Garbage is an inevitable product of human society. With the rapid economic growth, urban garbage seriously pollutes the environment and causes great harm to human beings. The treatment of municipal garbage has received universal attention. But medical waste is different from ordinary garbage, medical waste contains a large number of bacteria, viruses and chemicals, its arbitrary discharge and disposal will bring extremely serious threat to the environment and human health. So, what are the specific hazards of medical waste? How to deal with it?
What is medical waste?
Medical waste refers to all kinds of medical and health institutions in the medical, prevention, health care, teaching, research and other related activities with direct or indirect infectious, toxic and other hazardous waste [1]. Unlike domestic waste, medical waste contains a large number of bacteria, viruses and chemicals, with strong infectiousness, biological toxicity and corrosiveness, untreated or incompletely treated medical waste piled up arbitrarily, is very likely to cause pollution of water, soil and air, and produce direct or indirect harm to human beings. The issue of medical waste treatment has become a hotspot of concern all over the world, and our country has listed it as No. 1 hazardous waste in the Hazardous Waste List. Therefore, it is of great significance to strengthen the standardized management and harmless treatment of medical waste, both from the protection of the environment and from disease prevention and control.
Classification of medical waste
Medical waste has a complex composition, and according to the Classification Catalog of Medical Waste, medical waste mainly includes:
(1) Infectious waste? Refers to medical waste that carries pathogenic microorganisms with the risk of triggering the spread of infectious diseases.
(2) Pathological waste? Refers to the diagnosis and treatment process of human medical waste and medical laboratory animal carcasses.
(3) injurious waste? Refers to the ability to stab or cut the human body discarded medical sharps.
(4) pharmaceutical waste? Refers to the expiration, elimination, deterioration or contamination of the discarded drugs.
(5) chemical waste? Refers to toxic, corrosive, flammable and explosive waste chemicals.
What are the hazards of medical waste?
Easily become a source of disease-inducing
As medical waste has the characteristics of full-space pollution, acute contagion and latent contamination, it contains microorganisms that are hazardous to the ordinary living waste dozens, hundreds or even thousands of times, if not properly handled, it will become a source of hospital infections and social and environmental nuisance, the more serious can be a source of disease epidemics. Medical waste contains different levels of bacteria, viruses and harmful substances. And the organic matter in the waste not only breeding flies cause the spread of disease, and in the corruption of the decomposition of the release of ammonia (NH3), hydrogen sulfide (H2S) and other malodorous gases, generate a variety of hazardous substances, pollution of the atmosphere, endangering human health; at the same time is the cause of cross-infection in the hospital and the main cause of air pollution, caused by medical waste caused by the cross-infection of the social cross-infection rate of 20%.
Easy to pollute the environment
Medical waste exposed to the outdoor untreated medical waste medical waste on the atmosphere, groundwater, surface water, soil and other pollution. Garbage piled up in the open air, resulting in the release of a large number of ammonia, sulfide and other harmful gases, serious pollution of the atmosphere, in which the decomposition of garbage emitted PCBs, dioxins, etc., are carcinogens.
The pathogens, heavy metals and organic pollutants carried by medical waste can cause serious pollution to surface water and groundwater through the leachate produced by rainwater and biological hydrolysis. The heavy metals in the waste leachate enter the soil under the action of rainfall leaching and scouring, leading to the accumulation of heavy metals in the soil and pollution. Improper handling of medical waste can also cause secondary pollution of the environment.
Hazardous to human health
There are many disease-causing microorganisms in medical waste, and it is often a breeding ground for mosquitoes, flies, cockroaches and rats. These pathogens can be transferred to humans through organisms that live in the waste. Medical waste may also contain chemical pollutants and harmful substances such as radioactivity, which are extremely dangerous. If the management and training of practitioners who are directly exposed to medical waste is not rigorous, additional hazards may result.
Some people sell a large number of patients' used infusion sets, plastic potties, and so on, to plastic processing factories to produce daily necessities, and enter the supermarket sales. Drug dealers cheap acquisition of people in the hands of expired drugs, after modifying the batch number, repackaging, and again out of profit. Some people will use the disposable medical equipment sold privately to individual traders, processing and packaging sold to some individual clinics to use again. The newest addition to the list is the newest addition to the list, the newest addition to the list, the newest addition to the list.
