JPH04122490A - Synthetic treatment and utilization of environmental pollutant - Google Patents

Abstract

PURPOSE:To synthetically treat and utilize an environmental pollutant by obtaining charcoal from solid waste containing org. matter and bringing the same into contact with waste water to separate and recover charcoal-containing sludge and purified water, and utilizing the sludge as fertilizer and a soil conditioned. CONSTITUTION:Solid waste containing org. matter is baked in a closed system to obtain charcoal which is, in turn, brought into contact with waste water to separate and recover charcoal-containing sludge, and purified water and the charcoal-containing sludge is utilized as fertilizer or a soil conditioner and, by reducing the generation amount of carbon dioxide, an environmental pollutant is synthetically treated and utilized. When charcoal of dust containing calcium oxide is used, phosphoric acid in waste water is adsorbed and immobilized and, when charcoal containing magnesium oxide is used, the removing capacity of ammonia and phosphoric acid in waste water is drastically enhanced. When sludge containing calcium carbonate and magnesium carbonate is used at the time of carbonization, charcoal of dust becomes a waste water treatment agent.

Description

[Detailed Description of the Invention] [Technical Field] The present invention provides a method for comprehensively treating and utilizing solid waste, wastewater, or exhaust gas that is generated in the course of human life and activities and pollutes the global environment. do.

[Prior art and countermeasures]

Humanity is worried about the depletion of the resources it consumes in large quantities, and at the same time is at a loss as to how to deal with the large amount of waste it generates and environmental problems.

Conventionally, wastewater, solid waste, and exhaust gas have been treated separately, and the resulting secondary pollution has been a problem. For example, if municipal solid waste is left unattended, it will rot, generate flies, and eventually decompose into carbon dioxide and water. If this process is switched to landfill, flies will no longer occur, but it will contaminate groundwater, generate methane gas, and eventually decompose into carbon dioxide and water. Furthermore, if the process is switched to incineration, the process can be carried out quickly, but it still decomposes into carbon dioxide and water. It can be seen that these methods are not effective in suppressing the generation of carbon dioxide and methane gases, which are the causes of global warming, which is a worldwide problem.

In addition, environmental conservation through greening the earth has been widely advocated, but if agricultural waste is left alone, incinerated, or fertilized as compost, these organic substances will quickly decompose into carbon dioxide and water. Even if we fix carbon dioxide by planting trees, dead leaves and branches in the forest, and even standing trees left uncut, will eventually wither and decompose into carbon dioxide and water, so we have not been able to do so until now. The only hope of greening in the world was to stop it for a short period of time (several days to several hundred years) until organic matter fixed from carbon dioxide decomposed near the earth's surface.

On the other hand, humans mined fossil fuels made of organic materials, deprived of oxygen from the atmosphere, burned them, and extracted energy.
They have been causing pollution by releasing carbon dioxide and sulfur dioxide into the atmosphere. Therefore, many pollution treatment techniques have been invented to date. Although some desulfurization technologies have been perfected and are in practical use in industrialized countries, the use of substances by-products of the desulfurization process has been problematic. As carbon dioxide fixation generates a large amount of carbon dioxide, no technology or inventions that could be at the core of this process have been announced that would help improve the environment on a global scale.

Furthermore, the amount of water that humans require in their daily lives and industrial activities is rapidly increasing, and the amount of wastewater generated is also rapidly increasing. In developed countries, wastewater purification technologies have been developed and are becoming popular, in which wastewater is treated using methods such as coagulation sedimentation, methane fermentation, and activated sludge to decompose and remove toxic substances and organic matter.

However, as lifestyles change, sewage contains an increasing amount of phosphoric acid and nitrogen, causing so-called eutrophication, which causes green mold and red tide, and research has been conducted into countermeasures such as adsorption with activated carbon. It's here. However, in order to handle large amounts of water, there were insufficient raw materials for these treatment materials, and there was no place to dispose of the slag after treatment, resulting in secondary pollution. On the other hand, both phosphoric acid and ammonium are important fertilizer ingredients, and in particular, phosphoric acid resources are unevenly distributed in some regions of the earth as ore, and there are concerns about resource shortages. The ore was mined and used to make fertilizers and detergents.

Food and feed produced with the use of fertilizers are used,
As mentioned above, it is known that much of the excrement flows into the sewage system and causes eutrophication of rivers along with laundry wastewater, etc. However, due to lack of appropriate technology, treatment cannot be done. Even though they knew that the depletion of phosphoric acid was a threat to the survival of humanity, they did nothing but try to recover it.

