Environmental Protection Science Popularization | The Differences between Solid Waste and Hazardous Waste
Solid Waste
Solid waste refers to substances or materials in solid, semi-solid, or containerized gaseous form that are generated in production, daily life, and other activities, which have lost their original utilization value, or although they have not lost such value, have been discarded or abandoned. It also includes items and substances that are regulated as solid waste under laws and administrative regulations.
Items that have undergone harmless treatment, meet the mandatory national product quality standards, and do not pose a threat to public health or ecological safety, or have been identified as not solid waste according to the solid waste identification standards and procedures, are excluded.
According to pollution characteristics, solid waste can be classified into general solid waste and hazardous waste. The primary source of general solid waste is general industrial solid waste.
Hazardous Waste
Hazardous waste refers to solid waste that is listed in the national catalogue of hazardous wastes or identified as having hazardous characteristics in accordance with the national hazardous waste identification standards and methods.
Hazardous waste commonly exhibits five types of characteristics: toxicity (including leaching toxicity, acute toxicity, and biological toxicity), corrosiveness, flammability, infectivity, and chemical reactivity. Solid waste that possesses one or more of these hazardous characteristics is classified as hazardous waste.
Scope of Solid Waste and Hazardous Waste
Scope of Solid Waste
The scope of solid waste mainly includes industrial solid waste, mining solid waste, agricultural solid waste, municipal domestic waste, hazardous solid waste, radioactive waste, and solid waste from unconventional sources.
Solid waste can also be classified into four categories based on its sources:
Industrial solid waste: This refers to various slags, sludges, dust, and other wastes discharged into the environment during industrial production and processing.
Hazardous solid waste: This specifically refers to harmful waste that possesses characteristics such as flammability, corrosiveness, reactivity, infectivity, toxicity, or radioactivity, and is generated by enterprises that produce hazardous waste.
Medical waste: This refers to waste generated by medical and health institutions during medical treatment, disease prevention, healthcare, and other related activities, which possesses direct or indirect infectivity, toxicity, or other harmful properties.
Municipal solid waste: This includes industrial residues discharged during urban industrial production, such as mining waste rock, beneficiation tailings, fuel ash, smelting slag, and chemical process residues.
Solid waste is a source of environmental pollution. In addition to direct pollution, it often contaminates the environment through media such as water, air, and soil.
Scope of Hazardous Waste
1.Wastes listed in the National Catalogue of Hazardous Wastes, which mainly include the following categories:
Waste materials: Chemical reaction wastes, medical and pharmaceutical wastes, non-ferrous metal wastes, asbestos wastes, spent activated carbon, and surface treatment wastes.
Waste liquids: Chemical waste liquids, waste acid liquids, waste alkaline liquids, heavy metal-containing waste liquids, waste oil, and waste tar.
Waste products and raw materials: Obsolete chemical products, pharmaceutical products, pesticide products, batteries, and packaging materials.
Sludges: Metal sludge, chemical sludge, pesticide sludge, and surface treatment sludge.
Dusts: Non-ferrous metal dust, chemical dust, asbestos dust, and incineration fly ash.
2.Wastes with one or more hazardous characteristics—such as corrosiveness, toxicity, flammability, reactivity, or infectivity—that are identified as hazardous by the provincial environmental protection authorities.
3.Chemical substances listed in the Catalogue of Hazardous Chemicalsthat become hazardous waste once discarded.
4.Medical waste, which is classified as hazardous waste (used infusion bottles are not considered medical waste).
5.Waste medicines and packaging materials, waste pesticides, disinfectants and packaging materials, waste paints, solvents and packaging materials, waste mineral oil and packaging materials, waste films, waste photo paper, waste fluorescent tubes, waste thermometers, waste blood pressure monitors, waste nickel-cadmium batteries, waste mercuric oxide batteries, and electronic hazardous wastes in domestic garbage, except for the collection process, shall be collected centrally and managed as hazardous wastes.
6.Other solid and liquid wastes that, while not explicitly listed, are not excluded from possessing hazardous characteristics and may pose a threat to the environment or human health, as determined by environmental protection authorities.
Differences Between Solid Waste and Hazardous Waste
Scope:Hazardous waste is a type of solid waste. In scientific classification, solid waste encompasses hazardous waste, and its disposal must comply with the Law on the Prevention and Control of Environmental Pollution by Solid Waste.
Harm to the Environment and Human Health:Solid waste is generally less harmful and, in some cases, can decompose naturally. Hazardous waste, on the other hand, poses significant danger, often being fatal to humans. Once the environment is contaminated by hazardous waste, recovery is extremely difficult.
Treatment Methods:General solid waste can be treated through conventional methods such as decomposition, incineration, or landfilling, and generally does not produce toxic effects. Hazardous waste, however, must undergo harmless (non-hazardous) treatment. For example, waste mineral oil generated in industrial production must be settled in a sedimentation tank, filtered, transferred to a raw material storage tank, then sent to a distillation kettle where it is heated and refluxed under controlled temperature. The distillate is adsorbed with clay to produce white oil, while the residue at the bottom of the kettle is incinerated.
Treatment Costs:The cost of treating general solid waste is relatively low, and the requirements for treatment enterprises are less stringent. In contrast, the harmless treatment of hazardous waste is more costly and must be carried out by enterprises with specialized qualifications.
How to Store and Manage Hazardous Waste
Hazardous waste is different from general solid waste in that it possesses certain dangerous properties. Therefore, it requires focused control and strict management. The prevention and control of environmental pollution caused by hazardous waste involves several stages, including generation, storage, transportation, utilization, and disposal. Measures must be taken based on the specific characteristics of the waste, following the principle of "tailored control based on waste type and classified management."
The collection and storage of hazardous waste must be carried out by classifying it according to its hazardous characteristics. It is prohibited to mix and collect, store, transport, or dispose of incompatible hazardous wastes that have not undergone safety treatment.
Hazardous wastes are categorized based on their different hazardous properties, such as toxicity (including acute toxicity and leaching toxicity), flammability, corrosiveness, infectivity, and reactivity.
Therefore, for different types of hazardous waste, it is necessary to implement pollution prevention and control measures suited to their specific properties, adhering to the principle of "tailored control based on waste type and classified management."
If uniform pollution control measures are applied to hazardous wastes with differing properties, it may not only fail to effectively control pollution but could also exacerbate or intensify environmental hazards.
The enterprise, as the responsible entity for the prevention and control of hazardous waste pollution, shall effectively manage environmental risks during the construction, operation, and management of hazardous waste storage facilities in accordance with standards and specifications such as the Standard for Pollution Control on Hazardous Waste Storage and the Technical Specifications for Collection, Storage, and Transportation of Hazardous Waste.