We know what medical incineration is; it’s the burning of wastes produced by hospitals, veterinary facilities, and medical research facilities. But is this information enough to know about medical incineration? Let’s find out the detailed information about medical incineration in today’s blog!
What is Medical Incineration?
To know the term medical incineration firstly we need to know what is Incineration? Incineration is simply the high temperature (870 -1200 degree celsius ) burning of waste. You may have a question now if burning and incineration are the same then why we called the term incineration? So basically combustion and incineration refer to burning, but their operations are different .
The term combustion refers to a chemical reaction, while incineration refers to the destruction of material such as waste. Metals cannot be destroyed by this technique.The gases produced in the process must be treated to remove any remaining metal, acids (HCl, NOx, and SOx), and particles of ash before they are dispersed into the atmosphere. The soil or ash remaining in the incinerator after the burning and from gas treatment may be disposed of into a landfill or buried on site.
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Now let’s see the difference between medical incineration and combustion techniques in the table given below.
Incineration vs Combustion
Here are some key points to understand incineration and combustion-
|Incineration is the process of destroying something.||In combustion substances react with oxygen producing energy.|
|It gives ash ,flue gas and heat.||Complete combustion of heat gives carbon dioxide,heat and water.Incomplete combustion gives carbon monoxide,heat and water.|
|Burning organic matter in waste,||Burning something not specified.|
|Important as a waste treatment process.||Important in industries and in producing fires.|
7 Types of Medical incineration
There are 7 types of medical incineration, let’s have a look at them!
|Sr.No||Type of Medical Incineration||Description|
|1.||Burn Pile||It is the simplest and earliest type of waste disposal. They basically collect combustible waste and set a fire on open ground.|
|2.||Pyrolytic chamber incinerator||Most reliable and commonly used treatment process for healthcare waste.In the pyrolytic chamber, waste is decomposed through oxygen deficient, medium-temperature (800– 900°C) combustion process. That produces solid ashes and gases, which, if treated properly, can be disposed of in the landfill.|
|3.||Rotary kiln||It is used for solid and liquid waste incineration.It can process solid liquid and containerized waste.|
|4.||Single chamber incinerator||It is affordable to buy. It treats waste in batches. Incineration temperature ranges from 300–400°C. Operations like loading and de-ashing are performed manually. Air inflow is based on natural ventilation, sometimes maintained mechanically depending on the conditions. If the incinerator is properly operated, pathogens are annihilated. Ashes can consist of more than 3% of unburnt matter. It can be disposed of in a landfill. |
|5.||Drum incinerator and brick incinerator technique||It’s the simplest type of single-chamber incinerator and can only be used as a last resort to incinerate waste because it causes air pollution. It is only appropriate in emergency conditions as during acute outbreaks of communicable diseases.|
|6.||Fluidized bed||In this type of incinerator, a strong airflow is forced along the sandbed. Air penetrates through the sand to a point where it separates sand particles. The airflow starts with mixing and churning; it makes a fluidized bed. Then fuel and waste can be introduced.|
|7.||Specialised incinerators||An example is furniture factory sawdust incinerators. They need much attention as they must handle many flammable materials and saw sin dust. Controlled burning back burns prevention systems are crucial as the dust can easily catch fire under the influence of LPG.|
Significance of Incineration for biomedical waste
How important is the incineration of medical waste? We all know that Medical waste is any kind of waste that contains infectious and contaminated materials that are harmful for the environment as it results in carbon dioxide and other harmful gases that are further released into the earth’s atmosphere and contribute to climate change.Medical waste generally produced from hospitals, clinics,physicians offices, blood banks,dental practices ,veterinary hospitals etc.