Recently, there have been concerns about soil deterioration due to continuous use of chemical fertilizers and the resulting decline in biomass productivity, but by using charcoal as a soil conditioner, physical properties such as hygroscopicity, water retention, and air permeability can be improved. Its effectiveness is being reconsidered as a number of studies have been published showing that it suppresses the growth of harmful bacteria in the soil, provides a favorable environment for the growth of useful bacteria, and improves the ability to retain fertilizers. However, it is becoming difficult to find enough forest resources on earth to supply raw materials for the charcoal used on vast arable land.

[Problem of invention]

The present invention treats solid waste, waste water, or exhaust gas disposed of by human activities, and uses reaction products produced by the treatment to react with each other and create new uses, thereby converting it into resources and saving the earth. Its task is to provide methods that make it possible to improve environmental and resource problems.

[Means to solve the problem]

The present inventor has completed the present invention as a result of intensive research to solve the above problems.

That is, according to the present invention, clear water is obtained by using charcoal (garbage charcoal) obtained by steaming waste containing organic matter for wastewater treatment, while garbage charcoal that has adsorbed pollutants is used as a soil conditioner. The present invention provides a method for comprehensive treatment and utilization of solid waste and wastewater, which is characterized in that it is supplied to the soil as wastewater.

In addition, according to the present invention, by using garbage charcoal containing calcium oxide, phosphoric acid in waste water is adsorbed and fixed, and by using charcoal containing magnesium oxide, ammonium and phosphoric acid are insolubilized, and ammonium phosphate and magnesium phosphate are insoluble. As a result, the ability to remove ammonia and phosphoric acid from wastewater is dramatically improved, and a method for obtaining waste charcoal containing a complex fertilizer of soluble phosphoric acid and ammonia is provided. In addition, the waste charcoal used for this purpose is carbonized by using sludge containing calcium carbonate and magnesium carbonate to obtain a mixture of charcoal and calcium oxide or magnesium oxide, which can be used as a treatment agent for wastewater. . At this time, the water to be separated and recovered is clear but alkaline. In the present invention, neutralization can be achieved by further adding aluminum sulfate or iron chloride, and the flocs of aluminum hydroxide or iron hydroxide produced at this time create an insoluble substance with phosphoric acid and co-precipitate, leaving traces of nitrogen, phosphoric acid, iron, and COD. We provide a method to reduce this to a certain degree. The present invention provides a method for obtaining aluminum sulfate by treating an empty aluminum can with flue gas desulfurization sulfuric acid obtained by desulfurizing flue gas using activated carbon.

As described above, according to the present invention, solid waste, waste water, and flue gas treated products are reacted with each other and the by-products are made available for use as resources. At the same time, it is possible to provide a new comprehensive treatment and utilization system for wastes that can greatly reduce the amount of carbon dioxide produced compared to combustion, since it can be stably stored almost forever for supply to the soil.

In the present invention, the solid waste that is used as a raw material for garbage charcoal is waste paper, rice straw, rice husk, etc. containing natural organic substances such as lignin and carbohydrates.
In addition to potato vines, sawdust, dead branches, etc., there are many other types of plastic waste, and a mixture of these types of waste is also included.

Inorganic substances such as magnesium carbonate, dolomite, and calcilla carbonate 11 can be used as raw materials that yield magnesium oxide or calcium oxide through thermal decomposition during carbonization, but magnesium, calcium, and organic substances that are produced as by-products in the sea lime process such as pulp wastewater can be used as raw materials. It is also possible to use waste materials such as coal sludge consisting of calcium and organic matter produced by-product during sugar refining.

Raw materials for making aluminum sulfate in-house include empty aluminum cans and flue gas desulfurization acid, which is sold when flue gas is desulfurized using activated carbon.

Also, the reaction conditions for each step of the present invention will be described.

The conditions for carbonization are to cut off oxygen to the solid waste containing organic matter, or to heat it while cutting it, at a temperature of 250~1,
The temperature is maintained at 200°C, preferably 300-500°C.

At this time, paper waste, etc., which is particularly high in carbohydrates, should be heated to 250 to 400°C.
In the case of dead branches etc. with relatively high lignin content, 350 to 50
It is desirable to maintain the temperature at 0°C. Also, if nitrogen-containing or chlorine-containing compounds are mixed in and you want to decompose them,
It is desirable to maintain the temperature at 1,200°C. At this time, the yield of charcoal will increase if the amount of oxygen supplied approaches zero, but especially when there is a large amount of cellulose, the amount of air supplied will be increased until ignition occurs, and then the amount of air supplied will be reduced to almost zero. Carbonization will continue due to the heat of decomposition of cellulose.

