bacteria, or the aeration may not be carried out properly, resulting in slow bacterial growth and composting. There are problems in that fermentation is delayed and the number of processing days is too long.

The present invention accurately grasps the process of fermenting and composting livestock human waste through the action of aerobic bacteria through aeration, provides an appropriate supply of oxygen, accelerates the composting process, and automates these processes. The purpose is to

Hereinafter, the present invention will be explained based on the drawings. In Figure 1 (3), the horizontal axis shows the number of days for redness of the liquid of livestock human waste placed in the aeration tank. The vertical axis shows the air temperature, the liquid temperature in the aeration tank, and the pH, and FIG. 1 is a flowchart of the present invention. In Figure 1, the aeration tank is one tank, but even if the aeration tank is divided, it is the same because as long as aerobic treatment is performed, the liquid to be treated is simply transferred during the process.

In the present invention, a detector 3 is provided in the liquid λ of the aeration tank, and a signal from the detector 3 is sent to a control device as an electric signal. The control device includes, for example, a microcomputer, an amplifier circuit, and an output circuit, and its output drives a pump 6 by a motor 7 provided in the aeration tank to send liquid to an ejector S, and the ejector S is connected to an air introduction pipe. It opens to the atmosphere t through.

Detector 3 detects indicators of human waste related to changes in the amount of oxygen required during the composting process, and is equipped with a thermometer or pH sensor.
As shown in Figure 1, there is a close relationship between temperature and pH.

Instrument where detector 3 first detects the temperature of liquid λ ('/') A case will be explained below.

The temperature of the liquid placed in the aeration tank/was 27° C., which is approximately equal to or slightly higher than the air temperature.

Therefore, when the air temperature is low, the temperature of the liquid λ is also initially low. When the aeration tank is filled with the liquid 2, the motor 7 is energized, the pump 6 is driven, and the liquid flowing out from the pump 6 is injected from the nozzle in the ejector S, and air is introduced by the vacuum pressure generated around the injected liquid column. The air sucked through the tube is sucked into the injection liquid λ and is ejected from the ejector S into the liquid λ to perform aeration.

When the liquid is placed in the aeration tank, it is in a state where bacteria are not proliferating, and the bacteria are in the preparation stage to adsorb organic components in the liquid and adapt to the atmosphere. It's not the right temperature for that. Therefore, the aeration device is operated continuously, the motor radiates heat, and the liquid λ is sucked into the pump B, discharged into the aeration tank through the ejector S, and the temperature of the liquid λ is increased by stirring heat.

These heats are almost equal to the input to the motor 7 since the fermentation heat caused by the bacteria is still insignificant. After this initial stage, the amount of bacteria increases as the liquid temperature increases. Oxygen consumption also increases accordingly. The aeration tank is a closed tank and the liquid temperature is low, so the amount of heat released is small.
The liquid λ continues to rise linearly until it reaches about 3θ°C.

As the temperature of the human waste approaches the first indicator of 30°C, the temperature in the liquid becomes suitable for the growth of aerobic bacteria, and the rate of increase in bacteria increases. In addition, the generation of fermentation heat due to bacteria gradually increases. However, even if the temperature is suitable for bacterial growth, the amount of oxygen consumed is not large.

Then, based on the signal detected by the detector 3, the control device determines that the temperature has reached a temperature between 20 and 30°C, which is the temperature of the liquid.
The motor 7 is operated intermittently to limit aeration air. In this state, bacteria are in the process of multiplying. Therefore, if you give more oxygen than the bacteria need, the bacteria will die. That is, since the aeration device has the necessary capacity for oxygen consumption in the latter half of the aeration period, continuous operation of the aeration device will result in overaeration. Therefore, a timer preset in the control device energizes the motor 7 for one hour, then shuts off the power for the next seven hours, restarts it, runs for one hour, and rests for seven hours. These times and intervals are illustrative and are selected so that an appropriate amount of oxygen is supplied so as not to kill bacteria due to overaeration. Therefore, in this intermittent operation, it is preferable that if the time during which the motor 7 is energized is kept constant, the time during which the motor 7 is turned off and heated is gradually shortened as the fermentation process progresses.

When aeration is performed in steps from a liquid temperature of about 30°C, the speed of bacterial growth increases, the generation of fermentation heat increases, and the liquid temperature reaches 10°C! As the temperature approaches rO°C, the rate of temperature increase gradually decreases, and the rate of increase in bacteria also decreases. If necessary, the second indicator indicating the state of liquid temperature and human urine is yo℃~
When the temperature reaches SO° C., a signal is sent to the control device of the detector 3, which causes the control device to continuously energize the motor 7 and perform aeration. At this stage, the bacteria in the liquid reactor is rapidly multiplying, the amount of bacteria has reached its maximum, and the period of spontaneous respiration has begun, so the amount of oxygen required is high, so the ioo% of the aeration equipment is increased.
This requires the operation of the

Alternatively, since the amount of organic matter decreases when the temperature exceeds ro°C, the amount of oxygen required may also be reduced, so the temperature is maintained constant by intermittent operation.