Bio-medical Waste (Management & Handling) Rules, 1998 were notified by the Ministry of Environment & Forests (MoEF) under the Environment (Protection) Act, 1986. These rules apply to all persons who generate, collect, receive, store, transport, treat, dispose, or handle bio medical waste in any form including hospitals, nursing homes, clinics, dispensaries, veterinary institutions, animal houses, pathological laboratories, blood banks, ayush hospitals, clinical establishments, research or educational institutions, health camps, medical or surgical camps, vaccination camps, blood donation camps, first aid rooms of schools, forensic laboratories and research labs.
If you need help with incineration of bio-medical waste, you can connect with the best bio-medical waste consultants here.
Medical incineration or biomedical waste incineration involves the burning of wastes produced by hospitals, veterinary facilities, and medical research facilities. These wastes include both infectious (“red bag”) medical wastes as well as non-infectious, general housekeeping wastes. The emission factors presented here represent emissions when both types of these wastes are combusted rather than just infectious wastes. Three main types of incinerators are used:
- controlled air,
- excess air, and
- rotary kiln.
Of the incinerators identified in this study, the majority (>95 percent) are controlled air units. A small percentage (<2 percent) is excess air. Less than 1 percent were identified as rotary kilns.
So there are number of reasons why we should opt to medical incineration:-
- They are compact
- Won’t take up much space
- They have a small footprint
- Portable and easy to transport for field operations or to remote locations
- They are environmentally compliant and safe, with clean emissions
- Medical incinerators can burn up to 30kg of hazardous medical waste per hour,thus efficient way for incineration hazardous medical waste
- Efficient, economical and good for the environment
- They are easy and safe to use, with minimal training required.
- Minimal ash is left behind
Medical incineration process
Let’s learn the process of medical incineration of biomedical waste with respect to types of medical incineration described in this section include: –
- Controlled air,
- Excess air,
- Rotary kiln.
1)CONTROLLED AIR :-
- Controlled-air incineration is the most widely used medical waste incinerator (MWI) technology, and now dominates the market for new systems at hospitals and similar medical facilities. This technology is also known as starved-air incineration, two-stage incineration, or modular combustion.
- Combustion of waste in controlled air incinerators occurs in two stages.
- In the first stage, waste is fed into the primary, or lower, combustion chamber, which is operated with less than the stoichiometric amount of air required for combustion. Combustion air enters the primary chamber from beneath the incinerator hearth (below the burning bed of waste). This air is called primary or underfire air.
- In the second stage, excess air is added to the volatile gases formed in the primary chamber to complete combustion. Secondary chamber temperatures are higher than primary chamber temperatures– typically 980 to 1,095C (1,800 to 2,000F). Depending on the heating value and moisture content of the waste, additional heat may be needed. This can be provided by auxiliary burners located at the entrance to the secondary (upper) chamber to maintain desired temperatures. Waste feed capacities for controlled air incinerators range from about 0.6 to 50 kg/min .
2) EXCESS AIR INCINERATOR:-
- Excess air incinerators are typically small modular units. They are also referred to as batch incinerators, multiple chamber incinerators, or “retort” incinerators. Excess air incinerators are typically a compact cube with a series of internal chambers and baffles. Although they can be operated continuously, they are usually operated in a batch mode.
- The charging door is then closed, and an afterburner is ignited to bring the secondary chamber to a target temperature (typically 870 to 980°C [1600 to 1800°F]).
- When the target temperature is reached, the primary chamber burner ignites. The waste is dried, ignited, and combusted by heat provided by the primary chamber burner, as well as by radiant heat from the chamber walls.
- Moisture and volatile components in the waste are vaporised, and pass (along with combustion gases) out of the primary chamber and through a flame port which connects the primary chamber to the secondary or mixing chamber.
- Secondary air is added through the flame port and is mixed with the volatile components in the secondary chamber.
- Burners are also installed in the secondary chamber to maintain adequate temperatures for combustion of volatile gases.
- Gases exiting the secondary chamber are directed to the incinerator stack or to an air pollution control device.
- When the waste is consumed, the primary burner shuts off. Typically, the afterburner shuts off after a set time.