How to collect medical waste?
1. According to the category of placement in special packaging or containers, to ensure that the packaging or containers are not broken, leakage and other defects, broken packaging should be treated as therapeutic waste.
2. Waste can not be overfilled, more than 3/4 should be sealed, sealed tightly and tightly, indicating the department and the number of.
3. Classified collection, no mixing; no leakage; no pollution (sharps into the sharps box, non-sharps into the bag).
4. Transportation to prevent loss, leakage, diffusion and direct contact with the body; transportation of medical waste should be used to prevent infiltration, put spread, no sharp edges and corners, easy to load and unload and clean the special delivery tools, a variety of packaging and delivery tools should be dedicated to the identification of medical waste.
5. The establishment of medical waste storage, equipment, not open storage, and set up a person in charge of management.
6. Do a good job of registration, including the source, type, weight and quantity, handover time, the final destination and the operator's signature, etc., the information is kept for three years.
7. The temporary storage of garbage, facilities and timely cleaning and disinfection treatment, prohibit the transfer of medical waste trading.
8. Medical waste storage time shall not exceed 2 days, after the end of the daily work on the transportation tools for cleaning and disinfection.
9. Occurrence of medical waste loss, leakage, proliferation and accidents occur, should be promptly reported to the competent administrative department of health within 48 hours; resulting in the occurrence of infectious diseases, according to the relevant provisions of the report, and emergency treatment.
Methods of Medical Waste Disposal
Sanitary Landfill Method
Principle
Sanitary landfill method is the final disposal method of medical waste, which is based on the principle of burying the waste into the ground, and through the long-term decomposition of microorganisms, it will be decomposed into harmless substances. If the landfill system for medical waste does not have impermeable measures, all kinds of toxic substances, pathogens, radioactive substances, etc. will seep into the soil with rainwater, and harmful substances will enter the human body through the food chain, endangering human health. Therefore, sanitary landfills need to go through a scientific site selection, and lay an impermeable layer with clay, high-density polyethylene and other materials, but also must be set up to collect landfill gas and output pipelines, so the use of landfill disposal method must be very careful, and must be in accordance with the relevant provisions of the strict pre-treatment of medical waste.
Influence parameters
The use of landfill disposal method should be based on the characteristics of medical waste, select the geological conditions to meet the requirements of the site, combined with the soil and climate, the use of appropriate civil engineering technology, to determine the size of the site construction.
Advantages and disadvantages
The advantages of landfill disposal method are simpler, less investment, and can handle a large amount of medical waste. The main disadvantages are the need for disinfection before landfill, waste capacity reduction, landfill construction investment, the need to occupy a large amount of land, the production of methane, ammonia, hydrogen sulfide gas, nitrogen, carbon monoxide and a large number of hazardous gases, but also produces oxygen and hydrogen and volatile organic compounds, the need for long-term monitoring of the soil and groundwater.
High-temperature incineration method
Technical characteristics
Medical waste is mainly composed of organic hydrocarbons, contains more combustible components, has a high calorific value, the use of incineration has complete feasibility. Incineration treatment is a deep oxidizing chemical process, under the action of high-temperature flame, incineration equipment within the medical waste after drying, ignition, incineration of the three phases will be converted into residues and gases, the infectious agents in the medical waste and harmful substances in the incineration process can be effectively destroyed. Incineration technology is applicable to a variety of infectious medical waste, incineration requires incinerators with high and stable furnace temperature, good oxygen mixing conditions, enough gas residence time and other conditions, while the need for the final emission of flue gas and residue for harmless disposal.
Influencing parameters
The choice of incineration equipment must have a suitable degree of turbulence and mixing, to maintain a contemporary moisture content in the waste, combustion chamber filling, temperature and residence time, maintenance and servicing are important incineration parameters.
Advantages and disadvantages
The main advantages of incineration technology are the significant reduction in volume and weight, waste deformation is obvious; suitable for all types of medical waste and large-scale applications; stable operation, sterilization and pollutant removal effect is good; potential heat can be recycled; technology is relatively mature. Disadvantages are mainly manifested in the high cost, serious air pollution, easy to produce dioxin, polycyclic aromatic compounds, PCBs and other highly toxic substances and hydrogen chloride, hydrogen fluoride and sulfur dioxide and other harmful gases, the need to configure a perfect tail gas purification system; bottom slag and fly ash is harmful.