Next, the case where the detector 3 detects acidity will be described.

As shown in Figure 1, there is a close relationship between the acidity of the liquid and the temperature of the liquid. Therefore, aeration can also be controlled using a PH meter. According to aerobic fermentation, bacteria act in an oxidative manner on the organic matter in human waste, so by detecting the acidity in liquid waste, it is possible to know the process of composting liquid waste.

Therefore, the detector 3 is a PH needle that detects acidity.

The liquid λ put into the aeration tank/ is aerated by the aeration device 1 and heated by the heat generated by fluid friction due to stirring and the heat generated by the motor. At the beginning of the liquid, the temperature is too low for bacteria to grow, and a period of time (g) is necessary to prepare for the combination of bacteria and organic matter. Aeration was initially used to raise the temperature of the liquid, and as the temperature rose and bacteria multiplied over time, the pH, which was initially around 1.1, suddenly became saturated to around PHff. PH rises.

Therefore, the signal sent from the detector 3 to the control device is PH&
When a value corresponding to slightly less acidity is reached, the control device stops the continuous energization of the motor 7 and changes it to intermittent energization. The rate of interruption is the same as in the case of temperature detection, for example, one hour of operation and seven hours of suspension. As shown in Figure 1, the elapsed time of the liquid λ differs between when temperature is detected and when PH is detected. This is because PH indicates a state of saturated acidity in grams, so it is easier to detect pH at a slightly lower value. Therefore, when detecting liquid by PH, after detecting a pH value slightly lower than PHJ', the timer in the control device is used to continuously operate the motor until the elapsed time corresponds to the liquid temperature of approximately 30°C. The motor 7 may be operated intermittently at the end of the time period.

In this way, the motor 7 operates intermittently and aerates intermittently, supplying the bacteria in the liquid with an appropriate amount of oxygen, and the bacteria act on the organic matter in the liquid to show a certain degree of acidity. As the bacteria continue to proliferate, from about the 3rd day onwards, they proliferate more than the bacteria that decompose organic matter, the organic components decrease, and the PH increases, and at about the 7th day, the PH becomes r,
The value of p indicates the next saturation state. Then, when the control device receives a signal from the detector 3 when the PH becomes a value slightly smaller than lI, the control device operates the motor 7 continuously. That is, at this point, the amount of bacteria has reached its maximum, and the amount of oxygen required has also increased and is close to its maximum value. Alternatively, in this state, the organic components are also decomposed and reduced, so the pH can be kept constant by performing intermittent operation.

Thus, the ripening of the liquid λ is completed after a certain period of about three days as shown in FIG.

As described above, the present invention detects the temperature or acidity of human waste, which occurs in connection with the growth of aerobic bacteria and the decomposition of organic matter during the aeration process of human waste, and provides appropriate oxygen for the growth of aerobic bacteria through a control device. This prevents bacteria from being killed or inhibited from multiplying due to over-aeration, and the aeration equipment is operated intermittently during the process, reducing electricity costs.

In addition, when the aeration equipment is operated continuously during the pre-processing process when composting has matured and bacteria need oxygen, the aeration equipment is made small to avoid over-aeration, which can lead to oxygen deficiency. This means that sufficient oxygen can be supplied without any problems.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing changes in liquid temperature and pH in the aeration tank during the composting and fermentation process of human waste, and FIG. 2 is a flowchart showing the aeration method of the present invention. L...Aeration tank TS...Liquid 3...Detector D...Control device S...Ejector 6...Pump 7...Motor Z...Air introduction pipe.

Claims (1)

[Claims] l When human waste is placed in an aeration tank and aeration is performed by an aeration device, a detector is provided to detect the physical or chemical state of the human waste in the aeration tank, and the detector detects the state of the human waste. The control device uses the signal generated by the detection to operate the aeration system continuously until the temperature reaches a temperature close to the point at which the initial bacteria in the composting process begin to sufficiently proliferate. The detector detects the seventh indicator indicating the condition of nearby human waste in the initial state of the bacterial growth phase, and the control device operates the aeration system intermittently in accordance with the bacterial growth phase to reduce the amount of oxygen supplied. Aeration methods in processing. Following the above-mentioned human waste treatment, the amount of bacteria reaches its maximum and the amount of oxygen required approaches the maximum value, indicating the condition of human urine.
An aeration method for human waste processing in which an aeration device is operated continuously via a control device based on the signal detected by the indicator. 3 The index detected by the detector is the temperature of human waste, the first index is the temperature of about -0 to 30 degrees Celsius, and the λth index is the temperature of about IIo
The aeration method for human waste treatment according to claim 1, wherein the temperature is 50°C. The acidity of human urine is the most important index detected by the disease detector.
The index of PHg is less than the initial saturated acidity PHff
2. The aeration method for human waste treatment according to claim 1, wherein the index is a numerical acidity value near PHff that is smaller than the next saturated acidity PH.