Definition of hazardous waste:
1. Having one or more hazardous characteristics such as corrosiveness, toxicity, flammability, reactivity or infectiousness;
< p>2. It is not excluded that it has hazardous characteristics and may cause harmful effects to the environment or human health and needs to be managed as hazardous waste.Types:
1. Solid waste;
2. Liquid waste.
Hazardous waste hazards:
1. Destroy the ecological environment. Hazardous wastes that are randomly discharged and stored will pollute water bodies and soil under the long-term penetration and diffusion of rainwater and groundwater, and reduce the environmental function level of the region.
2. Affect human health. Hazardous waste causes poisoning through ingestion, inhalation, skin absorption, and eye contact, or causes dangerous events such as burning and explosion; long-term hazards include long-term poisoning, carcinogenesis, teratogenesis, mutagenesis, etc. caused by repeated exposure.
3. Restrict sustainable development. The pollution of the atmosphere, water sources, soil, etc. caused by the non-processing or non-standard treatment and disposal of hazardous waste will also become a bottleneck restricting economic activities.
Hazardous waste treatment methods:
1. Physical treatment: Physical treatment changes the structure of solid waste through concentration or phase change to make it easier to transport, store, utilize or dispose of Form, including compaction, crushing, sorting, thickening, adsorption, extraction and other methods.
2. Chemical treatment: Chemical treatment uses chemical methods to destroy harmful components in solid waste to make it harmless, or to transform it into a form suitable for further processing and disposal. The purpose is to change the chemical properties of the substance being treated, thereby making it less hazardous. This is a common pre-treatment measure before final disposal of hazardous waste, and its processing equipment is conventional chemical equipment.
3. Biological treatment: Biological treatment uses microorganisms to decompose degradable organic matter in solid waste, thereby achieving harmless or comprehensive utilization. Biological treatment methods include aerobic treatment, anaerobic treatment and facultative anaerobic treatment. Compared with chemical treatment methods, biological treatment is generally cheaper economically and widely used. However, the treatment process takes a long time and the treatment efficiency is not stable enough.
4. Heat treatment: Heat treatment uses high temperature to destroy and change the composition and structure of solid waste, while achieving the purpose of volume reduction, harmlessness or comprehensive utilization. The methods include incineration, pyrolysis, wet oxidation, roasting, sintering, etc. Wastes with high calorific value or high toxicity are treated harmlessly by incineration treatment process, and waste heat from incineration is recovered for comprehensive utilization and physical/chemical treatment, as well as employee bathing and living, etc., to reduce processing costs and energy waste.
5. Solidification treatment: Solidification treatment is to use solidification substrate to fix or cover waste to reduce its harm to the environment. It is a safer treatment process for transporting and disposing of waste. It is mainly used. For hazardous waste and radioactive waste, the volume of the solidified body is much larger than that of the original waste.