Pressure steam sterilization method
Technical principles and features
The principle of pressure steam sterilization treatment method is after sorting and crushing of medical waste in the 100 kPa, 121 cc process conditions run more than 20 rain, the pressure of steam to penetrate the object inside the microbial proteins coagulate and denaturation and be killed; after treatment of medical waste sent to a sanitary landfill or incineration. sanitary landfill or incineration. This method is also suitable for the disinfection of contaminated work clothes, syringes, dressings, microbial media, etc., but it is not suitable for dealing with pathological waste, such as human tissue and animal carcasses, etc., and it is not efficient in dealing with drugs and chemical waste.
Influence parameters
The main technical parameters of pressure steam sterilization treatment are temperature, steam quality and time of action, the size of the waste feed affects steam penetration, the treatment cycle time affects the thoroughness of sterilization, and incomplete removal of air from the container can affect the temperature inside the sterilizer.
Advantages and disadvantages
Pressure steam sterilization technology compared with low investment, low operating costs, easy to detect, low residue hazard, good disinfection, suitable for a wide range of treatment advantages. The main disadvantage is that the volume and appearance of the basic did not change; there may be air pollutants discharged, easy to produce odor, can not deal with formaldehyde, phenol and mercury and other substances.
Chemical disinfection method
Technical characteristics
The essence of chemical disinfection method is to break the broken medical waste and a certain concentration of disinfectant (sodium hypochlorite, peroxyacetic acid, glutaraldehyde, ozone, etc.) mixing action, and to ensure that its disinfectant and disinfectant have enough contact area and time, organic matter in the process of disinfection is decomposed, microorganisms are killed. Maximum contact between disinfectant agent and medical waste is a prerequisite to guarantee the treatment effect. By using rotary crushing equipment to increase the degree of crushing, it is ensured that the disinfectant can penetrate it. Chemical disinfection is suitable for the treatment of liquid medical waste and pathological waste, and has recently been progressively used for the treatment of medical waste that cannot be sterilized by heat or wetting.
Influencing parameters
The main factors determining the effectiveness of chemical disinfection are the concentration of the disinfectant and the temperature at which it acts, the choice of disinfectant with the appropriate pH according to the nature of the waste, the contact and mixing time between the waste and the agent, and the re-circulation of fluids are also important factors.
Advantages and disadvantages
The advantages of chemical disinfection method is simple and convenient equipment and operation; deodorization effect is good; the disinfection process is rapid one-time investment is small, low operating costs. For dry treatment, the waste of the high rate of reduction, will not produce waste liquid or waste water and exhaust gas. The disadvantage is that dry waste is more demanding on the crushing system and the pH monitoring (automation level) of the operation process is very demanding. Wet waste treatment processes generate waste liquids and gases, and most disinfectant solutions are harmful to humans. It is not suitable for chemotherapy waste, radioactive waste, volatile and semi-volatile organic compounds.
Electromagnetic Sterilization
Technical Principles
Electromagnetic sterilization consists of both microwave and radio wave methods. Microwave sterilization uses high-frequency electromagnetic waves of 2450 MHz, while radio sterilization uses low-frequency electromagnetic waves of 10 MHz, which are more penetrating than microwaves. The principle of electromagnetic wave sterilization method is that it can be absorbed by water, fat, protein characteristics, the use of microbial cells selective absorption of energy characteristics, will be placed in the electromagnetic wave high-frequency oscillation energy field, so that the microbial liquid molecules according to the frequency of the applied electric field vibration, this vibration so that the energy within the cell membrane increases rapidly, resulting in high temperature, and ultimately lead to the death of the cells, in order to kill the pathogens in medical waste. After electromagnetic wave treatment of medical waste can be sanitary landfill as domestic waste. Electromagnetic wave sterilization has been used in the United States, Australia, Germany, and the Philippines.
Impact parameters
Whether microwave or radio waves, the factors that determine the sterilization effect is the output power and the actual field strength, but also according to the characteristics of the waste, the waste moisture content of the microwave treatment of the impact of the obvious, storm radium duration and waste mixing range also has a certain impact.
Advantages and disadvantages