1. Landfill
Landfill takes up a lot of land. At the same time, the harmful components in garbage will also cause serious pollution to the atmosphere, soil and water sources, which will not only destroy the ecological environment, but also seriously endanger human health.
compost
Composting needs to sort out the garbage, which requires higher organic matter content. Moreover, compost cannot be reduced, and it needs to occupy a lot of land.
burn
The essence of incineration is to oxidize organic wastes into inert gas substances and inorganic incombustible substances under the conditions of high temperature and sufficient oxygen supply, and form stable solid residues. First, the garbage burns in the incinerator to release heat energy, and then the waste heat can be recovered for heating or power generation. The flue gas is discharged after purification, and a small amount of residual residue is discharged, buried or used for other purposes.
Its advantages are rapid volume reduction, complete high-temperature harmlessness, small floor space, little impact on the surrounding environment and heat energy recovery. Therefore, garbage incineration is an effective harmless, reduction and resource treatment method. With the continuous enhancement of people's awareness of environmental protection and the improvement of comprehensive utilization technologies such as heat energy recovery, the proportion of domestic waste treated by incineration technology in countries all over the world has increased year by year.
Extended data:
Garbage is solid waste produced in human daily life and production. Because of its large discharge, complex and diverse components, pollution, resource and sociality, it needs to be treated harmlessly, resourced, reduced and socialized. If it is not handled properly, it will pollute the environment, affect environmental sanitation, waste resources, undermine production and life safety and social harmony.
Garbage disposal is to quickly remove garbage, treat it harmlessly, and finally make rational use of it. At present, the widely used garbage disposal methods include sanitary landfill, high-temperature composting and incineration. The purpose of garbage disposal is harmlessness, recycling and reduction.
First, the main hazards
1, classification and hazard
Let's take a look at what human domestic garbage has:
(1) human and animal feces. There are infectious bacteria and viruses.
(2) Medical wastes generated by medical institutions. There are a large number of easily infected viruses and chemicals that are difficult to degrade.
(3) Building decoration garbage. There are volatile chemicals.
(4) Light industrial waste. Most of them are refractory chemical materials, such as plastics and paints.
5] Waste of electronic materials produced by the electronic industry. Include major heavy metal components, refractory glass fibers, plastics, etc. Heavy metals, including lead, tin, zinc, silver and gold, are harmful to human health.
[6] Waste of toxic and harmful substances produced by chemical industry. Volatile substances such as benzene.
Once the battery. It is an indispensable industrial product in people's lives, and its pollution is mainly reflected in heavy metals and chemical substances, including chemical components such as acid and alkali, and materials that are difficult to degrade, such as plastics.
Being all aspects of the city's domestic sewage and sewage discharged by industrial enterprises such as manufacturing.
Levies a small amount of radioactive pollutants.
⑽ Other unlisted human domestic garbage.
2. Secondary pollution
Incineration will also cause environmental pollution and long-term surface damage, mainly including air pollution after garbage combustion. This pollution mainly includes:
(1) Toxic and harmful substance pollution caused by chemicals during high-temperature incineration.
(2) Toxic and harmful substances (including sulfide, carbide and other substances) in the air are polluted.
(3) Environmental pollution caused by chemical waste in automobile industry, severe pollution caused by diesel automobile exhaust and low-level chronic pollution.
(4) Other toxic and harmful substances produced during the combustion of domestic waste.
Although there are high-tech dust removal and facilities to reduce the discharge of toxic and harmful substances, there are still long-term discharge and accumulation of trace harmful substances, which can still cause chronic pathological damage to earth creatures. However, due to the long-term precipitation and accumulation of trace harmful substances in the body, chronic diseases are becoming more and more serious, which brings difficulties to the diagnosis of diseases.
Second, the general treatment method
The general methods of garbage disposal can be summarized as material utilization, energy utilization and landfill disposal.
1, material utilization rate
Also known as material recycling, it refers to the reuse, recovery and recycling of the material properties of garbage through physical transformation, chemical transformation (including chemical modification and thermal transformation such as pyrolysis and gasification) and biological transformation (including microbial transformation, insect transformation and animal transformation), including the recycling of traditional material resources and the transformation of perishable organic garbage into high-quality material resources.
2. Use of energy
Also known as energy recycling, it refers to converting the internal energy of garbage into heat energy and electric energy, including incineration power generation, heating and cogeneration.
3. Landfill treatment
Refers to the landfill treatment of useless garbage that cannot be recycled (including material utilization and energy utilization).
From the whole life cycle of garbage, garbage disposal should also include source reduction and emission control. Strictly speaking, reduction refers to source reduction. By changing product design habits, changing raw material purchasing habits, changing consumers' purchasing and consumption habits, and changing business models, we can reduce resource waste and waste generation in the process of production and life.
Generally speaking, garbage disposal should adhere to the concept of classification and step-by-step utilization of source emission reduction control, material utilization, energy utilization and final landfill disposal, develop all aspects of garbage disposal in a balanced way, and give full play to the role of various garbage disposal methods, especially to strengthen the material utilization of classified garbage, reduce the amount of garbage generated and reduce the amount of garbage discharged after each level of treatment?
References:
Baidu encyclopedia-garbage disposal