The yield of charcoal is 5 to 25% based on the raw material organic matter, and the yield is generally high for raw materials having a benzene ring structure such as lignin.

In addition, raising the carbonization temperature or activating it with zinc chloride or steam will increase the density of the charcoal and improve its adsorption capacity, but carbonization at a lower temperature will increase the carbon yield and reduce the amount of carbon dioxide generated. This is desirable because it allows

Note that the gas and low-boiling point liquid generated during carbonization are flammable, so if they are mixed with other fuels, secondary pollution can be prevented and thermal energy can be recovered.

When obtaining magnesium oxide or calcium oxide from sludge or the like containing a large amount of magnesium or calcium, it is necessary to increase the carbonization temperature or increase the temperature by incineration. That is, when the purpose is to obtain magnesium oxide, the temperature is 550-1,100°C, preferably 600-1,100°C.
When the purpose is to obtain calcium oxide at 800°C, the temperature is 900 to 1,400°C, preferably 950 to 1,20°C.
Each was kept at 0°C. The total amount of magnesium oxide or calcium oxide contained in garbage charcoal is 0.02 to 2.
The appropriate amount varies greatly depending on the amount of phosphoric acid and ammonia in the wastewater to be treated with r, but preferably 0.05 to 0. It is brocade. It is desirable to adjust the desired content by mixing it with ordinary garbage charcoal.

Treatment of wastewater with garbage charcoal (or containing magnesium oxide and calcium oxide) is extremely easy. The high temperature of contact between the two is wide, 0 to 100°C, preferably 10 to 5°C.
It is 0'C. The mixing ratio of the two varies greatly depending on the degree of pollution caused by wastewater, but it is 0.1-50% per m3.
kg, preferably 0.5-1. It is OK.

As for the method, it is possible to mix the two and leave it to stand still or to continue stirring it, to put garbage charcoal in a bag and suspend it during drainage, or to use it as a filter bed in contact with the drainage water. The waste charcoal containing 7η dyed substances in the wastewater separated from the clear water after contact is obtained as a soil conditioner. The alkaline clear water obtained by contacting garbage charcoal containing magnesium oxide or oxidizing lucium t1 is neutralized with aluminum sulfate or iron chloride, and the remaining small amounts of phosphoric acid and COD substances are reduced to almost zero. removed to a near state.

〔Effect of the invention〕

]] The present invention has an extremely wide range of application, is easy to implement, and is expected to have great effects on the earth's environment, resource conservation, greening, and improvement of biomass productivity.

In other words, if solid waste contains organic matter, it is considered urban waste such as paper waste, agricultural waste such as rice straw, wheat straw chaff, potato vine, fallen leaves, dead branches, sawdust, fallen trees in cleared land, forestry waste, etc. The present invention can be applied to billions of tons of waste generated on earth, and it has become possible to obtain 200 kg of waste charcoal useful as a waste water treatment agent per 11 organic substances, which is about 1-1+ per year on earth.

As a result, compared to the conventional methods of dumping, incinerating, producing compost, and fertilizing the same, it has become possible to reduce the amount of carbon dioxide produced by approximately 600 units per 1 organic substance.

If the waste charcoal obtained in the present invention is used to treat various types of waste water, it is possible to adsorb mainly dissolved organic polymer substances and color substances, and if the waste charcoal containing calcium oxide or magnesium oxide is used, The former makes it possible to remove phosphoric acid, and the latter makes it possible to remove phosphoric acid and ammonia, etc., and the charcoal after water treatment is
In addition to providing the soil with its natural water absorption, air permeability, and water retention properties, it is also used in cultivated land, forests, and cultivated land to replenish organic matter that nourishes essential plant components such as nitrogen, phosphoric acid, magnesium, and calcium, as well as beneficial bacteria in the soil. If applied to other areas, it can be expected to promote fertilization, increase biomass productivity, and green the earth.

The water obtained by treating waste charcoal containing magnesium oxide or calcium oxide is alkaline, but by neutralizing it with a solution obtained by treating aluminum cans with aluminum sulfate, iron chloride, or flue gas desulfurization sulfuric acid. Almost all of the residual phosphoric acid was removed, resulting in almost neutral and clear water.