- Once the chamber cools, ash is manually removed from the primary chamber floor and a new charge of waste can be added.
3) ROTARY KILN INCINERATORS:-
- Rotary kiln incinerators, like the other types, are designed with a primary chamber, where waste is heated and volatilized, and a secondary chamber, where combustion of the volatile fraction is completed.
- The primary chamber consists of a slightly inclined, rotating kiln in which waste materials migrate from the feed end to the ash discharge end.
- The waste throughout rate is controlled by adjusting the rate of kiln rotation and the angle of inclination.
- Combustion air enters the primary chamber through a port. An auxiliary burner is generally used to start combustion and maintain desired combustion temperatures. Both the primary and secondary chambers are usually lined with acid-resistant refractory brick.
- Volatiles and combustion gases pass from the primary chamber to the secondary chamber. The secondary chamber operates on excess air. Combustion of the volatiles is completed in the secondary chamber.
- Due to the turbulent motion of the waste in the primary chamber, solids burnout rates and particulate entrainment in the flue gas are higher for rotary kiln incinerators than for other incinerator designs. As a result, rotary kiln incinerators generally have add-on gas cleaning devices.
Medical incinerator design
Let’s know about medical waste incinerator design, it is complicated but easy to understand! We need to follow medical incinerator specifications.
Following design criteria may be adopted for better performance:
1) The incinerator shall be designed for capacity more than 50 kg/hr. For 50 kg/hr capacity, the minimum hearth area shall be 0.75 sq. m (8 sq. feet) and the minimum flow of the flue gas in the secondary chamber shall be 0.6m3/sec at 1050°C.
2) The size of the opening through which the waste is charged shall be larger than the size of the waste bag to befed. The volume of the primary chamber shall be at least five times the volume of one batch.
3)The double chamber incinerator shall preferably be designed on “controlled-air” incineration principle, as particulate matter emission is low in such an incinerator. Minimum 100% excess air shall be used for overall design. Air supply in the primary and secondary chamber shall be regulated between 30%-80% and 170%-120% of stoichiometric amount respectively. Primary air shall be admitted near / at the hearth for better contact. Flow metre suitable flow measurement device shall be provided on the primary & secondary air ducting. The combustion air shall be supplied through a separate forced draft fan after accounting for the air supplied through burners.
4) A minimum negative draft of 1.27 to 2.54 mm of WC (Water Column) shall be maintained in the primary chamber to avoid leakage of gaseous emissions from the chamber and for safety reasons.
5) The waste shall be fed into the incinerator in small batches after the fixed interval of time in case of fixed hearth incinerator and continuous charging using appropriate feeding mechanism incase of rotary kiln incinerator or as recommended by the manufacturer. The size of the hearth i.e. primary chamber shall be designed properly.
6) The sides and the top portion of the primary and secondary chambers shall preferably have rounded corners from inside to avoid the possibility of formation of black pockets OR dead zones.
7) The size of the secondary chamber shall be properly designed so as to facilitate a minimum of one second of residence time to gas flow. For the estimation of residence time in the secondary chamber its volume shall be calculated starting from the secondary burner tip to the thermocouple.
8) The refractory lining of the chamber shall be strong enough to sustain a minimum temperature of 1000° C in the primary chamber and 1200° C in the secondary chamber. The refractory & insulation bricks shall have minimum 115 mm thickness each & conform to IS:8-1983 & IS:2042- 1972 respectively.
9) The Incinerator shell shall be made of mild steel plate of adequate thickness (minimum 5 mm thick) & painted externally with heat resistant aluminium paint suitable to withstand temperature of 250°C with proper surface preparation. Refractory lining of the hot duct shall be done with refractory castable (minimum 45 mm thick) & insulating castable (minimum 80 mm thick). Ceramic wool shall be used at hot duct flanges & expansion joints.
10)The thermocouple location shall be as follows: In Primary chamber- Before admission of secondary air In Secondary chamber – At the end of secondary chamber or before admission of dilution medium to cool the gas
11) There shall be a separate burner each for the Primary & Secondary chamber. The heat input capacity of each burner shall be sufficient to raise the temperature in the primary and secondary chambers as 800±50°C and 1050±50°C respectively within a maximum of 60 minutes prior to waste charging. The burners shall have automatic switching “off/on” control to avoid the fluctuations of temperatures beyond the required temperature range.
- A) Each burner shall be equipped with spark igniter and main burner.
- B) Proper flame safeguard of the burner shall be installed.
- C) Provide view ports to observe flame of the burner.
- D) Flame of the primary burner i. shall be pointing towards the centre of the hearth. ii. shall be having a length such that it touches the waste but does not impinge directly on the refractory floor or wall.
- E)The secondary burner shall be positioned in such a way that the flue gas passes through the flame.
12) There shall not be any manual handling during charging of waste in to the primary chamber of the incinerator.The waste shall be charged in bags through automatic feeding device at the manufacturer’s recommended intervals ensuring no direct exposure of furnace atmosphere to the operator. The device shall prevent leak age of the hot flue gas & any backfire. The waste shall be introduced on the hearth in such a way so as to prevent the heap formation. Suitable raking arrangement shall be provided for uniform spreading of waste on the hearth.
13) A tamper-proof PLC(Programmable Logic Control) based control system shall be installed to prevent: o Waste charging until the required temperature in the chambers are attained during beginning of the operation of the incinerator. o Waste charging unless primary & secondary chambers are maintained at the specified temperature range. Waste charging in case of any unsafe conditions such as very high temperature in the primary & secondary chambers; failure of the combustion air fan, ID fan, recirculation pump; low water pressure & high temperature of the flue gas at the outlet of the air pollution control device.
14) The incineration system must have an emergency vent. The emergency vent shall remain closed i.e it shall not emit flue gases during normal operation of the incinerator. xv. Each incineration system shall have graphic or computer recording devices which shall automatically and continuously monitor and record dates, time of day, batch sequential number and operating parameters such as temperatures in both the chambers. CO, CO2 , and O2 in gaseous emission shall also be measured daily (at least ½ hour at one minute interval).
15) The possibility of providing a heat recovery system/heat exchanger with the incinerator shall also be considered wherever possible.
16) Structural design of the chimney / stack shall be as per IS:6533-1989. The chimney/stack shall be lined from inside with a minimum of 3 mm thick natural hard rubber suitable for the duty conditions and shall also conform to IS:4682 Part I-1968 to avoid corrosion due to oxygen and acids in the flue gas.
17) The location and specification of porthole, platform ladder etc. shall be as per the Emission Regulations, Part-3 (COINDS/20/1984-85), published by CPCB.
Biomedical waste categories
The bio-medical waste generated from the health care facility falls into four categories based on the segregation pathway and colour code according to bio medical management rules 2016. Various types of bio medical waste are further assigned to each one of the categories, as detailed below:
1. Yellow Category:-
a) Human Anatomical Waste:-Human tissues, organs, body parts and fetus below the viability period (as per the Medical Termination of Pregnancy Act 1971, amended from time to time).
b) Animal Anatomical Waste:- Experimental animal carcasses, body parts, organs, tissues, including the waste generated from animals used in experiments or testing in veterinary hospitals or colleges or animal houses.
c) Soiled Waste:- Items contaminated with blood, body fluids like dressings, plaster casts, cotton swabs and bags containing residual or discarded blood and blood components.
d) Discarded or Expired Medicine:- Pharmaceutical waste like antibiotics, cytotoxic drugs including all items contaminated with cytotoxic drugs along with glass or plastic ampoules, vials etc.
e) Chemical Waste :- Chemicals used in production of biological and used or discarded disinfectants .