As mentioned above, the problems of secondary pollution such as eutrophication of rivers and treatment residues have been solved because conventional methods have been attempted to treat them side by side.In the present invention, solid waste is carbonized, flue gas desulfurized sulfuric acid and empty cans are used to solve the problem of secondary pollution such as river eutrophication and processing residue. The present invention has opened the way to a solution by making and reacting with each other and utilizing the reaction products.

〔Example〕

The present invention will be explained in more detail with reference to Examples below.

Example 1 500 g of paper waste (solid content 86.5%), dead branches (solid content 65%)
．． 2%) 500g, rice straw (solid content 87.4%) 500g
g, cut it into approximately 5 marks, mix it, put it in a furnace, and heat it to a maximum temperature of 450°C while restricting the amount of air flowing in.
Keep at the same temperature for 3 hours and use garbage charcoal for 30 minutes. ], g (yield based on solid content: 25.2%).

Example 2 Paper waste (solid content 86. Nishiki) 500g, planer waste (solid content 86.
7.1%) 500g, rice husk (solid content 87.1%) +o
og1. :, Sludge obtained by treating pulp wastewater with the sea lime method (solid content 22.2%, organic matter = 8.2%, M
gO: 4.5%, CaO: 1.3%) was added and mixed, and the mixture was heated at 720 °C in a furnace with limited air supply.
Garbage charcoal containing magnesium oxide held for a period of time 2], 2
．． 6g (solid yield 22.2%, MgO: 0.32
%) was obtained.

Example 3 Flue gas desulfurization sulfuric acid (H, SO4: 151g/U 195m
Dilute Q to 0.9Q with water and add 5.0Q to an empty aluminum can.
After treatment, water was added and a sulfuric acid acidic solution of aluminum sulfate (Al12(SO4) 3:31.7g/Q,
H2SO4: 2.2g #l) 1. ．． 000mD.

I got it.

Example 4 Water obtained by treating urban sewage with activated sludge method (BOD: 22
0ppm, N: 40ppm, P2O,: 59ppm
) to 1. Take OOOmQ and add waste charcoal obtained in Example 1 to it5. After adding Og and stirring, separate the liquid and clear water (B
OD: 5ppm, N: 0.8ppm) 980ml and garbage charcoal that adsorbed pollutants (N: 0°8% in dry matter, P
2O5:0.2%) was obtained as a soil conditioner.

Example 5 Urine methane fermentation residual liquid (BOD: 4,160 ppm) was treated with activated sludge (BOD: 140 ppm, N: 8
．． Oppm, P2O,: 1.40ppm) 1,000+
To nQ, 7 g of garbage charcoal containing magnesium oxide obtained in Example 3 was added, mixed, stirred, and the after-liquid was separated, and added to 1°000 ml of the obtained clear water (BOD near ppm, P2O: 1.6 ppm). To this, add the sulfuric acid solution of aluminum sulfate obtained in Example 4, filter the resulting precipitate,
Neutral clear water (pH: 6.9, COD: 2ppm, N
:0.8ppm, P2O5:0.5ppm) to 960
At the same time, garbage charcoal that adsorbed sludge substances (N+1.1%, P, 05:1.7% in dry matter) was recovered as a soil conditioner.

Claims (5)

[Claims] (1) Solid waste containing organic matter is steamed to obtain charcoal, and after contacting this charcoal with wastewater, the sludge containing charcoal and purified water are separated and collected, and the sludge containing charcoal is used as a fertilizer or soil conditioner. This is a comprehensive treatment and utilization method for environmental pollutants, which is characterized by using them as carbon dioxide and reducing the amount of carbon dioxide generated. (2) The method according to claim 1, wherein the wastewater is treated by adding magnesium oxide to the charcoal. (3) The method according to claim 2, wherein magnesium carbonate or a substance containing magnesium is added during carbonization and thermally decomposed to obtain charcoal containing magnesium oxide, which is used for treating wastewater. (4) Treat wastewater with a mixture of charcoal and magnesium oxide or calcium oxide, neutralize the resulting alkaline liquid by adding aluminum sulfate or iron chloride, separate and collect the resulting precipitate and water, and use the precipitate as fertilizer. or the method according to claims 2 and 3, which is used as a raw material thereof. (5) The method according to claim 4, wherein aluminum sulfate obtained by reacting aluminum scrap with flue gas desulfurization sulfuric acid is used.