f)Chemical Liquid Waste:- Liquid waste generated due to use of chemicals in production of biological and used or discarded disinfectants, Silver X – ray film developing liquid, discarded Formalin, infected secretions, aspirated body fluids , liquid from laboratories and floor washings, cleaning, house – keeping and disinfecting activities etc Discarded linen, mattresses, beddings contaminated with blood or body fluid, routine mask & gown.
g) Microbiology, Biotechnology and other clinical laboratory waste:- (Pre-treated) Microbiology, Biotechnology and other clinical laboratory waste: Blood bags, Laboratory cultures, stocks or specimens of microorganisms, live or attenuated vaccines, human and animal cell cultures used in research, industrial laboratories, production of biological, residual toxins, dishes and devices used for cultures.
2. Red Category:-
Wastes generated from disposable items such as tubing, bottles, intravenous tubes and sets, catheters, urine bags, syringes without needles, fixed needle syringes with their needles cut, vacutainers and gloves.
3. White Category:-
Waste Sharps including metal Needles, syringes with fixed needles, needles from needle tip cutter or burner, scalpels, blades, or any other contaminated sharp object that may cause puncture and cuts. This includes both used, discarded and contaminated metal sharps
4. Blue Category:-
Broken or discarded and contaminated glass including medicine vials and ampoules except those contaminated with cytotoxic wastes.
List of document for biomedical waste authorization under biomedical waste management rules,2016
A. For bedded Health Care Facilities (HCFs) :-
1. Application in Form-II of Biomedical Waste Management Rules, 2016
2. Authorization fees for five years for Red Category (Total wastewater generation more than
100 KLD or with incinerator) and ten years for Orange-category (Total wastewater generation up to 100 KLD and without incinerator) through online payment as per Board’s fee structure. 3. Copy of consent to operate order issued by SPCB, Odisha.
4. Agreement copy with the Common Biomedical Waste Treatment Facility (in case of units joined with CBWTF).
B. For non-bedded Health Care Facilities (HCFs) :–
1. Application in Form-II of Biomedical Waste Management Rules, 2016.
2. Authorization fees one time through online payment as per Board’s fee structure.
3. Agreement copy with the Common Biomedical Waste Treatment Facility (in case of units joined with CBWTF).
C. For Common Biomedical Waste Treatment Facility (CBWTF):- 1. Application in Form-II of Biomedical Waste Management Rules, 2016.
2. Authorization fee for five years through online payment as per Board’s fee structure.
3. Copy of consent to operate order issued by SPCB, Odisha.
4. Map with GPS locations of CBWTF and area of coverage. 5. Contingency plan of CBWT
Medical incinerator manufacturers in India
Here is some list of medical waste incinerator manufacturers in India:-
1)Bertin Technologies:-New Delhi
2) Indian society of hospital waste Management :- Dwaraka
3)Ramky group :- Hyderabad
4)Greenzen bio private Limited :-Kolkata
5)Scientico :- Ambala
6)Biotic waste solutions pvt.ltd:- North India
7)Vikas Engineering:- Ahmedabad
8)SMS Envocare Ltd:- Nagpur
9)EC Zone :- Chennai
10)C.R.I Pumps Private Limited:- Coimbatore
11)Vee Protect – a subsidiary of the sona group:- Bangalore
|Year||Treatment and disposal in metric tons per day|
Medical Incineration Health effects
Experimental data confirm that incinerators release poisonous substances and that humans are exposed as a consequence. Studies on workers at incinerator shops, and populations abiding near to incinerators, have linked a wide range of associated health impacts( see tables below). These studies give rise to great enterprises about possible health impacts from incinerators indeed though the number of studies( particularly those that have been conducted to meetly rigorous scientific norms) is largely limited. These should be seen, still, as explosively reflective that incinerators are potentially veritably dangerous to mortal health.
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A wide range of health goods have been associated with living near the incinerators or working at these installations. Similar goods include cancer( among both children and grown-ups), adverse impacts on the respiratory system, heart complaints, vulnerable system goods, increased disinclinations and natural abnormalities. Some studies, particularly those on cancer, relate to old rather than ultramodern incinerators. Still, ultramodern incinerators operating in the last many times have also been associated with adverse health goods.
How is medical waste disposed of?
Medical waste is primarily regulated by state environmental and health departments. EPA has not had authority, specifically for medical waste, since the Medical Waste Tracking Act (MWTA) of 1988 expired in 1991. It is important to communicate your state environmental program first when disposing of medical waste. Communicate your state environmental protection agency and your state health agency for more information regarding your state’s regulations on medical waste. To know more about it you can go through our blog on biomedical waste management!
More than 90 percent of potentially contagious medical waste was incinerated before 1997. In August of 1997, EPA announced regulations creating stringent emission standards for medical waste incinerators due to significant concerns over mischievous air quality affecting human health. EPA’s Office of Air Quality Planning and Standards continues to review and revise the Hospital Medical Infectious Waste Incinerator (HMIWI) standards as needed most recently in May of 2013.
Alternative Treatment and Disposal Technologies for Medical Waste
Potential alternatives to medical incineration of medical waste include the following:
- Thermal treatment, such as microwave technologies;
- Steam sterilization, such as autoclaving;
- Electropyrolysis; and
- Chemical mechanical systems, among others.
With EPA’s tighter HMIWI norms i.e.Hospital, Medical, and Infectious Waste Incinerators norms. The number of HMIWIs in the United States has declined since 1997. This has lead to an increase in the use of alternative technologies for treating medical waste. The alternative treatments are generally used to render the medical waste non-infectious then the waste can be disposed of as solid waste in landfills or incinerators. Many states have regulations taking medical waste treatment technologies to be certified or regulated. Check with your state for additional regulation regarding treatment of medical waste.
EPA stands for Environmental Protection Agency has jurisdiction over medical waste treatment technologies, which claim to reduce the infectiousness of the waste (i.e. that claim any antimicrobial activity) by using chemicals. This jurisdiction comes from the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA). Companies wishing to make such claims must register their product under FIFRA through EPA’s Office of Prevention, Pesticide, and Toxic Substances (OPPTS), Antimicrobial Division.
Ques 1) What is medical waste incineration?
Answer- Medical waste incineration involves the burning of wastes produced by hospitals, veterinary facilities, and medical research facilities.
Ques 2) Which medical waste material is appropriate for incineration?
Answer- Medical waste incineration involves the burning of wastes produced by hospitals, veterinary facilities, and medical research facilities. These wastes include both infectious (“red bag”) medical wastes as well as non-infectious, general housekeeping wastes.
Ques 3) Can expired medicines be incinerated?
Answer- Yes absolutely.Expired or unused medical and pharmaceutical products are incinerated at a facility which conforms to the “Incineration Facility Construction and Maintenance Standards” (Regulation of the Waste Disposal Law)
Ques 4) What are the health benefits of incineration?
- Efficient Waste Management.
- Reduced Quantity of Waste.
- Production of Heat and Power.
- Reduction of Pollution Compared to Landfills.
- Reduced Reliance on Transportation.
- Prevents the Production of Methane Gas.
- Better Control Over Odour and Noise.
- Provides Better Control Over Odour and Noise.
Ques 5) Is medical incineration harmful?
Answer- Due to increasing quantities of waste sent to incineration, incinerators will emit more toxins and pollutants that harm local air quality. Incineration makes a more significant negative contribution to local air quality than landfill.
Ques 6) What are the health problems of incinerators?
Answer- Respiratory problems, increased cancer rates, reproductive abnormalities, and other health effects are common in areas where incinerator plants are built. The leftover ash contains several poisons and heavy metals which require further treatment.
Ques 7) What are the common problems in incineration?
Answer- Incineration can also cause water pollution, odour, noise, and vibrations, which impact on residential and commercial neighbours. In addition, it produces hazardous wastes associated with fly ash and bottom ash, which require careful handling and disposal.